Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

Designing a simple tube opamp?
Designing a simple tube opamp?
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 24th October 2005, 02:47 AM   #1
bradd is offline bradd  Australia
diyAudio Member
Join Date: Oct 2005
Default Designing a simple tube opamp?

I've been interested in the idea of makinig a tube opamp suitable for stompbox use that uses 12U7 tubes for quite a while. Mostly because these tubes are happy running off a 12v wall-wart!

I've been checking out the ol' Philbrick tube opamps, but after seeing Joe Davisson's discrete transistor opamps (here & here), I'm keen to see if a much simpler alternative to the Philbrick version is possible.

Would it be possible to simply mirror Joe Davisson's Compression Opamp design by using one 12U7 as a differential pair going into another 12U7 acting as Class A stage? Would it then be possible to use the left-over half of the second 12U7 as the compression diode by omitting the grid?

Sorry if these are stupid questions!
  Reply With Quote
Old 26th October 2005, 06:24 AM   #2
reinhard is offline reinhard
diyAudio Member
Join Date: Dec 2000
Location: Germany
Default Op Amp

If you compare tubes and transistor you see that all tubes are
n-channel devices: There is no aquivalent for a pnp transistor.

Nelson Pass has wrote an article about discrete op amps. Think there was a tube op amp in the article,

  Reply With Quote


Designing a simple tube opamp?Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Designing a simple TPA6120A2 Amp cynric Chip Amps 8 6th March 2007 08:57 AM
Designing a simple dc filament supply? Dr.Frankenstein Tubes / Valves 5 27th September 2004 10:31 AM
Designing simple amplifier from scratch Cordraconis Solid State 20 29th July 2004 10:01 PM

New To Site? Need Help?

All times are GMT. The time now is 08:48 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 16.67%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio