I picked up a factory-wired Stereo 70 (along with a Fisher FM-50B tuner and a matching factory-wired Dynaco PAS-3) last summer from Craigslist for a too-good-to-pass-up price. I promptly flipped the Fisher and PAS-3 as I did not need them, but I did need the money to fund the restoration of the Stereo 70 (when factoring everything in, the amp and restoration was free and I still made about $150). The chassis, transformers, tube sockets, power tubes and rectifier were retained while the remaining parts were binned or (7199) sold. The power supply, bias and output circuits are more-or-less unchanged from stock (albeit with an 80/40/30/20 power supply cap, better X1/Y2 death caps, Ohmite wirewound power resistors and a CL-90 for slow turn-on and slight reduction in line voltage). The driver circuit was replaced with a DIYTube Stereo 70 circuit (it was pretty much a coin toss between this and the VTA board - if I ever get another Stereo 70, I'll try the VTA driver circuit). Coupling caps are Russian K40Y PIO and Orange Drops, while resistors are a mix of Kiwame and Takman carbon films. Phase splitter tubes are RCA black-plate 12AU7s and the driver tube is a triple-mica RCA 5751.
Oh, and my wife bought me a Triode PA060 power transformer for Christmas, but it hasn't arrived yet, so that'll be added shortly.
Here's how it arrived:
This is during smoke testing:
And here it is with a machined cover over the driver board and with a new set of Golden Lion KT77s:
I still would like to replace the front RCA jacks and figure out a better solution for the bias measurements than the existing front-mounted octal tubes. Perhaps something with three probe sockets on each side? However, for now, I'm happy with the results and it provides a good counterpoint to my Stereo 35.