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Pavel, shouldn't R27 be replicated for the amplifier on the right side? And while we are still at it, any comments on your BJT high power version versus Shaan's Mosfet version in terms of sonics.... yours is a dual supply and Shaan's is single supply; so not only will the different output devices but also the output cap in the latter affect the sound quality. Hence, my curiosity!
shaan is presenting my circuit 
Project 83 - MOSFET Power Follower
As I have enough experience with both, I have to disagree respectfully.
Project 83 - MOSFET Power Follower
As I have enough experience with both, I have to disagree respectfully
.
shaan is presenting my circuit
Project 83 - MOSFET Power Follower
As I have enough experience with both, I have to disagree respectfully
Reslly?
I thought Shaan is representing my circuit. Just a good old source follower loaded on a current source.
I have enough experience with symmetrical, quasi-symmetrical, asymmetrical topologies, and respectfully disagree with you: according to my experience asymmetrical stages sound much better than symmetrical ones. Symmetry is needed when and only when you tend to save some electricity. If it is not an issue such a restriction don't apply, so I prefer asymmetry: it gives more freedom to reproduce sound better.
This is a very interesting observation and I give it a lot of weight considering that comes from you.
I think it's a matter of taste - one needs to build both and listen for yourself.
No, it's not a matter of a taste. All sounds in nature are getting softer when decay, higher order overtones decay faster than lower ones. When an amp adds distortions that correspond to this Law of Nature human perception hears less distortions than when an amp (symmetrical one) adds distortions contrary to this Law. Distortions are unavoidable. They will present in both cases. But asymmetrical amp produces less audible distortions than symmetrical one.
However, if you build 2 amps, symmetrical and asymmetrical, that consume the same amount of electricity, symmetrical one wins on loud passages. But that does not mean symmetrical sounds better; that means it needs less electricity to sound the same on loud passages than asymmetrical one does need.
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It appears that Pavel likes less H2 and relatively more H3 (albeit all distortions minimised to levels practically achievable) and Wavebourn prefers more even order distortion!
Pavel you have not commented about R27.
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Do you mean symmetrical in terms of the topology or symmetrical in terms of operation ? For example, I found that with single supply rail a symmetrical circuit topology simulates so as to produce more H2 than H3 (etc.) because the output drives current through a load to only one supply rail (usually ground).
Emitter resistors - why an explosion ? if thermal runaway is controlled through other means what purpose do these resistors serve ?
Emitter resistors - why an explosion ? if thermal runaway is controlled through other means what purpose do these resistors serve ?
Wavebourn prefers to minimize all distortions, but first of all more audible ones. If to search for an equilibrium, it is better to measure according to perception thresholds, instead of according to measurement thresholds.
Topology, of course! Symmetrical topology is the way to go if electricity saving is the most significant criterion.
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If you mean sound, then no need for symmetrical topologies.
In my Tower-V I use both approaches: symmetrical and asymmetrical. Pure class A asymmetrical and class C symmetrical. Such a combination allows me both to get nice sound and save some electricity (a lot, actually, since one of 200W output channels consumes 1A of current only when idle). 150W / channel consume class A stage, and zero consume class C stages.
I agree with the above statement. But I wouldn't forget also the total amount of distortion. The spectrum IS more important, yes, when the THD is in the audible range, which IMO is >0.05%.
Let's assume that I have (I'm making hypotesis, since I dont have any working cirtuit at the moment, but i will) two OPS, driven by the same excellent VAS and a state of the art PSU. The symmetrical output stage has 0.02% 2nd armonic and 0.06% 3rd armonic. On the other side, the asymetric OP has 0.1% and 0.03% respectively.
Assuming to have a considerable headroom with both wattage and current, high efficient low-distortion speakers and that are both polarized in class A, which one will sound better?
My point is, if the higher armonics are already under the audible range (esp the 5th and up), would symmetry help the overall sound reducing a pretty prominent (0.1% and up) 2nd armonic? I tend to answer yes.
Are they in under audible range, or not, depend on many factors. 5'th harmonic popping up like a tooth when sound decay will be much better audible than the same 5'th harmonic masked by lower ones, especially when the sound attack. That's why when an amp is good and healthy THD is completely useless.
Also, I would distinguish between conscious audibility that allows to say what is wrong, and sub-conscious perceptibility that tells the sound is not real.
My goal is to fool imaginations, to cause sub-conscious reactions, to mask presence of an equipment, so listeners believe that frogs sing on my background, when in reality they sing on CD that plays piano.
Also, I would distinguish between conscious audibility that allows to say what is wrong, and sub-conscious perceptibility that tells the sound is not real.
My goal is to fool imaginations, to cause sub-conscious reactions, to mask presence of an equipment, so listeners believe that frogs sing on my background, when in reality they sing on CD that plays piano.
Wavebourn, I understand what you were saying. If something doesn't immediately make sense to me, I think more complex. The truth, however, was obvious!
I want to apologize to the thread starter about my tangent; I've been following this thread and lost track of the actual topic.
- keantoken
I want to apologize to the thread starter about my tangent; I've been following this thread and lost track of the actual topic.
- keantoken
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