diytube.com

A company named, Radial Engineering Ltd. - which owns the Dynaco name, is releasing a new version of the ST-70 - for ~$2,500 a pop. The major, non-cosmetic design changes appear to be that an EF86 has been substituted for the 7199, and the 5AR4 has been eliminated in favor of an SS rectifier.

http://www.enjoythemusic.com/HIGH_END_2016/Dynaco/

Glad to see this change:

"Also changed out is the troublesome selenium rectifier used in the bias circuitry, which has also been replaced by a solid-state rectifier with additional supply capacitance."

Enjoythemusic.com might need to maybe invest in a spell checker. It looks like a high schooler tapped it out on her phone, like I'm doing now.
As for the series or mk3 (they call it both), it looks like improvements from 1990 rather than 2016, or maybe something I would do. I would still rather get a vintage ST70. I like the smell of vintage.

you don't get "Centre Kooled" with no stinking silicon diodes !

And, selenium rectifiers released such a lovely (toxic) aroma when they failed

There is a lawsuit pending against Radial Engineering for copyright infringement for calling their amp a "dynaco."

More dope on the new ST-70. The power supply is supposed to have been beefed up, and the outputs are an updated version of the original design. Radial Engineering - by all accounts - thinks it owns the dynaco name. "The Hafler brand was purchased by Canadian based Radial Engineering Ltd. in 2014."

http://www.cepro.com/article/radial_eng ... eries_3_am

https://en.wikipedia.org/wiki/David_Hafler

They're not far from me and I know the people there.

Let's just say we do NOT get along.

Most people that that are of a certain age and that admire the original Dynaco ST-70, already have one. I wouldn't be tempted to buy this $2,500 highly modified "clone."

I wonder about replacing the 5AR4 rectifier with a solid-state plate supply. I'm concerned that the immediate, instantaneous ramp-up of B+ might cause wear and tear on the other tubes? For my ST-70, I have a Mullard made-in-England (G.E. branded) 5AR4, which should last indefinitely (unlike JJs or Chinese versions).

The new Radial offering has tone controls, which might appeal to millennials, but are considered by many old-timers as anathema.

Also, the A.C. power and the speaker connections are on the same (back) side - the original ST-70 separated them to reduce hum.

I'd still take a DIYTube driver board build, or a Latino full amplifier over the Radial Engineering version. More amp for less bucks.

-D

I have a ST70, made from a kit, which is a duplicate of the original - same tube lineup, same chassis arrangement, and with a duplicate of the original ckt board. I like it a lot, and don't want to ever modify it. Nor am I tempted to buy the Radial - which is not really a ST70 clone, at all. I have three other nice tube-type amps, probably superior in some respects, to my ST70. But my ST70 would be the last to go.

Radial should design a start-from-scratch amp. They would save legal fees.

dcriner wrote:Radial should design a start-from-scratch amp. They would save legal fees.

And it would show some originality.