Alternatives to the Dynaco ST-70

[percy]

Are there any good alternatives to the over-priced ST-70 ?
What other amps besides the Dynaco ST-70 had decent OPTs ? (and sell for half that price?! those st-70s are going for like $300+ easy, $400 on a good..er..bad day)

There were many in that era - Eico, Philco, Knight, RCA, etc... there's got to something else out there...monoblocks, integrated,..anything.. that could make a good worthwhile project.

[jackinnj]

Pilot, Heath and Eico come to mind ... and don't forget that there are much better xfmrs available today and a plethora of great designs...wanna buy my ST-70?

When I first rebuilt an ST-70 you could buy one for $35 at Audio Exchange in lower Manhattan -- at these prices they are a better sale than purchase. I also found one in a dumpster in NYC.

[SY]

Personal experience with Eico, Scott, Fisher, Fairchild, and Heath has been mostly positive. Sadly, these have become trophies themselves...

I'm in agreement with Jack- in 1985, it was a really good idea to rebuild an old Dyna. In 2007, I'd just buy new iron.

[audiosteve]

I can't agree with the previous posters. IMHO the Dynacos have very good iron and are still a bargain even if going as high as $300. Where else can you get a decent tube amp for $300.00? If you then add another $150.00 to $200.00 to update the driver board and hardware you then have a great little amp for $500.00 or less. I think you would still be hard pressed to find a contemporary amp of like quality at this price. Not to mention the added benefit of owning a legendary classic that will continue to hold its value or appreciate. My modded Stereo 70 has cost me a total of about $350, sounds great and won't be losing any value any time soon.

[Original Burnedfingers]

Are there any good alternatives to the over-priced ST-70 ?

There are a lot of good organ amplifiers out there that can be bought cheap. Wurlitzer made a 6SN7/6L6GT PP amp mono block that will blow away the Stereo 70.

I had a Dynaco stereo 70 and modded the heck out of it. I consider the transformers to be ok but nothing to write home about. Actually I consider a good set of Hammond transformers to be better than the stereo 70 transformers. I also don't consider the bass to be anything special. Its there but then again nothing special.

[SY]

IMHO the Dynacos have very good iron and are still a bargain even if going as high as $300. Where else can you get a decent tube amp for $300.00?

An ST-70 transformer bundle from Dynaclone, including power, output, and choke, is under $300. For that, you get transformers that are new, have cores which haven't deteriorated, wires with known good insulation (the cotton of the original Dynas is often brittle and uncertain) and have better performance and run cooler than original. For the restoration of an original, you need to replace driver, sockets, switches, and terminals anyway- the only cost adder for new is a chassis, and the old steel one is not particularly great and will generally need refinishing.

I'll put my money where my mouth is- I still have an old ST-70 here which I will trade to anyone in exchange for a new set of transformers.

[kstagger]

The price of all vintage tube equipment has risen considerably... I saw a pair of 3W SE 6BQ5 amps made by 'Voice of Music' go for over $225 on Ebay.

back in 'the day' - a ST70 would go for $80-$120 depending on condition and tubes. I sold a rebuilt/modified '70 a few weeks ago for over $300.

The best bet it to buy singles of mono amps... it takes some patience but a few years ago I got a pair of Heath UA-1 amplifiers that way. Or consider just building from scratch on a bud-box. You could knock together an amplifier pretty cheap with some careful parts selection.

[jackinnj]

Funny about the "Voice of Music" amplifier -- you can buy a pair of VM players with amplifiers for about $30 at most Goodwill stores. In fact, I gave one to my younger sister as a wedding present -- when we were kids she was a most avid listener of the Disney records (in the 1950's).

[kevinkr]

Originally posted by SY


An ST-70 transformer bundle from Dynaclone, including power, output, and choke, is under $300. For that, you get transformers that are new, have cores which haven't deteriorated, wires with known good insulation (the cotton of the original Dynas is often brittle and uncertain) and have better performance and run cooler than original. For the restoration of an original, you need to replace driver, sockets, switches, and terminals anyway- the only cost adder for new is a chassis, and the old steel one is not particularly great and will generally need refinishing.

I'll put my money where my mouth is- I still have an old ST-70 here which I will trade to anyone in exchange for a new set of transformers.

I'm pretty much with SY on this one, modern transformers and a Hammond chassis are probably the way to go. I sold a lot of upgrade kits for the ST-70 in the past, and thought at the time that the ST-70 offered a heck of a lot of value, but times have changed and it's not such a great deal any longer. Having grown up in the 1960/70's I find the revered status of the ST-70 a little puzzling, at the time the ST-70 was just about the least expensive option for a 70W stereo basic amplifier on the market, and all the rabid marketing claims by Dynaco aside there were (and are) far better sounding amplifiers out there. (Heathkit, Eico, and Scott Kit all offered amplifier kits that outclassed anything Dyna had to offer, and these even at significantly higher prices today might represent better value in the long term as they're not as quickly outgrown.) In automotive terms the ST-70 would be a ford falcon or chevy nova - very nice basic cars that got the job done, but didn't offer the performance or excitement of a Mustang, GTO or Charger.. (FWIW I like my Acura better than any of the classics mentioned.. )

On a more serious note lots of people around here have designed great sounding PP amplifiers (search) and there are reasonable priced opts from Edcor, Hammond, and Electra-Print in addition to those mentioned that could form the heart of a new amplifier with great performance.

[jackinnj]

Originally posted by kevinkr


In automotive terms the ST-70 would be a ford falcon or chevy nova - very nice basic cars that got the job done, but didn't offer the performance or excitement of a Mustang, GTO or Charger..

Mustang was built on a Falcon chassis.

The GTO was built on the LeMans chassis (at least the first ones were.)

And there was a Chevy Nova SS396 if you recall. (one of my high school buddies had his supercharged! )

This being said, I agree completely.