At 02:27 PM 5/18/2005, Philip Pemberton wrote: >In message > Peter wrote: > > > Tape playback preamp is in f.ex. LM387 datasheet. Recording is done > > without ac bias in those things. Sometimes dc bias is used (resistor > > from +Vcc feeds through head). > >The one thing I need to work out is the bias current. 5V Vcc, with a >record/playback head impedance of 92.5mH. Same thing for the erase head - >except that's 92.28mH (yeah, I know, big difference). If you go direct digital, you don't need to worry about that, and the record and play circuits are trivial. -- http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist