Thanks Thorsten,
The 20W Hiraga is one that I've considered, togheter with Aloia's Volksamplifier and Pass' Aleph series.
On the paper good design are also Sansui X-balanced topology (Diamond) and Self's Load Invariant Amplifier.
Good reports also for Giovanni Stochino and Alexander Current Feedback amplifiers.
How these compared in the top list You mentioned? I known that one should heard himself, but I cannot build everything! The community common Knowledge is precius in getting indication of which projects are worthing the time spent to make 'em.
PMA, I see on Yours site also another simple project, the TW-40. Have You some more information about this one? Is better than the Sinclair?
The 20W Hiraga is one that I've considered, togheter with Aloia's Volksamplifier and Pass' Aleph series.
On the paper good design are also Sansui X-balanced topology (Diamond) and Self's Load Invariant Amplifier.
Good reports also for Giovanni Stochino and Alexander Current Feedback amplifiers.
How these compared in the top list You mentioned? I known that one should heard himself, but I cannot build everything! The community common Knowledge is precius in getting indication of which projects are worthing the time spent to make 'em.
PMA, I see on Yours site also another simple project, the TW-40. Have You some more information about this one? Is better than the Sinclair?
TW 40 is based on one connection, which was published in RCA application manual from year 67'. Don't think about it, it is realy " stone age " 😀
Yes, Pavel, was a joke. But not all is old is to be forget. People are strange and many wasted electronics in the past now are top scores (Altec, for example).
I see also yours Gainclone variation and read also about the Mauro Penasa work. Two more to be added to the list.
Which one is the best sounding?
Whic one has the highes sound quality/price ratio?
I see also yours Gainclone variation and read also about the Mauro Penasa work. Two more to be added to the list.
Which one is the best sounding?
Whic one has the highes sound quality/price ratio?
I had never several gainclones for comparision, so I can't tell you results. GC is GC, simply amp for begginers, although some people think, that it is miracle... 😉 Good designed discrete amp will be better... PMA's one is this example ( if you can simply solution ). Belive me, we was making with PMA and other friends many listenig tests and comparision of both... 😉
plovati said:
😉 . The question is what you are seeking for. There are nice old-timer cars and there are new ones. Will you choose Morris Mini 1959 or the new Mini, only resembling shape of the old car? 😉
The same is with amps. TW-40 or Z-30 are examples of old-timers in my web pages. In case you seek for good, nice and pleasant sound, do not build them. If you only want to get some experience, build it 😉 .
Konnichiwa,
I heard Amplifiers very similar in design to the Alexander style a long time ago and build a "blameless" Self Amp, they may measure well, but the less said the better. The Alexander may improve with an AD811 in the input, that might worth trying but the frequency compensation would veed changing.
The "Volxamp" is more generica, no doubt okay sounding, but it shares a crucial weakness with >>90% of all other amplifier circuits out there, namely the use of poorely conceived and implemented long tailed pairs.
The LM3875 is notable for taking great pains to minimise the problems (no chip other than certain Overture series chips ever did) and is like a "Self Blameless" amp done well.
Hiragas circuits step well past that by using very low overall feedback and also at the same time current feedback. Some older single rail Amplifiers used a single ended input with CFB, they also sound(ed) uncommonly good, subjectively speaking. A good example is the standard east german 25W "HiFi" amplifier, capacitor coupled output and all....
Sayonara
plovati said:
I heard Amplifiers very similar in design to the Alexander style a long time ago and build a "blameless" Self Amp, they may measure well, but the less said the better. The Alexander may improve with an AD811 in the input, that might worth trying but the frequency compensation would veed changing.
The "Volxamp" is more generica, no doubt okay sounding, but it shares a crucial weakness with >>90% of all other amplifier circuits out there, namely the use of poorely conceived and implemented long tailed pairs.
The LM3875 is notable for taking great pains to minimise the problems (no chip other than certain Overture series chips ever did) and is like a "Self Blameless" amp done well.
Hiragas circuits step well past that by using very low overall feedback and also at the same time current feedback. Some older single rail Amplifiers used a single ended input with CFB, they also sound(ed) uncommonly good, subjectively speaking. A good example is the standard east german 25W "HiFi" amplifier, capacitor coupled output and all....
Sayonara
Kuei Yang Wang said:
If Your intention was to raise my ears, You're succesfull !
What's this amplifier? There is a schematic around?
Konnichiwa,
There was very little unusual about it. Classic 6-Transistor circuit (many variations of this where around in the 1960's & 70's), NPN only output devices, fairly high level of Bias, single rail, input and output coupled via a capacitors (electrolytics - no less), clever feedback loop, bootstrapped load for the second stage, both voltage amp stages using some local degeneration too. I fixed so many of these, I could nearly draw out a circuit diagram from (> 15 Years old) memory.
Nothing too unusual, it just sounded very good. Combined with an passive EQ circuit and a KSP215 8" Full Range driver these drove for example east german Radio/TV Monitors and these things where darn good.
Actually, managed to find a schematic that is basically what I am talking about.
Sayonara
plovati said:
There was very little unusual about it. Classic 6-Transistor circuit (many variations of this where around in the 1960's & 70's), NPN only output devices, fairly high level of Bias, single rail, input and output coupled via a capacitors (electrolytics - no less), clever feedback loop, bootstrapped load for the second stage, both voltage amp stages using some local degeneration too. I fixed so many of these, I could nearly draw out a circuit diagram from (> 15 Years old) memory.
Nothing too unusual, it just sounded very good. Combined with an passive EQ circuit and a KSP215 8" Full Range driver these drove for example east german Radio/TV Monitors and these things where darn good.
Actually, managed to find a schematic that is basically what I am talking about.
An externally hosted image should be here but it was not working when we last tested it.
Sayonara
Konnichiwa,
I appreciate that these designs are considerably outdated according to some criterias.
The later generation of Amplifiers in East Germany has the standard circuit (read Self if you want to know what i call standard) and DC coupled outputs etc. And they measured a lot better, had more power and all, but sonically they had a "typhical transistor sound" (in the negative sense), which the old outdated designs lacked and in a Studio where you can directly leave the studio and walk up to Mikes any significant deviation from subjective neutrality is easily heard.
In this day it is trivial to make an Amplifier with arbitrarily low THD and IMD, to make said Amplifier sound good seems to remain a rather spikey problem.
Too much generica out there that sounds in the main negative attributes as bad as the next (which is not to say all these amplifiers sound the same, they merely sound equally iriitating in different ways).
Sayonara
Upupa Epops said:
I appreciate that these designs are considerably outdated according to some criterias.
The later generation of Amplifiers in East Germany has the standard circuit (read Self if you want to know what i call standard) and DC coupled outputs etc. And they measured a lot better, had more power and all, but sonically they had a "typhical transistor sound" (in the negative sense), which the old outdated designs lacked and in a Studio where you can directly leave the studio and walk up to Mikes any significant deviation from subjective neutrality is easily heard.
In this day it is trivial to make an Amplifier with arbitrarily low THD and IMD, to make said Amplifier sound good seems to remain a rather spikey problem.
Too much generica out there that sounds in the main negative attributes as bad as the next (which is not to say all these amplifiers sound the same, they merely sound equally iriitating in different ways).
Sayonara
Thorsten,
KU607 were old czech transistors (Tesla Czechoslovakia), 1970.
The technology was MESA-epitaxial. They were designated for switching purposes. h21E is horribly current-dependend. They suffer from 2nd breakdown badly. Where is the schematics from? We had to work with similar transistors for the reason there was no import of suitable devices.
Hajimemashite, Pavel
KU607 were old czech transistors (Tesla Czechoslovakia), 1970.
The technology was MESA-epitaxial. They were designated for switching purposes. h21E is horribly current-dependend. They suffer from 2nd breakdown badly. Where is the schematics from? We had to work with similar transistors for the reason there was no import of suitable devices.
Hajimemashite, Pavel
Konnichiwa,
Yes, there where plenty bad by modern standards. The Studio Amp's used different devices....
East German HiFi 50 (25W+25W) Amplifier.
The whole Amp is an illustration of old style, politically incorrect design, which did not stop it from sounding rather good, with reasonably sensitive speakers anyway... ;-)
Sayonara
PMA said:
Yes, there where plenty bad by modern standards. The Studio Amp's used different devices....
PMA said:
East German HiFi 50 (25W+25W) Amplifier.
The whole Amp is an illustration of old style, politically incorrect design, which did not stop it from sounding rather good, with reasonably sensitive speakers anyway... ;-)
Sayonara
Kuei Yang Wang said:
Sure. But low distortions are parameters that should not be neglected. Instead of that we are facing strange SE ultra-nonlinear circuits and being persuaded it is like it should be. Neglecting necessity of low distortion is unfortunately survival of the seventies, when other important parameters were not taken into account.
PMA said:
Pavel, You prevent my question.
Is this schematic replicable today, replacing the output transistor with 2N3055 and driver with BC5XX for example?
Konnichiwa,
Why?
It has been shown more than conclusively that THD (and IMD) per se does not translate into audible degradation (or absence thereoff).
Given that making an amplifier with low THD does not garantee that the resulting amplifier will sound better, more realistic, less coloured; whatever term you wish to use; than one with higher THD, what reason exist that could make any SENSIBLE person bother about THD as anything but an academic excercise?
Of course there are people who slink off with the spec sheet of their amp to the gents, oooohhh, the low THD, ahhhh the high power and all that, but if it sounds bad it remains a bad amplifier, no matter what it measures like.
Of course, could it be that most designers clutch at straws like THD because they do not understand which parameters must be manipulated in what way to produce "good sound"?
Sayonara
PMA said:
Why?
It has been shown more than conclusively that THD (and IMD) per se does not translate into audible degradation (or absence thereoff).
Given that making an amplifier with low THD does not garantee that the resulting amplifier will sound better, more realistic, less coloured; whatever term you wish to use; than one with higher THD, what reason exist that could make any SENSIBLE person bother about THD as anything but an academic excercise?
Of course there are people who slink off with the spec sheet of their amp to the gents, oooohhh, the low THD, ahhhh the high power and all that, but if it sounds bad it remains a bad amplifier, no matter what it measures like.
Of course, could it be that most designers clutch at straws like THD because they do not understand which parameters must be manipulated in what way to produce "good sound"?
Sayonara
Piergiorgio,
probably some bias game would be needed.
Thorsten,
it was easier for amp to amplify signal from vinyl ...., and problems were not tha apparent as with digital ...
So you are from Eastern Europe, too ....
probably some bias game would be needed.
Thorsten,
it was easier for amp to amplify signal from vinyl ...., and problems were not tha apparent as with digital ...
So you are from Eastern Europe, too ....
Konnichiwa,
I am sure it is, however D. Self did a lot of work identfying the most linear devices for the various positions in his "blameless Amplifier" series in Wireless World, while I disagree with DS on about evererything, I agree with his choice of devices, for very different reasons though.
Sayonara
plovati said:
I am sure it is, however D. Self did a lot of work identfying the most linear devices for the various positions in his "blameless Amplifier" series in Wireless World, while I disagree with DS on about evererything, I agree with his choice of devices, for very different reasons though.
Sayonara
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