Oh I agree. I love the transparency of my (very neutral) Neurochrome amps, but there is also something really appealing about that 2nd harmonic dominant sound. A well designed SET driving high sensitivity speakers can be magical, but if you were to measure the distortion . . .
Indeed Anand!
Single choice is imposed here like in beauty pageant contests. If you ask me, I would like very much to have them all.
I mean, why not if all have passed all basic tests.
In fact, mathematically speaking there are necessary and sufficient conditions. Here, in this particular case, necessary conditions are empirical tests i.e. measurements, sufficient test is aesthetical.
I personally discard all that do not pass measurements, before aestethical testing. Why bother?
Simply, take a neutral amplifier and a preamplifier with dominant 2nd harmonic. Again, you have advantage of multiple choices.
Yup, it makes perfect sense to my mind, and I’m sure I’m not alone. It makes you think about what the ultimate amp would sound iike. For me it would have the outstanding clarity and transparency of Tom’s amps but with that added magic that a good SET brings to the party. Maybe those two things are mutually exclusive, well at least to some degree?
My approach is clean amp and musical pre. Its easy to find pre with just second harmonic. Here is hamptone circuit for instance. I have tube pre study somewhere too.
On the other hand, you do not want to overdo it with too much second harmonic either.
Thats why i say: right amount of proper harmonics is best.
https://www.diyaudio.com/community/threads/hamptone.405097/
On the other hand, you do not want to overdo it with too much second harmonic either.
Thats why i say: right amount of proper harmonics is best.
https://www.diyaudio.com/community/threads/hamptone.405097/
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Small steps each time....Heatsinks for the power supply were placed on the main transistors and diodes .Temp on it 38C and 40C.
Ambient temp 28-29C .
The heatwaves have already started in Greece.
Ambient temp 28-29C .
The heatwaves have already started in Greece.
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Hi Nikos,
You later asked whether the reduction in bias from 3a to 2.5a (by changing R141 & R142 from 0.12R to 0.15R) changed the sound.
Hugh came over yesterday (with a friend who wanted to hear the Class A amp) and he felt there was no degradation whatsoever.
Thanks my friend Andy..Hi Nikos,
You later asked whether the reduction in bias from 3a to 2.5a (by changing R141 & R142 from 0.12R to 0.15R) changed the sound.
Hugh came over yesterday (with a friend who wanted to hear the Class A amp) and he felt there was no degradation whatsoever.
Πολυ ζεστη εδω.
As for the quiescent current to achieve 2.5-2.6 I put in parallel the 0.15 resistors and a 1 ohm resistor..
No, not needed, just start at half voltage and check that the output current is close to your selected current. For that 8R version, that is about 1.7A, so check it's starting at around 1.6A. If yes, increase the supply voltage then be sure output is still around 1.7A and then adjust LTP stage current to get offset below 10mV.
HD
HD
Hi my friends.
One channel οnly.....
Very very impressive amp.
My mouth is still hanging open from hearing it
https://vimeo.com/965797256?share=copy
One channel οnly.....
Very very impressive amp.
My mouth is still hanging open from hearing it
https://vimeo.com/965797256?share=copy
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Thanks Anand
Thanks also for your assistance .
Yes they are 3way speakers Kevlar .....Crystal audio Twin 1000. Jws inside speakers Denmark...i think...
They are 20 years old speakers. 4R /300W 92 db.
Thanks also for your assistance .
Yes they are 3way speakers Kevlar .....Crystal audio Twin 1000. Jws inside speakers Denmark...i think...
They are 20 years old speakers. 4R /300W 92 db.
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