100W chip amp using massive parallelization

[cuallito]

Okay I know how this sounds but what'd be the drawbacks/advantages to making a single 100W amp by paralleling 20 or so simple op-amp amplifier circuits?

[geraldfryjr]

which opamps?
It would take a whole lot more than 20 regular dual opamp chips to get 100 watts. jer

[wakibaki]

It's been done. Not to 100W, but...

Doug Selfs NE5532 Power Amp. Thoughts anyone !

w

[cuallito]

I looked thru the thread but I couldn't really find much about how the thing sounded. Did I miss that?

[Conrad Hoffman]

Another way to do it is operate several credit cards in parallel and buy one of the big Apex chip amps.

Conrad

[woody]

For a 100w amp you would need something like a + & - 50v power supply. Opamps
that can operate at those voltages are hard to find and pretty darn expensive.

[wakibaki]

Originally Posted by cuallito

I looked thru the thread but I couldn't really find much about how the thing sounded. Did I miss that?

There are a couple of other threads on the subject but I haven't been able to find them using the search facility. I don't recall anyone actually having heard one, but the measurements were extremely clean.

w

[CharlieLaub]

Originally Posted by woody

For a 100w amp you would need something like a + & - 50v power supply. Opamps
that can operate at those voltages are hard to find and pretty darn expensive.

well that would depend on the load impedance, now wouldn't it, woody?

-Charlie

[AndrewT]

The highest common/cheap opamp voltage supply is 42V (=+-21Vdc).

This will allow maximum output voltage of ~ 18Vpk into a load.
Now parallel sufficient opamps to deliver the peak current that a speaker could demand from 18Vpk transients.
8ohms could be ~220 30mA opamps giving an effective output power of ~ 20W into 8r0.

Speakers seem to be a non starter. Medium or high impedance headphones would be a more suitable load.

Oh, before you ask you could bridge your opamp amplifiers for ~80W into 8r0 but this would require ~ 900 opamps each capable of delivering undistorted 30mApk (not the short circuit limit)

[Arty]

Originally Posted by cuallito

Okay I know how this sounds but what'd be the drawbacks/advantages to making a single 100W amp by paralleling 20 or so simple op-amp amplifier circuits?

As advantage i realy can't think of anything... At least keeping in mind the amount of op-amps you would need.
load sharing will more than probably not going to be equal so you can run into -more or less- n-1 problems, where n is the number of opamps You need to use.

Maybe if You need to, You might find a decent opamp that has enough current capacity and output voltage to paralell a quad opamp for a headphone.
or drive a piezzo tweeter (whatever is benefical in that, but who em i to know.. realy)

Actualy if You ask me, for those power levels it may not be usefull at all.
You might be better of just adding output transistors on some high supply/output voltage opamp. Not a clever solution but who knows, might actualy work out well.