I was in “cleanup mode” at the time, just like my house and garage projects now 🧹
I’m pretty sure you were working on an ST 70 as I was interested in the VTA version at the time.
The guys and I would enjoy seeing you revive an amp, so hopefully you can get the camera 🎥 set up.
I would have but the gent hung around for the initial look. All the output transistors were shorted on one channel of the board with the drivers being suspect. Depending on what he can obtain from the manufacturer, I may end up swapping the entire board or doing component replacement. I suspect it will be more cost effective to drop in a new board, but that all depends on what he works out with the builder. He is friends with the manufacturer, so I won't be surprised if a new board shows up.
The ST-70 rebuild had several more appearances on my bench. The second was to try and make it behave with EL34's, it had output transformers that were designed for KT-66's and it would break into oscillation without much provocation. The third visit was to swap out the transformers with new ones from Toridiy of Poland, that was a major job as there wasn't really room on the chassis for them without serious modification. I machined a new sub plate for the transformers to cover all the holes in the chassis and even so, they barely fit.
On the upside, he really loves the amp and it's been working great.
Pic is of the amp basically done. Very shiny once the protective film was removed.