Quite so, Richard. Not that it's hard to do, and the pleasure I have from it far exceeds all my total spenditures for audio and software. My headphone amp design cost me three months of experimentation until I managed to voice it just right, made it sound as I thought it could and therefore should. I think John and you would like it, a nice complementary all discrete design runing in true class A all the way, the only IC being an LM 411 DC servo circuit. It uses Motorola/ON semi MJE 15029/1530 output devices (50W/8A) biased for 140 mA each, hand selected and matched. True dual mono version, with separate 50VA toroidal tranformers for left and right, using F&T 4,700 uF caps and fully regulated shunt supplies, using ALPS Blue pots, etc.
In my view, the whole thing sounds heavenly with my Sennheiser HD598 cans, and as well with my speakers, current B&M 1041 and old AR 94s.
An interesting tube walked in the door the other day. Almost tempted to use it in an audio amplifier.
https://frank.pocnet.net/sheets/140/8/8281.pdf
Filament current is a bit much. But with the right output transformer it would make a stunningly powerful class A amplifier.
https://frank.pocnet.net/sheets/140/8/8281.pdf
Filament current is a bit much. But with the right output transformer it would make a stunningly powerful class A amplifier.
Great tubes, I've maintained a few in Harris FM 20K transmitters. They are stable and forgiving at 100 MHz. They would most likely be cannon-proof for audio. Plus you get the pleasure of discharging their DC 8 KV power supplies with the Jesus stick. I love watching a young engineer wanna-be doing that for the first time...First the crack of thunder,
then the poo comes out, 
followed by laughter from onlookers!Cheers,
Howie
I have a very bad story about FM transmitters and grounding sticks, that I'll skip for now. But didn't the Harris xmitter have discharge resistors.Great tubes, I've maintained a few in Harris FM 20K transmitters. They are stable and forgiving at 100 MHz. They would most likely be cannon-proof for audio. Plus you get the pleasure of discharging their DC 8 KV power supplies with the Jesus stick. I love watching a young engineer wanna-be doing that for the first time...First the crack of thunder,
Cheers,
Howie
* * * * * * * * *
But here is another thunder story. While working in R&D of a medical x-ray company. One of the FDA tests was to short out the high voltage supply. That's about 150 kVolts (+75kV and -75kV). The development bay was out in a 250,000 sq.ft factory. We used the table's remote control and hide behind the lead shields. It sounded like a rifle and worried everyone in the building.
Don't know why we did that test, they never did it before.
Richard, I did say "In my view, ...". It plays better music than any other headphone amp I had the opportunity to try for myself.
A friend was desolate when he heard it because he had just spent sone € 600 on a well know headphone amp from a well knon name, but he said he thought mine was better. Actually meant little to me, I wasn't in an compettiton for the first prize and I produced a very classic design I am sure most folks here could also produce with ease, including the DC servo.
The only not so everyday solution in it are the shunt regulators simply because manufacturers don't bother with them and go all classic.
Anyway, that was no attempt at manufacturing, simply a design exercise for my own benefit and requirements.
If there's an interest in it, I can dig up my log and find the complete schematics.
A friend was desolate when he heard it because he had just spent sone € 600 on a well know headphone amp from a well knon name, but he said he thought mine was better. Actually meant little to me, I wasn't in an compettiton for the first prize and I produced a very classic design I am sure most folks here could also produce with ease, including the DC servo.
The only not so everyday solution in it are the shunt regulators simply because manufacturers don't bother with them and go all classic.
Anyway, that was no attempt at manufacturing, simply a design exercise for my own benefit and requirements.
If there's an interest in it, I can dig up my log and find the complete schematics.
Congratulations to Scott for his work that helped make this happen
The 2017 Nobel Prize in Physics - Press Release
Cheers
Alan
The 2017 Nobel Prize in Physics - Press Release
Cheers
Alan
Isn't that the tube that Disaster Area (The Plutonium Rock Band) used in Parallel-Push-Pull for their amps?
no, it was the prototype used for characterization, the device used there hadn't been built yet as the Unobtanium mines hadn't been discovered yet and that was needed for the final act of assembly for the active devices.
Don't panic
George
Thankyou gentlemen, maybe Dr. Weiss could take on some of the quantum mechanical issues in audio now.
He too had the bug !
Meet the college dropout who invented the gravitational wave detector | Science | AAAS
George
Meet the college dropout who invented the gravitational wave detector | Science | AAAS
George
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