Vintage Asylum Classic gear from yesteryear; vintage audio standing the test of time.

---

[ Follow Ups ] [ Post Followup ] Thread: [ Display  All  Email ] [ Vintage Asylum ]

---

[ Alert Moderator ]

---

RE: Dynaco ST-70 Iron

Posted by unclestu (D) on December 10, 2014 at 22:06:13

In Reply to: RE: Dynaco ST-70 Iron posted by Eli Duttman on December 10, 2014 at 20:59:50:

The funny thing is Dyna OTs were never designed to be SOTA. The ultraliner design patented by Halfer and Keroes were all intended to be used in a cheaper build construction to make audio accessible more consumers. Prior to the ultralinear ( I know you now this, but others may not), OT were fixed screen grid designs and required or at least were often employed with regulator tubes for the G2 voltage, much more complex circuit.

Those non ULT were typically available by builders like the famed Peerless 20/20 output trannies, which I much prefer over any ultralinear design (although you can simply not use ultralinear taps). Hard to source the big stuff used in the big theater amps, though.

Hafler, IIRC, was still not satisfied with the sales of his UL OT and set up Dynaco to really pump out the transformers (IIRC Acrosound was the original company that H and K set up). He was damned successful since it is estimated that 500,000 ST-70s were made over the years.

While not designed to be top tier, Dyna stuff is considered petty decent by today's standards. I forget their designations, but if you were referring to the trannies in their 6BQ5 models, those were very sweet, probably the best sounding that Dyna (Acro) made.

I do have a pair of Dyna A-441, 25 pound OT with tertiary windings , that are supposed to sound very good. IIRC, The early Carver 200 watter used a pair in parallel per channel to build a tube amp which HP of TAS simply loved. When Victor Goldstein persuaded Carver to put it into production, you couldn't find enough of these older transformers (Dyna Mk VI). Word on the street that the production models never sound as good as the original with original Dyna Iron.

Incidentally I got the iron from a guy who claimed that he used them to build amps for the DEAD. He got so nostalgic praising them he refused to sell a pair of the ten he had and instead directed me to a friend whom he sold a pair to several years prior and had done nothing with them. Luckily he did sell although I confess to sitting on the OT for past decade myself

This post is made possible by the generous support of people like you and our sponsors:

Amplified Parts

---

[ Top of Page ] [ Contact Us ] [ Support/Wish List ] [ Copyright © 2024, Audio Asylum, all rights reserved ]

---

[ General ] [ Speakers ] [ Tubes ] [ Vinyl ] [ Digital ] [ Hi-Rez ] [ Video Asylum ] [ Cables ] [ Tweaks/DIY ] [ Music ] [ Films ]

---