Hello!
I ran a pair of Mark Levinson No 20.6 for many years. Later switching to a more conservative Sony TA-F808ES to lower my power bill. Not the same color sound as class A but still pretty good
What about you guys?
I ran a pair of Mark Levinson No 20.6 for many years. Later switching to a more conservative Sony TA-F808ES to lower my power bill. Not the same color sound as class A but still pretty good
What about you guys?
Those are Nice Amps. Good to know about other brands and models. Eventually I will retire the 808 and wanted something a bit more modern that still uses class AB.
https://www.diyaudio.com/community/threads/summer-consolation-amplifier-1995-adcom-gfa-5200.197406/
I'm squeezing 20W of class A out of this Adcom GFA-5200 by putting a fan on it.
I'm squeezing 20W of class A out of this Adcom GFA-5200 by putting a fan on it.
Class A: SIT-3, my class A triode EL84 PP amp is very close but outputs a sixth of the power
Class AB: A lot harder to choose, i remember the NAIM 250 fondly, but probably the best one is my LM3875 chip amp (25w/chan).
dave
Class AB: A lot harder to choose, i remember the NAIM 250 fondly, but probably the best one is my LM3875 chip amp (25w/chan).
dave
I prefer to have peaks of 50 w/ch @ 8 ohms for extreme climaxes in classical music CDs. I listen at about 1 vpp (1/8 w) during soft passages.
My favorite now, for having no hum, no fan, and 1/4 phone plug compatibility, is a Peavey M-2600. I use RCA cables from a disco mixer through pamona 1/4 phone plug adapters. RIAA CD & radio inputs all at level all the time, only the device power is switched. M-2600 could be improved by replacing the TL074 op amp by something quieter like 33079, but I haven't bothered. All 1980? electrolytic caps were replaced by industrial series long life caps from panasonic, nichicon, or rubicon.
My favorite now, for having no hum, no fan, and 1/4 phone plug compatibility, is a Peavey M-2600. I use RCA cables from a disco mixer through pamona 1/4 phone plug adapters. RIAA CD & radio inputs all at level all the time, only the device power is switched. M-2600 could be improved by replacing the TL074 op amp by something quieter like 33079, but I haven't bothered. All 1980? electrolytic caps were replaced by industrial series long life caps from panasonic, nichicon, or rubicon.
Goldmund. Not bad for classAB. Off course its been replaced with Mr. Nelson's classA amps like F1J, AlephJ, F3, M2 and others. Way better. So went the other way.
In fact, there is no division of class A. class AB in analog amplifier.
This is just an advertisement.
Virtually all analog amplifiers. It can work in class A or class ab.
And its effect will not make any difference.
A poor amplifier. Whether it works in class A or class B. It's all very bad.
An excellent amplifier. Whether it works in class A or class B. It is also excellent‘
We don't need to care about class ab. This is an advertising word.
There are many class A with poor performance, such as jlh1969, ksa50, pass lab. （Hope passlab doesn't get angry.+
There are also many good class b amplifiers. For example, quad405 and Naim (although it has many bugs that need to be modified). Musical Fidelity X-A50
Please forgive my offence. If you want to hit me. Please don't hit me in the face.
This is just an advertisement.
Virtually all analog amplifiers. It can work in class A or class ab.
And its effect will not make any difference.
A poor amplifier. Whether it works in class A or class B. It's all very bad.
An excellent amplifier. Whether it works in class A or class B. It is also excellent‘
We don't need to care about class ab. This is an advertising word.
There are many class A with poor performance, such as jlh1969, ksa50, pass lab. （Hope passlab doesn't get angry.+
There are also many good class b amplifiers. For example, quad405 and Naim (although it has many bugs that need to be modified). Musical Fidelity X-A50
Please forgive my offence. If you want to hit me. Please don't hit me in the face.
We are not going to revive the debate (yet) but it is not because an amp is mediocre in terms of measurements that it is bad at listening (far from it by the way) and there in this case (beyond the class of operation), it's really a business story.
after having listened, repaired, owned several hundred amps over the past 25 years, I can only say one thing, we know if an amp is good (listening) a few minutes after turning it on.
after having listened, repaired, owned several hundred amps over the past 25 years, I can only say one thing, we know if an amp is good (listening) a few minutes after turning it on.
The one I built in 1994, see pages 140...143 of https://worldradiohistory.com/UK/Wireless-World/90s/Electronics-World-1996-02-S-OCR.pdf It was my second attempt at making an audio power amplifier and it still works fine. The one I made before that had its emitter resistors spontaneously go up in flames the third or fourth time I turned it on.
Surprisingly, i agree with most of your other points. But class A not making a difference? There is no obligation to prefer the class A sound, in fact it may not be beneficial for some music genres, but to deny there is a difference is pushing it a bit. The single exception i can think of may be the F5, which in my opinion has very little typical class A sound.
This is not my point of view. This is the fact that I found.
The earliest time. We only have class a amplifier. Later, we invented push-pull amplifier. This allows the amplifier to work without having to work in classA.
But in order to avoid crossover distortion. We make the push-pull amplifier work in class A. This is actually just the understanding at that time. Later, we found that class AB did not cross distortion.
For example, an amplifier. When the output quiescent current is 10mA and 500mA.
The distortion has not changed. Of course, this is related to the amplifier design. MOSFET will have crossover distortion. BJT didn't. The smallest is cfp This is just the result of my measurement. It's not my theory.
In fact, this is not against anything. We can reduce the output quiescent current. Just keep it at 10mA.
The effect will not change. It can also be environmentally friendly.
For example, FM Goldmund MBL does not produce class a amplifiers.
In addition, we must measure on the same circuit.
Instead of comparing amplifiers of different circuits.
Finally, I want to add. What I said is basically the result of my repeated measurement and comparison. It may have errors. But I won't tell others uncertain opinions. I won't tell others the imagined results.
In fact, I didn't invent this word.
Just like some people create some English words. Then everyone knows.
Then it becomes something practical. The class AB we refer to refers to the case range of output power tube static current >0, < total output current.
Of course, if you want to say the wrong words in English. Concept. That's OK.
I’ve just measured the amp currently in my system. It’s 18 inches wide. Now please you can tell me how it sounds . . .
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Class AB Commercial -
Toshiba Aurex SB-A10 (I think it was the main amp of Toshiba System 10)
Class AB DIY - VHex by Valery Vzaichenko (because I was there since its inception 😉)
Toshiba Aurex SB-A10 (I think it was the main amp of Toshiba System 10)
Class AB DIY - VHex by Valery Vzaichenko (because I was there since its inception 😉)
This is simply not true. Take a simple open loop PP buffer with bipolars. Run it in both A and AB. Not only does distortion drop by an order of magnitude in class A, it also has a different spectrum. Seen both in simulation and measurement. And no, it does not sound the same either.
Of course if one only goes by numbers, class A distortion is easy to achieve in a class AB amp after the application of sufficient NFB.