Got a Van Alstine Dynaco 120 today wow!!

topround · « **on:** 27 Jul 2008, 02:48 am »

OK, I have a friend who is a tube repair guy, SS as well, he can fix anything. Anyway I went to his house today to pick up my tube amp for some mods, while I was there he gives me a Dynaco 120 SS amp and a Spatial Coherence preamp. BTW he has rooms full of gear, all sorts of stuff, so he usually sends me home with something to try.

So... he found this Dynaco 120 that had been rebuilt by Frank in a garage sale. Condition is great but the caps were leaking, so he replaces all the old stuff with new stuff, turns it on and it works, he is happy and puts it away. maybe 3 years later he decides to give it to me to try.
So I have a rebuilt AVA Dynaco 120 that still needs to be burned in, but on first glow it sounds... great, unbelievable bass and very powerful sounding. OK to be honest at first the huge bass was one note, and the soundstage was smeared and messy, but after about 30 minutes it cleaned up a lot.
I call him up and tell him Wow this little amp sounds great, very un solid state, he says Mike give it a few days of serious burn in time, it will get better..
I don't know the history of this little amp in regards to AVA history but man if you find one buy it, it may not replace your main modern gear, but in a second system your friends' jaws will drop.
I am bringing this to the next NYAR audio rave in August for others to hear.
It gets me psyched to find great gear that might otherwise be overlooked.

The only AVA gear I have owned was a Dynaco ST 70 with the AVA super 70 board , and that amp was great, sorry to see it go but I traded it for something I needed(yeah right)

needed
anyway, I wish I knew someone local who had a UltraFet550, I would love to hear that in my system

Frank might just be....THE MAN...

mike
\

martyo · « **Reply #1 on:** 27 Jul 2008, 11:17 am »

Quote

Frank might just be....THE MAN...

Yep. Enjoy.

Wayner · « **Reply #2 on:** 27 Jul 2008, 12:29 pm »

I have the Rebuilt Dynaco Stereo 120 known as the 170ex by Frank. It is a great sounding amp! I have a AVA T8 running into it and a mint pair of Dynaco A25XL's hooked up to it. Do you want to hear bass pounding vinyl? This setup will do it in spades!

Congrats on the nice score!

Wayner

topround · « **Reply #3 on:** 27 Jul 2008, 12:53 pm »

Well, it's not mine, but I do get to play with it, and yes it has bass in spades, I was very surprised.
It needs burn in time, but so far so good.
I am using it with my Mapletree Ultra 4 se preamp and they do seem to like each other!.
This is a very old unit and has no AVA badging
Mike

avahifi · « **Reply #4 on:** 27 Jul 2008, 04:35 pm »

Assuming that the St-120 has three black heat sinks still installed, and the original Dyna power transformer, that would date it as an early Mos-Fet series amplifier of ours from the 1980s. If it has all large "soup can" chassis mounted electrolytics (5 of them, 2 with coils of wires wound on them) it would date it as even earlier.

Current Insight 170 circuits use nothing of the original parts except the bare chassis and cover, the black and red output binding posts, and two of the black metal heat sinks after they are stripped bare. Its a whole new amplifier in the Dyna box.

I do have a schematic and bias information data sheet available for the early Mos-Fet 120 models if you would like that.

It is pretty interesting how good our old amplifiers can still sound years and years later. We did build them to live.

Regards,

Frank Van Alstine

P.S. If you can send me a decent closeup photo of the insides, I can help date it further for you.

topround · « **Reply #5 on:** 27 Jul 2008, 05:51 pm »

Thanks Frank , I will send a photo.

topround · « **Reply #6 on:** 27 Jul 2008, 06:50 pm »

Frank,
Here is a photo

Wayner · « **Reply #7 on:** 27 Jul 2008, 10:05 pm »

It looks like really old stuff! Send it into Frank and get it rebuilt!!!!!!!! You won't believe the 85 watts per channel.

Wayner aa

gjs_cds · « **Reply #8 on:** 27 Jul 2008, 10:39 pm »

Yeah--I'd look into rebuilding it. The chassis looks to be in pretty good condition, and those power supplies are bullet-proof.

I used to have some stock Dyna 120s in quite good condition... I used them to bi-amp my dipolar HT mains. After I picked up the AVA OmegaIII--they were sold. The difference is dramatic.

avahifi · « **Reply #9 on:** 27 Jul 2008, 11:43 pm »

Yes indeed, this is an old unit, an original Mos-Fet 120 done before we had even designed our first new circuit board back in the 1970s. This amp has Hitachi mos-fet output devices and regulator device with highly reworked original Dyna audio boards, revised to drive the mos-fets. It was smooth and liquid sounding, but lacking very much in transparency and dynamics.

It appears that all the "can" capacitors have been replaced, and all the big yellow axial lead capacitors dangling all over the place are certainly not our idea or installation.

Unfortunately, this unit predates our good computer based record keeping, and I do not have any written service information on it at all. How many trim pots are there on each audio PC card? I still may be able to help if I know that.

Regards,

Frank

P.S. The cost to upgrade to a new Insight 170 (50 percent more power and day and night better performance) is $595.00. We allow a $100 discount just because this is a unit we worked on in the past. (Normal price $695.00) As mentioned previously, everything inside will go except the case, two of the bare black heat sinks, and the red and black binding posts. The rebuild includes a new three year parts and labor warranty too.

http://www.avahifi.com/root/equipment/amplifier/omegastar_170.htm

topround · « **Reply #10 on:** 28 Jul 2008, 01:05 am »

Thanks for the info Frank

It is not my unit so I can't upgrade it and the owner has so much stuff, and the ability to upgrade it himself, if he wanted to, so it will probably stay the way it is, but even so I like it!!
Honestly if it were mine, I would just give it to my son and spend the upgrade money on a new Fet 550

I would love to hear one in my system. There are three amps I would like to try the Mccormack Dna 125 , the AVA fet 550, and the Pass 250.5, I am sure one of them will eventually make its way into my system to try or stay.

thanks

Mike

avahifi · « **Reply #11 on:** 28 Jul 2008, 02:16 pm »

Thanks for your kind comments.

Remember that we do offer a 30 day satisfaction guarantee on all new AVA products, so it will only cost you shipping if you order a Fet Valve Ultra 550 amp and decide it does not exceed your expectations.

Regards,

Frank Van Alstine

bregez · « **Reply #12 on:** 31 Jul 2008, 08:54 pm »

Does AVA sell an upgrade where only the case is replaced? If so here is a candidate.

http://cgi.ebay.com/Audio-by-Van-Alstine-Omega-II-170-Power-Amplifier_W0QQitemZ180271103080QQihZ008QQcategoryZ39783QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

Possibly the ugliest AVA amp in existence.

gjs_cds · « **Reply #13 on:** 31 Jul 2008, 09:21 pm »

Quote from: bregez on 31 Jul 2008, 08:54 pm

Possibly the ugliest AVA amp in existence.

I've cleaned up Dyna chassis before...and was pretty surprised just how good a result I was able to get. I'm interested to see what it actually goes for; t'would make a great amp for the office.

ohenry · « **Reply #14 on:** 31 Jul 2008, 09:26 pm »

Maybe it's one of those fabled boat anchor amps. Or the cat whizzed in it.

Wayner · « **Reply #15 on:** 31 Jul 2008, 10:13 pm »

I reverse engineered the case for Frank awhile back. It was decided back then that the case had something more to be desired (than side inputs/outputs and power) and there probably wouldn't be much demand for it anyway. Now the 170ex is avalible as a integrated amp with 85 watts per channel and a built in preamp section with less than usual amount of inputs. That is a swell product for someone looking for an all in one kind of deal that won't take up much space. Ckeck the website out.

Wayner

rustneversleeps · « **Reply #16 on:** 1 Aug 2008, 05:11 am »

What's this great amp for the office crap? I think assistant professors don't get a office that's big enough for a full system, even a boombox would be too big for your cubby hole with nothing but paper laying around from your students that never been out in the real world. Don't try to make yourself sound important, professor, instructor, or teacher, or whatever.

TjMV3 · « **Reply #17 on:** 1 Aug 2008, 08:46 am »

avahifi · « **Reply #18 on:** 1 Aug 2008, 03:20 pm »

Rusty, your last comments were very inappropriate and juvenile. I do not want more of this on my circle.

Frank Van Alstine

Wayner · « **Reply #19 on:** 1 Aug 2008, 07:37 pm »

I'm really challenging my 170ex today as my usual pre-amp, the AVA T8 is on the fritz with a bad capacitor. I've pulled out the 45 year old Dynaco PAT-4 to run this weekend as I am pre-ampless with my OmegaStar EC and 260ex into Frank for magic conversion into Insight products. While the PAT-4 works, it sounds just OK. I'm missing my equipment really bad. I NEED A FIX! (It really helps to have a good preamp to go with the 170).

Wayner

By the way, it's my birthday Sunday and of course, gifts are welcome!