This British-made bass head was dead to the world. After looking at the fuses, nobody would dare open it for service, possibly because there was no service literature available in this hemisphere, or perhaps out of reverence for the brand. This is a hybrid amplifier, with a tube in the preamp chain and a solid state power amplifier. Would the Unbrokenstring Crew run where angels fear to tread?
The owner said that he would clean up the front panel. Just get the thing working.
The steel chassis was just the ticket to keep everything in its place. You can see the Trace Elliot heritage in this brand.
Here’s a close-up of the rear panel. The footswitch must have a pair of switches and a pair of quarter-inch plugs. The line input jack is an interesting feature.
These plastic caps covered the screws that secured the chassis to the case. Well, it appears someone has been here before us!
A little care and a #3 Phillips was enough to bite into these screws and get the unit open.
Here, the power amp board is pulled free for inspection. That’s some big wire!
Can you see the failed solder joint? The four elongated tabs are the terminals on a large full-wave bridge rectifier.
Each of the solder joints were de-soldered and then re-soldered with fresh solder. The joint that failed may have been on an ever-so-slightly thinner trace, so a jumper wire adds some circular mils of copper to that part of the circuit to keep the temperature rise of the circuit board down.
Behold! Everything comes alive! This meter is really a nice-looking feature.
This unit is conservatively rated at 300 watts. The unit barely got warm after four hours at that power level. I think we fixed it!
Thanks for reading all the way to the end!
CONTACT – David Latchaw EE
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