#26 pre amp - Page 94 - 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 5th April 2011, 05:54 PM   #931
vgeorge is offline vgeorge  Greece
diyAudio Member
 
vgeorge's Avatar
 
Join Date: Mar 2004
Location: poros island
-9v bias and 150v B+ is around 8mA on a 26 tube so I would prefer 135v, in order not to stess the 1660 at 5mA. If you use a SSHV and have the proper sinks, you can adjust easilly. I drop around 90v on mine. I used a plate choke and prefered the 1660 transformer. Mind you that I use 4:1 for the 1660.
  Reply With Quote
Old 5th April 2011, 07:58 PM   #932
diyAudio Member
 
dvb projekt's Avatar
 
Join Date: Feb 2009
Location: Willich, Germany
Blog Entries: 37
Send a message via Skype™ to dvb projekt
Does it make sense to use the amorph version of the Lundahl 1660?

BTW, i dont find any datasheet of the 5mA version.
__________________
Reference TDA1541A DAC project PCBs / Tube-I-zator PCB / SSHV-Shunt PCB
Stock status in my Blog
  Reply With Quote
Old 5th April 2011, 08:02 PM   #933
diyAudio Member
 
Join Date: Sep 2003
Location: London
The 5mA version does exist. As far as I know it's the same as the PP version - same gap.

andy
  Reply With Quote
Old 5th April 2011, 08:18 PM   #934
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Hi!

Quote:
Originally Posted by Bas Horneman View Post
How about the Lundahl 1680. a Replacement built for the UTC ls-2
I tried the 1680. I prefer the 1660 it sounds and measures better

Thomas
__________________
http://vinylsavor.blogspot.com/
  Reply With Quote
Old 5th April 2011, 08:19 PM   #935
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Hi!

Quote:
Originally Posted by dvb-projekt View Post
Does it make sense to use the amorph version of the Lundahl 1660?
Matter of taste. I prefer the standard cores

Thomas
__________________
http://vinylsavor.blogspot.com/
  Reply With Quote
Old 5th April 2011, 08:19 PM   #936
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Quote:
Originally Posted by andyjevans View Post
The 5mA version does exist. As far as I know it's the same as the PP version - same gap.
Correct!
__________________
http://vinylsavor.blogspot.com/
  Reply With Quote
Old 5th April 2011, 08:44 PM   #937
diyAudio Member
 
dvb projekt's Avatar
 
Join Date: Feb 2009
Location: Willich, Germany
Blog Entries: 37
Send a message via Skype™ to dvb projekt
Quote:
Originally Posted by Vinylsavor View Post
Hi!



Matter of taste. I prefer the standard cores

Thomas
The 5mA or 10mA version?
__________________
Reference TDA1541A DAC project PCBs / Tube-I-zator PCB / SSHV-Shunt PCB
Stock status in my Blog
  Reply With Quote
Old 5th April 2011, 08:52 PM   #938
diyAudio Member
 
Vinylsavor's Avatar
 
Join Date: Feb 2002
Location: Lindau
Hi!

I have not compared the different cores for all transformers and all currents.

If you intend to run the 26 at 5mA or less and you want to use the transformer only for the 26 linestage, go for the 5mA. If you want to experiment with higher currents or maybe want to try other tubes as well. The 10mA will still work well with the 26. I use the 10mA version in my linestage which can be switched between 26 and 801A. Since the 801A runs at around 10mA, I used the 10mA transformer. I mainly listen with the 801A anyways since I prefer it.

Thomas
__________________
http://vinylsavor.blogspot.com/
  Reply With Quote
Old 5th April 2011, 10:56 PM   #939
diyAudio Moderator Emeritus
 
Bas Horneman's Avatar
 
Join Date: Apr 2002
Location: The Netherlands
Blog Entries: 18
Quote:
I tried the 1680. I prefer the 1660 it sounds and measures better
Thanks. Good info to have.
  Reply With Quote
Old 8th April 2011, 06:00 PM   #940
diyAudio Member
 
Join Date: Oct 2007
To Thomas and all others:
Have you tried the LL1692A as line output ?
The PP-Version with 5mA gap has 210Henry. This should be fine for the tube 26. The LL1660-PP has 290Henry.
I was comparing the data sheets of both transformers:
Both with a gap for 18mA in Connection Alt. Q in SE Line Output:
LL1660 Freq. Response: 11Hz - 35KHz
LL1692A Freq. Response: 10Hz - 55KHz
The LL1660 has 4.5 : 1 ratio and the LL1692A has 3.5 : 1 ratio. The 5mA gap version should have better Freq. Response than 18mA.
In this connection Alt. Q the LL1660 has a primary DCR = 1250 Ohm and the LL1692A has primary DCR = 690 Ohm.
On the site of K&K i have found, that the LL1692A has a resonance point that is moved up in higher frequency and has a lower amplitude compared to LL1660. No comment about sound.
What transformer should i use ?
Thank you. Johann
  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 11:18 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