Dynaco solid state recommendations?

acwd1950 · « **on:** 12 Sep 2009, 12:05 pm »

Which of the Dynaco SS amps are the best? As in sonically? Mods available and so on? Im posting this here because I keep reading that Frank is the MAN on these things! So Frank which ones of Dynacos SS is preferred? Is any of the SS close to the U70? Pre amp and amp combos? Ive been thinking about building a Dynaco system, separate components of course! Just need to know what to look for

Steve

Wayner · « **Reply #1 on:** 12 Sep 2009, 12:10 pm »

I have the Stereo 120, which Frank has converted to an Insight 170. It is a very musical amp. It is vastly superior to the old Dynaco amps and completely stable. The Dynaco 150 is also upgradable, not sure of the 400, 410 series.

Wayner

oneinthepipe · « **Reply #2 on:** 12 Sep 2009, 04:38 pm »

Steve:

Are you looking for a Dynaco amp to have upgraded or would you use the amp in stock form? I ask because the "AVA-upgraded" amps aren't really Dynaco amps anymore. The amp is gutted except for the chassis and transformers. If you want an AVA amp, buying a Dynaco to use as a host amp for an upgrade is not always cost effective, particularly when there are used AVA amps in the marketplace. However, if you picked up a host amp for very short money, you might be getting a bargain.

Regarding a solid state Dynaco amp being sonically comparable to a U70, I am not Frank, but I don't think so.

Good luck.

Brett Buck · « **Reply #3 on:** 12 Sep 2009, 09:19 pm »

Quote from: oneinthepipe on 12 Sep 2009, 04:38 pm

Steve:

Are you looking for a Dynaco amp to have upgraded or would you use the amp in stock form? I ask because the "AVA-upgraded" amps aren't really Dynaco amps anymore. The amp is gutted except for the chassis and transformers. If you want an AVA amp, buying a Dynaco to use as a host amp for an upgrade is not always cost effective, particularly when there are used AVA amps in the marketplace. However, if you picked up a host amp for very short money, you might be getting a bargain.

Regarding a solid state Dynaco amp being sonically comparable to a U70, I am not Frank, but I don't think so.

I have a stock ST-120, and have extensively listened to a stock ST-70 and the U70. The ST-120 is clearly superior to a stock ST-70 across the board. The stock ST-120 is not nearly as good as the U70.

And for what it is worth, while it's not a no-brainer, I think my Omega 260 is overall better than a U70.

Brett

rcag_ils · « **Reply #4 on:** 13 Sep 2009, 09:54 am »

I have never listen to a stock ST-120, but in the audio community, it has been referred to as "door stopper", whatever that means.

acwd1950 · « **Reply #5 on:** 13 Sep 2009, 04:12 pm »

I was wondering about buying a ST-120 and doing a upgrade on it to make it better. Im a DIYer so getting a kit and doing the upgrade myself. I would love U70, but just cant swing the kind of money that they are going for. As for a pre amp I got a HK 930 that the main amp is out of it and using it as a pre amp for now. Just wondering if the upgrade on the 120 is cost effective or not? and if its the best candidate for a upgrade? Compared to a 150 or other SS amps in the Dynaco lineup.

Steve

JerryM · « **Reply #6 on:** 13 Sep 2009, 04:32 pm »

Not to go OT, but don't forget that Frank does upgrades to Hafler amps, as well. There are some sweet deals to be had on old Hafler gear, and the upgrade prices from Frank seem relative to the upgrades to Dynaco gear.

Have fun,
Jerry

boycephoto · « **Reply #7 on:** 13 Sep 2009, 06:36 pm »

There are lots of different options available for you. First, I don't think a stock Stereo 120 sounded bad. They tend to be unreliable and would have catastrophic failure when they did blow. I am sure there are some ST120s that still play strong and have never had a problem. You can by a used 120 cheap but beware of it's condidtion. Frank does not sell the 120 upgrade as a kit, you need to send it to him, and it costs more than an Ultimate 70 upgrade kit but, you are going to pay more for a used ST70. So your investment bewteen the two might be close either way. I have never heard an Insight 170 just an older AVA Mos-Fet 120D I had years back. I really like my Ultimate 70!! Wayner has both amps, and says he likes both. If he had to pick one over another I am not sure which one would win... What do you think Wayner?

There are several people that sell an upgraded power supply kit for the ST120 on ebay, I think that would be a worth while investment for $50 or less. The power supply was a weak part of the 120.

Good luck,
Dave

gjs_cds · « **Reply #8 on:** 14 Sep 2009, 12:11 am »

The stock ST-120 is a fun amp to work on... And if you look back at Frank's articles, he clearly writes a few upgrades for them, complete w/ board schematic.

I had two of them, which were fun to play w/ and work on...They had an uncharacteristically warm sound to them (for a SS). But when it came down to it, modern amps just sounded better to me.

moboman · « **Reply #9 on:** 14 Sep 2009, 01:31 am »

Quote from: boycephoto on 13 Sep 2009, 06:36 pm

There are several people that sell an upgraded power supply kit for the ST120 on ebay, I think that would be a worth while investment for $50 or less. The power supply was a weak part of the 120.

A few years ago I picked up a restored/modified st120 from an older man on ebay. He used the van alstine power supply mod and a another mod that was not Van Alstine's and then just replaced everything else with new components. The seller said he even replaced the boards. So for $250 bucks I picked up a brand new excellent sounding amp. The chassis was even repainted.
So if you are looking for something relatively inexpensive and great sounding for the price, an st-120 would be a great start.

I only have a stock 120 and my 120B to compare it to and I'd say this amp is somewhere between the two. Better than stock but not as good as the 120B. But once again, for a new/rebuilt amp at $250, I havent found anything better.

It would seem like everything he did would be relatively easy to do if you knew which components to use.

oneinthepipe · « **Reply #10 on:** 14 Sep 2009, 02:22 am »

There are quite a few forums where the members will assist you with an upgrade. I don't dabble in electronics, but I build AR15 carbines, and I have found the everything usually goes fine until it doesn't. With 1911-style handguns, I don't attempt anything except the simplest projects; they aren't Glocks, which are similar to Legos. I don't do anything with my electronics without calling Frank. If you have the technical skills, go for it, I say. Just don't get electrocuted.

Best success.

avahifi · « **Reply #11 on:** 14 Sep 2009, 02:36 pm »

If you want to find an old Dyna St-120 for the purpose of having it transformed into a new Insight 170 amp, you need not find a working unit.

All we need is a good chassis, cover, two of the three bare black L-shaped heat sinks, and hopefully the red and black output jacks. Everything else that is original is trashed anyway.

You will end up with a quiet, delightful, and musical 90 watt per channel bulletproof amplifier in a compact useful chassis, complete with a new three year AVA factory warranty.

Not a bad deal.

Note that we will clean the chassis as much as practical, but removing extra holes, un-pitting of the finish, and removing rust beyond repair are not part of the normal rebuild process or cost.

Regards,

Frank Van Alstine

Listens2tubes · « **Reply #12 on:** 16 Sep 2009, 02:39 am »

I have a stock/working ST-120 sitting on a shelf. I often see "upgrade kits" on ebay, som include Frank's instructions for modding with the parts. I watch them for a few days until I come back to my senses and delete them. I bought the amp locally as an replacement for my Mark IV amps while I was working on them. In comparison to the Mk. IV's I found the ST-120 to have a decent midrange with somewhat thinner sounding highs. Really not bad for a solid-state amp.

You should be able to pick up a decent unit on ebay or under $100. Enjoy!

Neal

acwd1950 · « **Reply #13 on:** 17 Sep 2009, 03:13 am »

Well my plan was to build a component vintage system to play records on and was thinking SS. Well Ive changed my mind... Im going to go with tubes instead. I would love to get a 70 and preamp with a good phono section. But the 70 is out of my budget right now. So Im thinking integrated instead maybe more in my budget. Been looking on ebay for a deal.

Steve

Brett Buck · « **Reply #14 on:** 17 Sep 2009, 04:10 am »

Quote from: acwd1950 on 17 Sep 2009, 03:13 am

Well my plan was to build a component vintage system to play records on and was thinking SS. Well Ive changed my mind... Im going to go with tubes instead. I would love to get a 70 and preamp with a good phono section. But the 70 is out of my budget right now. So Im thinking integrated instead maybe more in my budget. Been looking on ebay for a deal.

I would think, on a budget, that the ST-120 is a good choice. I have seen mint copies for for $75 on Audiogon, practically free by hi-fi standards. The preamp is more of an issue. I have a stock PAT-4, and even with the tone controls defeated, it's nothing to write home about. I never had any exposure to a PAT-5, so I can't comment on that. But the PAS-2/3/3x, while much better than the PAT-4, are going for insane prices now.

If budget is a serious issue - and I mean "college student" money - don't overlook the little K12 amplifier:

http://store.tubedepot.com/diy-k12g.html

This amp is surprisingly good, and for $189 it's impossible to beat. Well, actually, when it was $125 it was even better. For multiple sources use an external rotary switch. It's certainly better than any other 8 watt amplifier you can get, including and particularly the ridiculous $10000+ SET amps - and with twice the power. It's trivial to build. I built mine in about an hour if you don't count finishing the board used for the base. OF course there's no real chassis or cover so you have to be very careful and forget it if there are kids around.

Brett

p.s. Actually, if you want a PAT-4 in near mint condition, you can have mine for free aside from the shipping. It works as well as it ever did. I would highly recommend the modifications Frank suggested in AB back in the 80's. The last time I did anything to it, the wiring was *extremely* brittle and rewiring the whole thing would not be a terrible idea., and might be mandatory if you have to take the boards out to do the modifications. So, almost free PAT-4, $75-$100 for an ST-120, rest for speakers, such a deal. I don't know if it would wind up sounding better than the K-12 - with a stock PAT-4 I would take the K-12 every time. Send me an email at buckbw@pacbell.net if you are interested.

p.p.s. or. alternately:
http://cgi.ebay.com/Vintage-1960s-Dynaco-Dyna-SCA-35-Stereo-Tube-Amplifier_W0QQitemZ250498360810QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item3a52dda5ea&_trksid=p3286.c0.m14#ht_907wt_1167

These are very nice-sounding/non-sounding amplifiers when they are working properly.

JerryM · « **Reply #15 on:** 17 Sep 2009, 04:32 am »

Quote from: Brett Buck on 17 Sep 2009, 04:10 am

Quote from: acwd1950 on 17 Sep 2009, 03:13 am
Well my plan was to build a component vintage system to play records on and was thinking SS. Well Ive changed my mind... Im going to go with tubes instead. I would love to get a 70 and preamp with a good phono section. But the 70 is out of my budget right now. So Im thinking integrated instead maybe more in my budget. Been looking on ebay for a deal.

I would think, on a budget, that the ST-120 is a good choice. I have seen mint copies for for $75 on Audiogon, practically free by hi-fi standards. The preamp is more of an issue. I have a stock PAT-4, and even with the tone controls defeated, it's nothing to write home about. I never had any exposure to a PAT-5, so I can't comment on that. But the PAS-2/3/3x, while much better than the PAT-4, are going for insane prices now.

If budget is a serious issue - and I mean "college student" money - don't overlook the little K12 amplifier:

http://store.tubedepot.com/diy-k12g.html

This amp is surprisingly good, and for $189 it's impossible to beat. Well, actually, when it was $125 it was even better. For multiple sources use an external rotary switch. It's certainly better than any other 8 watt amplifier you can get, including and particularly the ridiculous $10000+ SET amps - and with twice the power. It's trivial to build. I built mine in about an hour if you don't count finishing the board used for the base. OF course there's no real chassis or cover so you have to be very careful and forget it if there are kids around.

Brett

p.s. Actually, if you want a PAT-4 in near mint condition, you can have mine for free aside from the shipping. It works as well as it ever did. I would highly recommend the modifications Frank suggested in AB back in the 80's. The last time I did anything to it, the wiring was *extremely* brittle and rewiring the whole thing would not be a terrible idea., and might be mandatory if you have to take the boards out to do the modifications. So, almost free PAT-4, $75-$100 for an ST-120, rest for speakers, such a deal. I don't know if it would wind up sounding better than the K-12 - with a stock PAT-4 I would take the K-12 every time. Send me an email at buckbw@pacbell.net if you are interested.

p.p.s. or. alternately:
http://cgi.ebay.com/Vintage-1960s-Dynaco-Dyna-SCA-35-Stereo-Tube-Amplifier_W0QQitemZ250498360810QQcmdZViewItemQQptZVintage_Electronics_R2?hash=item3a52dda5ea&_trksid=p3286.c0.m14#ht_907wt_1167

These are very nice-sounding/non-sounding amplifiers when they are working properly.

You rock, Brett.

Nothing solves a problem better than something free.

Admirably,
Jerry

oneinthepipe · « **Reply #16 on:** 17 Sep 2009, 05:42 am »

Awfully nice of you, Brett. If acwd doesn't use the PAT-4, maybe the circle members can put together a stable of backup components for the memberships' use when a primary component is in repair or upgrade. I remember when my Insight + SL was with Frank, and I was without tunes, and I was in audio purgatory. I also learned that my preamp was the soul of my system. Additionally, the spar component might encourage some modification of the old pieces by also making them available to modders, Having a respositry would provide lending and upgrading opportunities. I think that such a program would be unique within the circles and would bring some recognition to our little band of ~~misfits~~ enthusiasts. If any others are interested, I am willing to provide the northeast depot. I only have a couple of NAD pieces to offer, but it is a start. (No, my vintage Omega 50 is staying out until Frank figures out how to upgrade the control amp.)

avahifi · « **Reply #17 on:** 17 Sep 2009, 12:53 pm »

We can put the new Insight+ circuits in the Dyna PAT-4 preamp too. There is not much demand for this as the preamp is pretty ugly and somehow that seems to affect the sound for some people. I just built one for Dennis Murphy to match his Insight 250 power amp and he seems to be pleased with the results.

We would prefer to put the SL (straight line) circuits in the Pat-4 and not use the tone controls because the tone control pots are pretty flaky. However we can do the EC version with tone controls if you insist.

The unit will get a new phono board, new line or line/tone control board, new power supply board, and new precision volume and balance controls. Sorry, a replacement jack set is not available from us for this chassis.

The rebuild price is $799 and it will give you musical performance identical to a new Insight+ SL or EC preamp.

Regards,

Frank Van Alstine

Brett Buck · « **Reply #18 on:** 17 Sep 2009, 08:16 pm »

Quote from: oneinthepipe on 17 Sep 2009, 05:42 am

Awfully nice of you, Brett. If acwd doesn't use the PAT-4, maybe the circle members can put together a stable of backup components for the memberships' use when a primary component is in repair or upgrade.

That's an interesting idea. I've got lots of stuff just sitting in closets and my storage unit accomplishing nothing, and that I am not going to use any more (although now that I know I can get my PAT-4 made into an Insight+, I am having second thoughts...). I would much rather see it go to someone who can make good use of it. It's not like I haven't amortized the cost over the last 35-40 years or so.

I don't think I would volunteer to be the West Coast repository of temporary spares - I don't have the space. But if someone wants to do something like that I might be able to contribute a bit. I have a fair number of spare parts lying around. Some are not in perfect working order but would be easy to fix to at least be reliable, if not super-high-quality.

Brett

avahifi · « **Reply #19 on:** 17 Sep 2009, 08:27 pm »

Hi Brett,

I would love to receive that old Dyna Pat-4 you have in storage. I will certainly pay for shipping and more.

I am thinking it might make a great "pass around and try out" loaner to interested AC members after I put a complete Insight+ circuit set into it.

Best regards,

Frank Van Alstine

P.S. I would be willing to do the same with that Dyna ST-120 amp you have if you want to see that it gets some respect. I can build an Insight 170 circuit into that too and put both the Insight Pat-4 and Insight 170 out for AC loan and evaluate. Now that combination is going to open some eyes (and ears).