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Frankly, I never thought it was that good of an amp. Maybe 60 years ago it was a big deal.
"To Learn Who Rules Over You, Simply Find Out Who You Are Not Allowed to Criticize."
-Voltaire
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that the 70 in all it's variations and rebirths is still a winner of an amp.
65 years from now how many El34 based amps made today will your grand kids be posting arguments over?
n/t
Maybe I missed it somewhere, but what was the list price scheduled to be?
One of their bullet points on the new Dynaco amp says:"The original 5AR4 tube has been replaced by Solid-State rectifiers, thus removing the 5AR4's inherent losses and reduced regulation, while eliminating a failure-prone out-of-production tube in the process."
While a 5AR4's "inherent losses, reduced regulation, and prone to failure" are open to debate, the fact that they are still in production, from multiple sources, is not.
It sounds like TAS was simply publishing ad copy they were handed. You would imagine that any competent reviewers of tube audio equipment should be aware that the 5AR4 isn't "out of production".
Edit: Oops. It does say, "The following is a press release issued by Hafler-Dynaco" right at the beginning of the article.
Edits: 05/12/16
I think at the time of that press release ALL tubes were going out of production.
There was a non related posting over at the vintage forum about how McIntosh started offering a trade in program of their old old tube amps for new SS amps. They claimed the out of date tube amps no longer had replacement parts and tubes. So they offered a trade in.
makes you wonder what happened to all those McIntosh tube amps that did get traded in??????
"Vancouver, BC | May 9, 2016" so I'm not sure what you mean about tubes going out of production "at that time", since that was three days ago.
I have a New Sensor catalog in front of me from Fall 1995, and Sovtek was making a 5AR4/GZ34 as long as twenty-one years ago, and probably longer.
A single 5AR4 has always been over-taxed in a ST-70, as noted in David Gillespie's testing (link below), and building the amp with two, one for each channel, would have been a good idea.
Replacing it with solid-state rectification may be a good idea in many ways. But the press release, at least regarding the 5AR4 being out of production is misleading at best. After seeing Bob Latino's link to the lawsuit, it seems that that's the least of their problems.
that the company producing this item is unaware of parts availability for it and making bizarre design decisions based on - who know's what? I mean, they're making a tube amp but claiming that tubes are out or production?
Really?
Big J
"... only a very few individuals understand as yet that personal salvation is a contradiction in terms."
...Got their 7199 mixed up with their 5AR4.
The post I was referring too was about tube amps some where in the mid to late 60's. Not the present.
At THAT time I actually remember seeing tube stereos being chucked out in the thrash. My neighbor who was apparently an audio nut had died. His widow asked ME if I wanted any of this stuff. Of course being a stupid kid and not knowing what the future held I said no. The next day there was a pile of stereos, tubes and what not about four feet high and four feet wide. I'm sure that pile could have paid for my house AND car at today's market values.
Another nice version was done by William Johnson of Audio Research. It was in the issue 4 1977 of the Audio Amateur. It was a complete remake, using only the chassis and transformers, and was very similar in topology to the D76. By what I remember, it was a very good sounding variation.
Like Nelson Pass has done with First Watt, he built them himself. :)
I still have the Audio Amateur magazines. I dont think this article is available anywhere anymore, so if anyone is interested in the Audio Research version, e mail me and I can send a pdf of it.
Many amps had come and gone in my system, but my ST-70 stays reliable and sweet sounding. Mine uses E88CC as driver tube (I have Amperex) and of course the Mullards (fx2 with double OO getters).
I had a number of the Cursio mod kits. The standard upgrades were quite nice from what I remember. However I compulsively when on to the premium upgrade. You know when you step over the line - it just sucked all the "niceness" out of the amp. After that I sound that ST-70 off.
With an EF86 and 12AU7 driving PP EL34's, it sounds more like a variation on the Mullard circuit.
Dave
Each channel uses one EF-86 and one-half of a 12AU7 so it's not a Mullard. I would bet serious money the circuit is basically the same as the old Triode Electronics board for the ST70. That board used the same tube complement and is essentially the same topology as the stock Dyna design but implemented with separate tubes. Dyna's 7199 combines a pentode (similar to EF-86) and triode (similar to 12AU7) in a single tube. The Triode Electronics board uses a separate pentode for each channel but the dual-triode 12AU7 is shared by the two channels. The second stage in each case is a split-load phase inverter, not a Millard.
I see. Thanks for the correction!
Dave
I happen to really like the EF-86/12AU7 circuit. It allows the potential of Dyna's topology to be realized without concern for out-of-spec 7199 tubes. Frankly I think the ST70 doesn't get the respect it deserves. Properly implemented with the EF86/12AU7 and carefully selected parts, the ST70 is capable of high quality sound by any standard. Most people have never heard it under these conditions though.
I have had one in my fathers house and mine for over 50 years. My fathers drove Bozac speakers in a basement system. The one I have now is an original with the Tubes 4 HiFi board. It blows away other new tube amps I had with double the power and the bass is much higher in quality too.
Had one New. Eventually Spent large on a Full Upgrade.
Had to Farty bass constrained highs... finally wore me down
Subsequently my Brothers' then new NAD made it sound like a Kid's toy.
Nostalgia is IMO 99% Selective (faulty?) memory.
Some things are best left as Dim memories.
As mentioned about a thousand times before - The new production 70's are NOT the same as the original. Having had both they don't even sound similar!
The newer versions tweaked out a few dozen typical vintage shortcomings as well as what you call "the farty bass".
Yes the original was jokingly called the poor mans McIntosh. But again as mentioned a thousand times, almost every builder cut their teeth on the 70 and many builder - and yes even companies still use it as a basic design platform.
The modern versions 70 can not only compete with the Mac but in many ways surpass it.
Charles - Proud owner of a VTA ST-70!!!!
+1. My Latino ST 70 (with the modest cap upgrade package) quickly dispatched a very decent CJ MV75A1 with Thalman mods. Once you settle on a solid combination of tubes that fit your ear, this amp is a real sleeper. FWIW, the new Gold Lion KT88 still remains my output tube of choice in this amp. And yes, I've tried the GL KT66 as well.
I have the GL KT66's - and wow is that one incredible sound combo. I really don't have a desire to change. But heck - why not have some fun while I'm here!
How would you describe the difference (I understand that isn't an easy thing to do) between the GL 66's and 88's?
Charles
Both the KT66 and KT88 are excellent, don't get me wrong. It's simply a matter of which one sounds best in a particular system. To my ear, the 88 has a warmer, richer presentation. The Salk Songtowers I'm currently using benefit from this. Now if a speaker was more on the warm side to begin with, the 66 might indeed be the better fit.
We'll see how it does against the Line Magnetic 211IA. Incidentally - Line Magnetic is closely connected to Cayin the latter of which you seem to like. The LM 211IA at $1500 is pretty difficult to beat. I have only heard a fixed up ST70 and the only reason I can see for its success was that it was cheap.
Edits: 05/10/16
Importer - tone imports. No phone number on their webpage. They say 'email to contact us' then don't reply to emails.
"To Learn Who Rules Over You, Simply Find Out Who You Are Not Allowed to Criticize."
-Voltaire
I still have one with a redesigned driver board and capacitor board I modified it with plus new components/parts. It is as good and in many cases better than anything else in its class.
Radial Engineering, as of 4/15/16 is being sued by Panor Corporation who AFAIK does legally own the rights to the "Dynaco" trade name. If Radial loses the law suit, their "Dynaco ST-70 Series III" will not see the light of day. See law suit link below.
Bob Latino
I'm always interested in these lawsuit deals.
Whatever happened with the Jolida/Jolida suit? I'm thinking the Chinese Jolida (the original) went broke.
"To Learn Who Rules Over You, Simply Find Out Who You Are Not Allowed to Criticize."
-Voltaire
Bob, it's nice to see you lurking about here.
I am STILL blown away at your amp kit!!!!!!
Again thank you for your expertise and kind patience.
charles
> > Frankly, I never thought it was that good of an amp. Maybe 60 years ago it was a big deal.
It was sure a hell of a lot better than the majority of the nasty transistor stuff that followed in the 60s and 70s!
I've rebuilt a number of Dynacos, though no longer have one. The biggest deficiency of the original was the power transformer -- just didn't quite have enough for the job, which hurt the bass a little. Upgraded transformers are available that substantially help with this issue.
The kit available from VTA addresses those very issues, amount a number of others.
In short - the VTA kit it is a TOP shelf of EL34 based tube amplifiers. Not much different from (perhaps even better than) the others that sell for literally thousands!!!!
Given the cost, especially if you bought the kit which was simple to build, the original Stereo 70 was an excellent amp in its day, just a bit behind the Macs and Marantzes. It was both an excellent amp and a super buy. I built one. You had to be there.
And historically it's even more important, perhaps the most important amp in the road to today's high end. It was available to so amny. And most of the great designers cut their teeth on a Stereo 70 some time during their learning curve.
my younger son still happily uses it, somewhat tarted up courtesy Bob Latino.
Jeremy
The newer version produced by VTA in kit form is NOT your fathers Dynaco ST70.
I've had a few of the original 70's and modded them. And the new VTA is NOT the old ST-70 but a VERY hard act to beat!!!!
Try one before you do an independent review without actually hearing one.
charles
I've rebuilt two vintage ST-70's using the VTA kits. An all new amp nothing like the old ST-70 much better in every way.
I had one back in the 1970's. A guy in Salem Oregon did some mods to the front end for me which picked up sonic performance to another level. It was a nice, reliable amp. One of the few I wish I had not sold.
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