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I just finished up working on a Fender 57 Twin Reissue and just wanted to post a few things about the amp.
One problem that i encountered was a sizzling sound which i initially though was coming from the PT. After isolating the problem more, i discovered that it was coming from the 12A fuse tied into the rectifier circuit. The fuse was hot to the touch and the ends were actually unsoldering themselves. The amp states that it takes a 12A 250v fuse, but the circuit is passing 500v at that stage. I bypassed the fuse block, including the 6.5A heater fuse.
It also seemed that the power tubes weren't happy until they were biased up around 40mA. Anything lower and i was getting a slight bit of distortion on certain frequencies. The bias circuit may need to be reworked a bit to supply the right negative voltage for cerain tubes, although the set i put in was able to reach 40mA within the scope of the bias pot.
All in all a nice amp. Well built and fairly faithful to the original design.
One problem that i encountered was a sizzling sound which i initially though was coming from the PT. After isolating the problem more, i discovered that it was coming from the 12A fuse tied into the rectifier circuit. The fuse was hot to the touch and the ends were actually unsoldering themselves. The amp states that it takes a 12A 250v fuse, but the circuit is passing 500v at that stage. I bypassed the fuse block, including the 6.5A heater fuse.
It also seemed that the power tubes weren't happy until they were biased up around 40mA. Anything lower and i was getting a slight bit of distortion on certain frequencies. The bias circuit may need to be reworked a bit to supply the right negative voltage for cerain tubes, although the set i put in was able to reach 40mA within the scope of the bias pot.
All in all a nice amp. Well built and fairly faithful to the original design.
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