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#1
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
I was just listening to my STAX electrostatic headphones plugged into
the matching STAX transistor amp. The amplification devices are standard, if only because my guarantee will go bye-bye if I alter them. But I've upgraded the wallwart by a factor of ten, to 3A, and the difference is very noticeable in a firmer sound and deeper bass. I imagine that one can go too far in this direction., too. 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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#2
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 19, 2:52 pm, Andre Jute wrote:
I was just listening to my STAX electrostatic headphones plugged into the matching STAX transistor amp. The amplification devices are standard, if only because my guarantee will go bye-bye if I alter them. But I've upgraded the wallwart by a factor of ten, to 3A, and the difference is very noticeable in a firmer sound and deeper bass. I imagine that one can go too far in this direction., too. Simply build a whole new amp and theyèll never know. A very superb one was published roughly 20 years ago in Glass Audio. |
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#3
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 19, 2:52 pm, Andre Jute wrote:
if only because my guarantee will go bye-bye if I alter them. Hi RATs! I have had many guarantees voided. They do not affect how anything sounds. Relax. Happy Ears! Al |
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#4
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 21, 6:43*am, wrote:
On Sep 19, 2:52 pm, Andre Jute wrote: I was just listening to my STAX electrostatic headphones plugged into the matching STAX transistor amp. The amplification devices are standard, if only because my guarantee will go bye-bye if I alter them. But I've upgraded the wallwart by a factor of ten, to 3A, and the difference is very noticeable in a firmer sound and deeper bass. I imagine that one can go too far in this direction., too. *Simply build a whole new amp and theyèll never know. A very superb one was published roughly 20 years ago in Glass Audio. Glass or sand? I've already designed a good little tube amp, my Type 213 "Bellybutton", to drive STAX +-300V fully differential with 6SL7 and 6SN7. Quite a few guys on RAT sent in super suggestions when I canvassed them offlist. But my final proto is in Japan and the guy's wife says, every time I call, that he's in his room listening to it and can't be disturbed. Next time I won't make the mistake of sending my own test CDs; people get bored of their own music sooner. When it eventually returns maybe I'll lose interest in the transistor OEM amp; shame because, except for the supplied power supply being a wee bit mingy, it is a perfectly good amp. I dunno that it is worth the time and effort to make a better tranny amp (if I even can -- at this kind of resolution, tiny track lengths must be a major factor in making a truly silent amp) if I'm anyway going to retire it the moment I have my "little" (it ain't!) tube amp back. But the gubbins of the better power supply belongs to a transmitting tube amp and must go back in it. Winter's coming and sallow soldernoses are sniffing the air for the last time before diving in to backed-up repairs and new projects... Autumn is definitely my favourite time of the year. Off for a ride on my bike. Omnia vincit nexus. Cyber Nexus (1) Pontiff http://members.lycos.co.uk/fiultra/B...20CYCLING.html (1) The cyclist who before his elevation was known as Andre Jute |
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#6
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
Jon Yaeger wrote:
in article , Andre Jute at wrote on 9/21/08 9:54 AM: On Sep 21, 6:43 am, wrote: On Sep 19, 2:52 pm, Andre Jute wrote: I was just listening to my STAX electrostatic headphones plugged into the matching STAX transistor amp. The amplification devices are standard, if only because my guarantee will go bye-bye if I alter them. But I've upgraded the wallwart by a factor of ten, to 3A, and the difference is very noticeable in a firmer sound and deeper bass. I imagine that one can go too far in this direction., too. Simply build a whole new amp and theyèll never know. A very superb one was published roughly 20 years ago in Glass Audio. Glass or sand? I've already designed a good little tube amp, my Type 213 "Bellybutton", to drive STAX +-300V fully differential with 6SL7 and 6SN7. Quite a few guys on RAT sent in super suggestions when I canvassed them offlist. But my final proto is in Japan and the guy's wife says, every time I call, that he's in his room listening to it and can't be disturbed. Next time I won't make the mistake of sending my own test CDs; people get bored of their own music sooner. When it eventually returns maybe I'll lose interest in the transistor OEM amp; shame because, except for the supplied power supply being a wee bit mingy, it is a perfectly good amp. I dunno that it is worth the time and effort to make a better tranny amp (if I even can -- at this kind of resolution, tiny track lengths must be a major factor in making a truly silent amp) if I'm anyway going to retire it the moment I have my "little" (it ain't!) tube amp back. But the gubbins of the better power supply belongs to a transmitting tube amp and must go back in it. Winter's coming and sallow soldernoses are sniffing the air for the last time before diving in to backed-up repairs and new projects... Autumn is definitely my favourite time of the year. Off for a ride on my bike. Omnia vincit nexus. Cyber Nexus (1) Pontiff http://members.lycos.co.uk/fiultra/B...20CYCLING.html (1) The cyclist who before his elevation was known as Andre Jute In my experience and opinion, "beefing up" a power supply has diminishing returns. For example, I had an Eico ST-70 rebuild that suffered from anemic bass and transient distortion. Adding about 40 MFD to the power supply "fixed" it and tightened up the bass response. OTOH, I installed Jim McShane's recommended power supply upgrade for the Citation II, which involved increasing the total power supply capacitance by a factor of X. Oh yeah, the amp had great bass response, but the high end was lifeless and drab. It is as if all of that capacitance robbed it of vitality. I thought the sound sucked, period. Again -- my opinion -- the amount of capacitance for a given amplifier should be sufficient to provide the extra joules during dynamic peaks or bass events, and no more. More capacitance is not necessarily better. Choosing the "right" amount of filter capacitance is like a finding a balance point of a tuned instrument. Jon If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. Keith |
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#7
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 21, 8:42*pm, Keithr wrote:
If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA |
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#8
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article
, Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42*pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. |
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#9
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 22, 10:35*am, Jon Yaeger wrote:
in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42*pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money.. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Jon: I think it is a matter of semantics. Extra capacitance vs. a power- supply that will not sag at full-demand are different things. I can run a radio on a 12V Lead-Acid car battery capable of making 400A if needed, or on eight D-size batteries capable of a few amps. The actual radio will not care as its actual demand is far less than either can provide. Putting a 1000-gallon pressure reservoir on a 0.5 gallon-per-hour pump with a 0.49999 gph demand does become rather silly - But a 1gph pump would need no special reservoir and be well able to respond to brief higher demands. And the reservoir would be required only to 'even out' the pumping action if that was required. Or even a 5 gph pump. Peter Wieck Melrose Park, PA |
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#10
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article , flipper at
wrote on 9/22/08 11:09 AM: On Mon, 22 Sep 2008 10:35:58 -0400, Jon Yaeger wrote: in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42*pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Well, I hear you say it but I'd like to hear some kind of theory as to why you'd think a stable voltage could possibly 'harm' the sound. Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass. I don't know if this "apparent" phenomenon can be measured or has any empirical basis. I suspect that it has something to do with the fact that an amplifier's power supply and output signal ought to be seen a parts of a tuned instrument as opposed to two separate and isolated components. Perhaps someone who agrees with the observation can offer a better explanation. Sorry that mine falls short. Jon |
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#11
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
In article ,
Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? As you said we need to be sure we are talking about the same thing. Many people perceive the effects of distortion and compression as an improvement of the sound. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
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#12
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article , John
Byrns at wrote on 9/22/08 3:48 PM: In article , Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? As you said we need to be sure we are talking about the same thing. Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source. Possibly pleasing to some people. |
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#13
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
Jon Yaeger wrote:
in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42 pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. I'd like to see some scientific results to back up the assertion. As a general principle in electronic engineering, the ideal power supply is viewed as a voltage source with zero series impedance, I.E. capapable of providing any amount of current with no modulation of the voltage. This is, of course, impossible, so the goal is to provide whatever current the load requires without significant voltage droop. The power supply cannot supply more current than the load is demanding no matter what it's actual capacity is so I find it difficult to understand how a supply with excess capacity can make an amplifier sound worse. Unless, that is, the amplifier itself has some shortcomming that only becomes evident when it can draw more current. It is, of course, also possible that with better supply regulation, and amplifier will sound "Different" and that may be viewed as worse by a listener used to the previous sound. Keith |
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#14
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
Jon Yaeger wrote:
in article , flipper at wrote on 9/22/08 11:09 AM: On Mon, 22 Sep 2008 10:35:58 -0400, Jon Yaeger wrote: in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42 pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Well, I hear you say it but I'd like to hear some kind of theory as to why you'd think a stable voltage could possibly 'harm' the sound. Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass. Some large capacitors can have a significant amount of inductance and resistance that appears in series with their capacitance. This may cause some distortion of the frequency response by boosting the bass more than the upper frequencies. I wouldnt expect the effect to be very great but it can be obviated by using some smaller value capacitors in parallel to the main reservoir ones. This is often done in wideband devices for noise reasons, the big capacitors have too much series impedance at high frequencies to effectively remove the noise from the supply rail. Never heard of it at audio frequencies though. I don't know if this "apparent" phenomenon can be measured or has any empirical basis. I suspect that it has something to do with the fact that an amplifier's power supply and output signal ought to be seen a parts of a tuned instrument as opposed to two separate and isolated components. No, the power supply should just appear to the amp as a current source with constant voltage. There are odd exceptions, but they certainly wouldn't apply to tube amps. Perhaps someone who agrees with the observation can offer a better explanation. Sorry that mine falls short. Jon Keith |
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#15
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 22, 4:41*pm, Jon Yaeger wrote:
in article , John Byrns at wrote on 9/22/08 3:48 PM: In article , *Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. *Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? *As you said we need to be sure we are talking about the same thing. * Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source.. Possibly pleasing to some people.- Hide quoted text - - Show quoted text - Jon: Why do you bite at all? Byrns is trolling again - nothing either interesting or useful to offer - just controversy. Occam's principle of the excluded middle applies. Either audio equipment is an 'instrument' or it is not. If it *is* an instrument, then the original recording is no more than a suggestion of what the actual sound output should be - and so all sorts of alterations are both permissable and desired. If it is meant to be as close to a faithful reproducer of the input signal, then any alteration of that signal is a failure of its specific task. Can't have it both ways and no use trolling for that position either. Peter Wieck Melrose Park, PA |
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#16
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article ,
Peter Wieck at wrote on 9/22/08 8:09 PM: On Sep 22, 4:41*pm, Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 3:48 PM: In article , *Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. *Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? *As you said we need to be sure we are talking about the same thing. * Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source. Possibly pleasing to some people.- Hide quoted text - - Show quoted text - Jon: Why do you bite at all? Byrns is trolling again - nothing either interesting or useful to offer - just controversy. Occam's principle of the excluded middle applies. Either audio equipment is an 'instrument' or it is not. If it *is* an instrument, then the original recording is no more than a suggestion of what the actual sound output should be - and so all sorts of alterations are both permissable and desired. If it is meant to be as close to a faithful reproducer of the input signal, then any alteration of that signal is a failure of its specific task. Can't have it both ways and no use trolling for that position either. Peter Wieck Melrose Park, PA I'm fully aware that John was setting up some traps. I wanted to dance around them without springing the mechanism. We'll see where he goes from there . . . |
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#17
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article , Keithr at
wrote on 9/22/08 8:02 PM: Jon Yaeger wrote: in article , flipper at wrote on 9/22/08 11:09 AM: On Mon, 22 Sep 2008 10:35:58 -0400, Jon Yaeger wrote: in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42 pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Well, I hear you say it but I'd like to hear some kind of theory as to why you'd think a stable voltage could possibly 'harm' the sound. Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass. Some large capacitors can have a significant amount of inductance and resistance that appears in series with their capacitance. This may cause some distortion of the frequency response by boosting the bass more than the upper frequencies. I wouldnt expect the effect to be very great but it can be obviated by using some smaller value capacitors in parallel to the main reservoir ones. This is often done in wideband devices for noise reasons, the big capacitors have too much series impedance at high frequencies to effectively remove the noise from the supply rail. Never heard of it at audio frequencies though. I don't know if this "apparent" phenomenon can be measured or has any empirical basis. I suspect that it has something to do with the fact that an amplifier's power supply and output signal ought to be seen a parts of a tuned instrument as opposed to two separate and isolated components. No, the power supply should just appear to the amp as a current source with constant voltage. There are odd exceptions, but they certainly wouldn't apply to tube amps. Perhaps someone who agrees with the observation can offer a better explanation. Sorry that mine falls short. Jon Keith Keith, I am aware of the science behind your points, which are well taken. What puzzles me is what I've "discovered" through experience doesn't seem to jive the scientific model as I understand it. I can't explain it, but I think I can hear it! Beefing up the Citation II with big caps had a detrimental effect to MY ears. I didn't like the results - that's all I "know" about the effect of pumping up the capacitance for that particular amp. In a comparable example, we can have an amplifier with immeasurable THD, IM, & TIM, that really sounds a lot worse than an amplifier with mediocre distortion specifications. Why is this so? Science should tell us that our ears are lying when we compare the two pieces. At the end of the day, perhaps there is no empirical basis for taste, or perhaps we just haven't discovered factor X that makes one sound better than another . . . Jon |
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#18
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
On Sep 22, 8:48*pm, John Byrns wrote:
In article , The question is, what are we really talking about when we say "bad sound", or good sound? This is really simple. It is that sound recognized as good by ears trained by years of concert-going. Messrs Briggs and Walker and Leak and suchlike were habitues of the London concert halls, and made music at home too. Mr Briggs was a distinguished pianist. Mr Walker wasn't just talking when he defined good sound as "the window on the concert hall"; everyone knew what he was talking about. Of course, you might argue that St Augustine wrote a millennium or so ago about the "just price", and that a millennium or so later everyone is still wondering what he meant by his final answer at the end of a thick book: "God knows." However, in the sense of too much capacitance, we do have some parameters. First of all, there are tradtional rules of thumb, usually aiming to reduce ripple per stage by 30dB, which, with doubled or trebled LC stages and maybe a bit of beefing up, have led some of us to the still modest pi-filters generally seen in polyprop-capped ZNFB amps. Then there are our experiences elsewhere in the amp, where capacitors can easily be heard by those with very high resolution audio chains including electrostatic speakers or horns. We know from tuning ("voicing" to the pretentious) amps that doubling or trebling the cathode capacitor changes the quality of the sound perceptibly, indeed in the case of horns, which become unloaded near Fs, can ruin the sound altogether and possibly even damage the driver. Since every component is in the signal path in an amp, the size and quality of the power supply caps matter, if not quite so blatantly as caps in the cathodes of drivers and even power tubes. Eveyone with experience of small SE amps, by far the most sensitive to power supply changes, at one stage or another overcapped a modest little amp, and gave it a nasty, pompous sound beyond its place on the food chain, with booming one-note bass and a fat, lingering treble, rubato where it isn't wanted. That is why I am so unhappy every time some techie (and Patrick does this too but more politely) tries to make me scale my amps to reach 1Hz. It is not only unnecessary, for a faithful amp it is very often counterproductive, and for amps destined for horns or electrostats or virtually any point source, it is positively harmful. All that current is also a source of noise that then requires NFB to kill, which brings with it a lot of other, even nastier problems. But by then you don't have an amp any more, you have a sort of rolling bodge that your try to talk good with catchphrases like "good amps aren't conceived, they're developed". And it all started with overcapping the power supply because the gang on the street corner thought it a good idea. In the end it comes down to Al's short answer: trust only your ears! Notice that chokes aren't included in my strictures. Mo' iron is good iron! A smart designer uses as many chokes as he can afford and, these days, even get. Two or three stages with high-Henry chokes will allow you to use the right, low micofarad film caps in the power supply. It's a better place to spend your money than on boutique coupling caps of doubtful veracity. 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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#19
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
In article ,
Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 3:48 PM: In article , Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? As you said we need to be sure we are talking about the same thing. Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source. Possibly pleasing to some people. To which I would add: BAD SOUND #3 = sound that sounds bad to me. But what we were trying to do was make sure we are talking about the same thing. When you said, "In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass." which criteria were you judging by, BAD SOUND #1 or BAD SOUND #2? -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
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#20
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
Jon Yaeger wrote:
in article , Keithr at wrote on 9/22/08 8:02 PM: Jon Yaeger wrote: in article , flipper at wrote on 9/22/08 11:09 AM: On Mon, 22 Sep 2008 10:35:58 -0400, Jon Yaeger wrote: in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42 pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Well, I hear you say it but I'd like to hear some kind of theory as to why you'd think a stable voltage could possibly 'harm' the sound. Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass. Some large capacitors can have a significant amount of inductance and resistance that appears in series with their capacitance. This may cause some distortion of the frequency response by boosting the bass more than the upper frequencies. I wouldnt expect the effect to be very great but it can be obviated by using some smaller value capacitors in parallel to the main reservoir ones. This is often done in wideband devices for noise reasons, the big capacitors have too much series impedance at high frequencies to effectively remove the noise from the supply rail. Never heard of it at audio frequencies though. I don't know if this "apparent" phenomenon can be measured or has any empirical basis. I suspect that it has something to do with the fact that an amplifier's power supply and output signal ought to be seen a parts of a tuned instrument as opposed to two separate and isolated components. No, the power supply should just appear to the amp as a current source with constant voltage. There are odd exceptions, but they certainly wouldn't apply to tube amps. Perhaps someone who agrees with the observation can offer a better explanation. Sorry that mine falls short. Jon Keith Keith, I am aware of the science behind your points, which are well taken. What puzzles me is what I've "discovered" through experience doesn't seem to jive the scientific model as I understand it. I can't explain it, but I think I can hear it! Has anybody else experienced this? Beefing up the Citation II with big caps had a detrimental effect to MY ears. I didn't like the results - that's all I "know" about the effect of pumping up the capacitance for that particular amp. The only physical reasons that I can think of are either you added crappy caps or the amp has some weird effect where it doesn't like a low impedance power supply. In a comparable example, we can have an amplifier with immeasurable THD, IM, & TIM, that really sounds a lot worse than an amplifier with mediocre distortion specifications. Why is this so? Science should tell us that our ears are lying when we compare the two pieces. At the end of the day, perhaps there is no empirical basis for taste, or perhaps we just haven't discovered factor X that makes one sound better than another . . . Jon It probably all comes down to perception what we think that we'd like to hear. Not very scientific, but it keeps the suppliers going. Personally, I think that some 50s and early 60s pop music sounds best through a 2" speaker attached to a Japanese 6 transistor radio with half flat batteries tuned to a distant AM station, but thats just the way that I first heard the stuff. Keith |
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#21
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
As has been well covered in many publications, increasing capacitance in
capacitor filter power supplies beyond a reasonable point causes transformer overheating, terrible power factor and the generation of short duration pulses of high current and unwanted EMI. Eventually the transformer takes a ****. In pure Class A circuits power supply impedance is not especially critical. People like Bob Fulton, a known schizophrenic, and the idiot vacuum cleaner salesmen who worship him have promulagated the goofy idea otherwise. A moderately high level of reserve energy in a well damped circuit is always best. Use the proper parts properly. That includes a well separated power supply and a RFC and RF bypassing when possible. -- Message posted using http://www.talkaboutaudio.com/group/rec.audio.tubes/ More information at http://www.talkaboutaudio.com/faq.html |
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#22
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Sonic advantages of beefing up the power supply
in article , John
Byrns at wrote on 9/22/08 11:53 PM: In article , Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 3:48 PM: In article , Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? As you said we need to be sure we are talking about the same thing. Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source. Possibly pleasing to some people. To which I would add: BAD SOUND #3 = sound that sounds bad to me. But what we were trying to do was make sure we are talking about the same thing. When you said, "In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass." which criteria were you judging by, BAD SOUND #1 or BAD SOUND #2? #1, because I didn't do anything empirical to test to see if the output signal deviated from the input in more than amplitude . . . |
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#23
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Sonic advantages of beefing up the power supply
Listen up, fellers:
On Sep 23, 6:40 am, "BretLudwig" wrote: In pure Class A circuits power supply impedance is not especially critical. This is absolutely the most relevant and smartest thing said so far in this thread, and by far the smartest thing I ever heard Bret Ludwig say. And his conclusion is spot on: A moderately high level of reserve energy in a well damped circuit is always best. Use the proper parts properly. That includes a well separated power supply and a RFC and RF bypassing when possible Exactly what I've been saying for years. 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 Here's Bret's full text: On Sep 23, 6:40*am, "BretLudwig" wrote: *As has been well covered in many publications, increasing capacitance in capacitor filter power supplies beyond a reasonable point causes transformer overheating, terrible power factor and the generation of short duration pulses of high current and unwanted EMI. Eventually the transformer takes a ****. *In pure Class A circuits power supply impedance is not especially critical. People like Bob Fulton, a known schizophrenic, and the idiot vacuum cleaner salesmen who worship him have promulagated the goofy idea otherwise. *A moderately high level of reserve energy in a well damped circuit is always best. Use the proper parts properly. That includes a well separated power supply and a RFC and RF bypassing when possible. -- Message posted usinghttp://www.talkaboutaudio.com/group/rec.audio.tubes/ More information athttp://www.talkaboutaudio.com/faq.html |
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#24
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Sonic advantages of beefing up the power supply
In article ,
Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 11:53 PM: In article , Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 3:48 PM: In article , Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? As you said we need to be sure we are talking about the same thing. Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source. Possibly pleasing to some people. To which I would add: BAD SOUND #3 = sound that sounds bad to me. But what we were trying to do was make sure we are talking about the same thing. When you said, "In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass." which criteria were you judging by, BAD SOUND #1 or BAD SOUND #2? #1, because I didn't do anything empirical to test to see if the output signal deviated from the input in more than amplitude . . . OK, thanks, it sounds like the bottom line is that beefing up the power supply changes the sound in a way that you don't like. What we don't know is whether the sound of the beefed up power supply is more accurate and you prefer the sound produced by the euphonic distortions of the power supply without the beef, or if the power supply without the beef has the more accurate sound? -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
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#25
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Sonic advantages of beefing up the power supply
In article , Keithr
wrote: Jon Yaeger wrote: in article , Keithr at wrote on 9/22/08 8:02 PM: Jon Yaeger wrote: in article , flipper at wrote on 9/22/08 11:09 AM: On Mon, 22 Sep 2008 10:35:58 -0400, Jon Yaeger wrote: in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42 pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Well, I hear you say it but I'd like to hear some kind of theory as to why you'd think a stable voltage could possibly 'harm' the sound. Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass. Some large capacitors can have a significant amount of inductance and resistance that appears in series with their capacitance. This may cause some distortion of the frequency response by boosting the bass more than the upper frequencies. I wouldnt expect the effect to be very great but it can be obviated by using some smaller value capacitors in parallel to the main reservoir ones. This is often done in wideband devices for noise reasons, the big capacitors have too much series impedance at high frequencies to effectively remove the noise from the supply rail. Never heard of it at audio frequencies though. I don't know if this "apparent" phenomenon can be measured or has any empirical basis. I suspect that it has something to do with the fact that an amplifier's power supply and output signal ought to be seen a parts of a tuned instrument as opposed to two separate and isolated components. No, the power supply should just appear to the amp as a current source with constant voltage. There are odd exceptions, but they certainly wouldn't apply to tube amps. Perhaps someone who agrees with the observation can offer a better explanation. Sorry that mine falls short. Jon Keith Keith, I am aware of the science behind your points, which are well taken. What puzzles me is what I've "discovered" through experience doesn't seem to jive the scientific model as I understand it. I can't explain it, but I think I can hear it! Has anybody else experienced this? Beefing up the Citation II with big caps had a detrimental effect to MY ears. I didn't like the results - that's all I "know" about the effect of pumping up the capacitance for that particular amp. The only physical reasons that I can think of are either you added crappy caps or the amp has some weird effect where it doesn't like a low impedance power supply. I'm not at all familiar with the Citation II, but doesn't it have a choke in the power supply? If it has a choke as I seem to remember, changing the amount of capacitance would change the resonant frequency of the power supply, and if the capacitance is increased the resonance would become less well damped, all of which would be expected to impact the sound to some extent. Better to replace the choke with a suitable small value resistor, and increase the values of all the capacitors in the filter network, eliminating the resonance and lowering the impedance of the supply. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
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#26
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article , John
Byrns at wrote on 9/23/08 5:34 PM: In article , Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 11:53 PM: In article , Jon Yaeger wrote: in article , John Byrns at wrote on 9/22/08 3:48 PM: In article , Jon Yaeger wrote: Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. The question is, what are we really talking about when we say "bad sound", or good sound? As you said we need to be sure we are talking about the same thing. Many people perceive the effects of distortion and compression as an improvement of the sound. John, Maybe I can make it easier for you: BAD SOUND #1 = sound that sounds bad to me; BAD SOUND #2 = a sound signal that deviates from the original or source. Possibly pleasing to some people. To which I would add: BAD SOUND #3 = sound that sounds bad to me. But what we were trying to do was make sure we are talking about the same thing. When you said, "In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass." which criteria were you judging by, BAD SOUND #1 or BAD SOUND #2? #1, because I didn't do anything empirical to test to see if the output signal deviated from the input in more than amplitude . . . OK, thanks, it sounds like the bottom line is that beefing up the power supply changes the sound in a way that you don't like. What we don't know is whether the sound of the beefed up power supply is more accurate and you prefer the sound produced by the euphonic distortions of the power supply without the beef, or if the power supply without the beef has the more accurate sound? We don't "know" the answer to your questions with certainty. I've got an idea . . . why don't you select an amplifier that you are familiar with, add lots more capacitance (temporarily, of course) and see for yourself if it makes any perceptible or measurable difference? It's an easy experiment with some alligator clips, etc. |
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#27
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
in article , John
Byrns at wrote on 9/23/08 7:43 PM: In article , Keithr wrote: Jon Yaeger wrote: in article , Keithr at wrote on 9/22/08 8:02 PM: Jon Yaeger wrote: in article , flipper at wrote on 9/22/08 11:09 AM: On Mon, 22 Sep 2008 10:35:58 -0400, Jon Yaeger wrote: in article , Peter Wieck at wrote on 9/22/08 10:23 AM: On Sep 21, 8:42 pm, Keithr wrote: If a power supply can supply the peak required current at good regulation, there is nothing to be gained by by going any further. But then, there is nothing to be lost either other than the waste of money. That would be the point. Peter Wieck Melrose Park, PA That's where Keith & I disagree. In my experience overkill in the power supply has a detrimental effect on the sound. Well, I hear you say it but I'd like to hear some kind of theory as to why you'd think a stable voltage could possibly 'harm' the sound. Let the flames begin. Peter is right . . . we have to make sure that we are talking about the same thing. A stable power supply is good. Nothing but distortion or compression can result if a supply is overtaxed = bad sound. In my experience, just adding capacitance for its own sake seems to harm the sound and suck the life out of it - particularly at the mid and high end. Granted, lots of capacitance can stiffen up the bass. Some large capacitors can have a significant amount of inductance and resistance that appears in series with their capacitance. This may cause some distortion of the frequency response by boosting the bass more than the upper frequencies. I wouldnt expect the effect to be very great but it can be obviated by using some smaller value capacitors in parallel to the main reservoir ones. This is often done in wideband devices for noise reasons, the big capacitors have too much series impedance at high frequencies to effectively remove the noise from the supply rail. Never heard of it at audio frequencies though. I don't know if this "apparent" phenomenon can be measured or has any empirical basis. I suspect that it has something to do with the fact that an amplifier's power supply and output signal ought to be seen a parts of a tuned instrument as opposed to two separate and isolated components. No, the power supply should just appear to the amp as a current source with constant voltage. There are odd exceptions, but they certainly wouldn't apply to tube amps. Perhaps someone who agrees with the observation can offer a better explanation. Sorry that mine falls short. Jon Keith Keith, I am aware of the science behind your points, which are well taken. What puzzles me is what I've "discovered" through experience doesn't seem to jive the scientific model as I understand it. I can't explain it, but I think I can hear it! Has anybody else experienced this? Beefing up the Citation II with big caps had a detrimental effect to MY ears. I didn't like the results - that's all I "know" about the effect of pumping up the capacitance for that particular amp. The only physical reasons that I can think of are either you added crappy caps or the amp has some weird effect where it doesn't like a low impedance power supply. I'm not at all familiar with the Citation II, but doesn't it have a choke in the power supply? If it has a choke as I seem to remember, changing the amount of capacitance would change the resonant frequency of the power supply, and if the capacitance is increased the resonance would become less well damped, all of which would be expected to impact the sound to some extent. Better to replace the choke with a suitable small value resistor, and increase the values of all the capacitors in the filter network, eliminating the resonance and lowering the impedance of the supply. You are correct . . . the citation has a choke in it. It's a doubler supply, too. I don't have the amp anymore to try your suggestion. But you may be onto something . . . |
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#28
Posted to rec.audio.tubes
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Sonic advantages of beefing up the power supply
In article ,
Jon Yaeger wrote: in article , John Byrns at wrote on 9/23/08 5:34 PM: OK, thanks, it sounds like the bottom line is that beefing up the power supply changes the sound in a way that you don't like. What we don't know is whether the sound of the beefed up power supply is more accurate and you prefer the sound produced by the euphonic distortions of the power supply without the beef, or if the power supply without the beef has the more accurate sound? We don't "know" the answer to your questions with certainty. I've got an idea . . . why don't you select an amplifier that you are familiar with, add lots more capacitance (temporarily, of course) and see for yourself if it makes any perceptible or measurable difference? It's an easy experiment with some alligator clips, etc. I have tried that in the past and have not been able to detect any difference in the sound except when there is hum due to inadequate capacitance in the original power supply design. But then it is well known that I am not a "Golden Ear" and can't hear many of the subtle sonic effects audiophiles are able to detect. As far as measurements go, my ancient vacuum tube Heathkit test equipment isn't sensitive enough to resolve issues such as we are talking about here. -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
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