mike stehr Posted February 6, 2002 Share Posted February 6, 2002 I could be wrong, and I am not sure if there is Class B tube amps, but I don't think there is very many Class B Solid State amps. Due to the fact of the transistor's crossover distortion.(Noise.) In a AB design the transistor's are switched on just a little bit, so the crossover distortion (switching between the two transistors)is at a minimum. Hence A mode at the first few watts, then AB as the transistors start switching between each other. This way the amp can run more efficient for heat dissipation, unlike Class A which is wide open all the time and requires massive heatsinking. A Class B design, the transistor's would switch completely off between each other, making the transistor's lower than their optimum operating range, resulting in the switching noise. Class A is superior sound-wise, but you'll pay for it on the power bill. A class D amp is a amplifier with a switchmode power supply?(There is a whole breed of Digital amps as well.) I'm glad you folks post all this tube amp information, Cream and Corned ain't the only one learning something here. Correct me if I'm wrong, I'm not scared. THANX! This message has been edited by mike stehr on 02-06-2002 at 02:31 AM Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 6, 2002 Author Share Posted February 6, 2002 Great information here. Thanks. I have copied the whole thread to an ongoing file of my own since I do not know how long these threads ultimately stay online. Now that I think of it I should click around this site and see if I can stumble onto the archives somewhere. -ikobodded and craned Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 I hate to be the annoying pest, but... A Single Ended amp can have multiple tubes in the output stage. It does NOT rely on ONE tube by definition as stated. Single-Ended by definition means the waveform is simply never split or divided. IT can have multiple power tubes if designed as such. This is simply called Single-Ended PARALLEL mode. This design is used by Audio Note extensively in many of their Single Ended amps. It gives more power since the undivided signal is entering more tubes for amplification; and it is STILL single-ended. Some consider it not as pure, however, since the signal is running through multiple tubes. All Single-ended amps ARE Class A. All preamps ARE Class A. I apologize for the "almost" left in to discourage the humanoid diving in to point out the past cirucit that was not Class A.... Class A tube amps run at the tube's optimum voltage as doned by the curves do not always "burn through tubes like a candle." This is a loaded statement that gives a rather dour impression of Class A. You can have a class A CIRCUIT and run the tubes cooler or hotter depending on design. Most beleive that tube sound best run at the optimum voltage although many manufactures like Cary, run their tubes HARD to get more power. Unfortunately, tube life can be shortened. But the idea of "burning through tubes like a candle" is a bit much. But you are right, higher BIAS does indeed run the tubes hotter which wears them out faster. Cary really does run their tubes at higher voltages...bringing on faster burn out. The Mac amps of yore were Class B units, which is one of the reasons I never felt totally enamored with the Mac amps, yet they did as good a job as any in making Class B power sound smooth and musical. Still, I believe their are other vintage designs that sound more refined. And Class A does not necessarily need HUGE ROBUST power transformers always. In fact, if you opt for the PARALLEL FEED output transformer solution, you can use a transformer that more resembles a CHOKE in size! The Parafeed transformer can literally be held with two fingers, yet does indeed produce very nice dynamics and tight bottom end. It is, however, pretty damn expensive, especailly if you like to buy by SIZE. The little beasts are amazing. kh ------------------ Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point CD Player Rega Planet Preamp Cary Audio SLP-70 w/Phono Modified Amplifier Welborne Labs 2A3 Moondog Monoblocks Cable DIYCable Superlative / Twisted Cross Connect Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover system one online / alternate components / Asylum Listing f>s> Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 mdeneen says: "The single-ended design has one power tube - just like the preamp tube except with "power", and is thus Class A. No other choice."s> What about the above quote confuses you, mdeneen? Read the first sentence of you quote. Please. This is in your definition of the Single-Ended Output stage. And it can CONFUSE people if you dont point out what you really mean by this... And it is not clear and precise. Therefore, when new users see an SE amp with more than one power output tube, they might assume it is not SE. I was mainly reacting to your opening paragraph saying that all the above response were somewhat incorrect. I said not a single incorrect statement in my initial response. You are WRONG about the voltage run to tubes and the ability for this to have just as much affect as biasing the tubes higher. The voltage has NOTHING To do with Class A or B, but DOES have a lot to do with how these CLASS A amps burn through tubes!!!! Read my paragraph in that post again. Carefully. Look at the phrasing, mdeneen. I am saying that a Class A design does not always burn through tubes like a candle! That it is controlled somewhat by the design, ESPECIALLY in a CATHODE BIAS arrangement where the bias is not user adjustable (where as you know, a user can indeed adjust the bias higher or lower -and this also affects life). and not user adjustable. I am particularly talking about the many SET amp that employ this method. Now, some run the tubes at a higher plate voltage which some do to increase power at the expense of tube life. In other words, the recommended PLATE VOLTAGE for a 2A3 is 250, yet Cary and others run the damn things at 350!!! This is what BURNS tubes in cathode biased SET design (as well as Cathode resistor value). If, on the other hand, you run the plate voltage at a conservative 250v, you will get relatively LONG TUBE life from this CLass A design. I was being a bit more specific in my post. There is no need for statements like "burn through tubes like a candle" which new users will take the wrong way. I find you use of these statements flippant. You dont EVER seem to read peoples' posts carefully before answering. kh ps - There IS a free lunch in some ways, mdeneen. Read up on Parafeed transformers. And while you are at it, you can explain to forum why there is no need for an "air-gap" as in normal SET design transformers. The PARAFEED trans solution allows you a free lunch in many ways... I was just saying you dont ALWAYS need a MONSTER output to deal with Class A circuits...nor an air gap for SE. This message has been edited by mobile homeless on 02-06-2002 at 12:38 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 mdeneen, better yet, let us call a truce here as this debate is getting absurd. We mainly agree on such matters. I, personally, want to just knock out misconceptions held by many concerning tube equipment, vintage equipment, single-ended amplification, integrated vs separates, etc. I find that whenever anyone makes a blanket statement using specs or preconceived notions, there is a more than likely chance it will run amok with more hands-on experience. Statements like integrated amps have poor sound, low watt SET amps are rolled off distorton boxes, tube amps are distortion boxes, high power = good sound, solid state is more neutral than tubes, low distortion figures always = better sound, measurements are the best forcast for sound, etc etc can all be fallacious. Yet people hold these preconceptions to be gospel. It simply is not always so. But on the whole, I find us agreeing more often than not. IT is just the wording of these posts that sort of sets me off (no pun intended). No real need for this rancor, however. I, for one, will try to stop. kh This message has been edited by mobile homeless on 02-06-2002 at 01:15 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 Here is the type of unnecessary statement I am talking about. Why include this? What does it serve? It does not even apply. mdeneen states: "Ok, at least now we are talking about something of substance. " kh This message has been edited by mobile homeless on 02-06-2002 at 02:45 PM Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 Actually, we really dont see eye to eye on just about anything. We have different views on electronics, sound, semantics, linguistics, humor, tone, philosophy, science...just to name a few. Discourse is worthwhile, but we dont seem to have a productive version of it. I imagine we will answer, comment, and react to others posts within here, but I dont see responding to each other as anything but painful, 9 times out of 10, unfortunately. Perhaps we can just leave it at that. kh Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 6, 2002 Share Posted February 6, 2002 Help out Clipped and Shorn, guys. Quote Link to comment Share on other sites More sharing options...
fini Posted February 6, 2002 Share Posted February 6, 2002 If I may interject: Who says we can have only one "annoying pest" around here? (Nominating myself) fini Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 Clipped and who? Fini, could you please keep it down? You're annoying me... I think you need a P Trap. kh Quote Link to comment Share on other sites More sharing options...
fini Posted February 6, 2002 Share Posted February 6, 2002 Sorry---just venting. fini Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 6, 2002 Share Posted February 6, 2002 har Quote Link to comment Share on other sites More sharing options...
fini Posted February 6, 2002 Share Posted February 6, 2002 Drano Quote Link to comment Share on other sites More sharing options...
fini Posted February 6, 2002 Share Posted February 6, 2002 (OOPS!) This message has been edited by fini on 02-06-2002 at 04:46 PM Quote Link to comment Share on other sites More sharing options...
Manuel Delaflor Posted February 6, 2002 Share Posted February 6, 2002 Mobile Homeless: "Statements like... can all be fallacious. Yet people hold these preconceptions to be gospel. It simply is not always so." Mdeneen: "Hey, we finally agree 100% on something!!! I suppose we agree, and yet take different appoach to dispelling those myths." Completly Agree. There are A LOT of myths surrounding the reproduction of the sound. Most audiophiles will fall in lot of them without further researching nor thinking. I personally want to thank you both because your clear thinking... even if sometimes you don't agree with each other! Manuel Quote Link to comment Share on other sites More sharing options...
Clipped and Shorn Posted February 7, 2002 Author Share Posted February 7, 2002 I think Yoda AND Obi-Wan-Kenobi both have a lot to offer here and I am gaining a perspective that is greater than the sum of the parts, although I barely understand some of the details {define 'bias' as it relates to audiophile concerns please} and feel like young Luke just quietly taking it all in hoping I will be able to put some small part of it to use, at least when I go shopping back on Earth. It is true that the metaphor about tubes burning out like candles did make me wince momentarily since I just went to great length to replace every darn incandescent light bulb on the property with one of those screwy flourescents. Conserving energy on this one hand and dreaming of heating my house with SET monoblocks on the other is a fun contradiction. Thinking about the prices I have seen for choice NOS tubes on eBay etc. and knowing how "critical" the tube choice can be as evidenced by comments on this forum, I am thinking ahead to the prospect of continually burning out and replacing tubes at $200 a pop. So it is indeed important that I have a realistic sense of exactly what the practical truth is here. "One" more silly question, por favor: For phono use only can one go directly to an amp from a phono stage OR must the phono stage first go to the line stage and then to the amp? Eg. is the line stage only necessary if one is using inputs other than phono (CD, Tuner, Video audio, etc.)? The big question for me, ultimately only answerable by some serious auditions, is whether this trade off in energy use, expense, etc. is justified by a significant and ultimately irresistible improvement {transformation even} of the listening experience. I am most tempted to make an upgrade that will maximize this possibility, that is to say, I want the upgrade to be as dramatic as possible. So if I am currently using a Dynakit-70 tube amp, then I probably don't want to just get a slightly better push-pull amp, but rather go for something extroaordinarily different. That is why I have been curious about SET, monoblocks, and other terms {equipment} which are relatively exotic to me at this point. This desired dramatic quantum leap into greatly improved sound at the same time must make the most bang -for-buck sense, that is I will prefer to "doubt" that it can only be done by having a turntable that costs 30K and cables that cost 2K etc. In other words I am being practical while at the same time being willing to start down the "high-end" path with open ears and cautious pocket book (the eBay Cornwall frenzy hopefully was the exception rather than the rule). -henrys and mhos Quote Link to comment Share on other sites More sharing options...
jazman Posted February 7, 2002 Share Posted February 7, 2002 henrys and mhos(aka Clipped and Shorn) Without joining the debate, and quickly provide answers your questions, quote: : For phono use only can one go directly to an amp from a phono stage OR must the phono stage first go to the line stage and then to the amp? In my case the answer is yes. I was able to use my PP-1 phono preamplifier to go directly to the Moondog monoblocks to connect my turntable as a source and play my vinyl. I did this before my line stage arrived. quote: Eg. is the line stage only necessary if one is using inputs other than phono (CD, Tuner, Video audio, etc.)? The answer is Yes. Though I did opt to move in a dramatic fashion to upgrade amplification, that was based on a golden oportunity to purchase an exceptional pair of Welborne Labs 2A3 Moondogs. The remaining pieces of the system are quality pieces, not "high end" as judged by cost. Hopefully, as I learn and evolve, so will my ability to discern any impact/benefits additional hardware expenditures will deliver relavant to an improved audio experience, not because it's high end hardware. I attempted to be practical, economicly speaking, when assembling my 2 channel system. My limitless desire to hear the music in the best possible audio environment, was indeed tempered by the limitations of my bank account. Klipsch out. PS. Read two post in this forum. Bi-wiring Belles and Welborne Labs...jazmans amps. 1975 Belle Klipsch Welborne Labs 2A3 Moondogs Cary SLP90L Preamplifier Asusa modified PP-1 Phono preamplifier Rega 3 turntable, Rega 300 tonearm; Elys cartridge AH!Tjoeb99 CD Player Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 7, 2002 Share Posted February 7, 2002 I apologize for this debate. I am going to attempt to avoid this type of exchange as much as possible. Ironically, iT is not too unlike exchanges I have had with the solid state contingent...it is just relative and in the same class now. Solid state to tubes.... push pull vs single ended. So many solid state proponents lambast tubes having never heard them properly done, or worse yet, having only gone by truisms and cliche as well as specs and numbers to back up their arguments. How many times have I had to go up against the "tubes are distortion boxes" only to have to go through it ALL over again via the Single-ended triode debate, a debate that is RARELY and almost NEVER carried out with someone that has actually had a properly designed SET amp connected to some full range, high efficiency speakers in their own home. A gaggle of SET circuits featuring classic iron as well as the latest Parafeed Cobalt output alternatives - 2A3/45/300B SET amps do not "burn through tubes like candles" and will NOT make your power bill suddenly tripple. And in the average SET amp, you have perhaps as few as TWO tubes with an average of three or four (per monoblock that is). The purest form of single-ended amp uses only TWO power tubes, not a quad or octet as in quite a few push pull designs. And some Single-Ended design employ cheaper outputs; indeed, some dont even use triode tubes (although I have found the triode set sound the most pure). I have had my current pair of Sovtek 2A3 power tubes for over a year, and when they are IN, they are ON. I leave these tubes on almost 24 hours a day when employed. Price of these 2A3? $50 for the pair, if you shop a bit online. A well designed SET amp is not a colored, euphonic device... so far in all my amp experiences, it is the only amp that does not feel or appear to be an electronic device at all! It makes most other tube designs appear grainy, coarse, and colored in comparison. Yet the problem is you NEED TO HAVE highly efficient speakers along with a system that is set up in such a way as to let the whole come forth. It is not always easy to configure such a system; once can walk away prejudiced to the whole mess without ever having heard the fruits it had to offer. SET amps are what I have found sound best on vintage Klipsch although I have yet to hear the latest OTL amps (one is coming this way I hope). And all single-ended triodes are not created equal. Poor designs and implementation can leave one feeling completely non-plused, scratching head while wondering what the hell it's all about. But when right, and when partnered with complimentary components and the right speakers, it is simply like no other. And the combination of a properly set up vinyl, SET, and horns system can just be amazing and only comparible to a live performance. Alas, it is the only in home setup that had every truly made me feel the music is equal to a live performance. Everything else sounds electronic by comparison. Still, I can still love to listen to push-pull designs because they bring their own set of positives. A good vintage push-pull amp with NOS valves can boogie and move like few others...and they bring a great sense of the substance of the performance. And one doesnt have to rely on vintage gear either, as there are many modern tube designs that are just as good...it's just you will sometimes be paying serious ducats to get there (although there is now a great collection of good priced tube gear now available, more than at any other time in the last 20 years). At the very least, however, your system, no matter what it is, should make you want to engage an all nighter of record-pulling glory (or CD slinging as it were). IT should make you want to listen! kh Phono Linn LP-12 Vahalla / Linn Basic Plus / Sumiko Blue Point CD Player Rega Planet Preamp Cary Audio SLP-70 w/Phono Modified Amplifier Welborne Labs 2A3 Moondog Monoblocks Cable DIYCable Superlative / Twisted Cross Connect Speaker 1977 Klipsch Cornwall I w/Alnico & Type B Crossover system one online / alternate components / Asylum Listing f>s> This message has been edited by mobile homeless on 02-07-2002 at 09:57 AM Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 7, 2002 Share Posted February 7, 2002 Ya know Kelly, You should consider yourself pretty lucky to even have so much exposure to tube amplifiers. I'm 37, the last time I heard a tube amplifier, was the late 60's early 70's, And this was from the junk record consoles my mother had. I guess I can kinda remember the sound, underneath all those trashed Supreme's records my older sisters played. If I did ever hear a good vintage tube amp back then, I was too young to care. So all my exposure is the infamous Solid State, and really only started to get into home audio 3 years ago. I live near Spokane, find a tube amp to listen to in this berg? Yeah, right! Not much to offer in the way of Hi-Fi in Eastern Washington, even SS. I would have to migrate to the West side of the State to find anything. No Prejudice toward tube amps, ain't heard one. Really would like to, I'm curious as Hell. THANX! Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted February 7, 2002 Share Posted February 7, 2002 That's funny, I am personally all for magic, superstition, and "cold-fusion" explanations for garden variety phenomena. kh ps- I didnt know a thimble could hold that much info...sounds like a magical thimble to me...Cheers! This message has been edited by mobile homeless on 02-07-2002 at 01:07 PM Quote Link to comment Share on other sites More sharing options...
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