KRK 10S powered sub - looking for transistor substitutes

[Delta362]

I'm repairing a KRK 10S powered sub. The amp is in protect mode. I found Q436 (A1024) shorted, R494, R481, R501 all burned. Q440 (C3206) also reading very low. The outputs transistors all test ok.

I'm struggling to find the replacement for Q436 and Q440. Any suggestions? Thanks!

Relevant part of the schematic is on page 4 of 57.

[Delta362]

How about the TTA004B,Q for the A1024; And TTC004B,Q for the C3206?

[Jazz P Bass]

Both TT's have the wrong package type & pinout.

[Delta362]

They have the same ECB pinout as what's in there. Yes, the package type is different, but since the existing ones aren't on a heatsink, I didn't think the package difference would be a concern.

[Delta362]

Do you have any suggested/recommended viable substitutes for the originals? I was looking for those that are of similar wattage, voltage ratings, hFE ratings, current consumption.

[Delta362]

What about the 2N5401 and 2N551, watching pinouts?

[Delta362]

And in my continued search, the KSC2383O and KSA1013O look like they may work.

Looking for any confirmation or other suggestions. Thanks!

[g1]

I like the TTA and TTC options, the package will deal with heat better than originals.

[mozz]

From Google.


"Old Thread I know, but I just repaired a Pioneer VSX-51 Home Theater receiver with the 1024/3206 pair in a predriver ckt. I subbed with the 1145/2705 and the unit powered up and runs audio just fine. Just thought I would pass along the info, sourcing the 1024/3206's in the US is a huge pain in the butt."

[Delta362]

Thanks! Given that I already have the TTA004B/TTC004B on hand, I'll go with them first. But I won't be able to test it until I get the replacement 68 ohm resistors ordered first, which may take a bit until I get a large enough order to make it worthwhile.