The sunn Forum

Sunn Musical Equipment => DIY => Topic started by: mojo2go on October 27, 2009, 05:06:02 pm

Title: Transformer question
Post by: mojo2go on October 27, 2009, 05:06:02 pm
Hi, I'm new to this site and have a question I'm hoping someone can help answer.
 I recently picked up a Fender Bassman head - Blackface made in '67. The output transformer in it now is a SUNN 3-60T. Someone had penciled in 6550 on the tube chart, but the amp now has 6L6's in it. Is it possible for the SUNN transformer to be wired for the voltages that a 6L6 takes, or am I waiting for a fire or something if I turn it on? The guy I got it from said it works fine like it is, but I'm a little skeptic and have not plugged it in because of a leaky cap I found in the power supply. Should I just put 6550's in there?
 Thanks 
Title: Re: Transformer question
Post by: loudthud on October 27, 2009, 07:56:34 pm
The amp needs to be biased properly no matter what tubes are in it. If it's biased for 6L6's, 6550s will probably run too hot and red plate if you just plug them in. The Sunn transformer will do just fine but may not give a full 50 watts with the Bassmans power supply.
Title: Re: Transformer question
Post by: mojo2go on October 28, 2009, 05:28:21 pm
Thanks for the info! If my amp tech can't get it biased, I'll most likely have him put in a transformer from Triode. I plan on using it for a guitar amp. Again, thank you.