Repairing Rotel RA-840BX3 and looking for trustworthy transistor source

Hey Everyone,

I'm looking for the following transistors to repair my RA-840BX3:

Q621 - 2SD600K
Q623 - 2SD600K
Q625 - 2SB631K
Q631 - 2SB817E

Does anyone know of a trustworthy online source? Looks like some of them are now obsolete. Would prefer to order them all from the same supplier, in Canada or USA if possible.

When I purchased the amp (used), the power resistors on the driver transistors were all open due to overheating, so I fabricated some higher wattage replacements. However, when trying to adjust the bias I accidentally shorted the left channel. I've run my multimeter diode checker on all of the transistors on that side and only the above seem to have failed. Once I replace these transistors, I'm planning on doing a dim-bulb test to check if everything is working correctly. If all goes well, I won't require further assistance...

Thanks!
 
Yeah.... a typical issue with those.... I restored one for a friend. Have a look.... I used heatsinks on driver transitions, soft switching fast diodes, high power resistors, and replaced power rail filter capacitors.

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