Rdmarsiii Posted December 2, 2015 Share Posted December 2, 2015 Hey guys, I have two Gold Tube Audio SE-40 amps that have been converted into mono amps. I've talked with Jeff at Sonicraft extensively about these things since he is the expert on the SE-40's. I plan on either sending them off to him to get the fixes done, or if there is someone in the area, teach me how to go about doing it. Either way, I'll need to be taught how to bias them. Just curious if there was anyone out there. Thanks, David Quote Link to comment Share on other sites More sharing options...
mike stehr Posted December 2, 2015 Share Posted December 2, 2015 What's wrong with them? Quote Link to comment Share on other sites More sharing options...
Rdmarsiii Posted December 2, 2015 Author Share Posted December 2, 2015 What's wrong with them? This is from Jeff's website-- Several resistors in the SE-40 are operating at or near their power limit. Some are experiencing voltage exceeding their max design limit. In many cases, the SE-40 comes with low quality electrolytics. Some caps are exposed to voltages which exceed their rating. Either way, your old electrolytics are quite tired. The factory cathode resistors are a recipe for disaster. One of the rectifiers is a ticking time bomb. Aged power switches are known to introduce noise. I have no idea if mine have been fixed, or if there's even anything wrong with them. They both have all new tubes, I have turned them on briefly to make sure they work, which they do and sound great, but being so unreliable has me afraid to turn them on, so they just gather dust. David Quote Link to comment Share on other sites More sharing options...
Wardsweb Posted December 2, 2015 Share Posted December 2, 2015 I think Jeff is talking about upgrading the parts to better than factory for both an increase in reliability and better sound. The circuit remains the same. It is a matter of replacing parts. Jeff is a great guy and knows his stuff. I wouldn't have any issue sending him something to work on. He has helped me source parts on several of my builds. Quote Link to comment Share on other sites More sharing options...
Rdmarsiii Posted December 2, 2015 Author Share Posted December 2, 2015 I think Jeff is talking about upgrading the parts to better than factory for both an increase in reliability and better sound. The circuit remains the same. It is a matter of replacing parts. Jeff is a great guy and knows his stuff. I wouldn't have any issue sending him something to work on. He has helped me source parts on several of my builds. We've already discussed sending him both the amps, I just don't have boxes. I'd love to be able to do it myself with guidance, I guess, and was curious if we had any guys that could mentor me. Quote Link to comment Share on other sites More sharing options...
xxJPMxx Posted December 2, 2015 Share Posted December 2, 2015 I'd love to be able to do it myself with guidance, I guess, and was curious if we had any guys that could mentor me. I would love to help you. Don't be afraid to tackle this if you have decent soldering skills and can use a multimeter. All we need are pictures, schematics etc..... Quote Link to comment Share on other sites More sharing options...
Wardsweb Posted December 2, 2015 Share Posted December 2, 2015 It is fairly easy to work on. Once you unscrew the PCB from the chassis, you can flip it back and forth to find the part you want to change and then unsolder from the bottom side. Note the trick is unsoldering the part without damaging the trace it is soldered to. You will want, at a minimum, some good solder wick and a good soldering iron. Even better will be a solder sucker in conjunction with the solder iron. Remember the solder is your heat bridge. Keep the tip clean and tinned. A dry iron solders/unsolders horribly. Quote Link to comment Share on other sites More sharing options...
xxJPMxx Posted December 2, 2015 Share Posted December 2, 2015 And there are so much trash electronics today that you can cannabalize something and practice removing components from PCB's. I am willing to bet within an hour you will get the hang of it provided you got the right tools as mentioned above. Quote Link to comment Share on other sites More sharing options...
Ol' Tex Posted December 3, 2015 Share Posted December 3, 2015 Frank Mufich is an audio electronics magician. He works full time on restoring audio equipment out of his house. Audiophile. Electronics wizard. McKinney, Texas. http://www.mufichaudio.com Quote Link to comment Share on other sites More sharing options...
Wrinkles Posted December 4, 2015 Share Posted December 4, 2015 I second Frank Mufich. A buddy of mine always has his equipment upgraded using him. Work has been great. Quote Link to comment Share on other sites More sharing options...
eq_shadimar Posted December 16, 2015 Share Posted December 16, 2015 Frank Mufich is an audio electronics magician. He works full time on restoring audio equipment out of his house. Audiophile. Electronics wizard. McKinney, Texas. http://www.mufichaudio.com Add me as a third to recommend Frank. He fixed my Fisher 500B and did additional fixes above and beyond what he quoted for the same price. It sounds awesome! Laters, Jeff Quote Link to comment Share on other sites More sharing options...
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