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

help needed with grounded grid CCS upgrade
help needed with grounded grid CCS upgrade
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 23rd March 2010, 06:03 PM   #11
Merlinb is offline Merlinb  United Kingdom
diyAudio Member
Merlinb's Avatar
Join Date: May 2006
Location: Lancashire
Originally Posted by ultrachrome View Post
In your example you have HT+ and V+. What range of voltage would V+ typically be? The 1.8V label suggests 12V or lower?
HT+ will be the usual, say 250V to 400V. V+ can also be anything; either a convenient low voltage supply, or R1 could even be connected to the HT, although that does mean more wasted power of course. When I built this circuit I used the DC heater supply for V+.

I built the circuit with 12AX7, but it should work even better with 12AU7, with suitable adjustment of the emitter resistor / base voltage.
Buy my tube hi-fi book! www.valvewizard.co.uk
  Reply With Quote
Old 23rd March 2010, 06:34 PM   #12
revintage is offline revintage
diyAudio Member
Join Date: May 2007
Hey Svein,
Did a quickie at Google and found them at 20-30EURs a piece. Could thankfully not find them at the price you indicate.
But 5687 or E182CC might be something to use.
  Reply With Quote
Old 23rd March 2010, 07:44 PM   #13
ultrachrome is offline ultrachrome  United States
diyAudio Member
Join Date: Jan 2002
Location: Puget Sound
Originally Posted by DougL View Post
FWIW, Figure 2.48 (b) or (e) on page 134 of "Valve Amplifiers" Third addition has the circuit you are looking for. The emitter of the PNP would be attached to the cathodes of the Long tail Pair. (Grounded grid is a misnaming of the circuit by the designer).
I agree with Svein that the circuit shown in post 4 by Merlinb is not what I would recommend because it does not use a negitive supply.
Page 128 Figure 2.46 has a FET CSS between stages. Looking again Page 136 figure 2.49 has a great example of what you are trying to accomplish.


Thanks. That's very helpful. I'll look at it tonight.

Revintage, thanks for that comment. Your mention of "SRPP" was an interesting clue.

Merlinb, that's what I was hoping you'd say. Looking at some of schematics in the salas thread and other CCS's, it was not yet obvious to me how they were connected.
  Reply With Quote
Old 23rd March 2010, 08:59 PM   #14
revintage is offline revintage
diyAudio Member
Join Date: May 2007
Hey Ultra,

This is to show how it could be done, avoiding unnecessary "sounddegrading" stages. Zout below 1kohm. Negative supply could be as low as 9-12V

An option isa to use a gyrator or CCS on top of the second tube instead of anoderesistor.
Attached Images
File Type: png GG.PNG (56.2 KB, 186 views)
  Reply With Quote
Old 23rd March 2010, 09:42 PM   #15
jerluwoo is offline jerluwoo  United States
diyAudio Member
jerluwoo's Avatar
Join Date: Feb 2006
Location: Ashland,Ky U.S
Here's some good reading about cathode coupled stages. PCB Update & Cathode-Coupled Amplifiers The links at the top that says background blogs also cover cathode coupled circuits.
  Reply With Quote


help needed with grounded grid CCS upgradeHide 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
Grounded Grid Preamp ray bronk Tubes / Valves 25 28th January 2008 11:03 AM
5842 grounded grid alexg Tubes / Valves 19 27th April 2007 11:49 PM
Grounded Grid jswen Tubes / Valves 0 17th May 2006 11:48 PM
Grounded Grid Help gelder Tubes / Valves 8 11th December 2005 02:00 AM
help needed diagnosing Grounded Grid power supply ultrachrome Tubes / Valves 3 20th October 2004 08:01 PM

New To Site? Need Help?

All times are GMT. The time now is 10:47 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio