Electronic Industries Modified DYNACO ST 70

[ppereira]

Does anybody have any info (a schematic would be great) about this ST-70 Mod? I think that Electronic Industries later became Audio Research. That's all I have so far... Any help would be greatly appreciated

Thanks

[ppereira]

Some pictures:

[ppereira]

More:

[ppereira]

Another:

[ppereira]

Last:

[SY]

That's a rare bird you've got there. I don't know for sure, but I'm willing to bet that this is pretty much the same circuit that later appeared in Audio Amateur (William Johnson's ST-70 mod article) in the late '70s. Cross-coupled inverters are cool.

[ppereira]

SY, thanks for the feedback. Do you know where these old issues of Audio Amateur can be sourced from? AudioXpress only goes back to mid 80's...


Thanks again

[Brett]

Originally posted by ppereira
SY, thanks for the feedback. Do you know where these old issues of Audio Amateur can be sourced from? AudioXpress only goes back to mid 80's...


Thanks again

I'm pretty sure I have the schematic at least. Ping me with a PM and I'll scan and email it to you.

[ppereira]

Thank you Brett. I emailed you offline.

[The-Planet]

I remember the Dynaco article, and will try and locate it for you. I have all issues from the first 10-15 years of AA in storage here.

I believe the modification used 6L6GC's as the output tube however, and your pic's look like EL34's. You might want to check before I go digging!

The schematic for all of the vintage Dynaco tube gear is on my website at www.the-planet.org