Review and Measurements of Dynaco ST 70

[Jaimo]

I just built up a Bob Latino ST-70. I live in Seattle and wouldn't have to worry about shipping if Amirm would be interested in testing it. New here so not sure how that works.

@amirm - if you are up to testing a variation of the ST70, Westy is your man...The much lauded Bob Latino version introduces a modified driver circuit that supposedly improves the original ST70 performance.

I got it! Let the solder flow...But not too much!

I can’t think of a better way to spend a cold winters night...

 

[AndreaT]

That's a fabulous FR (the good channel) for a 60+ year old tube amp into 4 ohms IMO. Must be some really good OPT TXFs.

A bit of work on the filtering, regulation and tightening up the tolerances to bring the channel balance back into line and it'd be a fun project.

I have a Dynakit ST-35 with the original transformers. It has been in use (heavy use from 1967 until 1983, as it was the only power amp in the family home) for the past 54 years, with updated (x2) boards and tubes. Remarkable.

 

[RoyB]

Finished it. Love the sound with Magnapan MMGs or Klipsch RP

 

[SIY]

Finished it. Love the sound with Magnapan MMGs or Klipsch RP

That's a very pretty build! The meters are a delightful touch.

 

[RoyB]

Meters are DC 0-1v for bias adjustment. Replaced a Yamaha M45. This amp sounds do much better. Much more "mellow" without the strident highs the SS amp had in my listening room. Using a Schiit Saga preamp and Bluesound Node2i for source. Could not be more pleassed with my current system.

 

[Sal1950]

Finished it. Love the sound with Magnapan MMGs or Klipsch RP

Wow, what a great looking build, a major thumbs up.
What is the knob for, an input level control or something else?

 

[RoyB]

Yes, input level control. Thanks for the kind words.