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Is it possible/advisable to build a ST70 from scratch using the ST70 driver board? From what I can see in the manual it doesn’t look too difficult, although there a few questions I would have.

rrd,

That's exactly what I did. The amp works great. You can find some references to pictures of the amp I built in this forum. I'm very happy with mine. If I can help let me know.

Regards,

No reason it couldn't be done, though using an existing chassis definitely makes the job a lot easier... If I were to staart from scratch, I'd use a larger chassis, maybe 17X10X3, just to have more room to work with, as the original does get a bit crowded.

I have a similar project in development, though not strictly a true ST70.
This will use the ST70 driver board, parallel push-pull EL84s, separate power supplies for each channel power stage, and a third smaller PSU for the driver board. For output iron, it is currently a toss-up between some Tamura F2020s or a pair of Eric's "1773" OPTs.

With the all too brief NH summer, I have set aside any major build projects until the fall and long winter.

The power and output transformers and the choke can be found used on E-bay, or new-manufactured replacements are available from Ned at Triode Electronics, as is the SDS cap board - which is a good alternative to the four-section "can" capacitor.

/ed B in NH

Thanks Ed and Ed. I'll get together a few questions and post them. By the way sorry to hear about your summers, but you'll get no sympathy from me.....I'm in Syracuse, NY.

Syracuse, I've not been there, but my best friend from high school days went to college there, he said it was "winter and fourth of july" there...
Or as they say about Burlington VT, eleven months of winter and four weeks of bad sledding.

I'm working on a cure for NH winters, looking at buying a place down in western NC later this year.


/ed B in NH

I've got ONE only brand new reproduction ST70 chassis and a set of 3 brand new repro transformers (2 OPTs & 1 PWR) that are extras that I'd be willing to sell.
I was gonna put them on Ebay but just read these posts and figured I'd give someone here a shot at them first.
Best offer over $400 which includes shipping, that's how much I paid for them. The chassis is an EXACT repro, you can't tell it from stock except that it is brand new. All holes and silk-screening are identical to original.
I'll include a copy of the original Dyna ST70 manual.
Email me direct as I only visit here a few times a month. Photos upon request.
roymottram@yahoo.com