Best Preamp = No Preamp?

No, it's a common misconception. If you're using the volume control on your source unit, THEN that piece is pulling double duty as your preamp. PERIOD

The heart of any preamp is Volume control.

I guess it's just a matter of time before people using a receiver, start saying they're forgoing a tuner and preamp.

The other main con is that the outboard DAC may not have enough output to drive the power amps. Some DAC's only have the volume control as an afterthought.

I heard a system which was substantially improved by the addition of a preamp. Before the preamp was added, the system would run out of puff when given something dynamic to play. Even with the volume control maxed out, the system could not go higher than 85dB. CD's that were mastered at low volume were especially problematic - the lack of gain made these CD's much too quiet to listen to.

It all depends on your DAC and power amp. Specifically, the output voltage and output impedance of your DAC, and the input sensitivity and input impedance of your power amp. If these are poorly matched then you won't be happy.

All the best from sunny Australia!

Keith

It really depends on your system, with multiple amps etc. I would think a preamp is necesary.
I am using passive preamp but I have very sensitive speakers (horns) and a very sensitive amplifier (low input voltage and very high input impedance) and in my case the passive did beat a top of the line preamp, by a very small margin.
In different cases active preamps do add body and dynamics to the music, but low quality preamps do mess everything up so it is dangerous. One of the most important parts of a preamp is the volume control which can vary in price and quality, I like resistor loaded attenuators, which can be used in active or passive preamps, a bad volume control can destroy the signal!

As always, there is no rule....

I guess the best answer is it depends as always...

Anyway, I just read a couple of manuals of the DACs with volume control.

Both of them kind of claiming that connecting directly to amp and using it's volume control is the best.

I guess for these DACs, better to follow the manufacturer's suggestion?

Benchmark DAC1
http://www.benchmarkmedia.com/manuals/DAC1_USB_Manual.pdf

Bel Canto DAC3
http://www.belcantodesign.com/pdfs/UG_Dac3.pdf

"Direct Interfacing to Power Amplifiers:

The DAC1 USB is designed to interface directly to power amps and powered studio monitors in order to provide the cleanest and shortest path from the digital source to the monitor output. This often results in a substantial improvement in sound quality.

10, 20, and 30 dB pads are provided for interfacing directly to monitors and amplifiers that often have too much input sensitivity to handle high-level (+29 dBu) signal levels."

Above is from the Benchmark DAC1 manual.