SX 950 AWH 050 Trannie Question

I have to replace the speaker output connectors on my 950. A few years ago I rebuilt the phono, PS and protection unit - and many thanks to those whose threads/posts who made that possible. No smoke!

While I have the unit benched I thought I would recap and at least replace Q1-4 on the power amp 050 board since I have the parts. I have some of the driver transistors but I'm not sure I want to go all in. Anyway, I noticed that in a recent parts list (likely from MTF & Mouser) Q11 is a KSA940. I have some KSA940TU's and (2) KSA940TU-Q.

Might these suffixes be interchangable? What would the "TU" and the "Q" refer to? Thanks in advance!:scratch2:

I think the last suffixes designates the type of packaging the transistors came in. I am sure that it wont make any difference in the circuits. Tape, reel, plastic sheath, ect.

Hi,

The KSA940 data sheet says nothing about the suffixes, so the assumption would be they are the same. Sometimes the suffix indicate variations, such as hfe, vce breakdown, lead forms, packaging etc.
The npn complement KSC2073 has H1 and H2 hfe grades
There are other subs as well, onsemi MJE150xx and a newer fairchild FJP5200/FJL4215 or isolated FJPF5200/FJLF4215.
it is not really needed to change the drivers, but cleaning them up and applying thermal compound, new mica, would help them keep cool.
Someone must have been easy on your unit, if the outputs are still intact, I blew mine years ago.

good luck
rick

TU was plastic tube packaging in a plastic bag instead of bulk in a plastic bag.

-q was old non-RoHs parts. No biggie, the Pioneers use 60/40 tin lead solder so that's a drop in the bucket.

q1-q4 per amp good, if old drivers ok, leave them, but grease them.

Thanks all! I knew that the suffixes often indicated the gain but wasn't sure about the TU or the Q. RCS16 - maybe it had an easy life, pretty clean inside. My first experience with shipping these heavy units (shipped to me) ended in a smashed in left side face panel and bonnet split apart at half the joints. I was able to repair it with parts from Glenn and a bunch of tlc -- after a total freakout! Miracle it still works

Shipping damage story is scary, fault of the packer or the shipper?

Really the fault of the shipper. It looked as though it was dropped on the front left corner but then #2, on close inspection it looked like a "spear' pierced the same side and direct hit on the glass.....I took some pics and might still have them, I'm tempted to look and post. This was my first vintage piece to boot!

After some disappointing transactions with some repair "techs" (I use that term loosely) -- nobody on this site -- I figured I had BETTER develop at least some skills at working on these receivers. Which again leads me to saying thanks for all of the AK folks whose expertise made it possible. I'm more of a solder monkey than a true tech but, hey, I'll take it!! Thanks - sorry about the digression! Dan

That's exactly how I got started in this crazy endeavor.

I can fix the electronics, but damaged mechanical is a bitch unless you can get spare parts easily.