What transformer for Gainclone?

[SoundQuest]

Getting started on my first Gainclone and was wondering which of you gainclone afficianodos/veterans out there have used for your transformers, where you ordered them from, and how much you paid? I will be building the standard Brian GT non-inverted GC.

 

[ccrobbins]

Tranny

I have one of these I am planning on using. I picked mine up from a surplus store, but it is the same tranny. Oh, and I am no means an expert, if this is wrong please let me know.

http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=122-640

 

[Variac]

I used that one and it's fine. ALso we can help you hook it up because lots of peole use it.

Apex jr has some smaller toroid that would be best used one per channel, but they are cheap:

http://www.diyaudio.com/forums/showthread.php?s=&postid=449180#post449180

 

[yoke]

What voltage should transformers be ?
Wasn't Peter use 18-0-18V , now I see pople use 25-0-25V ?

Thanks

 

[Doovieman]

the voltages you use are really up to you...you can look at the data sheet see at which power output the chip has least distortion, do some basic math and come out with the "optimal" values...I think for LM3875 optimal power output is something like 53W...I hardly ever listen to my music this loud so it doesn't really matter...as long as you minimize ripple (and of course your voltages are within the chip's range) everything should be ok. oh, if you've already ordered a transformer that's too powerful you can always build a regulator to get it "just right".

Doovieman

 

[maxw]

Here's a thread about GC transformer:
http://www.diyaudio.com/forums/showthread.php?s=&threadid=36194

 

[jhead]

If you want the best design type then R cores would be the one followed by Torodial if you have a search engine just type in the type of transformer your interested you'll probable get a least a dozen response's There are dozens of manufactures