difference between an active and a passive preamp?

Hi Al, The cable between the source component and the passive control plays a reduced role on account of the output impedance of the source. When the series resistance of the passive control is inserted into the circuit, the character flaws of the cable are essentially magnified. So most of the issue is downstream from the passive control.

The rather obvious solution is to install the volume control at the input of the amp, but this could be really inconvenient if you have monoblocks. A remote could solve that problem though...

I am bumping an old thread here!

I am leaning towards going with a passive preamp. Although, I am not into numbers too much because as long as you like the sound, who cares but in this case, I think it is important to check some numbers.

Is passive preamp suitable for my setup?

DAC: 

• Output Level: 3.0V RMS Max. (Analog).
• 
  
• Outputs: Stereo (RCA) 300 Ohms.

AMP:

Input Sensitivity (RMS) - @3Ω, 500W,1KHz 1.36V

Input Impedance - 33K ohms

@celo , maybe.

The real number to look at is the output impedance of the DAC at 20hz. If that is the same number then I would say your chanced are good with a passive control, if you keep the cables short.

I think that the output impedance is only half of the equation here. The other half is how the waveforms are generated from the source. Can you tell us the make/model of your DAC? Also, what kind of amplifier? I general don’t like to recommend passive preamps unless the source device has a very good Class A output stage or tube output stage. Generally, sources that use op-amps only as output stages may still have somewhat of a digital sound. It really depends what’s on the output stage. Sometimes there are excellent op amps and circuits (i.e. AD797 or something similar). The OPA2134, which is very popular, is okay but has more of a laid back sound and doesn’t have the resolution or separation-of-instruments as other circuits available.

My DAC is Musatex Bitstream. Amp is Class D. Thanks.