Members Vanny Posted December 15, 2006 Members Share Posted December 15, 2006 Is it? And what's the pros and cons for each? Link to comment Share on other sites More sharing options...
Members Kelly Posted December 15, 2006 Members Share Posted December 15, 2006 Both class a and class a/b amps use the same types of tubes. Link to comment Share on other sites More sharing options...
Members Plague dog Posted December 15, 2006 Members Share Posted December 15, 2006 Originally posted by Vanny Is it?And what's the pros and cons for each? They both use the same tubes, it is the amp circuit design that determines class A class A/B. Class A/B is more efficient and can generate more wattage output with the same tubes. Example, two EL34 power tubes in Class A would be about 28 watts, in class A/B it would be between 45 and 50 watts. Class A generally sound a little warmer but tube life is reduced. Class A tubes burn all the time while A/B only when there is an audio signal passing through. Link to comment Share on other sites More sharing options...
Members Vanny Posted December 15, 2006 Author Members Share Posted December 15, 2006 Originally posted by Plague dog They both use the same tubes, it is the amp circuit design that determines class A class A/B.Class A/B is more efficient and can generate more wattage output with the same tubes. Example, two EL34 power tubes in Class A would be about 28 watts, in class A/B it would be between 45 and 50 watts.Class A generally sound a little warmer but tube life is reduced. Class A tubes burn all the time while A/B only when there is an audio signal passing through. Oh okay. So tube amps like THD Bivalve and Orange Rocker won't have sucha long tube life compared to a Mesa F-series? Are all Mesa amps class A/B? And how much more is the tube life reduced if it's class A? Link to comment Share on other sites More sharing options...
Members Vanny Posted December 15, 2006 Author Members Share Posted December 15, 2006 Oh and btw, are Class A amps generally more expensive than Class A/B? Link to comment Share on other sites More sharing options...
Members Plague dog Posted December 15, 2006 Members Share Posted December 15, 2006 These things I don't know, there are some knowledgable gear heads on this site that can probably answer those questions. I have one class A amp, crate VC30. I don't play it that often, but I'm sure if I did replace the tubes I would get a hell of a lot better sound out of it. You are correct in that Mesa doesn't build a class A amp, unless it's something new they've come out with. Pre matchless I believe the only two class A amps in production were the Vox AC30 and the Fender Champ. As far as reduced tube life I would think it would be in the 40-50% range. I had a Bedrock when they first came out and I toasted the tubes in that within about 6 months of sporadic playing. Edit for additional questions... Yes... Top of the line 30 watt class A's like Matchless and Tophat are very expensive. Older Crate VC30's sound amazing and are inexpensive, but they don't hold a candle to more expensive well built amps and are extremely unreliable. Link to comment Share on other sites More sharing options...
Members tommythelurker Posted December 15, 2006 Members Share Posted December 15, 2006 Mesa's "Simul-class" is supposed to combine a class AB pair with a class A pair working together simultaneously. Apparently some amps marketed as class A (like the AC-30) don't really operate in class A and are actually closer to AB. Link to comment Share on other sites More sharing options...
Members Vanny Posted December 15, 2006 Author Members Share Posted December 15, 2006 Ooh, I'm was looking at the THD Bivalve. Does this thing use only ONE power tube and TWO preamp tubes? Link to comment Share on other sites More sharing options...
Members tommythelurker Posted December 15, 2006 Members Share Posted December 15, 2006 Originally posted by Vanny Ooh, I'm was looking at the THD Bivalve.Does this thing use only ONE power tube and TWO preamp tubes? come on dude, this stuff isn't THAT hard to research on your own http://thdelectronics.com/products/bivalve.htm Like the UniValve, the BiValve is a single-ended pure Class A design. However, it has two output valves which are wired in parallel and combined through a special output transformer to deliver up to around 30 watts. Link to comment Share on other sites More sharing options...
Members tlbonehead Posted December 16, 2006 Members Share Posted December 16, 2006 Originally posted by tommythelurker come on dude, this stuff isn't THAT hard to research on your ownhttp://thdelectronics.com/products/bivalve.htm Ya, its getting old. I like answering questions, but he's getting really redundant. Link to comment Share on other sites More sharing options...
Members solitaire Posted December 16, 2006 Members Share Posted December 16, 2006 The guy who founded Mesa/ Boogie did a great description of the A - A/B thing. I recommend you and who ever is interested to check that out. Link to comment Share on other sites More sharing options...
Members guitarrorist Posted December 16, 2006 Members Share Posted December 16, 2006 Mesa's Blue Angel was class A - they stopped making them a couple years back but they seem to pop up on ebay every now and again. The Lone Star Special is their current class A amp. Link to comment Share on other sites More sharing options...
Members hasbeen Posted December 16, 2006 Members Share Posted December 16, 2006 Mesa does make a "Class A" amp....the Lonestar Special. In general, tube won't last as long in most "Class A" (Cathode Biased) amps. They tend to run hotter. Link to comment Share on other sites More sharing options...
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