Replacement Power Transformers

[bobsamps]

So what is a good replacement for a Power transformer for a 2 tube Sunn amp? I got 3 old heads to repair for fun. One 100S, a Sceptor and a Solarius. These have been old project amps I have around. I did replace the power tranny on the 100s but it doesnt seem to be as loud as I remember these amps can be. Thanks to all that reply!

[52 Bill]

If you check a few earlier threads, I think that you'll find that a lot of Sunn amps were based in part on Dynaco Hi-Fi power amps. So try Triode Electronics in Chicago, as they have a number of Dynaco based replacement transformers.

Hope this helps.

[quint]

Sunn amps in general

One thing that Sunn did in some of their amp heads was to place the filter choke coil right after the rectifier, so the B plus power to the output tranny was limited by the filter. If you move the choke so that it regulates from the screens on down you will punch up the output power.

[J Martin]

You need the choke where it is because in an ultralinear output configuration there is no separate screen node filtering. Even though the screens are running over voltage, the ultralinear configuration keeps everthing in check. If you rewire the amp for non ultralinear operation, you will need to lower the screen voltage or suffer shortened tube life. There is no "limiting" of power. The choke is correctly sized. I have about six Sunn heads so I know them pretty well.