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#1
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The KISS AMP: a progress report
Friends, rodents and other tubies, hail!
The KISS AMP 300B project: http://members.lycos.co.uk/fiultra/T...mp%20INDEX.htm is one of many DIY tube and solid state amp projects, and also point source speakers, at JUTE ON AMPS: http://members.lycos.co.uk/fiultra/JUTE%20ON%20AMPS.htm Here is a mainly visual progress report for one of the two amps in The KISS AMP 300B project: T39 single tube input/driver stage proving prototype: http://members.lycos.co.uk/fiultra/K...0T68MZ417A.jpg Driver stage circuit (potato amp made by subtracting 300B): http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Layout suitable for potato (T68) version only (latest hi-cap filter version of T39 will not fit; the new caps -- see below -- are too fat to fit between the second choke and the output tranny at the top of the page) http://members.lycos.co.uk/fiultra/t68bismzlayout.jpg Circuit of T39 KISS Amp: http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg Transfer function for the KISS T39 Amp for those of you who want to calculate along with Rudy (go on, surprise yourself by discovering how little distortion there can be in a SET amp): http://members.lycos.co.uk/fiultra/112KISScurves.jpg What lies behind the curves -- the neddy introduction: http://members.lycos.co.uk/fiultra/K...dre%20Jute.htm Teach yourself to evaluate transfer curves: http://members.lycos.co.uk/fiultra/K...dre%20Jute.htm The KISS T39 original (low-cap) prototype (since transformed into T68 potato above; the interstage transformers shown in the T68 layout went in the space occupied by big turreted ceramic UX4 sockets for the 300B in the T39 -- before you ask, the T39 is silent enough without IST): http://members.lycos.co.uk/fiultra/t39kiss001.jpg More illustrations: http://members.lycos.co.uk/fiultra/KISS%20190.htm An amp like the T39 KISS AMP is not built in isolation: My DIY horns and other sensitive point source speaker designs for the KISS 300B amps: http://members.lycos.co.uk/fiultra/K...20T91HWAF3.jpg http://members.lycos.co.uk/fiultra/K...Impresario.jpg For a giggle, five files on a moderately economical fun experiment to approach DHT sound with a transistor amp: http://members.lycos.co.uk/fiultra/K...dre%20Jute.htm http://members.lycos.co.uk/fiultra/K...dre%20Jute.htm http://members.lycos.co.uk/fiultra/K...20mGBschem.jpg http://members.lycos.co.uk/fiultra/K...%20mGBmatr.jpg http://members.lycos.co.uk/fiultra/K...%20NoBleed.jpg Next I shall design the layout and appearance of the final version, for which I have a copper plate 13in wide by 1m long. I'm still trying to use a 17x10x4in Hammond box as a cover for the gubbins. I'm keen on the Hammond chassis as a cover idea because that is a promise I made with the original Lundahl Modular Amp series, of which the other KISS amp, the T44 (circuit and frequency response in these links, description in main KISS materials) is a development. http://members.lycos.co.uk/fiultra/T44bis-'Populaire'-crct.jpg http://members.lycos.co.uk/fiultra/T...x-6SN7-FQ-.jpg But Patrick's contribution to the T39 power filter (thanks a bunch for causing me endless trouble, Patrick!), and help from Triode Supply Japan in finding aliminium cannisters of suitable Solen polyprop values, have resulted in much more component footage than I originally contemplated. The original layout, on the left of the photographs he http://members.lycos.co.uk/fiultra/K...0T68MZ417A.jpg and in full he http://members.lycos.co.uk/fiultra/t68bismzlayout.jpg was already tighter than I like for a circuit published for DIYers. I might go back to my multilayer 'pagoda' design idea except that I built a sort of X-plane amp a few years ago, for standing on the cross end with the tubes sideways on, and soldering in the narrow space between the plates was a pig; the pagoda design would also require final soldering in narrow spaces. Well see. Andre Jute Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#2
Posted to rec.audio.tubes
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The KISS AMP: a progress report
Andre Jute wrote: Friends, rodents and other tubies, hail! The KISS AMP 300B project: http://members.lycos.co.uk/fiultra/T...mp%20INDEX.htm is one of many DIY tube and solid state amp projects, and also point source speakers, at JUTE ON AMPS: http://members.lycos.co.uk/fiultra/JUTE%20ON%20AMPS.htm Here is a mainly visual progress report for one of the two amps in The KISS AMP 300B project: T39 single tube input/driver stage proving prototype: http://members.lycos.co.uk/fiultra/K...0T68MZ417A.jpg Driver stage circuit (potato amp made by subtracting 300B): http://members.lycos.co.uk/fiultra/t...17acircuit.jpg If the two JPGs above are any indication of the progress of this project, you are in deep ****. And what about all those names of suppliers of bits & pieces on the LHS of the schematic? What have they to do with your flaky efforts? Are they on the schematic to somehow boost your questionable reputation by association? Did you ask for permission to include them? Better take up cooking on a full time basis! Puzzled to say the least by all the Bandwidth you have occupied over the last while on RAT. Better known as 'Verbal Diarrhea' by some! John Stewart |
#3
Posted to rec.audio.tubes
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The KISS AMP: a progress report
This sort of snippy and uninformative response-- no technical content,
no entertainment value, only unimpresive vitriol -- is typical of what in future in shall simply ignore. I started this thread in an effort to return this conference to technical matters and the first response is a nasty little piece of non-technical spite from someone who would benefit by the reversion. Sheesh! -- Andre Jute John Stewart wrote: Andre Jute wrote: Friends, rodents and other tubies, hail! The KISS AMP 300B project: http://members.lycos.co.uk/fiultra/T...mp%20INDEX.htm is one of many DIY tube and solid state amp projects, and also point source speakers, at JUTE ON AMPS: http://members.lycos.co.uk/fiultra/JUTE%20ON%20AMPS.htm Here is a mainly visual progress report for one of the two amps in The KISS AMP 300B project: T39 single tube input/driver stage proving prototype: http://members.lycos.co.uk/fiultra/K...0T68MZ417A.jpg Driver stage circuit (potato amp made by subtracting 300B): http://members.lycos.co.uk/fiultra/t...17acircuit.jpg If the two JPGs above are any indication of the progress of this project, you are in deep ****. And what about all those names of suppliers of bits & pieces on the LHS of the schematic? What have they to do with your flaky efforts? Are they on the schematic to somehow boost your questionable reputation by association? Did you ask for permission to include them? Better take up cooking on a full time basis! Puzzled to say the least by all the Bandwidth you have occupied over the last while on RAT. Better known as 'Verbal Diarrhea' by some! John Stewart |
#4
Posted to rec.audio.tubes
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The KISS AMP: a progress report
Why do you still have some 100 watts of dropping resistors on the
secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA |
#5
Posted to rec.audio.tubes
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The KISS AMP: a progress report
That's excellent timing, Peter. I unkillfiled everyone to see who wants
to work and who is a permanent flame merchant -- and there you are with a useful question. Give that boy's young lady the pink fluffy rabbit. wrote: Why do you still have some 100 watts of dropping resistors on the secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA "still" ? Always been there. The resistors I used are overrated (see below) and my associate who reverse-engineered the little amp for the schematic wrote in the rating they are rather than the ratings they should have been probably because I forgot to tell him to recalculate everything. Now that you've pointed it out to me, I've put the right ratings in the posted version. http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Thanks for the heads-up. While we're here, we may as well discuss resistors in secondaries, and dropping resistors in general. I made the T68bis potato amp by stripping out a pair of 300B on a proto and using my junkbox resistors to drop the voltages. When the little amp goes out of the door or is stripped down, they go back in the junkbox. My only concern at the time was that they were the right value and overrated for the job. NB: A 50W resistor doesn't dissipate 50W just because it is rated 50W. The heat it dissipates is related to current flowing through it and the resistance value. Colonel Ohm saves the day again: P = I*I*R -- says nothing about the rating of the resistor which by tradition is 2 or 3 times the dissipation arrived at for a safety margin. There are many reasons for using a resistor of the right value and a higher rating. 1. You have it in junkbox already and don't need to wait for a delivery from your component pusher. 2. The manufacturer doesn't make all the values in all the ratings, or your supplier doesn't stock the full range, so you buy the value you need in the next higher rating. 3. I like big chunky aliminium-cased resistors because they're cool-running with all that area and fins besides. 4. In the case of at least one of the resistors you think over-rated, the alternative was a nasty cement-cased pluggable resistor of the right rating. I like neither the looks nor the sound of those. 5. The standard resistor I keep in all values and both the available ratings is Kiwame. It gets a bit expensive sticking them in where they won't make a difference to the sound. 6. I'm designing for DIYers. The great thing is not to give Joe Doe a chance to say near enough is good enough and put an underrated part in. Better safe than sorry. 7. Those particular resistors derate to 50 per cent (IIRC, look it up if you don't know -- *that* is why I overrate them!) or less if they aren't on a heatsink, if they aren't in free air, etc. What you see isn't a 100W of power capability but only 50W inside a case, maybe less. It is for tricky little subtleties like this that Patrick wants people to hit the books rather than learn only by soldering. 8. It isn't so widely known that resistors have voltage ratings. It is not uncommon, though less so these days of CE marks over here, to see amps built with resistors that at least theoretically could burst into flames any moment. Those ali-cased resistors I like have very attractive voltage ratings too, so they live naturally in the junkbox of someone who moves casually from a little 175V 417A potato amp to a kilovolt-plus 845 or SV572.xx amp. The ali-cased resistors save the bother of having to check the voltage spec of some orphan resistor from the junkbox; I've long since cleared all the low-voltage stuff from my junkbox. **** Returning now to the particular resistors you mention, the two 330R in the mains secondary are ballasts. In a tube rectifier circuit you're supposed to have those, usually about 75R minimum. Check the spec sheets for various tube rectifiers, on some of which is an explanation and schematic of the equivalent circuit for various impedances in and around a tube rectifier (for each type of filter, cap input and choke input) and their effects. I have long since found that a pair of stiff ballasts smooths the power an agreeable fraction when you have a hefty bleed already. ******* Remember this: the idea isn't a perfect schematic but to build something, to listen, to develop it. I used to waste lots of time agonising over the perfect paper design and collecting all the perfect parts. Now as often as not I build the prototype on the fly with a few calculations on the logarithmic bezels of my watch (why is a rotary slide rule still called a "rule" -- tell me that and I'll think you clever) to check my mental arithmetic, then develop it right, and only then reverse engineer the amp to draw the schematic of the circuit. There are a few traps in that, as we have seen, when sharp eyes catch out your overrated junkbox parts but the amp gets done a lot sooner. The secret of designing good-sounding amps and still have time left to listen to music is to fail fast. Anyone who hasn't failed often, never mind "never" as too many claim, probably can't distinguish mud from music. Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#6
Posted to rec.audio.tubes
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The KISS AMP: a progress report
It would be useful to know the secondary voltage at that transformer
before the resistors are added, so as to get the 180V rectified voltage you require. Yes, you have 500V ~500ma at the bottom, I assume that is across the entire two coils (5-to-7) and not to the (virtual) center-tap, but that too would be helpful to know. Assuming that you are getting 250V/Coil at your stated input, the way I read your output from the rectifier tube, that would come to some 415V or so out of the 5AR4/GZ34, excepting the dropping resistors. So, how did the value of 660 ohms of total AC resistance get chosen, especially in light of the 4700 ohm bleeder resistor further down the line (at 25 watts) to get to the required 180V? And 'adding a small capacitor' to adjust voltage... this is an iffy (albeit nearly heatless) expedient, 'cause if that cap should fail, *poof*. So, it would be useful to know the required/expected voltages right down the line so that the correct choices might be made. Would it not be much simpler to drop the primary side to ~220V or so, thereby almost eliminating the need for filament-voltage dropping resistors excepting getting 5V on the rectifier? SWAG, assuming 230 single-phase hot/neutral at the primary, and about a 2A (allowing for losses) total load shouldn't take much of a single dropping resistor to get that 220V, or even slightly less. This way, individuals in other countries with different standards could work to the required _secondary_ voltages based on their wallplate voltage. If one is fond of iron, either a small autotransformer or a small bucking transformer could be used ILO a resistor for less heat. This might also greatly simplify the requirements for your B+ side? Two chokes? Why? The 5AR4 is a pretty good, quite rugged (if expensive) rectifier. And it would seem simpler to add additional capacitance on the line-side of the first choke, thereby eliminating the need for the second? With all your prior losses, you are running well below the saturation level of a single unit (400/575ma). 500V caps are cheap these days, even 50uF or better, certainly cheaper than iron. And if all you want to filter is 50/60Hz chop, one will do fine. As a small aside, the 5U4 rectifier is much cheaper, albeit not quite as rugged and without the slow-start characteristics that distinguish the 5AR4. But in any case, a single choke with sufficient capacitance would drop any chop way below other noise sources. Are you familiar with Mad Man Muntz? He would go into his skunk-works whenever his engineers decided they had a new product to develop, and start cutting out parts (he was an excellent EE, so this was not done at random) until whatever-it-was stopped working. *That* was the magic point from which to design. I question from the perspective of one who is usually presented with smoking ruins and given the mandate to 'make it work'. Many times without benefit of schematics, or if they are available, facing so many whimsical modifications to make the schematics of dubious value. So, "expected" and "actual" values are important things to know. At times, I thank my lucky stars that this is a hobby.... so I do not have to make a living at it. Otherwise, not 1 unit in 10 that I see would be worth the time and trouble to fix. Peter Wieck Wyncote, PA |
#7
Posted to rec.audio.tubes
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The KISS AMP: a progress report
Hi Andre, This is a superb reply to a dumb question that I would have thought PFJW would have already known the answer to, given his background. You thoroughly covered all the bases. Regards, John Byrns In article .com, "Andre Jute" wrote: That's excellent timing, Peter. I unkillfiled everyone to see who wants to work and who is a permanent flame merchant -- and there you are with a useful question. Give that boy's young lady the pink fluffy rabbit. wrote: Why do you still have some 100 watts of dropping resistors on the secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA "still" ? Always been there. The resistors I used are overrated (see below) and my associate who reverse-engineered the little amp for the schematic wrote in the rating they are rather than the ratings they should have been probably because I forgot to tell him to recalculate everything. Now that you've pointed it out to me, I've put the right ratings in the posted version. http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Thanks for the heads-up. While we're here, we may as well discuss resistors in secondaries, and dropping resistors in general. I made the T68bis potato amp by stripping out a pair of 300B on a proto and using my junkbox resistors to drop the voltages. When the little amp goes out of the door or is stripped down, they go back in the junkbox. My only concern at the time was that they were the right value and overrated for the job. NB: A 50W resistor doesn't dissipate 50W just because it is rated 50W. The heat it dissipates is related to current flowing through it and the resistance value. Colonel Ohm saves the day again: P = I*I*R -- says nothing about the rating of the resistor which by tradition is 2 or 3 times the dissipation arrived at for a safety margin. There are many reasons for using a resistor of the right value and a higher rating. 1. You have it in junkbox already and don't need to wait for a delivery from your component pusher. 2. The manufacturer doesn't make all the values in all the ratings, or your supplier doesn't stock the full range, so you buy the value you need in the next higher rating. 3. I like big chunky aliminium-cased resistors because they're cool-running with all that area and fins besides. 4. In the case of at least one of the resistors you think over-rated, the alternative was a nasty cement-cased pluggable resistor of the right rating. I like neither the looks nor the sound of those. 5. The standard resistor I keep in all values and both the available ratings is Kiwame. It gets a bit expensive sticking them in where they won't make a difference to the sound. 6. I'm designing for DIYers. The great thing is not to give Joe Doe a chance to say near enough is good enough and put an underrated part in. Better safe than sorry. 7. Those particular resistors derate to 50 per cent (IIRC, look it up if you don't know -- *that* is why I overrate them!) or less if they aren't on a heatsink, if they aren't in free air, etc. What you see isn't a 100W of power capability but only 50W inside a case, maybe less. It is for tricky little subtleties like this that Patrick wants people to hit the books rather than learn only by soldering. 8. It isn't so widely known that resistors have voltage ratings. It is not uncommon, though less so these days of CE marks over here, to see amps built with resistors that at least theoretically could burst into flames any moment. Those ali-cased resistors I like have very attractive voltage ratings too, so they live naturally in the junkbox of someone who moves casually from a little 175V 417A potato amp to a kilovolt-plus 845 or SV572.xx amp. The ali-cased resistors save the bother of having to check the voltage spec of some orphan resistor from the junkbox; I've long since cleared all the low-voltage stuff from my junkbox. **** Returning now to the particular resistors you mention, the two 330R in the mains secondary are ballasts. In a tube rectifier circuit you're supposed to have those, usually about 75R minimum. Check the spec sheets for various tube rectifiers, on some of which is an explanation and schematic of the equivalent circuit for various impedances in and around a tube rectifier (for each type of filter, cap input and choke input) and their effects. I have long since found that a pair of stiff ballasts smooths the power an agreeable fraction when you have a hefty bleed already. ******* Remember this: the idea isn't a perfect schematic but to build something, to listen, to develop it. I used to waste lots of time agonising over the perfect paper design and collecting all the perfect parts. Now as often as not I build the prototype on the fly with a few calculations on the logarithmic bezels of my watch (why is a rotary slide rule still called a "rule" -- tell me that and I'll think you clever) to check my mental arithmetic, then develop it right, and only then reverse engineer the amp to draw the schematic of the circuit. There are a few traps in that, as we have seen, when sharp eyes catch out your overrated junkbox parts but the amp gets done a lot sooner. The secret of designing good-sounding amps and still have time left to listen to music is to fail fast. Anyone who hasn't failed often, never mind "never" as too many claim, probably can't distinguish mud from music. Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review Surf my web pages at, http://users.rcn.com/jbyrns/ |
#8
Posted to rec.audio.tubes
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The KISS AMP: a progress report
You thoroughly covered all the bases.
Come ON, John.... Show me any commercially-produced circuit with anything approaching that much resistance (if any at all) on the B+ side _ahead_ of the rectifier tube. And whilst you are at it, please explain the reasons for all 660 ohms vs. a lower secondary voltage? Or are your Master's nits not to be picked? Peter Wieck Wyncote, PA |
#9
Posted to rec.audio.tubes
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The KISS AMP: a progress report
Bunk! Your Pal, John Stewart
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#10
Posted to rec.audio.tubes
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The KISS AMP: a progress report
" said:
Two chokes? Why? The 5AR4 is a pretty good, quite rugged (if expensive) rectifier. And it would seem simpler to add additional capacitance on the line-side of the first choke, thereby eliminating the need for the second? The 5AR4/GZ 34 rectifier is available from Sovtek for about $10, at least here in my neck of the woods. I agree that's more expensive than 2 1N4007s, but on par with the 5U4G you mention. It has indeed the advantage of being indirectly heated, thereby avoiding high surge peaks on the electrolytics. A second advantage, often neglected, is that the 300B will only draw current after the GZ rectifier is warm. This is much better for the 300B cathode, the tube will last longer. A third advantage, though of little use in this amplifier design, is the lower voltage drop wrt. a directly heated rectifier such as the 5U4G. André could try to use a swing choke at the cathode, this drops the voltage a bit, but when calculated correctly, also provides a certain voltage stability. Although a SE amp is always biased in class A, small voltage variations can not be avoided (depending on the load as well). I myself would have selected a more suitable transformer, or a combination of 2 or more, but apparently, André used what he had lying around in his junkbox, hence the series and bleeder resistors. I question from the perspective of one who is usually presented with smoking ruins and given the mandate to 'make it work'. Many times without benefit of schematics, or if they are available, facing so many whimsical modifications to make the schematics of dubious value. So, "expected" and "actual" values are important things to know. At times, I thank my lucky stars that this is a hobby.... so I do not have to make a living at it. Otherwise, not 1 unit in 10 that I see would be worth the time and trouble to fix. So true, I am familiar with this :-) However, being both a repairman and an amp designer and builder, there are differences in approaching both. -- - Never argue with idiots, they drag you down their level and beat you with experience. - |
#11
Posted to rec.audio.tubes
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The KISS AMP: a progress report
André could try to use a swing choke at the cathode, this drops the voltage a bit, but when calculated correctly, also provides a certain voltage stability.
Actually, I would test a single diode on the secondary side of the B+, to drop the voltage to ~353V+/- to the rectifier. Through the rectifier, that would give a mere 292V *excepting resistors* on the output side. This is a heatless solution with an open-circuit failure mode. The question/test would be one of the downstream effect of feeding chopped DC into the 5AR4. Worth a test to get to smaller resistors anyway, and a way to reduce the load on the secondary coil considerably. I am always loath to put dropping resistors (or "ballasts" as so elegantly noted) on the secondaries, why load the poor windings? If a suitable transformer were not available, I would drop on the primary side as much as practical. Peter Wieck Wyncote, PA |
#12
Posted to rec.audio.tubes
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The KISS AMP: a progress report
" said:
Actually, I would test a single diode on the secondary side of the B+, to drop the voltage to ~353V+/- to the rectifier. Through the rectifier, that would give a mere 292V *excepting resistors* on the output side. This is a heatless solution with an open-circuit failure mode. The question/test would be one of the downstream effect of feeding chopped DC into the 5AR4. Worth a test to get to smaller resistors anyway, and a way to reduce the load on the secondary coil considerably. I am always loath to put dropping resistors (or "ballasts" as so elegantly noted) on the secondaries, why load the poor windings? If a suitable transformer were not available, I would drop on the primary side as much as practical. While the resulting DC voltage will be lower in that case, the ripple is certainly going to be far greater than in case of the dual-diode power supply design. Getting rid of ripple means big caps, pushing the average DC voltage up again. More ripple also means higher charge/discharge currents, which in turn can cause hum induction in the actual amplifier circuit. Dropping resistors don't load the windings, bleeders do. A vacuum rectifier must see some DCR in the anode circuits, to prevent cathode stripping. A beefy tranny has a lower DCR, so series resistors *must* be added to avoid large cathode peak currents caused by the electrolytics. In case of a class A amplifier, burning some volts and watts away in series resistors isn't a big sin IMHO, unless one is designing to utmost efficiency. Looking at the schematic again, I noticed that André actually uses the Lundahl LL1638 choke as a swing choke. As this choke wasn't designed as such, it won't regulate as good as a correctly designed swing choke (without air gap). It will provide some additional voltage drop and series resistance, though. -- - Never argue with idiots, they drag you down their level and beat you with experience. - |
#13
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The KISS AMP: a progress report
While the resulting DC voltage will be lower in that case, the ripple is certainly going to be far greater than in case of the dual-diode power supply design.
I think you misunderstand. The single diode is to drop the voltage _into_ the 5AR4, thereby reducing the size needed for the dropping resistors. The effective output ripple should be neither greater nor worse than straight AC. So, 0.707 x input Voltage = output voltage from the winding. A big drop, no heat generated and load still removed from the winding. Now, let me see if I understand you correctly. A bleeder resistor dissipates a limited amount of current-to-ground, so the heat geneated by the resistor will be a function of the available current, and a dropping resistor dissiptates it in heat, but not to ground, so it drops voltage but only wastes a limited amount of current? I understand that would reduce the total load. But it would seem that eliminating the need for 'ballasts' altogether would be far-and-away the better approach. Without getting cute about it, just keep in mind that this design is being presented as the 'ultimate' in SET design, and as the ultimate in simplicity. There is nothing whatsoever represented as 'junk-box' about it, most especially as it is reputed to have significant value tied up in two tubes alone. A 'magnum opus' if you will. Now, with your observation on the two chokes, there seems much to improve in this unit, starting with the iron itself. That the various parts-and-pieces are carefully specified by-the-numbers and without the qualifier "this is what was lying around" shows at least that much. I would still like to understand the "expected" vs. "actual" voltages so as to understand the function of the ballast resistors and how precise they must be. And whether it would be practical to test other expedients. Ah, well. Salieri said of Mozart: Too many notes. Does "too many parts" have the same ring? Peter Wieck Wyncote, PA |
#14
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The KISS AMP: a progress report
In article .com,
" wrote: While the resulting DC voltage will be lower in that case, the ripple is certainly going to be far greater than in case of the dual-diode power supply design. I think you misunderstand. The single diode is to drop the voltage _into_ the 5AR4, thereby reducing the size needed for the dropping resistors. The effective output ripple should be neither greater nor worse than straight AC. So, 0.707 x input Voltage = output voltage from the winding. A big drop, no heat generated and load still removed from the winding. Peter, I hate to be the one to have to tell you this but your slip is showing. The above statement is utter nonsense, would you care to explain it further? Regards, John Byrns Surf my web pages at, http://users.rcn.com/jbyrns/ |
#15
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The KISS AMP: a progress report
First, show me the nonsense. Expose and explain the nits.
Peter Wieck Wyncote, PA |
#16
Posted to rec.audio.tubes
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The KISS AMP: a progress report
In article .com,
" wrote: First, show me the nonsense. Expose and explain the nits. Peter, there are no "nits" here, just massive "nonsense" on your part. You made the following unsupported claim in a previous post: "I think you misunderstand. The single diode is to drop the voltage _into_ the 5AR4, thereby reducing the size needed for the dropping resistors. The effective output ripple should be neither greater nor worse than straight AC. So, 0.707 x input Voltage = output voltage from the winding. A big drop, no heat generated and load still removed from the winding." Yet you refuse to explain exactly how and where you would connect the "single diode" "_into_ the 5AR4" to produce this miraculous reduction of the voltage by a factor of "0.707". With a few minor exceptions most of us here are not mind readers, and we haven't a clue how you propose to produce this result? Face it Peter you are in way over your head with this, the air of authority you traditionally try to cloak your pronouncements with just won't cut it here, you must either back up your claims with some facts, or accept that they are nonsense. Regards, John Byrns Surf my web pages at, http://users.rcn.com/jbyrns/ |
#17
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The KISS AMP: a progress report
John:
Take a simple diode capable of handling the 500V. Say.. 1N4007. Connect it to one of the secondary winding leads. That will drop the voltage across the winding from 500V to .707 x 500V. Feed that to the rectifier. So, instead of windings-to-rectifier (assuming no dropping resistors), now it is winding to diode to rectifier to winding. In only _one_ of the two leads. Or, do you not remember curtain-burner radios where this simple expedient off the line-cord drops the 120V to about 84V or so? Peter Wieck Wyncote, PA |
#18
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The KISS AMP: a progress report
Peter:
It is quite clear to me that you are totally out of your depth here and in your other posts in this thread. Here are just some samples: 1. You appear not to understand the rationale behind the various power supply topologies and in particular how a choke input works or why it is traditionally built with two sections, meaning two chokes. 2. As we saw earlier, you appear to think that a resistor will give off heat exactly matching its power rating, which is totally untrue; the heat dissipated is related to the resistance value, the current flowing in the resistor, the mounting and the air flow over the resistor. 3. You appear not to understand, or to have overlooked despite being told (if you do it again I will assume you are doing it maliciously and react accordingly), the fact that the T68 was made from a 300B proto merely to prove the driver stage of the KISS amp, and therefore uses the 300B amp's power supply regardless of its precise suitability. It is not presented as the ne plus ultra of anything. If you seriously want to discuss power supply design, discuss the T39 circuit, also published at the same time. http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg Giving you the benefit of the doubt, I shall assume you're still working your way down to. Work faster. 4. Your questions reveal that you do not to have the faintest idea of the conventions guiding SE amp design towards the desired result. In the light of these misunderstandings, and because I don't want to repeat myself if and when we come to the T39 http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg my answers to the rest will be shorter than usual. (Hallelujah chorus starts up!) wrote: It would be useful to know the secondary voltage at that transformer before the resistors are added, so as to get the 180V rectified voltage you require. Yes, you have 500V ~500ma at the bottom, I assume that is across the entire two coils (5-to-7) and not to the (virtual) center-tap, but that too would be helpful to know. The convention is that a 250-0-250 transformer is described as 500Vct, usually abbreviated on the schematic to 500V. The centre tap is not virtual but real. Assuming that you are getting 250V/Coil at your stated input, the way I read your output from the rectifier tube, that would come to some 415V or so out of the 5AR4/GZ34, excepting the dropping resistors. So, how did the value of 660 ohms of total AC resistance get chosen, especially in light of the 4700 ohm bleeder resistor further down the line (at 25 watts) to get to the required 180V? It'll be in a chapter of the KISS files on my Fiultra site when I get around to writing the chapter. Basically you decide the current required by the tubes, allocate a bleed (which in the absence of a swinging choke must be higher than a certain amount in a choke input design -- not essential in my design with the 11 second delay on the GZ34 filament but I always put in a hefty bleed for stability, safety and just in case someone else plugs in an instantly-on rectifier), add the two together, work back over the copper drop of the chokes, transform the voltage and current via the rectifier tube backwards from DC to AC, and then apply to Colonel Ohm for the value of the ballasts. And 'adding a small capacitor' to adjust voltage... this is an iffy (albeit nearly heatless) expedient, 'cause if that cap should fail, *poof*. You do talk a lot of manure, Wiecky. The cap will have the same rating as any of the other caps, just lower value. It is in the same position as the cap in a proper cap input filter. There is no reason for it to fail or precedence for it failing. (The idea of the voltage-tuning small cap in front of a choke input filter was given to me by Gordon Rankin, whose caps would *dare* fail...) So, it would be useful to know the required/expected voltages right down the line so that the correct choices might be made. They are written on my circuit, every single one of them. What are you talking about? (We might note that I am one of the few designers who write all the necessy information on the circuit.) Would it not be much simpler to drop the primary side to ~220V or so, No, no, no, never! Your winder will come cut you, pal. thereby almost eliminating the need for filament-voltage dropping resistors excepting getting 5V on the rectifier? Peter, you have these resistors on the mind. The desire to eliminate them arises from your ignorance about how much heat big resistors radiate when only a little current flows, and cheap production paradigms. In good audiophile tube design, and especially DIY work, such resistors are treasured for the advantages they bring, which Sander has tried to describe to you. SWAG, assuming 230 single-phase hot/neutral at the primary, and about a 2A (allowing for losses) total load shouldn't take much of a single dropping resistor to get that 220V, or even slightly less. This way, individuals in other countries with different standards could work to the required _secondary_ voltages based on their wallplate voltage. If one is fond of iron, either a small autotransformer or a small bucking transformer could be used ILO a resistor for less heat. No. This might also greatly simplify the requirements for your B+ side? Again, this is a temporary chassis for a proto for a part-amp. If you want to discuss power supplies in terms of simplicity, look at the T39 design, which is the whole amp. http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg Two chokes? Why? Because that is how one builds a choke input supply. It cannot be wound/specified/built more economically (Patrick?) or efficiently in terms of smoothing than as two (equal) sections. The 5AR4 is a pretty good, quite rugged (if expensive) rectifier. So what? I'm specifying a couple of grand's worth of tubes already. Anyway, it sounds better than semiconductor diodes and lasts longer too unless you heatsink diode bridges properly. In the T39 the GZ34 will be replaced with a GZ37, which will really hurt if you worry about costs! And it would seem simpler to add additional capacitance on the line-side of the first choke, thereby eliminating the need for the second? See above about efficiency and cost (cost at least in days of old -- maybe today a humongous choke could be cheaper). Furthermore, the power supply is part of the transfer function. The signal literally runs through it. In your mind's eye draw a line from the bottom of the last filter cap on the T39 http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg to the ground of the RCA socket, and you will get the idea. In an SE amp you want control over all the time constants, and therefore in the power supply too. You can't just throw around extra capacitance without considering the specification of available chokes, the time constants you want further on, and so on, even onto your speakers (you can't output too much below 32Hz in Lowthers, for instance, so you that is a time constant in the 300B circuit which influences time constants all the way back to the power supply). Again, this is an example of why Patrick despairs of repair hacks who won't hit the RDH hard ever learning anything really useful about tube amps. I mentioned Rankin above for a purpose; he is a very thorough engineer and he says that *after he had designed an amp* there were an additional 100 or so checks he makes to be sure the thing will work right. With all your prior losses, you are running well below the saturation level of a single unit (400/575ma). 500V caps are cheap these days, even 50uF or better, certainly cheaper than iron. And if all you want to filter is 50/60Hz chop, one will do fine. No, no, no! See above about time constants in the filters, efficiency in the choke sections, etc. Then, as a practical matter, check a catalogue for the physical size of the polyprop caps I have specified, and you will be absolutely horrified at the floor space already on the amp. As a small aside, the 5U4 rectifier is much cheaper, albeit not quite as rugged and without the slow-start characteristics that distinguish the 5AR4. I have a box full of 5U4 sitting three feet to my left as I write this. If I wanted a 5U4, I would have specified and fitted it. Peter, put any consideration of cost out of your mind unless and until *I* or another *established* audiophile come to mention it; cost considerations simply do not apply to DIY ultra-fi amps. The GZ34 is there because it sounds right and, important this, to protect the 300B in DIY-built amps with its slow-start filament. It is being replaced with GZ37, cost no object, because that sounds better still. But in any case, a single choke with sufficient capacitance would drop any chop way below other noise sources. No. RTRDH. Are you familiar with Mad Man Muntz? He would go into his skunk-works whenever his engineers decided they had a new product to develop, and start cutting out parts (he was an excellent EE, so this was not done at random) until whatever-it-was stopped working. *That* was the magic point from which to design. I question from the perspective of one who is usually presented with smoking ruins and given the mandate to 'make it work'. I have never had an amp fail to work on switch-on. Many times without benefit of schematics, or if they are available, facing so many whimsical modifications to make the schematics of dubious value. So, "expected" and "actual" values are important things to know. The voltages and currents are on my circuit, together with the value and rating of every other component, together with the maker's name of every component, and in may cases the name of a supplier if the component is rare. Again, you'd do better to study and discuss the T39 circuit. At times, I thank my lucky stars that this is a hobby.... so I do not have to make a living at it. Otherwise, not 1 unit in 10 that I see would be worth the time and trouble to fix. I find it cheaper at the hourly rates my time is worth to design and build a new amp rather than fix a broken one if much more than the fuse is gone. It seems to me that amateur troubleshooting of high-voltage devices is an ulcer-making pastime. Anyone who doesn't find it ulcer-making lacks the imagination to be afraid of high voltage and should find another hobby. Peter Wieck Wyncote, PA Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#19
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The KISS AMP: a progress report
Sander deWaal wrote: " said: Two chokes? Why? The 5AR4 is a pretty good, quite rugged (if expensive) rectifier. And it would seem simpler to add additional capacitance on the line-side of the first choke, thereby eliminating the need for the second? The 5AR4/GZ 34 rectifier is available from Sovtek for about $10, at least here in my neck of the woods. I agree that's more expensive than 2 1N4007s, but on par with the 5U4G you mention. It has indeed the advantage of being indirectly heated, thereby avoiding high surge peaks on the electrolytics. A second advantage, often neglected, is that the 300B will only draw current after the GZ rectifier is warm. This is much better for the 300B cathode, the tube will last longer. A third advantage, though of little use in this amplifier design, is the lower voltage drop wrt. a directly heated rectifier such as the 5U4G. Those Mullard designed GZ types also sound pretty good. André could try to use a swing choke at the cathode, this drops the voltage a bit, but when calculated correctly, also provides a certain voltage stability. The point of a swinging choke is to provide a fractional delay while capacitors charge up. The slow heater on the GZ34 already provides a delay. Furthermore, a hefty bleed loads the choke even with an instantly-on rectifier so that there is also an instant demand for current. All these matters tend to reduce the need for a swinging choke, which today is a very rare item. Although a SE amp is always biased in class A, small voltage variations can not be avoided (depending on the load as well). Yes, that is indeed the great advantage of the choke input filter over the cap input filter for SE amps where the demand is essentially static. I myself would have selected a more suitable transformer, or a combination of 2 or more, but apparently, André used what he had lying around in his junkbox, hence the series and bleeder resistors. The T68, under discussion here, is a proto to prove the driving stage of a bigger amp. I simply lost the two 300B and used what was on the plate, adding droppers to make it work. It would be better, if Peter really wants to learn something about SE power supply design, to discuss the proper T39 amp he http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg I question from the perspective of one who is usually presented with smoking ruins and given the mandate to 'make it work'. Many times without benefit of schematics, or if they are available, facing so many whimsical modifications to make the schematics of dubious value. So, "expected" and "actual" values are important things to know. At times, I thank my lucky stars that this is a hobby.... so I do not have to make a living at it. Otherwise, not 1 unit in 10 that I see would be worth the time and trouble to fix. So true, I am familiar with this :-) However, being both a repairman and an amp designer and builder, there are differences in approaching both. Vast, apparently. -- - Never argue with idiots, they drag you down their level and beat you with experience. - Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
#20
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The KISS AMP: a progress report
wrote: While the resulting DC voltage will be lower in that case, the ripple is certainly going to be far greater than in case of the dual-diode power supply design. I think you misunderstand. The single diode is to drop the voltage _into_ the 5AR4, thereby reducing the size needed for the dropping resistors. The effective output ripple should be neither greater nor worse than straight AC. So, 0.707 x input Voltage = output voltage from the winding. A big drop, no heat generated and load still removed from the winding. Forget it. You will hear that diode. I go to very great trouble to keep all kinds of clicks and whirs out of the amp, and now you want me to add a diode across one winding? Yech! To avoid resistors demanded by the rectifier? Why? You want to go to Philly from Alston, you don't first go to Santa Barbara. Now, let me see if I understand you correctly. A bleeder resistor dissipates a limited amount of current-to-ground, so the heat geneated by the resistor will be a function of the available current, and a dropping resistor dissiptates it in heat, but not to ground, so it drops voltage but only wastes a limited amount of current? I understand that would reduce the total load. But it would seem that eliminating the need for 'ballasts' altogether would be far-and-away the better approach. Without getting cute about it, just keep in mind that this design is being presented as the 'ultimate' in SET design, Who says that? It has been repeatedly clearly described as prototype to prove the driver stage of another amp. It is described as a "prototype" on the circuit. You are confusing a proving proto with the proper design which is he http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg and as the ultimate in simplicity. Sure thing, the earlier T68 with a dedicated power supply was designed and built to beat the parts count of the Gaincard. There is nothing whatsoever represented as 'junk-box' about it, most especially as it is reputed to have significant value tied up in two tubes alone. A 'magnum opus' if you will. A trial run of a part of a magnum opus. Now, with your observation on the two chokes, there seems much to improve in this unit, starting with the iron itself. Holy Moses! Wiecky, you are talking through the back of your neck. You never heard of swing chokes until today, and five minutes later you want to teach me power supply design. Go read the RDH before you embarrass yourself some more. That the various parts-and-pieces are carefully specified by-the-numbers and without the qualifier "this is what was lying around" shows at least that much. These prissy-mouthed judgemental statements of yours irritates people who can see plainly that you are a newby and none too quick a newbie either. None of us have a lot of patience with idiots. This is your second chance and your wasting it in pretence that you know better than I do. I would still like to understand the "expected" vs. "actual" voltages so as to understand the function of the ballast resistors and how precise they must be. And whether it would be practical to test other expedients. Build your own and listen to it. It is always practical to test other expedients. I did, and I ****ed people off going on about those dumb ideas, just as you do now. But hey, maybe you learn something new. I did, that business about the harmonic distribution of the remnant of distortion. Ah, well. Salieri said of Mozart: Too many notes. Does "too many parts" have the same ring? Well, if you got off your arse and found the right circuit, rather than some part-proto, we could discuss parts count. Try he http://members.lycos.co.uk/fiultra/T...trafi-crct.jpg Peter Wieck Wyncote, PA |
#22
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The KISS AMP: a progress report
In article .com,
" wrote: John: Take a simple diode capable of handling the 500V. Say.. 1N4007. Connect it to one of the secondary winding leads. That will drop the voltage across the winding from 500V to .707 x 500V. Feed that to the rectifier. So, instead of windings-to-rectifier (assuming no dropping resistors), now it is winding to diode to rectifier to winding. In only _one_ of the two leads. OK, so we connect a 1N4007 diode between one of the transformer secondary leads and the corresponding anode of the 5AR4 rectifier tube, have I got it right so far? Which way around do we connect the 1N4007 diode? What do we do with the other end of the CT HV winding, do we leave it connected to the other anode of the 5AR4, or do we disconnect it, or what? Or, do you not remember curtain-burner radios where this simple expedient off the line-cord drops the 120V to about 84V or so? We are not talking about a "curtain-burner radio" here, we are talking about a sophisticated ultra fidelity amplifier! What you say is true of the heater string in a "curtain-burner radio" when feed from an AC sine wave power source, but it is not true of the B+ supply. If you put a silicon diode in series with the AC feed to the anode of the rectifier tube, it will either have virtually no effect on the B+ voltage, or it will reduce the B+ voltage to zero, depending on the orientation of the added diode. In the heater circuit of a "curtain-burner radio" it is the RMS value of the voltage that counts, while in the B+ rectifier it is either the peak value, or the average value of the voltage that counts, depending on the type of filter circuit used with the rectifier. The diode has different effects on each of these values, hence you can't apply your "curtain-burner radio" knowledge to the B+ supply of a sophisticated audiophile amplifier like this. Regards, John Byrns Surf my web pages at, http://users.rcn.com/jbyrns/ |
#23
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The KISS AMP: a progress report
Sander deWaal wrote: " said: [silly bit of transformerless table radio gimmickry about silicon diodes on one winding snipped] If a suitable transformer were not available, I would [another silly idea snipped] Even a blind squirrel must find a nut occasionally. I looked up the chicken scrawl on the clipboard from my workbench. I used a 250-0-250Vac secondary transformer with 330 ohms of ballast in each leg. According to my notes the alternatives we a) special-order a proper power tranny 240-0-240. Gee, just 10 volt difference? b) use the tranny already on the chassis and drop c110mA in the bleeder; this lets you use the GZ34 with a standard spec sheet 100 ohms of ballast in each leg. c) use the tranny already on the chassis and boost the ballast resistors to finetune the voltage, as the makers of the GZ34 clearly intended you to do because they limited the capacitance you may use. Of course I went for option c! Those ballast resistor are supposed to be there, regardless of how they bother Peter Wieck. Sorry, Peter, the other blind squirrel got the nut. While the resulting DC voltage will be lower in that case, the ripple is certainly going to be far greater than in case of the dual-diode power supply design. Getting rid of ripple means big caps, pushing the average DC voltage up again. More ripple also means higher charge/discharge currents, which in turn can cause hum induction in the actual amplifier circuit. Dropping resistors don't load the windings, bleeders do. A vacuum rectifier must see some DCR in the anode circuits, to prevent cathode stripping. A beefy tranny has a lower DCR, so series resistors *must* be added to avoid large cathode peak currents caused by the electrolytics. In case of a class A amplifier, burning some volts and watts away in series resistors isn't a big sin IMHO, unless one is designing to utmost efficiency. A fellow of Scottish extraction owned one of my favourite small tube manufactories. He delivers a set of transformers to me, of which he says he has plenty on his shelves. I am to design an amplifier using these transformers. He also gives me one unit of the amp currently built with them and says I must use the stainless steel topplate from that. So I reverse engineer this existing amp and discover that the other designer (a much-respected Englishman) ran the poor power supply tranny to within 1mA of total rated capacity. This is clearly a monstrous miscalculation but I can't find out where I went wrong, so I call the tranny designer and say to him, "According to my calculations, this tranny is stressed out to within a milliamp of its life." And the tranny designer says, "Don't tell Mr X! He will make you design for the last milliamp as well! And don't put the amount of current you want to bleed on circuit or he'll try to bargain you down!" Peter must have learned that sort of "production economy" somewhere and had it impressed on him for life in order for him at this stage of his life, in ultra-fi amps at that, to be so worried about 10 volts and possibly three or four buck wasted in over-rated resistors -- on a disposable part-prototype to prove a sub-assembly! Looking at the schematic again, I noticed that André actually uses the Lundahl LL1638 choke as a swing choke. As this choke wasn't designed as such, it won't regulate as good as a correctly designed swing choke (without air gap). It will provide some additional voltage drop and series resistance, though. I've answered this in my first reply to this letter but there is an additional fine point about the chokes that is easily overlooked unless you already know about the trick. It is mounting a split choke with two coils on common iron to straddle both voltage rails; this is a super means of achieving that extra edge of common mode rejection that in the long run will make the amp so much more satisfying that it is worth any amount of money for chokes with this capability. -- - Never argue with idiots, they drag you down their level and beat you with experience. - I dunno. I would never have discovered half this stuff if I weren't an idiot who would ask any question and not care if the clowns sneered and jeered as long as someone gave me the answer. Andre Jute Visit Jute on Amps at http://members.lycos.co.uk/fiultra/ "wonderfully well written and reasoned information for the tube audio constructor" John Broskie TubeCAD & GlassWare "an unbelievably comprehensive web site containing vital gems of wisdom" Stuart Perry Hi-Fi News & Record Review |
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The KISS AMP: a progress report
wrote in message oups.com... Ah, well. Salieri said of Mozart: Too many notes. Does "too many parts" have the same ring? Mozart performed a "medley" of the highlights of Salieri's life's work, It lasted just under two minutes:-) Iain |
#25
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The KISS AMP: a progress report
" wrote: Why do you still have some 100 watts of dropping resistors on the secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA I cannot see any 100watt dropping resistors anywhere. Do you mean the 2 x 100 ohm to ground the 417 heaters? Which transformer do you mean? output or power? Patrick Turner. |
#26
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The KISS AMP: a progress report
Mr. McCoy changed them.... As _specified_ originally, there was over
100 watts of dropping resistors. Peter Wieck Wyncote, PA |
#27
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The KISS AMP: a progress report
Mozart performed a "medley" of the highlights of Salieri's life's work, It lasted just under two minutes:-)
That long? This entire saga reminds me of the Parable of the Elephants and their Child. Much trumpeting, alarums & diversions at the conception, but no results for some two years thereafter. It does seem that Mr. McCoy does want it both ways. He should be massively grateful to Mr. Byrns for keeping him out of serious trouble and telling the rest of the world what he really means. But, the elephants are looking like mayflies as against the time this "perfect" amp is taking. Peter Wieck Wyncote, PA |
#28
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The KISS AMP: a progress report
John:
OK. So, what you are writing is that clipping off half the sine wave will have no effect on the secondary voltage, or it will drop it to zero, depending on the orientation of the diode? This due to the nature of the rectifier used? And apart from that, have you found an application other than the one in question where such 'ballast' resistors are used? That is, apart from home-brew necessities adapting not-quite-suited parts to a particular purpose? Careful about using the word "sophisticated" in this application. Function: adjective Etymology: Medieval Latin sophisticatus 1 : not in a natural, pure, or original state : ADULTERATED a sophisticated oil 2 : deprived of native or original simplicity: as a : highly complicated or developed : COMPLEX sophisticated electronic devices b : having a refined knowledge of the ways of the world cultivated especially through wide experience a sophisticated lady 3 : devoid of grossness: as a : finely experienced and aware a sophisticated columnist b : intellectually appealing a sophisticated novel One has to go pretty far down for a positive definition, and as the goal is KISS, even that seems in direct conflict with the stated goal in any case. Peter Wieck Wyncote, PA |
#29
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The KISS AMP: a progress report
wrote in message oups.com... Mozart performed a "medley" of the highlights of Salieri's life's work, It lasted just under two minutes:-) That long? Do you know the extent of Salieri's output? Mozart probably played at tempo "Largo" :-) Iain |
#30
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The KISS AMP: a progress report
wrote in message ups.com... As I remember, his output was largely equivalent to Mr. McCoy's. Much fuss, pomp and pretence, little substance. Salieri was acctually quite a good composer. It was unfortunate for him that he had to be born in the same era as W.A.M. Bing Crosby said of Frank Sinatra. "His is a talent one meets only once in a lifetime. Why did it have to be in mine?" One of my favourite 20th century composers, Einar Englund, suffered the same misfortune, and lived constantly in the shadow of Jean Sibelius. Iain |
#31
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The KISS AMP: a progress report
Salieri suffered much as Moltor (Bach then Hayden), Gluck (more-or-less
similarly) and quite a few others being in the shadow of the 'greats'. He was, as you say, a fair composer, but much of what he did suffered by being tight-to-formula. Apart from the Movie and Play, historically, his objections to Mozart were that he was not so formulaic, and as a rebel a direct threat to his position. Almost the same (musical-only) comparison as Telemann to Vivaldi. Telemann was a competent composer, wrote some great stuff, but as compared to Vivaldi, he is a little bit elephantine. Moltor and Gluck, now... there are some wonderful pieces by these two. I use the Moltor Trumpet concerto as a check-piece quite often. Gluck is an acquired taste, but stunning. Peter Wieck Wyncote, PA |
#32
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The KISS AMP: a progress report
wrote in message oups.com... Salieri suffered much as Moltor (Bach then Hayden), Gluck (more-or-less similarly) and quite a few others being in the shadow of the 'greats'. He was, as you say, a fair composer, but much of what he did suffered by being tight-to-formula. Apart from the Movie and Play, historically, his objections to Mozart were that he was not so formulaic, and as a rebel a direct threat to his position. Almost the same (musical-only) comparison as Telemann to Vivaldi. Telemann was a competent composer, wrote some great stuff, but as compared to Vivaldi, he is a little bit elephantine. Moltor and Gluck, now... there are some wonderful pieces by these two. I use the Moltor Trumpet concerto as a check-piece quite often. Gluck is an acquired taste, but stunning. Peter Wieck Wyncote, PA Hello Peter. Nice to discuss music with you. Just been looking through some catalogues. Considering his repertoire, Salieri is not well represented. As regards being tight to formula, one could accuse Haydn and also perhaps Mozart of the same thing. Personally, I find the genius of Mozart overwhelming. It is funny how composers become known for their "potboilers" I recently worked on a corporate film where the client had gone to great expense to clear copyright for the use of Sibelius:Karelia Suite. At a production meeting, we were talking about the music edit, and how and where this incredibly wonderful (and very expensive) music could be used. The client said "We only need about forty seconds. Cut all the the best bits together!" I very much enjoy Telemann - good solid technique. Vivaldi is best known for some of his less-good works (Four Seasons) For me, the Concerto for two Oboes, Bassoon, Two Horns and Violin (Fmaj RV574) is a much more interesting work (but maybe lacking the catchy melodies) There are also some very interesting little known European composers particularly of the Baroque era. One of my favourites is the Dutrchman Willem Fesch. (my music tutor calls him Handel in clogs!!) Neither Moltor nor Gluck have really fired my imagination. But now you have kindled a spark........:-) I find I may spend weeks listening to baroque works, and then suddenly switch to Charles Ives, or Ellington or Thomas Arne. So much music, so little time:-) Iain |
#33
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The KISS AMP: a progress report
Vivaldi Mandolin
Moltor Trumpet Nice transition from Mozart to Beethoven and beyond: Johann Nepomuk Hummel, with specific reference to his Mandolin and Trumpet works. Done right and at a resonable volume, a test of any system. Ellington, definitely. Ives, at the right time and mood. Arne, I have not acquired that taste, but neither have I rejected it... So much great music, so little time. Peter Wieck Wyncote, PA |
#34
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The KISS AMP: a progress report
On 31 Mar 2006 11:32:10 -0800, " wrote:
Vivaldi Mandolin Moltor Trumpet Nice transition from Mozart to Beethoven and beyond: Johann Nepomuk Hummel, with specific reference to his Mandolin and Trumpet works. Done right and at a resonable volume, a test of any system. Ellington, definitely. Ives, at the right time and mood. Arne, I have not acquired that taste, but neither have I rejected it... So much great music, so little time. Peter Wieck Wyncote, PA All great music, I'm sure - but I wouldn't use any of those to test a system; they are far too musically dense. They are really hard to hear past to see what the system is like. For system testing I use speech, from friends - both male and female. That is a really severe test, and very few systems actually sound like my friends. For musical testing I favour Bartok quartets - get a nicely staged recording and you will find both physical and tonal space between all the instruments that will reveal the actual quality of the system. d Pearce Consulting http://www.pearce.uk.com |
#35
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The KISS AMP: a progress report
I do happen to have the "Bartok Quartet" recordings of Beethoven's
string quartets. Sadly, it is a marginal recording technically and not a fair test of any system. Not the same thing, for sure but you triggered a memory. As my primary test pieces, I use a Kiri Te Kanawa recording of various classical and baroque pieces giving a good deal of solo soprano voice. She has a lot of color in her voice, more-so than most sopranos and can reach well down into the contralto-range. Done right, she is 'right there' and breathing. Done wrong and I picture her on a stage about fifty feet away. Also solo trumpet and solo harpsichord. I am overly fond of baroque trumpet. For full-range, the Saint-Saens Organ Symphony will reach well down into the nether regions, yet demand clarity up top. If the systems pass the above test, then I trot out this last. If I can pick out the parts-and-sections of the orchestra, great. If I hear lots of mud, not-so-great. Peter Wieck Wyncote, PA |
#36
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The KISS AMP: a progress report
On 31 Mar 2006 12:06:03 -0800, " wrote:
I do happen to have the "Bartok Quartet" recordings of Beethoven's string quartets. Sadly, it is a marginal recording technically and not a fair test of any system. Not the same thing, for sure but you triggered a memory. Well, it does have to be a super-nice recording. As my primary test pieces, I use a Kiri Te Kanawa recording of various classical and baroque pieces giving a good deal of solo soprano voice. She has a lot of color in her voice, more-so than most sopranos and can reach well down into the contralto-range. Done right, she is 'right there' and breathing. Done wrong and I picture her on a stage about fifty feet away. I find Kiri a bit affected in her vowel sounds - very hard to establish what is "right" from her voice, I find. Got any old Emma Kirkby? Also solo trumpet and solo harpsichord. I am overly fond of baroque trumpet. For full-range, the Saint-Saens Organ Symphony will reach well down into the nether regions, yet demand clarity up top. If the systems pass the above test, then I trot out this last. If I can pick out the parts-and-sections of the orchestra, great. If I hear lots of mud, not-so-great. That will do nicely. d Pearce Consulting http://www.pearce.uk.com |
#37
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The KISS AMP: a progress report
Iain Churches wrote: Gluck Iain Glug, glug. Way my disc storage system works, with about 250-300 catalogue entries (more discs, of course, as many are in sets) per box, with the boxes stacked on top of each other, it is a pain to move up and down the alphabet by restacking heavy boxes, so I'm still in the Gs, where I went looking for Gregorian Chant a while ago when we last discussed point source drivers, horns, etc. It must be serendipity that I'm playing Gluck as I read your post, at present Gardiner's Iphigenie en Aulide, from a box set which also includes Don Juan and Les Pelerins de la Mecque (and, to fill out the box, I suppose, Scubert Ss 8 & 9). Next Orphee et Eurydicee with Dawn Upshaw, the SF version under Runnicles. That should be enough Gluck to keep me honest for a few years of gorgin on Handel... For some totally subliminal reason, something in Gluck has reminded me of the moment in Schutz's Christmas Story where the countertenor comes in, a startling moment in one of my two recordings of the composition and yet not in the other, so I'll be in the S boxes next... I can't remember which is the startling recording, the Oxford Camerata/Naxos or the King's Consort/Hyperion version, so I'll just play them both for double the pleasure. Andre Jute Logical progressions are so predictable |
#38
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The KISS AMP: a progress report
Patrick Turner wrote: " wrote: Why do you still have some 100 watts of dropping resistors on the secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA I cannot see any 100watt dropping resistors anywhere. Do you mean the 2 x 100 ohm to ground the 417 heaters? Which transformer do you mean? output or power? Patrick Turner. Witless Wiecky is looking at the circuit of a different amp, on an already replaced version of the schematic -- but there aren't any 100W resistors on there either. Poor Witless thinks that if one uses a 50W resistor it will give off 50W of heat, regardless of how much current flows in it. It really is frustrating trying to help him. Sander and John and I tried to explain to him why: 1. Why one shouldn't use halfwave rectification. 2. Why a bleed resistor (he counts the bleeder in his list of "unwanted heat dissipators") is necessary. 3. Why a stiff bleed stabilizes the power delivery. 4. Why ballasts are in the secondary legs of the power transformer. 5. Why one doesn't lower voltage by inserting resistors into the primary. 6. Why choke input power filters are made with two sections. Etcetera, a very, very long list of things we take for granted that I was amazed to discover even a repair hack doesn't know, and especially a repair hack like Witless, who has the presumption to lecture us. I have concluded that Witless Wiecky is obdurately and permanently ignorant and a waste of my time. I've already put him back in my killfile. I really can't understand the sort of person who arrives on RAT without any visible achievement --and starts telling the doers how they should do a job they have been doing well for years. Doesn't it occur to clowns like Witless Wiecky that they should read Morgan Jones and at least a few relevant chapters of the RDH before they start preaching to someone who has been designing amps for fifteen years? As far as I can make out, Witless doesn't know the most basic things about electricity or amplifers. Even as a repair hack his knowledge must be suspect if he doesn't even understand the difference between DC and AC, which is the implication of his suggestion of a diode on only one winding of a power transformer secondary and the subsequent horrifying exchange with John Byrns. The people who let Wiecky "clean" (his word; one presumes he didn't attempt repair) their Conrad Johnson amps are either rich enough to afford a new one when he wrecks it or reckless with their property. Witless must be a danger to himself too; ignorance and high voltage are fatal neighbours. Andre Jute |
#39
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The KISS AMP: a progress report
"Andre Jute" wrote in message ups.com... Patrick Turner wrote: " wrote: Why do you still have some 100 watts of dropping resistors on the secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA I cannot see any 100watt dropping resistors anywhere. Do you mean the 2 x 100 ohm to ground the 417 heaters? Which transformer do you mean? output or power? Patrick Turner. Witless Wiecky is looking at the circuit of a different amp, on an already replaced version of the schematic -- but there aren't any 100W resistors on there either. Poor Witless thinks that if one uses a 50W resistor it will give off 50W of heat, regardless of how much current flows in it. It really is frustrating trying to help him. Sander and John and I tried to explain to him why: 1. Why one shouldn't use halfwave rectification. 2. Why a bleed resistor (he counts the bleeder in his list of "unwanted heat dissipators") is necessary. 3. Why a stiff bleed stabilizes the power delivery. 4. Why ballasts are in the secondary legs of the power transformer. 5. Why one doesn't lower voltage by inserting resistors into the primary. 6. Why choke input power filters are made with two sections. Etcetera, a very, very long list of things we take for granted that I was amazed to discover even a repair hack doesn't know, and especially a repair hack like Witless, who has the presumption to lecture us. I have concluded that Witless Wiecky is obdurately and permanently ignorant and a waste of my time. I've already put him back in my killfile. I really can't understand the sort of person who arrives on RAT without any visible achievement --and starts telling the doers how they should do a job they have been doing well for years. Doesn't it occur to clowns like Witless Wiecky that they should read Morgan Jones and at least a few relevant chapters of the RDH before they start preaching to someone who has been designing amps for fifteen years? As far as I can make out, Witless doesn't know the most basic things about electricity or amplifers. Even as a repair hack his knowledge must be suspect if he doesn't even understand the difference between DC and AC, which is the implication of his suggestion of a diode on only one winding of a power transformer secondary and the subsequent horrifying exchange with John Byrns. The people who let Wiecky "clean" (his word; one presumes he didn't attempt repair) their Conrad Johnson amps are either rich enough to afford a new one when he wrecks it or reckless with their property. Witless must be a danger to himself too; ignorance and high voltage are fatal neighbours. Andre Jute Yep, could be. OR maybe, just maybe, Peter is just pulling your leg. Heh Heh! If he is, then these, and his other posts, rate as a fairly brilliant piece of usenet hijinx. Peter has kept you and others quite busy lately. Chasing your tails maybe? I, myself, don't really care. Try it out, you might live longer with less stress. Unless you happen to trive on Bull****; I suspect a few do. It's a beautiful spring evening in Flemington; windows open ect. and the I've just cracked my first of a few (maybe more!) Yuenglings. 90.1 is on the box and sounds pretty good right now. Eyeing, though, some vinyl I've haven't heard in awhile. M |
#40
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The KISS AMP: a progress report
MarkS wrote: "Andre Jute" wrote in message ups.com... Patrick Turner wrote: " wrote: Why do you still have some 100 watts of dropping resistors on the secondary side of the transformer? http://members.lycos.co.uk/fiultra/t...17acircuit.jpg Peter Wieck Wyncote, PA I cannot see any 100watt dropping resistors anywhere. Do you mean the 2 x 100 ohm to ground the 417 heaters? Which transformer do you mean? output or power? Patrick Turner. Witless Wiecky is looking at the circuit of a different amp, on an already replaced version of the schematic -- but there aren't any 100W resistors on there either. Poor Witless thinks that if one uses a 50W resistor it will give off 50W of heat, regardless of how much current flows in it. It really is frustrating trying to help him. Sander and John and I tried to explain to him why: 1. Why one shouldn't use halfwave rectification. 2. Why a bleed resistor (he counts the bleeder in his list of "unwanted heat dissipators") is necessary. 3. Why a stiff bleed stabilizes the power delivery. 4. Why ballasts are in the secondary legs of the power transformer. 5. Why one doesn't lower voltage by inserting resistors into the primary. 6. Why choke input power filters are made with two sections. Etcetera, a very, very long list of things we take for granted that I was amazed to discover even a repair hack doesn't know, and especially a repair hack like Witless, who has the presumption to lecture us. I have concluded that Witless Wiecky is obdurately and permanently ignorant and a waste of my time. I've already put him back in my killfile. I really can't understand the sort of person who arrives on RAT without any visible achievement --and starts telling the doers how they should do a job they have been doing well for years. Doesn't it occur to clowns like Witless Wiecky that they should read Morgan Jones and at least a few relevant chapters of the RDH before they start preaching to someone who has been designing amps for fifteen years? As far as I can make out, Witless doesn't know the most basic things about electricity or amplifers. Even as a repair hack his knowledge must be suspect if he doesn't even understand the difference between DC and AC, which is the implication of his suggestion of a diode on only one winding of a power transformer secondary and the subsequent horrifying exchange with John Byrns. The people who let Wiecky "clean" (his word; one presumes he didn't attempt repair) their Conrad Johnson amps are either rich enough to afford a new one when he wrecks it or reckless with their property. Witless must be a danger to himself too; ignorance and high voltage are fatal neighbours. Andre Jute Yep, could be. OR maybe, just maybe, Peter is just pulling your leg. Heh Heh! If he is, then these, and his other posts, rate as a fairly brilliant piece of usenet hijinx. Peter has kept you and others quite busy lately. Chasing your tails maybe? Scary thought, that, MarkS. But, nah, I used to work in the theatre and in films and I still do the odd thing in television, and nobody is an actor so good he can deliberately look as stupid as Witless Wiecky does, nor for as long as Witless Wiecky has looked so convincingly stupid. I, myself, don't really care. Try it out, you might live longer with less stress. Unless you happen to trive on Bull****; I suspect a few do. It's a beautiful spring evening in Flemington; windows open ect. and the I've just cracked my first of a few (maybe more!) Yuenglings. 90.1 is on the box and sounds pretty good right now. Eyeing, though, some vinyl I've haven't heard in awhile. Yeah. I have some Fats Domino on LP that I don't have on CD. But it is such a bother unpacking and setting up a turntable... Andre Jute M |
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