LM12CL as an amp ???

[la9]

I was thinking of using an lm12 for an amp. Seems like everyone here supports other chips and the links that used to be around for the lm12 amps are dead.

It looks great from the datasheet, just wondered why it doesn't seem to be very popular.

Thanks

 

[li_gangyi]

it's possible to do that...but at a higher price...the 3886 from national also does 10A+...so it would really depend on ur budget I guess...

 

[JojoD818]

The answer to your question is the cost of the chips.

 

[SY]

I built some LM12-based amps maybe 10 years ago. They worked just fine, but I wouldn't do it again- the new purpose-made power amp chips are much cheaper and more suited to the task (e.g., better protection circuitry). The LM12s were also more difficult to handle physically, being in a rather non-standard TO3 package with a pinout that required some time on a milling machine modifying heat sinks.

 

[FBsHT]

I found 14 LM12CLKs on some scrap boards. I will need to test them to make sure they are good but I would bet they are. They are already mounted on heat sinks so it seems most people's complaints are not applicable (cost and heat sink drilling).

Can anyone comment on the sound quality of the LM12CLK? I plan to build these into a bridged/parallel sub amp so they should be fine for this. Can anyone point me to a schematic.

FB

 

[carlosfm]

The LM12s were also more difficult to handle physically, being in a rather non-standard TO3 package with a pinout that required some time on a milling machine modifying heat sinks.

Don't even tell me.
I made 8 holes on each heatsink just to try the OPA541AM (TO3, 8 pins).
Milling machine?
No, just my old Black&Decker.

 

[SY]

You've got steadier hands than me. Must be the Port.

 

[yopi3622]

Hey guys, why not use this LM12 as a regulator in order to feed our little gainclones (with out the drawbacks of a standard regulator of course ) ???

The datasheet explains how to use it as a regulator. It is "capable of driving 10A into -/-25V"... peak current of 12A....

 

[carlmart]

Hey guys, why not use this LM12 as a regulator in order to feed our little gainclones (with out the drawbacks of a standard regulator of course ) ???

The datasheet explains how to use it as a regulator. It is "capable of driving 10A into -/-25V"... peak current of 12A....

I'd say why not use the little gainclones as regulators for little gainclones? They can even go higher in voltage.

Even better: why not use a high voltage chip, like OPA445, for a Sulzer/Jung/Didden style regulator? They can even go lower in impedance and all other specs.


Carlos

 

[jackinnj]

Don't even tell me.
I made 8 holes on each heatsink just to try the OPA541AM (TO3, 8 pins).
Milling machine?
No, just my old Black&Decker.

First on the LM12 -- they occasionally show up on EBay, elsewise you will pay $9 to $12 per piece.

Secondly, with respect to a milling machine -- once you use one you'll never go back. I have a small Grizzly (made in PRC) unit which I use for milling aluminum and drilling those annoying holes for printed circuit boards. It's acurate, fast, repeatable, no more broken carbide bits etc., etc. A dremel is fine if you only use high-speed steel bits...

 

[cm961]

I built a 4 channel LM12 amp. It worked great. Well, I didn't build THAT much of it. The power supply came in the case, and four LM12s attached to heatsinks (Sides of case). So all I had to do was point to point wire them. Actually I used terminal blocks and it worked great! However, I ended up switching to LM3886s eventually, and that worked too. But alas, they pop when I turn them on.

Pete