Recent content by Prairie Dawg

As a point of information because of this forum and some help I got from Enzo I was able to understand how this system works and how to test it. The problem turned out to be a whisker of solder that had bridged two contact points on the back side of the relay board. It was intermittent but...

You should. I'd buy the first autographed copy and take you to lunch.:hyper:

After some study of the matter I decided to replace the TL072 op amp and the RTD14005 relay.I checked and rechecked all my connections and verified that all my connections were properly done. I then bypassed the relay, set the bias, let it cook for half an hour or so and shut down. Alles in...

I hear you Paul. I've got some work to do here. I realize now that my initial mistake was in not doing a road test before digging into it. It's going to be a learning experience. Got some good ideas here to work with and I've blocked out the time needed to get to the bottom of it all. As a...

I've got an SVT Classic in the shop that has (don't they all) problems with the fault detection network. The customer reported that sometimes it would not come out of standby at all or would trip the fault detector system after a couple hours of playing. I disassembled it and checked the...

I haven't checked the tubes for idle current in the amp yet. My guess is the split will be pretty much similar.

Somehow or other I have ended up working on more local SVTs than I'm happy about and I have this theory that the biggest problem people have with them is general unreliability of power tubes and how that triggers the fault detection circuitry a/k/a the "Honey, I've got a headache tonight"...

I did change all the screen resistors and I've just opened it up and they look fine. I'm about to open the rest of the chassis and check everything out. I did have one a while ago that did the same thing and what cured it was redoing all the solder joints in the fault detector circuit-for lack...

I've got an SVT here that will throw itself out of gear every once in a while, sometimes it'll happen on startup and sometimes after a few hours. I have replaced the screen resistors, three of which were defective. Since I had this amp in the shop last, it was part of the reason I built a...

I've gotten a commission to resurrect GMT 600B serial number 2769, and there's a bunch of toasted stuff on the power supply board. Is there any chance that service information or a schematic is available? My friend has had this amp for a long time and is emotionally attached to it. Thanks...

Folks, I've got an SVT-VR on the bench here that's kicking my butt up and down the street. It's about four month old B stock so no warranty which is why it's here. I should add that it looks like it was put together with old parts because the boards are all dated 2007. I't's got a splattery...

I'm new here and I just want to say thanks. I'm a semi pro amp mechanic, converted over from antique radio collecting and restoration and a former aircraft engine mechanic and my first SVT came in as a referral from Professional Music here in central Iowa. It was an ebay buy, ran pretty well...

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