Just got the PS Audio Perfectwav DAC -- Amazing

With 100 kOhms input impedance you can match any preamp. The minimum ratio would be 10:1 - its my arbitrary number, provided that preamp, otherwise is fantastic. Somebody else will have different number. I feel that with 20:1 ratio the audible effect of mismatch is negligible.

My Joule-Electra preamp has the two outputs: buffered with 300 Ohms and with bypass buffer - 1200 Ohms. I would choose, most probably 1200 Ohms output even if my power amp would have low input impedance... sort of trade-off. Here, I gain transparency and immediacy bypassing buffer and would take the some roll-off at the top and bottom simply because preamp is fantastic (the best I ever auditioned) there and I can sacrifice it a bit.

All The Best
Rafael

I don't know a whole lot about pre amps. I thought that really what you wanted to match was the Vrms out to the Vrms of the amps. The PW does 3Vrms RCA and 6Vrms XLR. The Bel Cantos are 3Vrms XLR and 2Vrms RCA. Currently I have them connected via XLR and don't crank the volume too loud.

Other than helping level these kinds of discrepancies, what does a preamp add? Is it the case that the preamp is simply coloring the sound in its own way which may sound better or worse? Or would a solid pre amp definitely improve the sound / why?

i was thinking the same thing. seems to go against the "less is more" theory i was looking into.

not to hijack the thread but if true...what does one look for in a pre that makes it "a good one"?(for applications like this). am actually more concerned about price point for a "good pre-amp". this could kill the estimated budget for my future upgrade.(like that hasn't happened before lol!)

i think it should be a new (old!) thread if we want to discuss DAC-amp vs DAC-PRE-AMP vs DAC-passive pre-AMP.

I'm very eager to know how the MW Transporter compares to the PWD.

I don't know why you guys are not talking about this, but I think that the real issue with using the DAC to attenuate the volume is whether that is achieved by analog or digital methods.

If it is done digitally, then you are definitely losing original bits from the songs. Lossy. Think mp3. No surprise if you lose "3D", and you're probably losing something in the 2D and 1D and 4D and 23D as well, whatever that means. Lossy. Worse with more and more attenuation, and if you're bringing it down from 100 to 60ish then you can forget about hifi.

If the attenuation is done via analog, then of course it depends on how well it is done. Now that is precisely what a preamp is suppose to do! A good one should do it well, and if the DAC outperforms it then we are talking about one hell of a great DAC (or one lousy pair of interconnect cables).

I know that the squeezebox attenuates by digital manipulation; I'm pretty sure that the Transporter does the same thing. This thread will shed some light on this,

http://forums.slimdevices.com/showthread.php?t=30916

Basically, you want to listen to the slimdevice gadgets at maximum volume and attenuate with something else; or use them to get the 1s and 0s into whatever DAC you like, and then go through there to, once again, a preamp.

Anything else and you're asking for lossy data. Mp3s, maybe nice mp3s, but still mp3s. The whole point of flac gets tossed into the bitbucket.

I have no idea what the PS Audio dac does to achieve this. If it trumps a preamp, then it's a better preamp than that preamp. If it trumps all preamps, then it's a hell of a preamp (well, except for its lack of non-digital inputs!). But if it does it digitally, then it's lossy. The fact that their web site does not mention this issue is not encouraging,

http://www.psaudio.com/ps/products/description/perfectwave-dac?cat=

since it is a clear big selling point and they should be explicit on the method (sadly, the logitech transporter site does not mention it either). For $3k, I would expect one hell of a volume knob...