Dynaco stereo 400 amp

doggie750

Hi polks.... any thought on this? Should I pull the trigger? The amp has faulty lefty, likely a known bad soldering with this amp. It’s a $300 used unit, might bring it down to half. Any 2cents is appreciated. Cheers

pumpkinman

I bought a basket case for fifty bucks and had it recapped. New front fuse holders.
Maybe it’s me but $300 sounds like a little to much.

F1nut

Buy something that you know works.

mhardy6647

They -- require a fair amount of TLC to be brought to a functional state. At that, I am not sure how reliable/robust they could be, even after investing a fair amount of time, money and/or effort into one.

I've got one sitting in the basement. I have plenty of spare time -- and I still don't have the inclination to look into it in any way, shape or form.

lightman1

Hardy runs the corner to chase the lob! Aaand gives an underhanded slapback to his opponent!
Brilliant strategy!

mhardy6647

The 400 was, in a very literal way, the progenitor of the Ampzilla

I think if one were looking for a vintage 200 watt soiled solid state amplifier, the 416 would be a better choice than the 400. The 400's pretty crude.
Unfortunately, none of the Dynaco solid stuff was very good, either in terms of design, robustness or sonics.

The GAS stuff (Bongiorno started at Dynaco and did indeed work on the 400) was persnickety but much, much better.


PS the one I have was given to me. I think it was guaranteed to hold a door propped open in a gale if it were so employed.

BlueFox

Interesting. I always thought Dynaco kits produced good gear. Depending on who puts it together.

mhardy6647

The vacuum tube stuff was pretty good, and some was great (ST-35). The solid state stuff's all pretty dismal.

There's a PAT-4 and an ST-120 sittin' not too far from me as I type this - and that's about as good as they're (ever) going to sound (i.e, unplugged and disconnected).

The PAT-5 was a little better.
Frank van Alstine made a career out of improving the Dynacos (ss in particular).

BlueFox

Oh well. I guess if I ever retire, and bring the soldering iron out of retirement, then it will be building Pass amps.

mhardy6647

The ss FM-5 and AF-6 tuners aren't bad, in fairness.

DSC_9819 by Mark Hardy, on Flickr

(top to bottom: PAT-4, SCA-35, AF-6. The SCA-35 is a pretty good sounding, if crude, PP EL84 integrated amplifier with a minimalist preamp section)

I actually used the SCA-35, on and off, for a while while we had two houses.

DSC_6212 by Mark Hardy, on Flickr

doggie750

Thanks for all your inputs, all well taken. I let the Dynaco pass by.

mhardy6647

FWIW, I think I'd recommend staying away from pretty much all of the high-powered vintage ss amplifiers. By and large, they weren't renowned for their reliability or ruggedness when they were new -- and the passage of 40 years hasn't been kind to their guts. Add to that the challenge of sourcing new (or NOS) driver and power output semiconductors for most of 'em (counterfeits abound) and it just seems like a poor risk to me. Plus, most of those amps didn't sound that great to start with.

One exception might be the venerable Crown DC-300 (150 wpc, I guess). Those don't sound great, either, but were known as pretty rugged, at least 3 or 4 decades ago!

One other brand whose high-powered amplifiers aren't that familiar to me is (was) SAE. In other words, I cannot extend my blanket statement above to SAE, although I suspect it would be true of their big amps, too, I just don't know them well enough. They just weren't popular where and when I came along.

"Modern" high-power amps are probably a much better investment if one wants to have behemoth amplifiers.

OK, I'm off my soapbox now!

mhardy6647

I just happened to notice that there's an ST-400 restoration thread @ AK:
http://audiokarma.org/forums/index.php?threads/lets-restore-a-dynaco-st-400.735401/

Strictly FYI and FWIW.