Thread: A Comparison
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Arny Krueger
 
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Default A Comparison

"Trevor Wilson" wrote in
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wrote in message
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"Sander deWaal" wrote in message
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" said:

Krell 350 Watt monoblocks @ $17,500.00 per pair
350 watts wpc @ 8 Ohms
700 wpc @4 Ohms
1400 wpc @ 2 Ohms
Signal to noise = 118db 95 db @ 2.83 V
THD = .05% 20 Hz - 20 kHz
Input Impedance = 100 K Ohms
Input Sensitivity = 2.6v RMS for max power
Voltage gain = 26.4 db

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QSC PLX 3402 Stereo amp $1200.00
700 wpc @ 8 Ohms
1100 wpc @ 4 ohms
1700 wpc @ 2 ohms
Signal to noise 107 db
THD = .03% 20 Hz - 20 kHz
Input Impedance = 6 K ohms
Input sensitivity = 1.9 Volts @ 8 ohms
Voltage gain = 32 db


One of the things that I noticed immediately is the
ability of the Krell to deliver twice the power
(meaning current) in half the load, up to 2 ohms.
I suspect that even in 1 ohm the figure would be close
to the required 2800W, be it for a brief period of time.
The QSC has only marginally more power into 2 ohms (not
that those insanely high wattages have any meaningful
use, you will note). Also, the current doesn't double
with half the load.
This means the Krell has a stiffer power supply,
despite the lower average wattage. It is a true
constant voltage source.


You've jumped to a conclusion that's not borne out by
the figures. The power output into a variety of load
impedances is simply part of the spec. It does not mean
that the power output of the Krell will double just by
changing the load from 8 to 4 ohms. In other words, it
has nothing to do with the "stiffness" of the power
supply. What it DOES mean, on the other hand, is that
the Krell
is a 1400W amplifier designed for optimum performance
into a load of 2 ohms or less. Since the output is
voltage limited, it's an inefficient amplifier choice
for an 8 ohm speaker.


**All well and good Norm, but when was the last time you
measured a perfectly resistive loudspeaker load?


Maybe he's measured a ribbon tweeter lately.