> I think Florian is right...16*4= 64 potentiometers cost quite some cash.
> I haven't seen the inside of the 154, but i PRESUME it has a 4 bit
> counter inside for the adressing ..

right, but the address bits are not generated by a normal 4 bit counter but
by a microcontroller to obtain the different modes (forward, backward,
pendulum, random, voltage controlled and so on).

You could use e.g. CD4051 analog multiplexers for the sequencer circuit
(same are used in the A-155 and MAQ16/3).

Best wishes
Dieter Doepfer