hi ModelCitizen, The Transporter's unbalanced analogue output puts out 2Vrms which is enough to drive any of my amps without a pre-amp.
Historically, the job of a preamp was to boost the signal from phono or tape deck inputs up to the required voltage for an amp. Also, some input signals needed filtering (RIAA??) so the preamp did that. While we are talking about voltages it is worth remembering about DC voltage. To prevent DC voltage getting to the speakers we insert a DC blocking cap in the signal path. You'll will find your amp input probably has one, but also preamps will often have one (or more) as well. Some people don't like caps in the signal path so adding a pre-amp isn't desireable to them. Next, you need to look at the input and output impedances of the devices in your system. If your amp is happy with the 100 ohm output impedance of the transporter and the transporter is happy with the input impedance of your amp (mine's 47K) then everything will work fine. If this is not the case, a preamp can be included in an attempt to isolate the transporter from the amp and hopefully supply the transporter with the ideal load and your amp with the ideal source. I use a valve preamp, which actually is just a buffer because it has amplification of just less then one. It acts to isolate the transporter and amp, adds an extra DC blocking cap and adds some warm (or is that distrortion?) to the sound. I find my preamp is a very minor improvement to the sound to my ears. So, there are many issues and combinations, and that's why we all have different opinions. regards Greg -- Greg Erskine ------------------------------------------------------------------------ Greg Erskine's Profile: http://forums.slimdevices.com/member.php?userid=7403 View this thread: http://forums.slimdevices.com/showthread.php?t=30852 _______________________________________________ audiophiles mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/audiophiles
