IIRC the PB worked best with a stereo input to better define noise and make the choice of switching between groove sides. Better to sum the channels post-PB. joe salerno John Eberle wrote: > Playing 78s through an RIAA preamp basically rolls off the highs and > boosts the lows dramatically altering the frequency response from what it > should be . The RIAA pre-emphasis eq curve is applied during the disc cutting > stage of 45 and LP record mastering . 78 RPM records > were not cut with RIAA pre-emphasis ; but rather were cut mostly > flat with perhaps some low end roll of to control the size of the bass > groove excursions . > > A simple and cheap way to playback 78 RPM records is to connect the > turntable or tone arm audio out to the HI-Z microphone inputs available > on many preamps . This will give the flat response desired for 78s and a > little low boost will bring the lows back in to proper perspective . > Also , most cartridges in current use for playing 78s are actually stereo > and of course 78s are mono . It is totally weird to hear a 78 RPM disc > being played with stereo clicks and pops . The cartridge can be wired in the > headshell to reproduce lateral mono modulation only . This makes the record > noise a lot less and less need for the Packburn or any other analog or digital > transient noise reduction and better over all quality . > If anyone would like an mp3 of one of my commercial 78s reproduced > in this manner , just contact me off list and I will email it to you . > > John Eberle : Over 27 years disc cutting experience and over 35 years in > Mastering ! > AMERICANA CD MASTERING > 313 EAST COLLEGE STREET SUITE 3A > DICKSON , TENNESSEE 37055 > 615-441-4660 > > **************Feeling the pinch at the grocery store? Make dinner for $10 or > less. (http://food.aol.com/frugal-feasts?ncid=emlcntusfood00000001) >