Building a headphone amp from parts

[minhaj]

Dear Bob,

Tx wire code is different in different countries I personally do not rely on that. Pls measure DC resitance of both side higher resistance side is primary, connect red wire with B+ and brown wire with tube plate, for the secondary connect any to any check bass response and swap connection if needed.

Power Tx

Connect primary and check output from 0 to one 210 and another 210 if it is 210 volt for both cased then it is 210V ct Tx. But I feel E is for earthing the Tx.

Circuit

Usually I do not refer to others circuit for copying (if it is even for personal need) because one designers curcuit is best suited for his / her own taste/audio chain. But if it is for start only please check the net their are dozens of them.

Pls excuse me if I sound rough but there is no short cut to paradise.

Regards

[Smokehouse Bob]

You weren't rough, just real! Thanks! I will read up more and maybe find someone closer (Atlanta) to mentor me "one on one".

[minhaj]

I wish you every success in DIY audio, Bob.

Remember that audio is science plus personal test no black art. There are people / org who promot it as one and try to suck your money.

Regards

[richwalters]

Originally posted by dsavitsk
There isn't any real difference between designing a headphone amp and anything else.

True in some ways but....

The real problem with any tube o/p stage is to keep the noise down with close headphone coupling to ears. Unless one likes music really loud, most o/p stage tube circuits are hard pressed to get quieter than -70dB down. If you like classical tones with many quiet passages then -90dB is min requirement to avoid hearing background hiss. So I'm ruling out the standard true pentode output stage unless it's wrapped up with so much feedback to keep it quiet. Any power stage must have low gain with low noise and a triode config is better with the gain coming elsewhere.
One can at a last resort use o/p attenuators i.e series # shunt resistors but again one needs the voltage drive to do this.

In the end I was forced to use 10 x 5534 ic's in parallel to drive the lowest Z phones.

richj