Dynaco ST-120 & ST-70

[Shub]

Any feedback on these amp kits??



I'm new to both ML world and have ZERO experience with tube amps - so please don't flame me

I am very good with soldering and electrical work so the "kit" aspect doesn't faze me -0- just seems to cheap to be true/good....

any advice would be great..........

 

[aliveatfive]

The Dyna St70 probably will not be able to drive an electrostatic. I just completed building the mod that you describe and I will say that it's one really good amp, but a low powered amp at that. I use that amp to drive a pair of new Strling Broadcast LS3/5a's that I really like. This is a second system that I use in a living room. The preamp is a "Grounded Grid" Trancesdence kit. Believe it or not, I find this system exremely listenable - not the total equivalent of my Summits driven by ARC compnents, but pretty damn good, nevertheless. To summarize, the ST70 is a really good amp, but I would not use it on my MLs.

 

[Bernard]

To summarize, the ST70 is a really good amp, but I would not use it on my MLs.

I definitely agree with that.

 

[tonepub]

Me too...

Now if you had a pair of original Quads you'd be pretty happy
with a ST-70.

Plus if you are new to this, the assembly of an ST70 might be
more than you want to mess with.

 

[hotroady]

I have a Van Alstine Ultimate 70. Drives my mildly modded Claities just fine, with the exception of damping factor. Very nice mid range, fairly extended highs. Gets bloomy w slight boom w stock Clarity. I only play at moderate level at night..it's pretty much the min wattage tube amp. Have to look into the Dynaco ST-120 to see what they are all about.

 

[jtwrace]

I have a Van Alstine Ultimate 70. Drives my mildly modded Claities just fine, with the exception of damping factor. Very nice mid range, fairly extended highs. Gets bloomy w slight boom w stock Clarity. I only play at moderate level at night..it's pretty much the min wattage tube amp. Have to look into the Dynaco ST-120 to see what they are all about.

http://dynakitparts.com/store/catalog.aspx?cid=1

 

[hotroady]

The 120 would have enough power. The upgraded power supply would be needed, as they are marginal on a ST 70. Two chokes good. I haven't had a chance to do a shoot out with all Dyna 70 types out there, I'm keeping my U70. Also have AVA Pat 5 and stock FM-3. Very high bang for buck, vintage line. Well regarded.

 

[khenegar]

st70/120

why don't use use the st70 on the panel's and the st120 on the bottom end, the st70 just might do the job. good listening.

 

[Shub]

Q

What about this for an idea -

I am currently using an Adcom GFA-545 for the Vista's -

What if I used the ST-70 to power the panels and the Adcom for the bottom end?? or even the ST-120 for panels etc..??


Quality wise - anybody think doing a kit like this is a bad idea???

 

[Speedskater]

One thing to remember about buying Dynakits sight unseen is that they started making these kits almost 50 years ago. Some are total junk and many need some work. Just saw a rebuild project on another forum, drop dead gorgeous! So don't buy with-out checking the unit.

 

[aliveatfive]

Two things:
1. I'd still be very skeptical about trying to drive ML stat panels with a Dyna ST 70. (If you must, audition first before buying.)

2. Brand new ST70s can be purchased from several sources. (One is Dynakitparts.com) My totally modified ST 70 was constructed out of all brand-new parts.

 

[hotroady]

One thing to remember about buying Dynakits sight unseen is that they started making these kits almost 50 years ago. Some are total junk and many need some work. Just saw a rebuild project on another forum, drop dead gorgeous! So don't buy with-out checking the unit.

Dynaco is the Original kit..Dynakit is not Dynaco. There is so much info out there for DIY's and the ST-70's. Yes, a 'ST-120' would be better for power, the ST-70 would be the min. required, but marginal.

 

[DonAudio]

Ran a pair of ST-70's for years. Once modded they sound very respectable. Power supply must be solid state (full wave rectifier bridge I believe), replace all resistors and caps with high grade components throughout. I know there were reasons for looking for cloth lead trannies but the reason escapes me. I believe the trannies were made by Hammond Manufacturing; that might be the reason. I bridged these for mono and had gobs of power to run my Maggies back then.

 

[aliveatfive]

Ran a pair of ST-70's for years. Once modded they sound very respectable. Power supply must be solid state (full wave rectifier bridge I believe), replace all resistors and caps with high grade components throughout. I know there were reasons for looking for cloth lead trannies but the reason escapes me. I believe the trannies were made by Hammond Manufacturing; that might be the reason. I bridged these for mono and had gobs of power to run my Maggies back then.

Cloth leads were made by Dynaco. Plastic-covered were made in Japan for Dyna (or not by Dyna as replacements.) According to some there are sonic differences. I have a pair of both and will report on differences if anyone is interested.

 

[Speedskater]

Dynaco is the Original kit..Dynakit is not Dynaco. There is so much info out there for DIY's and the ST-70's. Yes, a 'ST-120' would be better for power, the ST-70 would be the min. required, but marginal.

Not quite sure what you're trying to say but my old PAS-2 Pre-amp kit that I built in maybe 1962 or 1963 was a "dynakit" made by the Dyna Company. (Don't know if I can find the assembly manuals for the amp. an FM tuner.)

 

[DonAudio]

It was the Dynaco 400 that used a Hammond power transformer. Crossed wires.

 

[hotroady]

Not quite sure what you're trying to say but my old PAS-2 Pre-amp kit that I built in maybe 1962 or 1963 was a "dynakit" made by the Dyna Company. (Don't know if I can find the assembly manuals for the amp. an FM tuner.)

Yeah, this gets confusing..look at post #6 link..it says dynakit. They make replica parts of original Dynaco/Panor corp. The original Dynaco had "Dynakit Stereo 70" badge on it. The company I am referring to, is trading in on the original manufacturer's name. I read something, somewhere....Frank Van Alstine mentioned some certain vendors do indeed have some good trannys and power supply..try audio circles or ava(audio by van alstine) sites. Dynaco Doctor site is interesting.

 

[hotroady]

Cloth leads were made by Dynaco. Plastic-covered were made in Japan for Dyna (or not by Dyna as replacements.) According to some there are sonic differences. I have a pair of both and will report on differences if anyone is interested.

Yes, do! I have a set of cloth lead opt's from a rebuilder, and wonder if it would worth it to swap into my U70, that has vinyl lead. I to heard bandwith goes to 30khz w cloth leads. Can you hear a difference?

 

[hotroady]

Here's an ongoing U70 build. :rocker: http://www.audiocircle.com/circles/index.php?topic=59784.0