|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
38.118.25.194
In Reply to: RE: Dynaco ST-70 Iron posted by Eli Duttman on December 10, 2014 at 08:36:58
Hi Eli,
I think that you had mentioned in the past that the Triode Electronics Dynaco output transformers are also very high quality.
Dave
Follow Ups:
The Z565 is the best O/P of the Dyna bunch. As such, it is the "Gold Standard" for "El Cheapo" builds.
Dyna O/P "iron" tends to give good bang for the buck, but you look elsewhere for 1st class performance. Expect to pay MORE for that 1st class performance.
Eli D.
That is the SCA/ST-35 output transformer, although is lists a number of tubes it will work well with.
I have to ask ... What transformer would you consider to have 1st class performance?
Dave
McIntosh unity coupled, the Freed stuff in a "Deuce", the stuff in the Heath W6M ...
There are some fine winders currently working. They can make GOOD stuff too. The good stuff never comes cheap. You can't buy a Cadillac at a Chevrolet price. If you're careless, you can pay for a "Caddy" and get a "Chevy".
Eli D.
Vintage trannies are great, but expensive (as you say) and scarce. What do you consider the best of he modern output transformers. For example, Tamura has some very exotic cores. MagneQuest (Peerless) transformers look to be very good to me. Plitron toroidal transformers are interesting to. However, I have no hands on (or ears on) experience. I have just read that they are good.
Dave
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
Don't say Plitron a third time. Andre Jute will appear from thin air like Beetlejuice, to boast about how he designed this or that.
Hi Audiosoul, I know zip about transformers compared to Uncle Stu,Eli,and the rest but I dug out an article from Listener 2001 Sept/Oct on the Dynaco Stereo 70 by Peter Breuninger. Peter was asking about the lure of vintage hifi when every thing he learned from a bunch of fellow hifi nuts came down to transformers.He quoted Walt Bender,the founder of Audiomart,which if any one is too young to remember was the predecessor to Ebay for hifi crazies. Walt said this about transformers; Transformers take 3 to 6 months before they get to 80 percent but take over 40 years to gain the remaining 20 percent. Audiosoul, that ought to stir up Mikey,Stu,and Eli and sorry if I missed anyone else.......Mark Korda
I almost bought a pair of Mark VI's in the early 80's, but they did not have a reputation for sounding all that good, and I could not verify the condition. It sure was a cool looking amp. I wound up with a pair of Mark IV's. At the time I knew nothing about iron. I was just trying to get into tubes on the cheap. It probably would have been too big a project for me.
Dave
Dave, I did the same thing with a pair of Mark IIIs. I found two really beat ones for about $20 for the pair. I bet it took over 10 years before I decided to get them running. One was missing a PT. I did find an original Mark III PT but probably should have just bought a Triode Electronics PT or Allied.
My Fisher x101 suffered similar PT failure and I just used an Allied. It is too big if I want to add a case but it works great built in my TV hutch.
looking for some jazz and a little libations - joe strummer
KT-88/6550's in UL give some serious power!
Dave
Driver on the Mk VI sucked. IIRC they use a 6AN8 input for the four 8417s.. The amps were powerful but the power supply was pitiful.
The MkVI never really entered the consumer market as Dyna folded before actual distribution ever took place I remember seeing them sold as kits in the back pages of various magazines for many years. I have the feeling that Dyna had not really finished full development of the amp when they sold out.
That would have been Stereo Cost Cutters/Sound Values Inc. in Columbus OH. The bought the inventory when the last owner of Dynaco, ESS Inc., liquidated the assets.
Dave
Post a Followup:
FAQ |
Post a Message! |
Forgot Password? |
|
||||||||||||||
|
This post is made possible by the generous support of people like you and our sponsors: