T62A-40 Crossover Issue

[sjgrall]

Hello,

I have an original T series T62A-40. I replaced the electrolytic capacitors last fall, and saw a substantial sound quality improvement. However, recently, the crossover is not working correctly; at nearly any position, 60-75 Hz is at a lower volume than the rest of the 40-100 Hz range. The only way around this is to set the crossover almost at 250 Hz, which is less than ideal. Does anyone here have any idea which component on the amp to troubleshoot? I'm thinking one of the replaced capacitors may be failing prematurely, but I don't want to replace ALL of them again, and they look fine visually. I've also tried cleaning the level and crossover potentiometers. The 4 year old WF641.5 replacement woofer has a very small crack in the surround, but I don't think that would cause this type of issue….

I ordered a new BTA6250D to replace it, but I'd hate to throw the antique away when it may be something simple to repair, and then perhaps I could put it on eBay.

[heavyduty]

Originally Posted by sjgrall

Hello,

I have an original T series T62A-40. I replaced the electrolytic capacitors last fall, and saw a substantial sound quality improvement. However, recently, the crossover is not working correctly; at nearly any position, 60-75 Hz is at a lower volume than the rest of the 40-100 Hz range. The only way around this is to set the crossover almost at 250 Hz, which is less than ideal. Does anyone here have any idea which component on the amp to troubleshoot? I'm thinking one of the replaced capacitors may be failing prematurely, but I don't want to replace ALL of them again, and they look fine visually. I've also tried cleaning the level and crossover potentiometers. The 4 year old WF641.5 replacement woofer has a very small crack in the surround, but I don't think that would cause this type of issue….

I ordered a new BTA6250D to replace it, but I'd hate to throw the antique away when it may be something simple to repair, and then perhaps I could put it on eBay.

The potentiometer would be the first component to check. If that is not the problem, you are then looking at the active filter on the board.

[sjgrall]

I'm by no means privy to all that goes into an amplifier's design. What components make up the active filter, and where might I find replacements for those components, as well as another compatible potentiometer?

[sjgrall]

For those who are curious, the issue was traced to the crossover potentiometer itself. I was able to resolve the issue with Deoxit Fader products.