Hi Daiwai
Here is a thread I started regarding the exact same issue. If you care to read it.
Basically what I've discovered is - The culprit which must be avoided is DC (as in electrical current) leaking out of the pre amp back into the power amp. It really depends on the maker of the pre amp and the type of capacitors they use. I believe the newer Cary units are safe, the TAD-150 is safe also. I contacted the companies and asked if their units (specify which unit you are interested in) leaked DC.
hope this helps
Paul
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1103939290&openmine&zzOldpet&4&5#Oldpet
Here is a thread I started regarding the exact same issue. If you care to read it.
Basically what I've discovered is - The culprit which must be avoided is DC (as in electrical current) leaking out of the pre amp back into the power amp. It really depends on the maker of the pre amp and the type of capacitors they use. I believe the newer Cary units are safe, the TAD-150 is safe also. I contacted the companies and asked if their units (specify which unit you are interested in) leaked DC.
hope this helps
Paul
http://forum.audiogon.com/cgi-bin/fr.pl?aamps&1103939290&openmine&zzOldpet&4&5#Oldpet