Go Back   Home > Forums > > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Tubelab Discussion and support of Tubelab products, prototypes and experiments

Reply
 
Thread Tools Search this Thread
Old 5th October 2017, 01:26 PM   #1
first_1st is offline first_1st  Thailand
diyAudio Member
 
Join Date: Mar 2005
Location: bangkok
Send a message via MSN to first_1st
Default TSE45 change to TSE2A3

Now I had finishes TSE45 if I want to change output tube from 45 to 2A3

How to do?

Thank you.
  Reply With Quote
Old 5th October 2017, 07:24 PM   #2
mkane77g is offline mkane77g  United States
Always Learning
diyAudio Member
 
Join Date: Nov 2014
Location: 100 miles N. of S.F.
TSE45 change to TSE2A3
Depending on which power transformer you have it could be just a rectifier change. Output transformers won't be optimum but it it will work. Need to set bias.
  Reply With Quote
Old 6th October 2017, 05:44 AM   #3
first_1st is offline first_1st  Thailand
diyAudio Member
 
Join Date: Mar 2005
Location: bangkok
Send a message via MSN to first_1st
For Power Transwer I use Edcore Xpwr131.

If I want to try 2a3 for temp . Can I change 45 to 2A3 by not change any parts ?
  Reply With Quote
Old 6th October 2017, 01:31 PM   #4
mkane77g is offline mkane77g  United States
Always Learning
diyAudio Member
 
Join Date: Nov 2014
Location: 100 miles N. of S.F.
TSE45 change to TSE2A3
Sure you can. I tried this myself using modern 2a3's and had lot's of hum. And I'm trying this exercise right now. Setting the bias as I type

Last edited by mkane77g; 6th October 2017 at 02:00 PM.
  Reply With Quote
Old 6th October 2017, 02:06 PM   #5
Tubelab_com is offline Tubelab_com  United States
diyAudio Member
 
Tubelab_com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
Quote:
modern 2a3's and had lot's of hum.
The hum you experienced was likely because the filament regulator on the board was operating on the edge of dropout. For the regulator to be hum free the voltage across C1 needs to be 3.3 to 4 volts. Sometimes a big cap in parallel with C1 helps.

The 2A3 draws 2.5 amps nominal from a 2.5 volt source for the filament. This is right at the limit for the 5 amp regulator on the TSE board. Some "modern" 2A3's draw more than 2.5 amps, while some draw less. I have not tested any 2A3's in 6 or 8 years so I can't say which is which any more with certainty.

The XPWR 131 was created by another forum member for 45's and 300B's but 2A3 operation was never intended for that transformer. The 6.3 volt winding is only rated for 4 amps. At the time Edcor stated that they could not offer a 6 amp or so 6.3 volt winding on that sized core.

My 2A3 amp used a Hammond 272JX transformer, but this was done over 10 years ago. I have been told that modern versions of this transformer put out too much high voltage, but I haven't tried it myself.

To use 2A3's in a TSE board you need a 6.3 volt CT winding that can provide 6 amps or more. This could come from a separate transformer.

The heat sinking on the regulator chip will need to be upgraded. I used an old CPU heat sink from a Pentium 1 chip (yeah it was a while ago).
__________________
Tubelab, it's 5 year mission. To explore strange new tubes, to seek out new circuits and topologies, to boldly go where no tube has gone before......
  Reply With Quote
Old 6th October 2017, 02:18 PM   #6
mkane77g is offline mkane77g  United States
Always Learning
diyAudio Member
 
Join Date: Nov 2014
Location: 100 miles N. of S.F.
TSE45 change to TSE2A3
Sounds nice. Doing FM upstairs.
Attached Images
File Type: jpg DSC_0205 (1).JPG (178.1 KB, 89 views)
  Reply With Quote
Old 6th October 2017, 02:20 PM   #7
mkane77g is offline mkane77g  United States
Always Learning
diyAudio Member
 
Join Date: Nov 2014
Location: 100 miles N. of S.F.
TSE45 change to TSE2A3
And after reading Georges post this experiment will stop.
  Reply With Quote
Old 6th October 2017, 03:41 PM   #8
Tubelab_com is offline Tubelab_com  United States
diyAudio Member
 
Tubelab_com's Avatar
 
Join Date: Jul 2005
Location: West Virginia panhandle
Quote:
this experiment will stop.
If it works.....

The filament regulator will simple shut down if it gets too hot. Obvious symptoms, loss of sound. It just fades out as the filaments go dark. Usually power cycling is needed to restore operation, but sometimes the regulator will restart once it cools off. In this case check the heat sink. If it's too hot to touch (after you have pulled the power plug) add some additional heat sinking.

Check your power transformer. Again if it's too hot to touch an upgrade is needed.

Note, this is the usual rule of thumb. My original Lexan TSE has its second power transformer. The original transformer got really wet during a hurricane, and still lived for a year despite being full of rust inside (determined by autopsy). The second power transformer is a "too small" Allied 6K56VG (made by Hammond) which gets too hot to touch and starts to smell funny after several hours of continuous play with 300B's, yet lives on. Over 10 years now however most use has been with NX483's (5 volt 45's).
__________________
Tubelab, it's 5 year mission. To explore strange new tubes, to seek out new circuits and topologies, to boldly go where no tube has gone before......
  Reply With Quote
Old 6th October 2017, 05:30 PM   #9
mkane77g is offline mkane77g  United States
Always Learning
diyAudio Member
 
Join Date: Nov 2014
Location: 100 miles N. of S.F.
TSE45 change to TSE2A3
Well then the 2a3's will go back in. without the top cover on it may keep cool. Onwards.
  Reply With Quote
Old 6th October 2017, 05:54 PM   #10
mkane77g is offline mkane77g  United States
Always Learning
diyAudio Member
 
Join Date: Nov 2014
Location: 100 miles N. of S.F.
TSE45 change to TSE2A3
3.34v @ C1
  Reply With Quote

Reply


TSE45 change to TSE2A3Hide 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
first time build TSE45 need help first_1st Tubelab 35 6th June 2017 04:08 PM
How much to set Bias on TSE45 first_1st Tubelab 3 2nd May 2017 03:39 PM
Power transformer for TSE45 first_1st Tubelab 3 19th April 2017 01:02 AM
If I change B+ do I have to change the circuit? nige838 Tubes / Valves 3 18th August 2011 11:16 AM
Change nafanja Swap Meet 2 14th April 2008 09:40 AM


New To Site? Need Help?

All times are GMT. The time now is 08:03 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.00%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio
Wiki