My new filiment PS for Push Pull GM70 - 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 18th April 2011, 03:22 AM   #1
djn is offline djn  United States
diyAudio Member
 
djn's Avatar
 
Join Date: Oct 2004
Location: Waterford Michigan
Default My new filiment PS for Push Pull GM70

A friend just gave this to me. 2 channles of 24volt, 6 amp DC power. I think it would be a great filiment PS for a push pull GM70 amp. The GM70 needs 20v, 3a. It weights 38lbs!!! Talk about a boat anchor....and that is just a fraction of the whole amp. I think it will do nicely.

Click the image to open in full size.

Click the image to open in full size.
  Reply With Quote
Old 18th April 2011, 10:27 AM   #2
diyAudio Member
 
Join Date: Jul 2003
Location: Ann Arbor, MI
hey-Hey!!!,
For PP Dh amps I have not found DC heating required...at least not with 10V 813's. 5V tubes absolutely not, and 2.5V tubes...not even close.
cheers,
Douglas
__________________
the Tnuctipun will return
  Reply With Quote
Old 18th April 2011, 11:04 PM   #3
djn is offline djn  United States
diyAudio Member
 
djn's Avatar
 
Join Date: Oct 2004
Location: Waterford Michigan
Hey D, sorry we missed you yesterday. I know this might be over kill and I still have three amp projects on the bench, but what the hey! George asked me if I wanted it, so what the heck.
  Reply With Quote
Old 19th April 2011, 11:15 AM   #4
diyAudio Member
 
Join Date: Jul 2003
Location: Ann Arbor, MI
Quote:
Originally Posted by djn View Post
Hey D, sorry we missed you yesterday. I know this might be over kill and I still have three amp projects on the bench, but what the hey! George asked me if I wanted it, so what the heck.
That's mighty strange, I've never known you to go in for 'overkill'...LOL

Douglas
__________________
the Tnuctipun will return
  Reply With Quote
Old 19th April 2011, 11:52 AM   #5
djn is offline djn  United States
diyAudio Member
 
djn's Avatar
 
Join Date: Oct 2004
Location: Waterford Michigan
Bad habits die hard
  Reply With Quote
Old 19th April 2011, 04:41 PM   #6
kevinkr is offline kevinkr  United States
diyAudio Moderator
 
kevinkr's Avatar
 
Join Date: Sep 2004
Location: Boston, Massachusetts
Blog Entries: 6
Quote:
Originally Posted by Bandersnatch View Post
hey-Hey!!!,
For PP Dh amps I have not found DC heating required...at least not with 10V 813's. 5V tubes absolutely not, and 2.5V tubes...not even close.
cheers,
Douglas
These are 20V tubes and DC is advisable if you need really low hum even in PP. I found with 300B PP amps driving very efficient speakers (>100dB) that DC was also advisable, although not strictly required if you can live with a mVrms or so of hum/buzz on the output..
__________________
"Extraordinary claims require extraordinary evidence." - Carl Sagan
  Reply With Quote
Old 19th April 2011, 06:56 PM   #7
djn is offline djn  United States
diyAudio Member
 
djn's Avatar
 
Join Date: Oct 2004
Location: Waterford Michigan
I agree Kevin. I generally run compression drivers that are 115db eff. and any hum is audable. Besides that, it is a simple one piece unit that just needs wire hooked up. no muss, no fuss.
  Reply With Quote
Old 19th April 2011, 09:05 PM   #8
diyAudio Member
 
Join Date: Apr 2009
Good starting point and good luck with new project djn!!!

GM70 PP would be a beast ...
__________________
tubes.rs
  Reply With Quote
Old 19th April 2011, 09:21 PM   #9
djn is offline djn  United States
diyAudio Member
 
djn's Avatar
 
Join Date: Oct 2004
Location: Waterford Michigan
Thanks Radio. I have three other amps on the bench but getting ready to move, so I dont think this one will be up and running any time soon, but that only means I have time to collect parts. Should do well with 800v B+. I don't know how to figure what the WPC will be but I'm sure it will be more than my GM70 SET.
  Reply With Quote
Old 20th April 2011, 11:07 AM   #10
diyAudio Member
 
Join Date: Jul 2003
Location: Ann Arbor, MI
Quote:
Originally Posted by kevinkr View Post
These are 20V tubes and DC is advisable if you need really low hum even in PP. I found with 300B PP amps driving very efficient speakers (>100dB) that DC was also advisable, although not strictly required if you can live with a mVrms or so of hum/buzz on the output..
I have 813's on AC with horn-loaded EV DL10x and don't hear anything unless I stick my shoulders into the horn. I can live with that. Individual coils for each tube and their own hum pot. Variac on the primary to dial in exactly 10V, though it seems to be quite happy with 10.2-10.5V on them.
cheers,
Douglas
__________________
the Tnuctipun will return
  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
"Push-Pull" for push und "Push-Pull" for pull (like Gamnut) - whats the right name? tiefbassuebertr Solid State 70 15th August 2012 08:08 PM
Push-Pull vs Push-Pull-Parallel rsumperl Tubes / Valves 8 10th July 2012 05:34 PM
modify parallel push-pull EL84 to single push-pull chungtat Tubes / Valves 12 3rd November 2005 11:25 PM
Push Pull bellx Solid State 3 25th January 2004 10:59 AM
Double push-pull versus single push-pull jraraujo Tubes / Valves 19 19th October 2002 12:23 AM


New To Site? Need Help?

All times are GMT. The time now is 01:11 PM.


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