Steinhart TR-80 mystery IC

[ludo]

I'm trying to figure out what the chipamp in the Steinhart TR-80 amplifier is. It appears to be one of the Sanyo STK ICs that were popular in mini-hifis in the 90s, but the number has been sanded off. It has 16 pins, with + inputs on pins on 1 & 16, like the older types (ie STK4152II etc, but those have 18 pins... ) Newer 16 pin types have all the input pins on one side of the row, so won't work on this PCB. I'm not finding any Sanyo data for anything that will fit here.

Pin numbering/function is

1 +In1
2 -In1
3 Gnd/(Mute(?)
4 Bootstrap R 1
5 V-
6 Out1
7 Out1
8 Soft start(?)/Mute(?)/V+ filter for driving circuit(?)
9 V+
10 Out2
11 Out2
12 V-
13 Bootstrap R 2
14 Gnd/Mute(?)
15 -In2
16 +In2

Body of the package measures 78mm x 44mm and supply here is +/-33V

PCB is labeled TVP 4021G and Steinhart Elec- so I presume it is original and they were all like this.

Anybody have any idea what this IC is before I make a new board and fit some different rubbish in stead?

[chipwelder]

Was that the multi-channel steinhart?

[ghostinthemachine]

Uhm - was mr Steinhart and van den Hul friends? (in reference to the VDH monoblocks with defaced components)

[LAV]

When I still worked in electronics repair, I used to curse manufacturers who sanded IDs off components. Of course, the moment I saw components with markings removed, I mostly questioned the manufacturer's motives and integrity... The opposite also applies - if you open a manual or box and find a circuit diagram inside, it just makes you more positive about the company concerned.

[ludo]

Was that the multi-channel steinhart?

It's a small solid stater. Shoe box shape, powder coated, with a granite face for audiophile credibility. Just a stereo power amp.

Uhm - was mr Steinhart and van den Hul friends? (in reference to the VDH monoblocks with defaced components)

I don't suppose so This one is wired with stove wire, which I believe he was fond of. Not a bad idea to my mind, but a chassis earth would have been a nice touch...

When I still worked in electronics repair, I used to curse manufacturers who sanded IDs off components. Of course, the moment I saw components with markings removed, I mostly questioned the manufacturer's motives and integrity... The opposite also applies - if you open a manual or box and find a circuit diagram inside, it just makes you more positive about the company concerned.

If one has something to protect, I guess one will try to. But what was most in need of protection here was not intellectual property. It was the nasty mess of a board inside that had to be hidden. I'm all for a quick hack and could not pass myself off as Mr Neatness, but for something produced in some quantity this is really not nice

Anyhow, if someone knows what IC this was, it might be a very good idea to mention it here. There's probably a good number of these amps in circulation in this part of the world, no Steinhart Electronics any more, and just about zero info on them on the net.

If one takes off the top cover (4 screws) one can see the IC in there. Would be great if they didn't all lose their lettering and someone could spill the beans with a part number.

[Steerpike]

Maybe a photo of the chip showing its package type?

[Steerpike]

STK465 matches your pin-out labels, its 30W at +/-28VDC

[ludo]

That's the one. Thanks Steerpike!

They're R30. Not half bad then. Still, a nice opportunity to see if the gainclone board works. Might freshen the whole thing up a bit. Will post a pic of the new horror when it's done