I have a TU-8600 300B amp with all of the upgrades (transformers, resistors, caps) but Gold Lion 300B tubes. One of the tubes is red plating.
Diagnosis and Prognosis anyone?
Diagnosis and Prognosis anyone?
Check the tube first, but it could also be a coupling capacitor or a bad connection.
Did the amp work for a while, before the problem happened?
Did the amp work for a while, before the problem happened?
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If you have to do trial and error, swap tubes and see if the problem follows the tube.
If not, it's below in the circuitry.
If not, it's below in the circuitry.
Strangely the problem stopped and hasn't resurfaced. But I pulled the unit from my current setup so I haven't had more than an hour on it since the problem started and then stopped.
Yep! just like vk said. check your voltages! I wish the manual included tolerances. My 8600 ended up red plating a couple of times, each time was with Gold lion tubes. JJ tubes did better. But eventually a pair of gold lion fried aa few components on the left channel. my voltages were higher than the manual stated. I ended up using a step down transformer, 120 to 110, that's used in Japan. voltages came down to within a few volts of what the manual states, amp runs a lot cooler too. It's been almost a year and no more red plating
Yes, I had the issue with Gold Lion 300Bs, but only one time and it's gone. I ran tests and didn't find any problem. Go figure!