Tube headphone amp problems - Page 2

SY · 1st August 2003, 07:02 PM

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 · 1st August 2003, 08:06 PM

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 · 1st August 2003, 08:13 PM

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 · 1st August 2003, 11:23 PM

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 · 1st August 2003, 11:38 PM

Hi,

Quote:

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,

1st August 2003, 07:02 PM	#11
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX	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. __________________ "It is not seemly, after wiping your nose, to spread out your handkerchief and peer into it as if pearls and rubies might have fallen out of your head." - Erasmus

1st August 2003, 08:06 PM	#12
SY diyAudio Moderator Join Date: Oct 2002 Location: Austin, TX	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/ __________________ "It is not seemly, after wiping your nose, to spread out your handkerchief and peer into it as if pearls and rubies might have fallen out of your head." - Erasmus

1st August 2003, 08:13 PM	#13
HDTVman diyAudio Member Join Date: Aug 2001 Location: Chicago area	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 __________________ What ever makes the tunes flow

1st August 2003, 11:23 PM	#14
G diyAudio Member Join Date: Apr 2002 Location: Belleville, IL.	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 __________________ Gavin

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
TPA6120A2 Headphone Amp Offset Problems	cynric	Chip Amps	4	10th July 2007 10:42 AM
Octal tube as headphone amp output tube	yagoolar	Tubes / Valves	6	25th November 2006 10:11 PM
47B tube headphone amp	lgqliu	Tubes / Valves	2	8th July 2006 03:50 PM
Tube Headphone Amp !	-_nando-_	Tubes / Valves	5	4th April 2006 12:06 AM
My new tube headphone amp	MCLL	Tubes / Valves	7	24th July 2005 09:44 AM


<a rel='nofollow' href='http://www.diyaudio.com/openx/www/delivery/ck.php?n=aa5cb2e9&cb=719264' target='_blank'><img src='http://www.diyaudio.com/openx/www/delivery/avw.php?zoneid=3&cb=719264&n=aa5cb2e9' border='0' alt='' /></a>	We're saving for a new server - help us to serve you by Donating Today and become a friend with benefits! Ads on/off / Custom Title / 2009 Tshirt / More PMs / Bigger Images / Advanced printing

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

New To Site?	Need Help?
Register to Participate Search Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read