JLM 111DC for solid state Pultec output transformer?

[JW]

Hey folks,

I have a solid state pultec that I'd like to try a different output transformer in. I happen to have a couple JLM 111DC transformers. http://www.jlmaudio.com/shop/jlm111dc-output-transformer.html

They can do 1:1. I think they would be wired as 150:150 though. So, different than the 600:600 Triad HS56

I'd like to know what you guys think about that.

 

[mitsos]

The original had the HS56 wired 250:600, which is about 1:1.55 turns ratio.  You can run the JLM 1:2 or 1:1, either way will work, you'll just need a few more dB of gain from your amp if you go 1:1.

 

[JW]

Thanks a bunch Mitsos

One more quick question. Since this is a gapped transformer, can I omit the 150uF cap right before it? It's to block DC correct?

 

[mitsos]

Yes, it is to block DC from the output of the amp. 

You can probably omit it in your situation, depending on the amp you are using and how much DC it has at the output.  If in doubt, check JLM's schematics for their preamps, especially the one using the JLM99V opamp, which has very high DC offset.  I'm pretty sure they run it straight into that transformer.