Hartke Schematics; any solid state guys out there?

[Enzo]

You are right, those particular numbers are screwy. The schemo calls for:
Q309 - 2SC2238
Q310 - 2SA968

And what do you know, that pair is one from the MCM suggested TO220 section. They are 160v 1.5A 25W parts. Most any xstr with those specs will work there. If I had none of those, I would not hesitate to mount a 2SC3298/2SA1306 pair.

MCM sells a Jap Xstr manual. Just quick data for each type. Once I identify a type's spec, then I can look through my stocks for suitable swap. On my drawer labells I include the V/A/W specs along with type number just to make subs easier.

I suggested making sure the resistors were intact, I don't think I meant replace them anyway.

Stay away from that NTE stuff. I just looked up TDA2040 on Mouser last night for someone and they wanted $2.73 for it, the NTE equivalent was like $14. If I have to find a sub for a part, rather than buy NTE, I'll just use another similar part.

[wizard333]

Thanks Again guys!

Enzo I had a dyslexic moment there; I typed power resistors but I meant the big power transistors that follow those. As long as they dont read as shorted should I replace those as well?

[Enzo]

If you mean the row of outputs, I'd lift their legs and use the diode function of your meter. Obviously if they are shorted, pitch them, but if not, the diode test of their junctions at least can give extra information about its condition. Remember, when one xstr in a row goes E-C short, it REMOVES the stress from the ones next to it. C-B short usually destroys the whole row anyway. SO no, I don't just replace the outputs wholesale. On the other hand if 3 of 4 or 5 of 6 are bad, then I will go ahead and do them all.

[Amp Kat]

Those are Japanese Semiconductors and many Domestic Co.'s don't carry them. If you call MCM and give them the numbers they will throw it in the computer and tell you if they have them. Mouser can tell you who has them if they don't. It isn't always in the book and I'm not too big on NTE for Japanese Semi's

[oc disorder]

Hartke power amp modules

A few years ago I had one to repair.
For memory it was the 700 watt version with a massive toriodal pwr trans.
I spent ages making a shopping list of all the parts transistors -
flame proof resistors- etc sourced locally and internationaly only to
find the distributor could supply the modules (mounted on the heatsinks)
for aprox $160 aust ea so I bought two - screwdriver fix .. just plugged them in and hey presto instant fix for less than what it would have cost to
repair both modules...and I kept the old ones for spares...
Dunno if the modules are still available but saved myself and the owner a lot of time...
Just my 2 cents worth...

[Enzo]

Last time I checked - a few years ago - they still had the modules. I even bought a spare. But that was the only time I replaced rather than repaired one.