Tube headphone amp problems

[SY]

If you're going to use a pentode as a cathode follower, you need to have the screen grid be at a positive, fixed potential above the cathode. The simplest way to do that is to put a bypass cap from cathode to screen, then feed the screen through a resistor to B+.

The REAL answer is to not try to adapt a circuit that isn't really designed to do what you want. I'm certain that with a bit of searching you can come up with a finished, tested design for an OTL tube headphone amp. In fact, I think Joe Curcio may have published one.

The usual warnings: unlike much solid state gear, tube amps carry potentially LETHAL voltages. If you're unsure of what you're doing, DON'T DO IT.

[SY]

Follow up: I didn't see on at Curcio's site, but there are a few interesting designs posted here: http://www.headwize.com/projects/

[HDTVman]

Try looking at "tubecad.com". He has done headphone amps a couple of times and if you take the time to do some reading you will get an education.

Later BZ

[G]

If you are going to build a headphone amp you are doing yourself a disservice by not visiting the Headwize Forums:

http://headwize2.powerpill.org/ubb/f...num=3&fdays=20

Also you should take a look at this simple and effective headphone amp project:

http://headwize2.powerpill.org/proje...aarde1_prj.htm

This is a good starting point and the sound is purported to be wonderful. Since you are using 600 ohm cans a good 470uF output cap bypassed by a good poly cap should work well. Just register for the forum and you will have all of the help you will need. I hope these links help.

G

[fdegrove]

Hi,

This is a good starting point and the sound is purported to be wonderful.

It is one of the best on that site and I can only recommend it...especially with the Ying Mingyao PSU.

I know this circuit since it first appeared in the now defunct Dutch audio mag Audio & Techniek and it even drove my 92dB speakers to reasonable levels and with great sound.

There's still room for improvement, but as is it won't disappoint.

Cheers,