#26 pre amp - Page 72 - 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 November 2010, 11:06 AM   #711
diyAudio Member
 
merlin el mago's Avatar
 
Join Date: Sep 2009
Location: Catalonia - Europe
Quote:
Originally Posted by nicoch46 View Post
my suggestion is Thomas Mayer he can supply a full kit if you want the top....and kit



better if compatibile 26&10y ,filament bias







.
Thanks for the link, no doubt is very good kit, but it's also ultra expensive.
  Reply With Quote
Old 19th November 2010, 04:07 AM   #712
diyAudio Member
 
coolzero's Avatar
 
Join Date: Sep 2009
Location: UAE
Quote:
Originally Posted by mach1 View Post
Coolzero, you wrote:



Have you tried lithium batteries?
No. I couldn't find something suitable.
  Reply With Quote
Old 26th November 2010, 10:57 AM   #713
regal is offline regal  United States
diyAudio Member
 
Join Date: Jan 2004
Location: MD
For a 26A-71A linestage are there any suitable 1:1 interstage transformers with the reqired high primary impenance and inductance for the 26?
  Reply With Quote
Old 26th November 2010, 06:00 PM   #714
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Hi!

Quote:
Originally Posted by merlin el mago View Post
Thanks for the link, no doubt is very good kit, but it's also ultra expensive.
Well, 2 chokes per filament and a high quality power transformer and output transformer don't come cheap

Even myself I only apply filament bias to my cost no object preamps. If budget is a concern I rather use regular cathode bias, instead of a solid state regulated filament supply. But tastes are differnt, this is just my opinion,

Best regards

Thomas
  Reply With Quote
Old 26th November 2010, 06:01 PM   #715
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Hi!

Quote:
Originally Posted by regal View Post
For a 26A-71A linestage are there any suitable 1:1 interstage transformers with the reqired high primary impenance and inductance for the 26?
If you want the best, use Tango NC20. If on a budget and 1:1.125 is ok, use Lundahl 1660

Best regards

Thomas
  Reply With Quote
Old 26th November 2010, 06:55 PM   #716
diyAudio Member
 
nicoch58's Avatar
 
Join Date: Oct 2004
HI Thomas nice to see here ,I read all post on AA about filament bias....

Can I ask if for 10y driver stage IT is good 400v/25ma or better lower Vak and up to 30ma ? (I know is not so simple

thanks
__________________
Sic58
  Reply With Quote
Old 26th November 2010, 07:13 PM   #717
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
hi!

Quote:
Originally Posted by nicoch46 View Post
Can I ask if for 10y driver stage IT is good 400v/25ma or better lower Vak and up to 30ma ? (I know is not so simple;
It depends on the current capability of your driver stage. If you use Tango NC20. Run it at 15-20mA.

If you want to drive say a 845 which needs large grid swing, go to as high b+ as possible

Best regards

Thomas
  Reply With Quote
Old 26th November 2010, 07:20 PM   #718
diyAudio Member
 
nicoch58's Avatar
 
Join Date: Oct 2004
thanks !

Btw 300Bxls and Tribute IT 30ma 80H
__________________
Sic58
  Reply With Quote
Old 26th November 2010, 07:31 PM   #719
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Hi!

I'd say around 400V B+ and choose a op point which will give the maximum possible voltage swing. Check the plate curves and draw in your op point there. This way your driver stage has the best possible headroom

Best regards

Thomas
  Reply With Quote
Old 25th December 2010, 07:35 AM   #720
vgeorge is offline vgeorge  Greece
diyAudio Member
 
vgeorge's Avatar
 
Join Date: Mar 2004
Location: poros island
Just finished a 26 pre. B+ is with LCLC to SSHV to an LL1667 25mA choke at 150V on anode. Cathode resistor is 1.8K bypassed by a 1000uF capacitor.
Thinking to move to battery bias soon.
Heating is with Rod' s regulators.
Also thinking to use a LL1660 wired 4.5:1 for line out. Should I use the 5mA or 10mA version? Right now I have about 6mA. Also would it be better or not to keep the anode chokes?

Last edited by vgeorge; 25th December 2010 at 07:40 AM.
  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



New To Site? Need Help?

All times are GMT. The time now is 07:33 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