*UPDATE* It was discovered that this amp has a 1st gen Welborne Labs kit hastily installed inside.
Hello all, long time lurker -1st time poster here.
Anywho, I just purchased an ST-70 on eBay, and as you will see in the following pictures; it's had an interesting past. I'm currently investigating it's config, trying to do some reverse engineering to try to decide what to keep and or change to make it playable for me. The things I know right now:
1. Apparently, this unit was owned by either Paul McGowan of PS Audio *or* Arnie Nudell of Genesis Technologies? -according to seller.
2. Driver and Bias boards must be prototype, or early run of some type. No markings.
3. Driver circuit is a 6U8A - 5751 combination. 6U8A's are PRO/COMM, 5751's are RAM Tube Works.
4. Finals are Tesle E34L's. Rectifier is a Sylvania 5AS4 .
5. Input looks to have been modified to a low impedance drive.
If one of these Veteran Gurus here can help identify where these boards originated from -that would be of great help!
Now, for the pics:
I'll post more pictures as I dig deeper into this mystery piece. For now, thanks for looking