Power Transformer for Class A Amplifiers -- What are your experiences ? - diyAudio
Go Back   Home > Forums > Amplifiers > Pass Labs

Pass Labs This forum is dedicated to Pass Labs discussion.

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 2nd March 2011, 03:09 PM   #1
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Default Power Transformer for Class A Amplifiers -- What are your experiences ?

Following a discussion for power transformers for the F5X, I think it is a topic which deserves separate attention.

Apart from what VA rating and what core size in relation to to real power consumed, there are many other issues, such as :

1) Core type -- Toroidal, EI, R-Core, C-Core ....

2) Winding type -- multiple thin wires vs single thick wire, bifilar or not, how much insulation between primary and secondary, single-layer secondaries each occupying half of the core perimeter, primary inside or outside, ...

3) Encapsulation 8potting) or not ...

4) Shielding -- electrostatic shield or no shield, magnetic shield will belly belt or case, Mu-metal vs steel vs aluminium, ....


I hope you will share your experiences and have an open discussion. And I particularly hope that Nelson would shed some light on the topic.

So I open the forum to you all.


Patrick
  Reply With Quote
Old 2nd March 2011, 09:17 PM   #2
Banned
 
Join Date: Nov 2006
You want mu-metal or better for the magnetic shield. That is about all I can contribute.
I can discuss a bit further if interested.

Regarding electric shield. I think it is a good idea for toroidals.
  Reply With Quote
Old 2nd March 2011, 11:41 PM   #3
Banned
 
Join Date: Nov 2006
Just one more thing.
I very rarely hear people discuss the importance of correctly annealing the core which a lot of manufactures do not do
  Reply With Quote
Old 3rd March 2011, 03:19 AM   #4
diyAudio Member
 
d to the g's Avatar
 
Join Date: Aug 2006
Location: minimalopolis
since it's been so quiet, i'll just point out jcarr's experience (and other people's measurements) that toroids have the largest bandwidth, followed by the EI, and then the R core. It goes without saying that a power transformer should be a low bandwidth device (either 50 or 60 Hz only).

However, I've never seen a low voltage/high amperage R core transformer.
  Reply With Quote
Old 3rd March 2011, 03:23 AM   #5
Banned
 
Join Date: Nov 2006
Placing an electric shield between primaries and secondaries should take care of this problem
  Reply With Quote
Old 3rd March 2011, 03:59 AM   #6
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
> However, I've never seen a low voltage/high amperage R core transformer.

Nikon 1975 bought one for his F5 in Japan if I remember correctly.
Please search one of the F5 threads.


Patrick
  Reply With Quote
Old 3rd March 2011, 05:20 AM   #7
Banned
 
Join Date: Nov 2006
Just so we don't get off track.
I think what we really want to know is, what is going to give us the best bang for buck in terms of making a real audible difference.

I am sure it would be possible to spend big dollars on a transformer and not end up with any audible improvement.

It would be nice if Nelson could set us straight here
  Reply With Quote
Old 3rd March 2011, 05:51 AM   #8
qusp is offline qusp  Australia
diyAudio Member
 
qusp's Avatar
 
Join Date: Oct 2009
Location: Brisbane, Australia
i believe that tx that Nikon1975 got from japan was insanely pricey
  Reply With Quote
Old 3rd March 2011, 09:29 AM   #9
diyAudio Member
 
wktk_smile's Avatar
 
Join Date: Dec 2009
Location: Kyoto
In japan, EI is most popular/widely used for electronics diy purpose.
Besides, large trafos suitable for such ClassA amplifier are expensive here.

Thus I can't say that's insane price for custom-made Universal primary/suitable to F5 R-core trafo.
  Reply With Quote
Old 3rd March 2011, 10:56 AM   #10
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
F5 components, parts you use

RAシリーズ 寸法表
価格表
  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
non surface mount class D mono audio power amplifiers Conor Digital Source 10 4th October 2013 07:38 PM
Experiences with class-d.com ? FUCHSAUDIO Solid State 10 12th November 2010 09:58 PM
For sale, 2 x Hypex Ucd180HG class-d amplifiers 1x SMPS180 Power Supply. cirrus18 Swap Meet 0 16th May 2009 08:24 AM
Class-T Audio Experiences BeanZ Class D 33 16th March 2007 12:08 AM
fs. pwm / class-d / class-t amplifiers km Swap Meet 1 27th December 2002 03:55 PM


New To Site? Need Help?

All times are GMT. The time now is 08:29 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ゥ1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2