Tube amp repair recommendations - San Diego?

I am looking to repair/upgrade my original Dyna ST70s with modern circuit boards. Any San Diego area recommendations?

If I still lived in Bay Area, I would be dropping these off Nick Gowan...(sigh)

Hi, I would ship you Dynas to someone who knows what they are doing and you trust and forget about convience.
Just my 2 cents
Good Luck
You have an expert in town:

Mike Zuccaro, 858 271 8294, he is highly qualified.
I second the recommendation of Mike Zuccaro.I don't think he's an upgrade guy but he will bring your componet back to what the designer intended as new. I sent my GAS Thaedra to him from MA and am totally satisfied.
Might be same person:: I found someone who 'loves tubes' when trying to get a friends ancient Zenith TransOceanic fixed. Want me to track down?
Magfan, would appreciate your help.

Nkj/Rickmac...thanks...I will give Mike a call.
I called Mike. Turns out he is less than 15 minutes from my work. Very reasonable. I will probably drop off both ST70s to him for service next week. I will post my results.

Re. mods...RickMac is correct; he prefers to do non mod work, which is ok with me.
I dropped off my 2 Dyna ST70s yesterday (Aug 25 2009). Mike asked me good questions re. history, service, issues. (a good sign).

First impression - A service engineer's service engineer based on his line of questions and his "lab" equipment. It was nice to see a a mix of new and older analog test equipment on his bench. My Dad's Heathkit tube based volt ohm meter would feel right at home on Mike's shop bench. I have built my share of Heathkits and small electronic equipment for an old hobby - long ago (amateur radio WB6YRW - general class). I just don't have time to trouble shoot anymore.

At the time I dropped of my amps Mike was working on a Mcintosh amp.

Mike was very personable. He is a little backlogged (also a good sign) and will be giving me a call next week to give me an update status. He said he should have these units completed by end of next week assuming no transformer issues, which I don't think is the issue.

I will keep this thread posted on the results.

* Received a call from Mike yesterday 8/31/09, as he promised. How many service shops have you worked with that have follow through like this?
* Amp status updates - couple of original diodes went out; transformers and tubes all fine; one on/off switch went out; biases checked and were fine; mono switch on one amp was out
* Mike is going let them run for awhile and check the amps on a spectrum analyzer
* He expects to have these amps ready for pickup Wed/Thurs this week
* No extra / unusual findings to drive ticket markup
* Very very reasonable price for the work is all I can say
* I will give an update once I get the amps back and run them in the system
* Picked up my amps yesterday, Thursday; 6 days after dropping off
* I have one amp already plugged in and warming up for 24 hours.
* Played some of my records through it. (Sota/ETII/Sumiko,AudioResearch SP14 pre, Dyna --> Janzen electrostat low boys). It is great hearing these amps again in my system.
* Mike was a pleasure to work with. When I picked up the Dynas he received and was working on a relatively rare BOSE amp from the mid 1970s. He said this is the 2nd one he has ever seen/worked on in his career. The BOSE amp reminded me of an early Mark Levinson; Mike had the amp splayed open. Mike definitely works on some interesting equipment.
* I can not say enough positive things about Mike's timeliness, honesty, service craftsmanship and service cost reasonableness; a gem/keeper service provider.
* Yes I would recommend and use him again. No doubt
* I am going to take two of my Dyna Pas3x for a tuneup before I sell these preamps.
Stuogawa, I'm glad Mike worked out for you. I'm considering sending him an amp which no one out this way can help me with. It's a seventies vintage AEA A620 350wpc monster. I feel though if anyone could fix it he's the one. Thanks for the updates.
* Dropped off my Conrad Johnson PV 1 preamp to Mike about 3 weeks ago.

* PV 1 stopped working.

* Mike had never worked on a PV 1 and did not have schematic.

* Traced problem to two main caps failing.

* Dropped PV 1 on a Monday and got it back that Thursday.

* All tube system (PV 1 and Dyna ST 70s) sounds tubey groovy!

* Again very reasonable repair cost and timely service.

* What I have begun to appreciate with Mike is that he will tell you right up front if he is too busy to accept more work. He is a one man shop and only accepts work that he can complete within what appears 2 weeks time. I have been fortunate because I am close by and can drop off my equipment if he finishes work up earlier.
* Started getting intermittent static discharge noises from the Dyna ST 70s. Occurs after about 15 to 30 minutes of warm up time.

* Issue characterized as if a build up of electricity is occurring and then intermittently discharges and sounds like a loose connector through the speaker.

* Spoke with Mike and his initial reaction was that the 7199 tubes were probably failing.

* I purchased a pair of NOS RCA 7199s from

* Received and installed 7199s this week. Intermittant discharge still occurring.

* Swapped in my Audio Research SP 14 and Conrad Johnson PV 1 to test the Dyna ST 70s. Intermittant discharge still occurring.

* To ensure the Audio Research SP 14 and Conrad Johnson PV 1 were not introducing the discharge, I put the SP 14 and PV 1 in front of my Audio Research D115 solid state amp. No intermittent discharge occurring.

* Spoke with Mike today (9/5/09). He said drop them off this afternoon and let's solve the problem.
* Received call from Mike late afternoon 9/5/09.

* Problem identified and solved. No charge.

* Two ceramic capacitors intermittently failing. One for each channel.

* Mike stated in the 30 plus years of servicing Dyna ST70s, he has never seen these two capacitors fail. Typically the 7199 tubes begin failing and cause the intermittent noise 99% of the time. This was the last component he would have considered turned out that it was indeed that last components in the food chain to fail.

* I picked up amps the next morning. Played music through the amps for 12 hours a day / 5 days in a row. No issues.

* Mike stood behind his work and backed it up.

* Looks like I will be dropping of my Dyna PAS 3 preamps for a check up next.
I also wanted to share my experience with Mike. My mono amps started having issues and rather than sending them to the manufacturer I decided to give Mike a try in San Diego (I live in LA). I dropped them off on a Sunday and by Tuesday he called with his analysis. He even found two errors in the overall design of the amps and fixed those as well as a burned capacitor. He checked all solder points with a magnifying glass, tightened tube sockets, re-biased the amps, tested all tubes, and provides warranty on his work. He shipped the amps back to me and they are now singing better than ever before. VERY HIGHLY recommended.