Tweet
I periodically run into things which give me pause.
Mouser has in stock some TI Class C power amp chips. The published specs on audio performance, THD+noise, etc. look good - as good as Class AB amps in general up through the 80s and into the 90s for most consumer stuff. And the jellybean/glue parts that go around them are no longer as nasty and impractical as the first couple of generations of Class D amp chip designs. For instance, they do not need or use external MOSFETs to do the heavy lifting. All the active devices are inside the chip, which sports a large rectangular area on the top for connection to a heat sink directly. About the only difficult part to a home hacker is that the packages are SMD, and quad flat pack to boot, so magnifiers and a very steady soldering hand are needed. But the PCB is two-layer, and they not only show it to you, they tell you that you need to use this one to get good results.
They have several variants, but the top three powers are 100W, 150W and 600W (!) RMS into 4 ohms. These cost $13 to $16 for the big kahuna in ones. I was at least mildly amazed.
This brings home the truism that electronics are tending toward zero cost while anything that deals with people or power - external enclosure, speakers, controls, power supply, decoupling caps, connectors, etc. - come to constitute almost the entire cost of a unit. A $600W amp costs $16, and really works. Of course, you're going to need some interesting speakers to live through it, a power supply that creates 700W of DC to power it, and some biggish filter caps, inductors and heat sinks to make the amp live up to its potential.
To a first order, the amp is free. The stuff to make it work may cost you a bit.
Mouser has in stock some TI Class C power amp chips. The published specs on audio performance, THD+noise, etc. look good - as good as Class AB amps in general up through the 80s and into the 90s for most consumer stuff. And the jellybean/glue parts that go around them are no longer as nasty and impractical as the first couple of generations of Class D amp chip designs. For instance, they do not need or use external MOSFETs to do the heavy lifting. All the active devices are inside the chip, which sports a large rectangular area on the top for connection to a heat sink directly. About the only difficult part to a home hacker is that the packages are SMD, and quad flat pack to boot, so magnifiers and a very steady soldering hand are needed. But the PCB is two-layer, and they not only show it to you, they tell you that you need to use this one to get good results.
They have several variants, but the top three powers are 100W, 150W and 600W (!) RMS into 4 ohms. These cost $13 to $16 for the big kahuna in ones. I was at least mildly amazed.
This brings home the truism that electronics are tending toward zero cost while anything that deals with people or power - external enclosure, speakers, controls, power supply, decoupling caps, connectors, etc. - come to constitute almost the entire cost of a unit. A $600W amp costs $16, and really works. Of course, you're going to need some interesting speakers to live through it, a power supply that creates 700W of DC to power it, and some biggish filter caps, inductors and heat sinks to make the amp live up to its potential.
To a first order, the amp is free. The stuff to make it work may cost you a bit.
Comment