I bought a used Yaqin mc10 el34 intergraded that had been modified by previous owner to bring to work, it ran 8 hours a day for 4 years before I sold it with no issues. When I researched Yaqin before I bought one I noticed you can buy them new with upgraded blue tubes what ever those are instead of stock tubes, that to me tells me they know stock tubes may be crap. If one of those tubes go out with fireworks it could take out something in the amp. Do the plates on one or more of the tubes get red hot? I ran mullard xf2 which cost more than the amp with nice results.
Yaqin MS-300C Integrated Amp Keeps Shutting Down
Hi, I've been stumped for a while with my Yaqin amp shutting down. Most times when I turn the unit on, I have no output until I touch one probe of my multimeter in test opening, then it comes on. Many times however, I can't even get to adjust the bias for 24 hours as it appears to go into protective mode. After the 24 hour wait, the protection circuit goes off and I can bias the 300B tubes to .8 Volts per the manual. However, after a day or two, the process repeats itself: I have to touch the probe to the test point to start it, or it shuts down for 24 hours. I bought it used, and was told there were few hours on the stock tubes. Could it be the 300B tubes are just not holding their bias? I've used the 4 ohm and 8 ohm taps with several speakers with the same results.
Any help would be greatly appreciated.
Any help would be greatly appreciated.