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

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

Anyone tried Plitron transformers?
Anyone tried Plitron transformers?
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
Thread Tools Search this Thread
Old 8th February 2016, 06:50 AM   #1
G is offline G  United States
diyAudio Member
G's Avatar
Join Date: Apr 2002
Location: Belleville, IL.
Default Anyone tried Plitron transformers?

My God! They must be wound with gold wire or something. I can build a entire amplifier with Magnequest transformers for what they are asking just for a pair of output transformers.
  Reply With Quote
Old 8th February 2016, 07:29 PM   #2
obseedian is offline obseedian  Canada
diyAudio Member
Join Date: Apr 2006
Location: Ontario
I have built amps with these. The big problem with them is their sensitivity to both DC and AC imbalance. This is especially a problem when applying GNFB around the amp as it can exacerbate core saturation during large transients.

The best sound that I was able to get from these involved PP class-A DHT output stages with no feedback. In that application they had superb transparency and low level resolution (assuming you had a clean B+).

While that is no doubt true for any OPT, I found it to be especially the case with the Plitrons.

Last edited by obseedian; 8th February 2016 at 07:32 PM. Reason: Added PP
  Reply With Quote
Old 8th February 2016, 07:46 PM   #3
SpreadSpectrum is offline SpreadSpectrum  United States
diyAudio Member
SpreadSpectrum's Avatar
Join Date: Nov 2007
I have. They have very low winding DCRs so they work very well for making an amp without global feedback that still has a low Zout. My amp's Zout is just over 1 Ohm, no feedback around the output transformer. It is a Unity-Coupled amp so it has very heavy local feedback in the output stage that drives the transformer.

I also tried to find the -3dB point on the low end and found that my measurement setup could not get low enough. I was still at full amplitude at 10 Hz. This was small signal bandwidth. The transformer spec was for -3dB @ 500kHz on the high end but my driver stage ended up limiting my amp bandwidth to 120kHz. Probably not a bad thing.

I used the Guido Tent/Van der Veen bias servo to maintain tight DC balance. It works very well but adds a minute or two to the time it takes for the amp to be ready to play music. It starts at full negative bias with a delay until the tubes warm up and then slowly reaches target bias current, about 30 seconds after the delay times out.
My Blog: http://tubeswithatwist.blogspot.com/
  Reply With Quote


Anyone tried Plitron transformers?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

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
Plitron Transformers vinay Swap Meet 1 18th June 2014 02:53 AM
Plitron Transformers. simaduio Group Buys 11 2nd February 2010 12:22 AM
FS 2 Plitron transformers woody Swap Meet 3 8th April 2008 01:32 PM
Plitron Transformers For Trade gaborbela Swap Meet 5 10th November 2005 12:49 AM
Plitron New Transformers trigon Parts 39 20th July 2002 06:07 AM

New To Site? Need Help?

All times are GMT. The time now is 07:12 AM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio