I have got to say that I was skeptical about being able to hear differences between various amplifiers via this method, but to my surprise one can get a sense of the amplifiers' character. This evening I spent some time downloading the clips and having a listen. Not enough time for a good evaluation, just enough to be able to say that differences do exist, some very subtle and others more noticeable.
Quick edit: I can say immediately that the M2 definitely would NOT be for me
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Quick edit: I can say immediately that the M2 definitely would NOT be for me
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The M2 isn't fairing so well against these nice class AB amps. Sometimes maybe a few more transistors is a good thing 🙂
I am going to be open minded and keep it in for long term listening. I also just ordered qnty 8 x 33000uF 25v caps to make the proper recommended power supply and see if that improves things. Should be here in a few days and I will whip up a pair on mini block PSU's with P2P.
So many people say such good things about the M2, there must be something to it.
I am going to be open minded and keep it in for long term listening. I also just ordered qnty 8 x 33000uF 25v caps to make the proper recommended power supply and see if that improves things. Should be here in a few days and I will whip up a pair on mini block PSU's with P2P.
So many people say such good things about the M2, there must be something to it.
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Quick edit: I can say immediately that the M2 definitely would NOT be for me
What is it about the M2's sound that isn't to your liking?
The easiest short description I have is harsh or raspy. It would be very fatiguing quickly. Sounds 'artificial'.
Imo, so much better. I have many commercial amplifiers and the cost is usually a representation of the cosmetics and of course they need huge profit margin for the business to survive.
You can find the schematic of almost all famous commercial amps on the net. Simulate it, and you will find that they are inferior to many amps here in this website. Actually, many amps here (including the ones posted by Apex) are a collection of modified best commercial amplifier circuits.
BTW, don't forget the Goldmund clone 🙂
Distortion is not everything (some say you cannot hear less than 0.1%). The M2 here do have advantages, but the disadvantage is too much for me, but probably some other prefer and value the advantage more than the disadvantage?!
J2 is also simple and in the same category as M2. The distortion of J2 is as far as I can remember, extra-ordinary (I have simulated, studied and cloned the amp). I would choose J2 any day over M2 (even if I haven't heard the amps).
I myself prefer the (average) high distortion class-A amps than the (average) low distortion class-B amps. In my study this is related to the HF distortion components. Not many class-B amps have special distortion at HF. VSSA is the first I know (one of the first CFA that I know), then surprisingly an LTP input like FX8 can have such signature as well.
BTW, don't forget that simple class-A amps require different speakers than complex class-B amps (which has better damping, lower output impedance)
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That's crazy awful!
Conventional THD measurement is at 1kHz and it is 0.04%, acceptable. But look at the LF distortion 😱
Jay,
When you say it's extraordinary, does that mean it is high or low or a special siganture?
I removed the preamp and looked at the RTA and get about the same thing. Here is 50Hz, 200Hz, 400Hz:
50Hz:
200Hz:
400Hz:
And here is clip 3 re-recorded without the preamp at max volume. Then I really had to apply gain in Audacity to produce a -3dB below full scale sound file. You will hear hiss but see if the fatigue goes away?
When you say it's extraordinary, does that mean it is high or low or a special siganture?
I removed the preamp and looked at the RTA and get about the same thing. Here is 50Hz, 200Hz, 400Hz:
50Hz:
200Hz:
400Hz:
And here is clip 3 re-recorded without the preamp at max volume. Then I really had to apply gain in Audacity to produce a -3dB below full scale sound file. You will hear hiss but see if the fatigue goes away?
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I was talking about First Watt's J2 Power JFET amplifier. The JFET version is a lot better than the IRFP240 version, but my version of using another HEXFET was good. But now I remember that J2 has actually LTP input (so no wonder the distortion is lower than M2)
Still fatiguing, same signature.
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I'm really trying here to give the M2 a fair shake but H3 is not improving down in the bass and mid bass region. I only measure 50mV ripple on PSU at amp. Not sure if big 33mF caps are going to improve this much. I do hear the distortion in listening sessions. It's about 1.5% THD at 50Hz and 90dB at 0.5m. Will report back once I get new caps for PSU.
Uhmmm... sorry (for not following carefully), this distortion, is it measured at amplifier output or at speaker output?
I asked about M2's H3 dominance in Pass Forum and they said it's expected and measurements show 3rd order dominance in same range I observe below 500Hz. So looks like native resoonse of M2 is just this way.
http://www.diyaudio.com/forums/pass-labs/281520-official-m2-schematic-138.html
http://www.diyaudio.com/forums/pass-labs/281520-official-m2-schematic-138.html
Oh, I forgot I need to use one of them fancy Lowthers with whacked frequency response curve and it will all be good. My speaker is not quite ordinary - 2 way FAST with first order XO at 600Hz.
Over in the M2 thread there are many folks who say it sounds like a tube amp and they don't mind the H3 distortion. It depends on what sounds you are after. I am now seeing how many of the very simple class AB designs can pretty much compete head to head, and even beat a much hotter running pure class A design.
I have the extremeA 100w class A on the books to be built. That amp is said to have immeasurable distortion, so just the opposite - but it is complex with more transistors than I have seen for ANY amp.
I have the extremeA 100w class A on the books to be built. That amp is said to have immeasurable distortion, so just the opposite - but it is complex with more transistors than I have seen for ANY amp.
thanks yep tube sound .....the Hd can be change with more clean jensen iron as Np post
sit v2 is the right one maybe
sit v2 is the right one maybe
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