diytube.com

Well hopefully anyway. The two days of allowing capacitors to slowly but surely reform has finally paid off. Full power does NOT cause a heated dummy load. Tomorrow evening I get to attach the cheap speakers and have a listen.

This was a $75 flea market purchase from a small asian man who instantly regretted selling it so cheaply. He outfitted the amp with new Electro-harmonix EL34s and a Sovtek 5AR4 rectifier. Those are what appear to be two stock dynaco 7199s front and center.



Wish me luck. Work is going to suck because I'll be thinking all day about powering this baby up after 6pm.

Congratulations on your flea market find. I unfortunately never find deals like that but then again I don't go to many flea markets or garage sales.

So your quad electrolytic reformed? 2 sections were shot on my capacitor, replaced it with a now quad cap I purchased on ebay.

You will like your amp. My goal was to get a complete Dynaco system, in less than 3 months I purchased a Dynaco ST-70, Pas-3 and Pas-4 preamps, FM1 tuner with multiplexer and yesterday a FM-3 tuner. I also purchased a Dynaco SCA-80 Solid State amp (awesome amp) and this past weekend, I procured a set of Dynaco A-25 speakers. I am done for now. I have to restor the tuner and preamp.

Regards,
Sal Brisindi

Found the St70 manual on Curcio.com (thanks Tom) and followed the biasing instructions to a T, but couldn't get anywhere close to 1.56 vdc from the dual top pot adjustment. Meanwhile, an angry hum continued to course from the crap speakers.

Is this yet another cap job?

Forgot to mention, that the stock GZ-34 rectifier has been swapped out for a Sovtek 5AR4. How much would that change the voltage output? What should I try biasing for with that rectifier? My guess is that I shouldn't even try biasing at all at this point and would be better off ordering capacitors.

What parts suppliers would you guys suggest?

If you want to replace the quad cap with a board that fits underneath and does the bias and HV caps - check into the SDS Labs board, or look on eBay for "Dynaco Capacitor" and you'll find the CChong board ... Triode Electronics has the quad cans also. Yep, you should fix the capacitors before you proceed, the rectifier tube and voltages don't matter much if it's all hummmmm.

Cool yeah I picked up Sheldon's boards for my Heathkit W5M monoblocks a while back... just gotta get around to stuffing 'em. I found that quad cap board you were talking about--makes the task a lot less daunting. Thanks.

Whoa Shannon, nice driver board kit! Thorough documentation as well. I'll definitely be sending some business your way once I get the SDS capacitor board installed.

Just wondering, where is this flea market that you scored this amazing deal? Was it in San Fran? Somewhere in the bay area? I drive down there time to time and I might check it out sometime. Used to go as often as once week swing dancing a couple of years ago. Let me know, thanks!

The amp was found at Laney College in Oakland. Laney's only open on Sundays so when I went back a week later and saw it still sitting in the same stall, I knew the guy might be ready to bargain a bit.

Lemme know when you head this way, I'd enjoy being tour guide of the local flea markets, thrifts and junk shops.

lol i'll join you guys too hahaha

Ok, you're our designated tour guide the next time I am down there to go treasure hunting! Thanks!

My daughter and design consultant are making noises about hitting Ikea for furniture for the new house--assuming it ever gets started. I might hitch a ride. What about Foothill's flea market?

Wow, I didn't realize there was a good number of you in this forum from Nor Cal. Cool! We might not have any treasure left on flea markets in the area if this got rolling. hahaha...[pause]...hmmm...

SDS-PAGE wrote:Wow, I didn't realize there was a good number of you in this forum from Nor Cal. Cool! We might not have any treasure left on flea markets in the area if this got rolling. hahaha...[pause]...hmmm...

Yellow_Light_Colorz_PDT_16


I found two regular ham radio fleamarkets that I've been wanting to check out. I got them in my bookmarks somplace. They might be worth checking out too

Saturdays are good for me, not sure about this Sat though. I would welcome the cool breeze of the bay. It's getting pretty hot in the valley...3 digits this weekend!

One of these swap meats is first sunday of every month and the other is second saturday of a month. But this needs to be confirmed as these links are ancient :)