Tube Amps / Music Electronics
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|previous: Tim P Anybody have any experience with ba... -- 10/20/1999 8:50 PM||View Thread|
|10/29/1999 2:27 PM|
|Dave Stork||Re: Help w/ Failing Blues Deluxe|
I'm a Fender "Gold" tech and have worked on a bunch of those amps. Cold/cracked solder joints are very common, indeed. Pay special attention to the pots, the 1/4" jacks (the jacks themslves often go bad), the tube socket pins, and the ribbon cables that connect the main PCB to the tube PCB. Also, be sure to check the two large wirewound resistors in the +/-15V supply. These tend to overheat and damage their solder joints and cause intermittents in these supplies, which will show up as popping sounds from the preamp, intermittent channel switching, etc. If these resistors are 330 ohm (as on some older units), they should be changed to 470 ohm to reduce the current through the 15V zeners and reduce heating of board and solder pads. Use the wirewound resistors with the little "feet" on the bottom to stand them off the board and allow free flow of air around the resistor. In a pinch, you can use a regular square wirewound with nonconductive standoffs placed around the leads. Good luck.
|Tim P Thanks Dave for the excellent advic... -- 10/29/1999 2:48 PM|