What's what in Dynaco gear?

[-=Rudy=-]

Did the Dynaco model numbers tell whether the gear was tubed or solid state? I'm finding things like a PAS3, Stereo 70, Stereo 120, etc., but in some descriptions, it doesn't indicate which is tubed or solid state. It's more out of curiosity. Is there a good website dedicated to Dynaco gear? TIA.

[Clay]

here is one of my favorites - there are a bunch
http://www.enter.net/~cae/

[jeff e.]

There's actually not much in the model numbers to give an indication of whether they are tubed or solid state. However, here is what I can tell you...

Every Dynaco PAS preamp is tubed--the later transistor models had the "PAT" designation. (On the other hand, a PAM is an early mono-only preamp.)

AFAIK, the ST-35 and ST-70 were the only tubed power amps. The number indicates the total wattage on these models, e.g. a ST-70 is 35 wpc. All of the higher numbers, such as 120 or 400, are solid state.

There was also a SCA-35 tubed integrated amp.

Hope this helps.

[-=Rudy=-]

Jeff--that does help. I was almost figuring out the PAS/PAT designation. But it didn't seem right that an ST-120 would be tubed in so small of a case...makes sense it's transistors.

Didn't David Hafler design some of those Dynaco models way back then?

[indy mike]

Ahhhh, Dyna chat! Try this site out iffen you wanna learn about Mr. Hafler's fine work: http://home.indy.net/~gregdunn/dynaco/

[-=Rudy=-]

Mikesters: that's a good 'un! Or a bad 'un...since I'm now lusting after some Dynaco gear after drooling uncontrollably at some of those pictures online... ;)

[Clay]

Great Dynaco Site. Thanks for the link Mike
IMO the PAS with a ST70 have a "easy to listen to" sound. My PAS has a bit of a hum so it is OOC at the moment. Joe Curcio is in my neighborhood, so if I decline learning how to fix it myself, that is my best bet.

[-=Rudy=-]

I've found a PAS3/ST120 pair for $300 online. I'm not really in the market, but I don't know if the "early transistor" sound of the ST120 is what I'd be interested in. (Could always resell the ST120, I guess.) I'd almost rather get a Hafler DH220 or DH500 if I were going to go solid state. (I've wanted a DH500 for years, BTW. ;) ) But that PAS3 does look nice. Don't know if it's an "X" version or not (whatever the difference is).

[Joel Cairo]

Rudy:

In the "X" version of the PAS preamps, the tone (treble/bass) controls are taken out of the audio circuit when they're at the "flat" position.

I just picked up a PAS-3X for my system, with a beefed-up capacitor section... should be a nice improvement, but I have to pick up some Telefunken 12AX7's for it... :)

-Kevin

[-=Rudy=-]

Kevin--thanks! :) That'll be one Telefunkin' PAS when you get it retubed! :D

Are the capacitor mods in the power supply section? I've considered doing that to my older Hafler DH101. I've actually gone through capacitor failures in the power supply section. The voltages are well below the ratings on the capacitors, but they've wigged out on me a couple of times over the past 20 years.

[Joel Cairo]

Rudy:

Yeah, mostly a higher-rated filter can, but you can see for yourself, if you're curious... here's the link:

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3066176743

(...you can "supersize" the pics, if you like...)

As you can see from the BIN price, I definitely paid for it, but it's remarkably clean inside and out, and I've purchased from the seller previously, so I don't have much question about reliability... I suppose if I get ambitious (or experimental), I'll finish updating the other caps, but frankly, assuming it works fine, this is about as modded as I need it to be... I think. ;)

But I can tell you with certainty that my girlfriend just **raves** about the stock PAS-2 and ST-70 combo that I gave her for Christmas!! :D

-Kevin

[indy mike]

The ST-120 is notoriously harsh and transistory - off to Frank Van Alstine if you wanna make it listenable: http://www.avahifi.com/root/about/greeting.htm

[-=Rudy=-]

Originally posted by Joel Cairo
Rudy:

Yeah, mostly a higher-rated filter can, but you can see for yourself, if you're curious... here's the link:

........

But I can tell you with certainty that my girlfriend just **raves** about the stock PAS-2 and ST-70 combo that I gave her for Christmas!! :D

-Kevin

I'm resisting the temptation to be your next girlfriend if you'd give me a PAS-3X and ST-70 next Christmas! ;)

That PAS-3X is a beaut though... :eek: Very nice. I don't think you paid too badly over blue book though, since it was updated. If I could buy quality parts somewhere, I could do a lot of that updating myself. No stranger to the soldering iron here. :) If I end up finding one of these, I just don't want to end up with a noisy, hummy unit that's in need of a complete overhaul to make it listenable. Just a fear I have with older tubed equipment. (Might be time to hunt down a cheap used oscilloscope.)

If I were 30 years younger, I would gladly have built some Dynaco kits. Sad that nobody still does anything like this. I built my Hafler, but with Hafler's kits the main circuit boards were already assembled. The fun part was already finished. ;)

Mike: agreed about the transistory sound. I'd rather stick with one of the tubed units...a pair of those monoblocks would be cool, if pricey. ;)

[indy mike]

Frankie V. is well regarded for his Dynaco/Hafler work (basically, all stock circuitry is dumped and the chassis, transformer and mebbe the filter caps are kept). You could get a ST-120 upgraded (including initial purchase of the amp) for under 1K - just a thought...

[Joel Cairo]

Rudy:

After looking around, I'd say you pretty well **could** build one of these yourself-- there are higher-grade re-issue versions of the original circuit boards available (same circuit, same hole numbering, etc.), and I'm sure you can buy most if not all of the parts you need online... even new cap cans. And, since the original manuals are fairly readily available, the assembly steps wouldn't be a problem.

Of course, by the time you'd assembled all of the pieces and NOS tubes, you'd be spending much more money (and time) than if you just picked one up used and did whatever minor troubleshooting it needed, so if you're like me, you should just take the lazy man's way out!! :D

(And although you didn't ask for my opinion, I'd advise that you stick with the tube units, also... both Sckott (and I) can wax on and on of the virtues of the ST-70. Particularly since you can mod them so easily for any minor changes you might feel the need to make!!)

Hope you join us on the tube side soon...believe me, once you've had a taste of the yummy smooth mid-range goodness, you'll never go back!!

-Kevin

[-=Rudy=-]

It would be distant future if I got into tubes, really...I'm working on the last few pieces of my LP-to-CD transfer chain, and then next up it's a big-screen hi-def TV, and surround gear. If anything I'd use tube goodies for my monitoring system on the computer. ;) It would definitely have to stay low-budget though, which is why I'd rather find a stock unit and do any troubleshooting myself.