ST 70 best sounding version?

I have heard, and owned, quite a few, and still have a couple in the closet. Rather than answer with a brand, I will suggest the areas that I feel bring the greatest benefits.

Although most concentrate on the front end, the basic Dyna front end, using 7199 or, with different wiring, 6GH8A is quite nice. Not that it cannot be bettered, by boards like the Tubes4hifi.

No I think the greatest weakness in the amp is the power supply, and would look for an upgraded power transformer, such as those made by Triode Labs and Dynakitparts, allied with increased, and lower esr capacitance, such as the Curcio board. IMHO, if you buy the best power supply that you can it will give the best result. And you can always play with input boards later.

One thing that I always do from the get go is strap the output tubes into triode, which is cheap as it only involves soldering in four resistors.

If you want something pre built the Latino ST70 and ST120 are great amps, with highly upgraded power supplies. The 120 should not be used with the 5AR4 tube rectifier, so I would stick to solid state rectification of the B+ voltage with that one:

http://bob01605.50webs.com

Best of luck with the hunt. I am sure that other members I’ll forward other, equally valid, perspectives.

I'm partial to Bob Latino's version but the only other one I've heard is the original and I'm going from memory there.

I have built a pair of Mark IIIs from the Triode Electronics kit and the power supply upgrades are nice but the chassis is more utilitarian than Bob's.

There's enough stuff out there you could build any kind of 70 you want.

I was searching for the link that rodman provided. I have not heard the new series 3, but it is selling for $1,500 when its price when it was introduced just a couple of years ago was $3,000, so it was obviously not too popular.

So bear in mind I have not heard it or any of the modded ones, but it is the one I would purchase. I do have the original ST70 with the desirable cloth lead transformers (I think that what they were referred to as), an original with the Japanese sourced transformers and a series 2 made by the Panor corporation. I just purchased another amp and will be putting these up for sale when I get around to it since I don’t need them all.

The latest issue of TAS has a review of a new version of the ST70. Looks pretty impressive! 

And I just let my TAS subscription expire, in November. I’d have enjoyed reading that review.