I have used fixed attenuators (rothwell -10dB ) built in to a rca plug . Between poweramps and preamp .
The do not have a sound of their own they are simple resistors . But it is possible to get a mismatch but with "typical" transistor electronics it is unlikely, that is low output impedance of the source typical and fairly high and -even- not frequency dependent load impedance . Cable capacitance can come into play with passive attenuation if they are long or has to high Capacitance. These mismatch can roll of the treble slightly I think you are safe with stuff from blue jean or similar avoid "exotic" designs with mystery boxes on them or other weird stuff, you normally don't hear signal cables but if you do "caveat emptor" So in the application I tried attenuators they have no effect expect the one you want better gain scaling which gets you a lover noise floor and that is a very good thing :) Note that this was between an active preamp and an active power amp and fixed value attenuator. For a squeezebox I sugest one of those not using a stepped one as volume I suspect that linearity near the end positions is not that good, set the stepped attenuator to a reasonable value and and use the squeezebox volume. I suspect that missmatch and channel imbalance get worse at high or low attenuation (thats why we have preamp or digital volume ) so use at -6 -20dB . Stepped is much better than passive with a potentiometer as a stepped attenuator can have the right values on both resistors . Preamp Power amp mismatch is typical I had a classe that gave full power at 0.7 volt ? preamps can blast out anything between 2 -20 volt ? So if you ever use more than the first third or half of your volume control on preamp you may suffer from this I did own a semi passive preamp that side stepped the passive potentiometer problem in a nifty way it had an input buffer that could drive a rather low impedance potentiometer 500 Ohm or 1kOhm then the output impedance from this design was never really to high -- Mnyb -------------------------------------------------------------------- Main hifi: Touch + CIA PS +MeridianG68J MeridianHD621 MeridianG98DH 2 x MeridianDSP5200 MeridianDSP5200HC 2 xMeridianDSP3100 +Rel Stadium 3 sub. Bedroom/Office: Boom Kitchen: Touch + powered Fostex PM0.4 Misc use: Radio (with battery) iPad 64gB wifi +3g with iPengHD & SqueezePad (in storage SB3, reciever ,controller ) ------------------------------------------------------------------------ Mnyb's Profile: http://forums.slimdevices.com/member.php?userid=4143 View this thread: http://forums.slimdevices.com/showthread.php?t=93776 _______________________________________________ audiophiles mailing list audiophiles@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/audiophiles
