what's 'Active preamp' vs 'Passive preamp'?

Eandylee

"Is it better because I'm skipping additional device that I don't need? or A good preamp somehow does some good thing to improve the sound quality?"

I'm of the opinion that the simpler the signal path, the better the sound MUST be, in theory. HOWEVER, practically, that doesn't always result. There are techical reasons having to do with characteristics measured by input sensitivity, impedance, etc. I can't fully understand that stuff so, I resort to trying it out and listening. It's pretty inexpensive to try...Give it a shot!

Eandylee, most volume controls that are in DACs are not of the best quality- particularly if they are digital. Digital volume controls essentially subtract bits to lower the volume; the result is audible loss of resolution as you turn the volume down. If you want to do it right, an active preamp (especially one *without* remote) will have a better chance of doing the job right- you would run it and have your DAC turned all the way up for maximum resolution.

One other task of active preamps is to control the interconnect cable. If set up properly, the line section of the preamp will minimize or eliminate the effects of the interconnect cable. Be careful though- many preamps may do their other jobs well but fall flat on their face in this department, introducing coloration due to the cable. BTW, this is a serious weakness in 'passive preamps' which in fact are not preamps at all.

Only a brief comment about passive pre-amps and gain. Although passive, if they use transformers (TVC) they can add gain too. Typically +6 dB. And that is sufficiant in most applications.

Transformers can add voltage (gain) but only at the expense of current and add current (gain) at the expense of voltage. Because they are passive, no net increase in energy is possible.

Kal

Eandylee,
I am now using my APL CD Player direct to my Pass Amp and it is better than when I used a Melos Preamp. Sound is purer.
Plus, as was mentioned, I eliminated one power cord, interconnect, rack space .