Friedman DS40 type build with pics

[daveyajd]

Hello,
Well I have finally finished my build of a Dirty Shirley. I built this entirely from photos and the knowledge that it is based on a JTM45. The input jacks are a giving me a bit of grief but I will dive in and fix that when I can. Everything is working great and this thing rocks! I have not raised the heaters in this yet but the amp is still very quiet at idle. Thanks for all the help through the process.


Aaron
https://imgur.com/a/HhJLLz5

[imgumby001]

She’s beautiful man!

[Opry Audio]

Nice, that looks pretty awesome!

[pdf64]

Yes, looks nice, is that a custom faceplate?
What transformers did you use? I seem to remember that the DS has a JTM45 PT but JTM50 and later OT (~3k4 784-139 type).
Note that the JTM45 / 5F6A standby is a hot switching type, best not to use it.

[daveyajd]

Hello,
Thank you. Yes, I design the faceplates and have them made up for me locally.


https://imgur.com/a/Fitt5hY


I had my transformers made by Matt at MPS. The PT is 690v CT and the OT is 7.5k so I can reflect 3.7k by switching the impedance. I did not put a standby on this build at all.

[fast960]

Wonderful build Dave! I know this is a few years ago but as I recall from your circuit board drawing that you switched the resistors at the power tubes (going to bias)from 2-220ks to 2-100ks ... Did that change remain the same?