Dynaco Stereo Amplifier

xjghost

Ok this has been in my closet for a couple of years now. Same friend that gave me the Hafler 500 gave me this. I don't know much about this company other then what I read on Wikipedia. Apparently it was David Hafler's first company or partnership. Trying to id this amp:



It might be a ST-150 but there are a couple different pictures of them and one shows VU meters on the front which this one obviously does not have. Any idea? I did not see any Id numbers on first glance at lunch when I pulled it out. I plugged it in and it powers on. I was going to plug it in to a pre-amp I recently acquired and test it with the monitor 10's in my bedroom. Any suggestions or words of wisdom?

Looked here but did not see it: http://home.indy.net/~gregdunn/dynaco/index.html

Dennis Gardner

I think you identified it properly. It looks like an ST-150 with meters deleted. Lots of info around about the tube gear and kits from Dynaco, but there isn't much love for their solid state gear. It didn't lend itself to as much experimentation as the tube stuff did.

xjghost

Opened it up to clean it some. This thing was in an attic when I got it and it's been in my closset for the last couple years.









To me the best part of this was finding my friends dad's signature and date inside it.



Got this on flea-bay for $49.95



Glad to say both work and work well together. I was really impressed with how the monitor 10's sounded. I think I have found my bedroom system replacement. Now to find a remote that will run the Carver.

mhardy6647

Unfortunately, most of the Dynaco ss amplifiers are -- shall we say -- sonically undistinguished. Some of them also were sort of metastable (at best); Gary Kaufman, who owned an ST-120 in his student days, likes to say that the ST-120's clever design employed the output transistors as fuses, so he always kept a supply of the transistors on hand! :-)

This particular amplifier (i.e., the titular amp), I don't know - it could be much better than the early ST-80/ST-120.

It is worth noting that there's (still!) an immense cottage industry of upgrades and mods for the ss Dynaco components (just as there is for the vacuum tube Dynacos); they are a great platform for improvement (sort of like the classic Klipsch loudspeakers).

It's also worth noting that the ST-400 and its kin were actually pretty nice ss amplifiers for their time. I have an ST-400 doorstop in the basement someplace (not entirely coincidentally).

The single best resource for Dynaco information (which, unfortunately, is incomplete and AFAIK no longer updated) is
http://home.indy.net/~gregdunn/dynaco/

There are tons of other interesting sites, though.

Here're a couple of gratuitous, roughly contemporary catalog (LRE) scans:

Scan_Pic0043 by mhardy6647, on Flickr
Scan_Pic0049 by mhardy6647, on Flickr

xjghost

So I have been running my bedroom system with this amp for a couple weeks now. Very pleased with it on the Monitor 10's. The Carver CT-24 does what I want it to do. Tunes in the radio and plays my iPod through a Sherwood dock very well. I have lost my dock to my son now however. I noticed last night at very low volume the output doesn't seem balanced. Amp or pre-amp? I have a Parasound HCA 800II I found on eBay for $100 to my door that will be here next week. I figure between it and the NAD pre I can figure out which one is the issue. My bet is this old amp.

mhardy6647

My opinion: most likely (Occam's Razor and all that) explanation is poor tracking of the volume control on the preamp -- try a different preamp with the power amp or vice versa to isolate the problem.