How much power is this thing ? If it is not too high you can just rewire it to use a pair of LM3886 or something. They are not bad chips. I did that a year or two ago on a unit that used an SVI chip, which is an STK but just considered fancy.
***********************************************************************
I now think it would make more sense to use another cheap, easily available STK module. They are pin for pin compatible and bolt straight onto the heatsink.
10 minutes to change them.
The 2 x LM or TDA options are going to mean an absolute rat's nest of wiring to individual IC pins in mid air, not to mention having to sort out a suitable mute conversion. How many hours is that going to take?
Gareth.
*********************************************************************
Well, having ordered a STK 442-120 and expecting it to arrive in 2 days max as usual, it didn't. Wasn't even dispatched until friday, I assume half the staff are probably on holiday. Most unusual.
Anyway I decided to have a look at using a pair of LM's/TDA's or whatever, only to find a new STK 442-130 in my TDA drawer I didn't know I had. I must have ordered two some time in the distant past and gave myself a spare.
So, swapping them out really was very quick, and it works. I believe these 130 version are rated 150W, but I've no idea what they base this upon, as it is probably bogus. The Onkyo I have doesn't look hugely powerful power supply wise, so this IC is probably well overkill over the original, whose specs I could not find anywhere.
Check out the prices of these, they are not expensive. I even found a US retailer who were guaranteeing theirs were genuine Sanyo parts.
Another thing. This Onkyo has 2 STK parts, the 442 and a 443 part. The
443 part has 3 amplifiers, the 442 has 2. Consequently the 443 has more pins. It turns out that the pinout for the 443 follows exactly the 14 pins of the
442, and simply tacks on an extra 4 pins for the 3rd amp (2 in, 2out).
The motherboard of this Onkyo actually has 18 pins available at the site the
442 was occupying, with circuitry not fitted regarding a possible third amplifier. Meaning it was a generic motherboard that could use either 2 x 443 chips, or
1 x 443 and 1 x 442, depending on which model it went into.
So this leads me to believe that these STK chips are indeed simply plug and play, you select the particular chip with regards to how many amplifiers you want and at what power.
Which is why people like Onkyo use them? It would make sense to know you could produce a generic PCB and simply plug in whatever STK's were appropriate in a single design, and that any future improved STK's could simply be plugged in instead without any major redesign work.
Anyway, for not much more that a couple of LM/TDA's, you could perhaps just find an appropriate STK, you just need to find a reliable source of these.
Good luck, I don't do hi-fi repairs, this is a very good example of why not.
Cheers,
Gareth.