Single supply 6922 buffer with 2SK CCS - diyAudio
Go Back   Home > Forums > Amplifiers > Tubes / Valves

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

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
Reply
 
Thread Tools Search this Thread
Old 12th January 2009, 04:16 AM   #1
Will is offline Will  Malaysia
diyAudio Member
 
Join Date: Sep 2001
Location: Kuala Lumpur
Default Single supply 6922 buffer with 2SK CCS

Hi,
I'm a bit poor on this tube topic so please help me out.

The circuit on the right (dual supply buffer) has been done before so I guess it's a working model.

My question is, can the diagram on the left using single supply be used with the same CCS?

The reason being I have the trafo and choke to provide a good 80V supply and if possible I would like to use high voltage PIO as ouput caps.

Many thanks.
Attached Images
File Type: gif 6922 buffer.gif (5.3 KB, 902 views)
__________________
regards,
Will
  Reply With Quote
Old 12th January 2009, 04:29 AM   #2
WT is offline WT
diyAudio Member
 
Join Date: Jun 2002
Location: Bangkok, Thailand
I don't think you have enough voltage to make the ccs work for the single supply.
  Reply With Quote
Old 12th January 2009, 04:33 AM   #3
Will is offline Will  Malaysia
diyAudio Member
 
Join Date: Sep 2001
Location: Kuala Lumpur
How much more voltage do I need to make it work?
__________________
regards,
Will
  Reply With Quote
Old 12th January 2009, 04:44 AM   #4
diyAudio Member
 
Join Date: Apr 2004
Location: Monroe Township, NJ
Will,

Aside from the lack of Volts, the single supply circuit will NOT work, as drawn. Where's the negative bias on the triode's grid? A DC coupled I/P is possible, only when a bipolar PSU is employed.

What are the ratings of the power trafo's rectifier winding? Depending on the rectifier winding's wiring, it may be possible to get the Volts you need, either by bridge rectification or Greinacher voltage doubling.
__________________
Eli D.
  Reply With Quote
Old 12th January 2009, 04:50 AM   #5
WT is offline WT
diyAudio Member
 
Join Date: Jun 2002
Location: Bangkok, Thailand
You can use -6V on the tail of CCS by using the V from heater supply. Also take out the 6.8K resistor as well, or change it to 10 ohm or 1 ohm so you can use it to measure current.

Another way is to replace all of the ccs with choke which I think will make this circuit more elegance.
  Reply With Quote
Old 12th January 2009, 05:43 AM   #6
Will is offline Will  Malaysia
diyAudio Member
 
Join Date: Sep 2001
Location: Kuala Lumpur
Quote:
Originally posted by Eli Duttman
Will,

Aside from the lack of Volts, the single supply circuit will NOT work, as drawn. Where's the negative bias on the triode's grid? A DC coupled I/P is possible, only when a bipolar PSU is employed.

What are the ratings of the power trafo's rectifier winding? Depending on the rectifier winding's wiring, it may be possible to get the Volts you need, either by bridge rectification or Greinacher voltage doubling.
Thanks for the info, do excuse my lack of knowledge.
I have a 120v trafo (secondary) and when after full wave rectification will produce 120x1.4 = 168v. Hence plenty of headroom to bring voltage down. I have a 50H choke. Any suggestion?
__________________
regards,
Will
  Reply With Quote
Old 12th January 2009, 05:46 AM   #7
Will is offline Will  Malaysia
diyAudio Member
 
Join Date: Sep 2001
Location: Kuala Lumpur
Quote:
Originally posted by WT

Another way is to replace all of the ccs with choke which I think will make this circuit more elegance.

How would you calculate the choke value? Assuming I want to bias the tube at 15mA.
__________________
regards,
Will
  Reply With Quote
Old 12th January 2009, 04:01 PM   #8
diyAudio Member
 
Join Date: May 2007
The 6922 is totally unusable if you want to make single supply CF.

If you use a pair of 12B4A with I=10mA you will get 7Vrms with Zout=150ohm.

If you use a 6N30P you will get 3Vrms with Zout=120ohm.
  Reply With Quote
Old 12th January 2009, 04:07 PM   #9
diyAudio Member
 
leadbelly's Avatar
 
Join Date: Dec 2002
Location: Calgary, Alberta
Quote:
Originally posted by revintage
The 6922 is totally unusable if you want to make single supply CF.
Why? The ECC88/6DJ8/6922... family are great for CF's.
__________________
Aerodynamics are for people who can't build engines. Enzo Ferrari
  Reply With Quote
Old 12th January 2009, 04:48 PM   #10
diyAudio Member
 
Join Date: May 2007
Hey Leadbelly,
Read the whole sentence ! It says "single supply" as in the Wills left picture. Otherwise you are right, it is really good as CF (if you happen to like CFs).

If one decide to use a input cap and lift the triodes grid from ground potential it will not be a problem to use 6DJ8.
  Reply With Quote

Reply


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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
6N1P for buffer instead of 6DJ8, 6922 JojoD818 Tubes / Valves 39 28th April 2010 01:17 AM
6922 tube buffer sarrisk Tubes / Valves 6 20th October 2008 01:46 AM
Heater supply recommendation for 6922? leadbelly Tubes / Valves 18 20th March 2007 03:14 AM
Tube Buffer for CD-PRO2M (6922) Rarkov Tubes / Valves 22 4th March 2005 07:37 AM
power supply for 6922 mu follower AudioGeek Tubes / Valves 5 30th June 2004 04:25 AM


New To Site? Need Help?

All times are GMT. The time now is 01:12 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2