Crumar Musical Instruments User Group.

i'm sorry... you can tell me that i'm late but this is the list of 
the IC's on my P857/2 (and not /12 like you but i think it's the 
same boards):
IC 1                    =>  MC1458P (op_amp)
IC 2 & 3              => SN74LS221N (a dual monostable multivibrator)
IC 4                    => DM74LS05N (hex inverters with open 
collector outputs)
IC 5, 6, 7, 8  & 9  =>SN74LS00N (nand gates)
IC 10 & 11           => M083B1 (The TOS chip)
IC 12                   => SN74LS93N (4-bit binary counters)

and so you're board is without the tos! can you tell me wath problem 
you have with your trilogy? you can't heard somehing?