Carver M400 specs

Input impedence? What makes you think the Carver is different from most amps out there? If it follows the norm, input impedence should be in the neighborhood of 50K. The odd amp here and there might have an input impedence of 20K and I've even seen a few at 10K, but 50K is almost an industry norm.

If you really, really need to know, it can be discovered with a pot in series with an input signal...a tuner would work well for this. You'd need to hack an phono cable and install a potentiometer in series with one of the output channels (100K pot). Turn off muting, and dial in a point on the dial with no station (close to pink noise source, some call it 'rose' noise). Measure output of the tuner at the tuner with a DMM (we aren't splitting hairs here, so meter frequency response is a non-issue). Set it to something like .5V RMS or so (you may not want speakers hooked up). Now measure the voltage across the pot. Set the pot so that half the tuner's output voltage is dropped across it. When you have achieved this, disconnect the pot and measure it. This will be the input impedence of the amp.
 
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I'll admit to not being knowledgeable about such technical aspects, but here are specs from BAT amps. Don't know what relevance this might have to the Carver amp, but it seems to contradict the statement that 50K is the norm.

TY
BTW, the VK-1000 is a monoblock (that's why its impedance is 50K why other stereo amps are 100K???).
 
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Contradict? Not really. The load difference between 50K and 100K is pretty small. 50K is usually a good compromise because higher input impedences require higher value input resistors...and higher value input resistors create noise. The exception is with JFET input devices, but these are not used as input transistors that often because of the ease with which they can be destroyed.

Your specs on the BAT amps essentially confirm my previous post. Large input impedences are not a problem for the device to be connected, especially when we are talking about values above 30K or so...which is why I concentrated my thoughts on values of 50K and below. A 100K input impedence is barely seen as a load for anything plugged into it, provided it has a reasonable output impedence.
 
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