"Robert Morein" wrote in message


What's the IM for each of these?

The QSC amps are not slouchy - even in tests of high
frequency IM.

What is the damping factor?

Way high, so high that a little speaker cable would be the
determining factor.

What is the slew rate, not measured under small signal
conditions, but, say, half way to the rails?

Irrelevant.

What is the power supply capacity of each?

I have here the service manual for a PLX 3402 including full
schematics.

I've seen Krells with their covers off.

My recollection is that Krells have a traditional 60 Hz
transformer, bridge rectifier, filter cap-based power
supply.

The QSC has a two-voltage (each for both plus and minus)
switchmode power supply. IOW there are 4 main voltages for
the output stage in addition to the seperate power supply
voltages for the signal amps and logic.

The output VCCs are +/- 117 and +/- 67 volts. Power FETs
route the proper voltage to the output stage depending on
what it takes to produce an undistorted signal.


Does anyone know if the QSC amp uses "blameless design"?

Nothing like it! It's a very characteristic design. For
example, the output stage BJT transistors all have their
collectors grounded - no insulators on the heat sinks.

IOW, does it use active current sources?

There's a ton more to the blameless design that just that.

Does the QSC have a regulated output supply?

For the op amps and logic.

This feature has been a mainstay of Krell design.

More Morein moronic nattering.

Contrary to what the mckelviphiban stinks, I am not a
subjectivist. I do believe my ears can tell me alot,
however, without the necessity of blind testing.

See Morein moronic nattering, above. :-(