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#1
Posted to rec.audio.tubes
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A Stupid Idea
The latest AudioXPress has on its cover a stereo amplifier using one
4D32 tetrode in Class AB2 per channel as an output device. Why do people persist in acts that aren't just stupid but willfully destructive? The 4D32 was neither designed for nor is it really any good as an audio amplifier. Its only use today is as an RF output tube for the beautifully built Collins V-line transmitters and a few military field transmitters. The supply of these tubes is limited and it is doubtful any more will ever be made. No really good substitute exists, although the set can be kluged to operate at reduced power and efficiency with the VHF twin triodes paralleled together. Yet we have self centered and ****ish audiophools who persist. Can you see why I get mad? If the 4D32 were a fantastic audio tube, I'd say go ahead and use them up. Make them make more. But it is in fact terrible. It sucks as an audio tube. Even an 811 is far better. Rein Narma made them work just fine. |
#2
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 5:59*pm, Bret L wrote:
*The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? *The 4D32 was neither designed for nor is it really any good as an audio amplifier. Its only use today is as an RF output tube for the beautifully built Collins V-line transmitters and a few military field transmitters. The supply of these tubes is limited and it is doubtful any more will ever be made. No really good substitute exists, although the set can be kluged to operate at reduced power and efficiency with the VHF twin triodes paralleled together. *Yet we have self centered and ****ish audiophools who persist. *Can you see why I get mad? If the 4D32 were a fantastic audio tube, I'd say go ahead and use them up. Make them make more. But it is in fact terrible. It sucks as an audio tube. *Even an 811 is far better. Rein Narma made them work just fine. Calm down me boy or you'll explode. One could say an 807 was only meant for RF because there is a top cap connection for the anode which reduces stray C and makes an amp less likely to arc from anode to something nearby at lower potential. Ditto a 6CM5/EL36. Except that the 6CM5 can give SE triode performance better than a 2A3. In PP, the ""queer"" 6CM5 line output beam tetrode can make 44W in AB, and have low Ea, and only 4ka-a. But 20W in PP near class A is possible. The hi-fi cognescenti and audio magazines have always hated such tubes like they hate the 6L6. As time marches along, fewer and fewer DIYer ppl are building anything with vacuum tubes. The old wannabes are decaying into decrepitude and or dreamers who build nothing and can learn nothing, and who can't hear anything properly. Given the number of declining ppl making anything with vacuum tubes and considering the number of tubes being sent to landfill, maybe tube stocks or rare tubes are actually increasing if you say stocks = number of tubes divided by users. The last 20 years has seen a dramatic decline in people wanting to take up amateur HF radio. When one does venture out onto a ham band one finds oneself listening for hours to yet another ancient old giza telling his story about his bowel cancer operation or prostate troubles, and frankly, after the first hour you become monumentally bored stiff. So there are these mountains of suplus amateur radio gear out there lurking in sheds/ barns and gathering dust, fabulous antennas that cost a bomb 20 years ago but now oxidizing to bits. And to resurrect an antena and its nice mast on a suburban plot is so difficult because ot neighbours abd concil regs etc, that only a masochist would bother to make his own ham radio outfit. At my wesbite I have around 100 odd different types of OPTs for sale at prices similar to the lowest common denominator prices charged by Hammond Engineering. The OPT mainly have C-cores and plenty of interleaving but the interest from DIYer is almost ZERO. In fact the total weight of all the transformers I have for sale is over 1 tonne, and after 18 months I have sold two pairs and used another two pairs in amps I have made for customers. At this rate when I die in 10 months or 10 years there will still be a huge pile of unsold trannys here and they will all go to the re-cyclers for the cppper and iron if nobody buys them, and I strongly doubt anyone ever will, even if I reduced the price by -12dB. So it is with many old vacuum tubes. I know a guy who must be about 82 and last time I spoke to him he had 25,000 tubes AFTER having sold off all the audio tubes in his collection. He's Morris Obrien at SanRemo Vic, Aust. When he dies, the tubes in his estate might be auctioned for $100 and the next die hard will have to find a barn and get transport for them and then sort them out and that can take weeks of work. But perhaps they end up all being crushed and secretly dumped to avoid the problems with expenses of toxic material disposal. There are some idiots who are trying to make tiny tube amps putting out huge power for their size and the only way is to go class AB2 plus a shirt&trouser load of negative feedback. There is a good market for the 25yo dudes who can think of nothing cooler than having a tube amp beside their PC for the headphones or small speakers. So don't worry, be happy, We all end up expiring. Patrick Turner. |
#3
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 5:59*pm, Bitchy Loser wrote:
*The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? Hi RATs! Some people are having a bit of fun, occasionally. You could never imagine that, but, it happens, anyway. Almost as if you are not the Supeme Being you assume... Happy Ears! Al |
#4
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 1:50*pm, "Watt? Me worry?" wrote:
On Apr 18, 5:59*pm, Bitchy Loser wrote: *The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? Hi RATs! Some people are having a bit of fun, occasionally. You could never imagine that, but, it happens, anyway. Almost as if you are not the Supeme Being you assume... You are being willfully obtuse. These people are destroying other people's fun for no reason, because the 4D32 is a poor audio tube. It doesn't work well. If they persist I hope they shock themselves so badly they have to quit building things for total motor control failure. Then they will quit being ****ups. |
#5
Posted to rec.audio.tubes
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A Stupid Idea
Bret L wrote:
On Apr 18, 1:50 pm, "Watt? Me worry?" wrote: On Apr 18, 5:59 pm, Bitchy Loser wrote: The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. Why do people persist in acts that aren't just stupid but willfully destructive? Hi RATs! Some people are having a bit of fun, occasionally. You could never imagine that, but, it happens, anyway. Almost as if you are not the Supeme Being you assume... You are being willfully obtuse. These people are destroying other people's fun for no reason, because the 4D32 is a poor audio tube. It doesn't work well. If they persist I hope they shock themselves so badly they have to quit building things for total motor control failure. Then they will quit being ****ups. Bret, the difference between you and the average 5 year old is the 5 year old is way more grown up than you. |
#6
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 7:50*pm, "Watt? Me worry?" wrote:
On Apr 18, 5:59*pm, Bitchy Loser wrote: *The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? Hi RATs! Some people are having a bit of fun, occasionally. You could never imagine that, but, it happens, anyway. Almost as if you are not the Supeme Being you assume... Happy Ears! Al While there's no accounting for taste, on the other hand: Anyone who thinks Class AB2 bears any relationship to music deserves to have Bret Ludwig as his only friend. Andre Jute Not everything in materials is dreamt of in Timoshenko |
#7
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 19, 8:29*am, Andre Jute wrote:
On Apr 18, 7:50*pm, "Watt? Me worry?" wrote: On Apr 18, 5:59*pm, Bitchy Loser wrote: *The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? Hi RATs! Some people are having a bit of fun, occasionally. You could never imagine that, but, it happens, anyway. Almost as if you are not the Supeme Being you assume... Happy Ears! Al While there's no accounting for taste, on the other hand: Anyone who thinks Class AB2 bears any relationship to music deserves to have Bret Ludwig as his only friend. There was a time when anyone with a sense of style wouldn't set foot a beach without a battery powered radio to acompany they posing. Because the batteries didn't last too long with high draw, the best audio amps in the portables has class AB1 or AB2 circuits biased almost for class B. Nobody complained much and nothing got much better when the Japanese invented portables for the beach with nearly class B transistor circuits. But the early car radios had class A tubes and then class A transistor amps; just one TO3 transistor with 12V feed and 1 amp idle. Same Pda as a 6BQ5 Sound was OK. But I once repaired a Lennard amp with 8 x *L34, Ea = 900V, Eg2 = 450V, and PO = 450W class AB1, and with very little class A. Only 12dB global NFB. It sounded very well in a hall with 300 ppl - much better than a huge bjt amp. Patrick Turner. Andre Jute *Not everything in materials is dreamt of in Timoshenko- Hide quoted text - - Show quoted text - |
#8
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 6:29*pm, Andre Jute wrote:
On Apr 18, 7:50*pm, "Watt? Me worry?" wrote: On Apr 18, 5:59*pm, Bitchy Loser wrote: *The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? Hi RATs! Some people are having a bit of fun, occasionally. You could never imagine that, but, it happens, anyway. Almost as if you are not the Supeme Being you assume... Happy Ears! Al While there's no accounting for taste, on the other hand: Anyone who thinks Class AB2 bears any relationship to music deserves to have Bret Ludwig as his only friend. Andre Jute *Not everything in materials is dreamt of in Timoshenko- Hide quoted text - - Show quoted text - Bret and Andre are conjioned twins with the same disposition. |
#9
Posted to rec.audio.tubes
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A Stupid Idea
*** Al wrote:
Almost as if you are not the Supeme Being you assume... *** What? But I've just ordered 5000 luminous statues of the baby Bret... |
#10
Posted to rec.audio.tubes
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A Stupid Idea
Hi RATs!
I did not say tubes were not purposely designed. I said using tubes for audio that were not designed for audio is neither sinful nor foolish. Whatever works, works. It is not as if audio is the highest destiny of electronics... nor that it is somehow more noble to send them to the landfill than to have a listen out of simple curiosity. Not quite the same thing. To some of us Happy Ears! Al |
#11
Posted to rec.audio.tubes
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A Stupid Idea
In article ,
flipper wrote: On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?" wrote: Hi RATs! I did not say tubes were not purposely designed. I said using tubes for audio that were not designed for audio is neither sinful nor foolish. Not quite. You said "The reason a tube sounds good is the circuit it is in, if it ever sounds good. Not because it was "designed" for low (audio) frequency... . . . It doesn't matter what the tube was designed to do..." It most certainly does "matter what the tube was designed to do." A remote cutoff pentode, for example, is a lousy choice for 'hi-fi' because it was specifically "designed" for a different purpose and, as a result, isn't very linear. Still anyone who has listened to an AM, FM, or even an FM stereo broadcast in the early years has listened to audio processed through remote cut off tubes, specifically chosen because of their particular nonlinearity. Now, what's true is that some purposes share similar needs or may, at least, be non conflicting. One would, for example, probably like a non distorted TV picture and, so, use reasonably linear sweep tubes that might also be suitable for audio. At least in the Horizontal Sweep I didn't think the linearity of the tube entered into the linearity of the Sweep? My gut feel may be wrong on this, it's an interesting question, I will have to study up on it. Regards, John Byrns -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#12
Posted to rec.audio.tubes
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A Stupid Idea
Hi RATs!
Some tubes are fun to put into audio circuits. Not all. Some comments aid understanding. "Most certainly" not "quite" all. Happy Ears! Al |
#13
Posted to rec.audio.tubes
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A Stupid Idea
" Note: The author of this mesage requested that it not be arched. This message will be remed from Groups in 5 days (Apr 26, 6:53 pm).
On Mon, 19 Apr 2010 12:08:26 -0700 (PDT), "Watt? Me worry?" wrote: Hi RATs! I did not say tubes were not purposely designed. I said using tubes for audio that were not designed for audio is neither sinful nor foolish. Not quite. You said "The reason a tube sounds good is the circuit it is in, if it ever sounds good. Not because it was "designed" for low (audio) frequency... .. .. .. It doesn't matter what the tube was designed to do..." It most certainly does "matter what the tube was designed to do." A remote cutoff pentode, for example, is a lousy choice for 'hi-fi' because it was specifically "designed" for a different purpose and, as a result, isn't very linear. Now, what's true is that some purposes share similar needs or may, at least, be non conflicting. One would, for example, probably like a non distorted TV picture and, so, use reasonably linear sweep tubes that might also be suitable for audio. The previously mentioned 807 is simply the guts of a 6L6 repackaged to make it even more suitable for RF but that does not negate the audio characteristics (or vice versa); a case of 'non conflicting'. The guts were also used for the 6BG6 sweep tube. You create a straw man in saying "Not because it was "designed" for low (audio) frequency." "Low frequency" isn't the 'design' criteria. Linearity, noise, hum, etc. are some of them. Whatever works, works. It is not as if audio is the highest destiny of electronics... It also isn't quite as trivial as you imply if your goal is more than to simply make noise. " |
#14
Posted to rec.audio.tubes
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A Stupid Idea
At my wesbite I have around 100 odd different types of OPTs for sale at prices similar to the lowest common denominator *prices charged by Hammond Engineering. The OPT mainly have C-cores and plenty of interleaving but the interest from DIYer is almost ZERO. In fact the total weight of all the transformers I have for sale is over 1 tonne, and after 18 months I have sold two pairs and used another two pairs in amps I have made for customers. At this rate when I die in 10 months or 10 years there will still be a huge pile of unsold trannys here and they will all go to the re-cyclers for the cppper and iron if nobody buys them, and I strongly doubt anyone ever will, even if I reduced the price by -12dB. Last I checked you were wanting considerably more than new Lars Lundahl items. Those are a known quantity. I'd buy some if the price were right, certainly at just over scrap price. |
#15
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 19, 6:04*am, Bret L wrote:
At my wesbite I have around 100 odd different types of OPTs for sale at prices similar to the lowest common denominator *prices charged by Hammond Engineering. The OPT mainly have C-cores and plenty of interleaving but the interest from DIYer is almost ZERO. In fact the total weight of all the transformers I have for sale is over 1 tonne, and after 18 months I have sold two pairs and used another two pairs in amps I have made for customers. At this rate when I die in 10 months or 10 years there will still be a huge pile of unsold trannys here and they will all go to the re-cyclers for the cppper and iron if nobody buys them, and I strongly doubt anyone ever will, even if I reduced the price by -12dB. *Last I checked you were wanting considerably more than new Lars Lundahl items. Those are a known quantity. I'd buy some if the price were right, certainly at just over scrap price. I think your'e wrong about my pricing, and it depends whach OPT you want and the wieight and so on. Damned If I could afford to give the stuff away. Hammond charge more than I do. I always though Lundahll were more expensive than Hammond By the time you add in freight and GST, the cost of what I have is less than Hammond which has already been shipped here by sea. I did the research and found Hammond had a certain approximate cost per Kg, and I went under that. Usually buyers consult me about the transformer use and the circuit so they get $300 worth of free advice that both Lundahll and Hammond cannot offer. Most DIYers haven't a clue what they want, or why. But then the AUD has climbed a bit. Patrick Turner. |
#16
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 20, 12:16*am, Patrick Turner wrote:
On Apr 19, 6:04*am, Bret L wrote: At my wesbite I have around 100 odd different types of OPTs for sale at prices similar to the lowest common denominator *prices charged by Hammond Engineering. The OPT mainly have C-cores and plenty of interleaving but the interest from DIYer is almost ZERO. In fact the total weight of all the transformers I have for sale is over 1 tonne, and after 18 months I have sold two pairs and used another two pairs in amps I have made for customers. At this rate when I die in 10 months or 10 years there will still be a huge pile of unsold trannys here and they will all go to the re-cyclers for the cppper and iron if nobody buys them, and I strongly doubt anyone ever will, even if I reduced the price by -12dB. *Last I checked you were wanting considerably more than new Lars Lundahl items. Those are a known quantity. I'd buy some if the price were right, certainly at just over scrap price. I think your'e wrong about my pricing, and it depends whach OPT you want and the wieight and so on. Damned If I could afford to give the stuff away. Hammond charge more than I do. I always though Lundahll were more expensive than Hammond By the time you add in freight and GST, the cost of what I have is less than Hammond which has already been shipped here by sea. But most of the potential market is abroad so it has to be shipped the other way. If you included shipping it might be attractive for US or European customers. The other problem s you have a lot of different pairs of two each instead of a big bunch of the same. usually MOST DIYers want a known design that appeals to them and then buy the transformers that fit it. Sad to say there are US vendors selling a couple of hundred Dyna ST70 copies a year each because people actually use them in new builds even though they stink. Of course are replacement for existing ST70s too. If you had a lot of one you could build one unit around it, advertise it for a huge sum, then people would build clones of it and feel their sense of larceny satisfied. If you advertised "These will fit________" (insert establisnhed unit like marantz 9, VTL, ARC, what have you) this would help provided this was actually true. |
#17
Posted to rec.audio.tubes
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A Stupid Idea
In article
, Bret L wrote: The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. Why do people persist in acts that aren't just stupid but willfully destructive? The 4D32 was neither designed for nor is it really any good as an audio amplifier. Its only use today is as an RF output tube for the beautifully built Collins V-line transmitters and a few military field transmitters. The supply of these tubes is limited and it is doubtful any more will ever be made. No really good substitute exists, although the set can be kluged to operate at reduced power and efficiency with the VHF twin triodes paralleled together. Yet we have self centered and ****ish audiophools who persist. Can you see why I get mad? If the 4D32 were a fantastic audio tube, I'd say go ahead and use them up. Make them make more. But it is in fact terrible. It sucks as an audio tube. Even an 811 is far better. Rein Narma made them work just fine. Hi Bret, Do you have any idea how audioXpress was able to build an amplifier using only a single tetrode per channel operating in class AB2? Class A2 I can understand, but class AB2 only works for audio in push-pull circuits. If these people have actually built a class AB2 SE amplifier they certainly aren't audiophiles! On the other hand it isn't obvious why you say that the 8D32 isn't "really any good as an audio amplifier"? It looks OK to me, certainly better than a 811, and it has some interesting characteristics, I may have to try a design with it, although I would probably go for the 8D22 variation, so you can rest easy. Regards, John Byrns -- Regards, John Byrns Surf my web pages at, http://fmamradios.com/ |
#18
Posted to rec.audio.tubes
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A Stupid Idea
Hi RATs!
The reason a tube sounds good is the circuit it is in, if it ever sounds good. Not because it was "designed" for low (audio) frequency. Low frequency is not a huge technological leap, unlike GHz, for instance. I am using old TV horizontal amplifiers, 6BQ6, My music is not as demanding as kicking the electron beam across a CRT. But, having a ten watt continuous plate rating is a bit less limiting when the tube is also speced for 500 watts for short periods. It doesn't matter what the tube was designed to do. If you put it in an audio circuit and like what you hear, it is an "audio" tube. No rules for us fools. If it doesn't work, blame mgmt Happy Ears! Al |
#19
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 11:48*pm, "Watt? Me worry?" wrote:
Hi RATs! The reason a tube sounds good is the circuit it is in, if it ever sounds good. Not because it was "designed" for low (audio) frequency. Low frequency is not a huge technological leap, unlike GHz, for instance. I am using old TV horizontal amplifiers, 6BQ6, My music is not as demanding as kicking the electron beam across a CRT. But, having a ten watt continuous plate rating is a bit less limiting when the tube is also speced for 500 watts for short periods. It doesn't matter what the tube was designed to do. If you put it in an audio circuit and like what you hear, it is an "audio" tube. No rules for us fools. They built specific audio, HF RF, VHF/UHF RF, and sweep tubes for good reason. Audio types were designed for linearity and to operate their screen grids at close to the plate supply voltage to make ultralinear operation feasible. Some smaller transmitting types are perfectly okay for audio use, with others it's bad practice when any others are available. The 4D32 is an especially bad choice, plus being rare. The 807 is a decent choice, as is the 6146 if a separate screen supply is available. Ultralinear operation of them requires an output transformer with screen windings. Sweep tubes are in the same predicament. They are expensive because the CB keyclowns still run a lot of 11 meter amplifiers with them. |
#20
Posted to rec.audio.tubes
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A Stupid Idea
On Apr 18, 11:08*pm, John Byrns wrote:
In article , *Bret L wrote: *The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. *Why do people persist in acts that aren't just stupid but willfully destructive? *The 4D32 was neither designed for nor is it really any good as an audio amplifier. Its only use today is as an RF output tube for the beautifully built Collins V-line transmitters and a few military field transmitters. The supply of these tubes is limited and it is doubtful any more will ever be made. No really good substitute exists, although the set can be kluged to operate at reduced power and efficiency with the VHF twin triodes paralleled together. *Yet we have self centered and ****ish audiophools who persist. *Can you see why I get mad? If the 4D32 were a fantastic audio tube, I'd say go ahead and use them up. Make them make more. But it is in fact terrible. It sucks as an audio tube. *Even an 811 is far better. Rein Narma made them work just fine. Hi Bret, Do you have any idea how audioXpress was able to build an amplifier using only a single tetrode per channel operating in class AB2? *Class A2 I can understand, but class AB2 only works for audio in push-pull circuits. *If these people have actually built a class AB2 SE amplifier they certainly aren't audiophiles! Busted. I meant to say Class A2. On the other hand it isn't obvious why you say that the 8D32 isn't "really any good as an audio amplifier"? *It looks OK to me, certainly better than a 811, and it has some interesting characteristics, I may have to try a design with it, although I would probably go for the 8D22 variation, so you can rest easy. Its plate curves are humpty as hell: it isn't linear. It is just pretty inconveniently configured for its plate rating in terms of screen requirements, and there is good reason why Collins eschewed it even for audio (the modulators used 810s for this power range typically.) It isn't common or cheap either. |
#21
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Quote:
If someone feels the tubes are scarce , they need to buy spares when they can . In fact , the EF Johnson Viking I transmitter is a far more worthy use for those 4D32 s . At present , I am drawing up a guitar amp using a QUAD of 4D32 in PP parallel ! The 4D32 is actually plentiful from what I have seen . I picked up 50 of them for $2 each just two years ago . |
#22
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Class AB2? With a single output tube? How did the designer accomplish that? I will pick up a copy of the magazine if Barnes & Noble has it.
Class A2 I can understand, but I am unaware of any design methodology in which one could achieve class AB2 (or B) operation with a single output device. Peace, DrRick Quote:
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#23
Posted to rec.audio.tubes
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A Stupid Idea
On May 7, 6:19*am, DrRick wrote:
Class AB2? With a single output tube? How did the designer accomplish that? I will pick up a copy of the magazine if Barnes & Noble has it. Class A2 I can understand, but I am unaware of any design methodology in which one could achieve class AB2 (or B) operation with a single output device. Peace, DrRick Bret L;906635 Wrote: The latest AudioXPress has on its cover a stereo amplifier using one 4D32 tetrode in Class AB2 per channel as an output device. Why do people persist in acts that aren't just stupid but willfully destructive? The 4D32 was neither designed for nor is it really any good as an audio amplifier. Its only use today is ......................... -- DrRick You need TWO tubes for class AB because the term class AB infers that one tube of the pair cuts off during each wave cycle before the other tube reaches a crest in the peak tube current when working at power near clipping. The data for 4D32 is at http://www.mif.pg.gda.pl/homepages/f...138/4/4D22.pdf Its a grunty tube with Pda rated at 47W, and with RLa-a = 3k, you get 112W in class AB1 using two in PP. I recall AudioXpress had a class A2 SE amp desogn some years back using one lone 6550. Patrick Turner. |
#24
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Quote:
Cheers, J |
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