> -----Ursprüngliche Nachricht-----
> Von: Doepfer_a100@yahoogroups.com
> [mailto: Doepfer_a100@yahoogroups.com ]Im Auftrag von David Salter
> Gesendet: Freitag, 19. Mai 2006 10:29
> An: Doepfer_a100@yahoogroups.com
> Betreff: RE: 1 Problems with 4096 stages BBD modules
>
>
> Excuse my ignorance here as I'm sure it's been said before.
>
> When I purchase a BBD module will I be able to swap different BBD chips,
> i.e. are the chips pin compatible
>
> Thanks
>
> David

David,

it depends .....

For the first two series of A-188-1 only these BBD circuits can be used:

MN3204 (512 stages)
MN3205 (4096 stages)
MN3206 (128 stages)
MN3207 (1024 stages)
MN3208 (2048 stages)
MN3209 (256 stages)

The other BBD circuits can be used only with some modifications (additional
parts and wiring, interrupted pcb tracks). But we do not recommend this. We
also manufactured a small quantity of adapter boards for the MN3005 (4096)
so that this BBD can be used even in the first module series. We had many
customers who wanted badly to have the module with 4096 stages and asked if
there is a change without waiting for the revised module (~ June 2006).

From the third series of A-188-1 (available about end of June 2006) the
revised version of the module is delivered. In this version additionally
these BBD circuits can be used:

MN3004 (512 stages)
MN3005 (4096 stages)
MN3006 (128 stages)
MN3007 (1024 stages)
MN3008 (2048 stages)
MN3009 (256 stages)

The type of BBD module can be selected with several jumpers on the pc board
of the revised version.

But in every case the module has to be re-adjusted because of the different
clock range of the BBD circuits (see A-188-1 user's manual), the different
resonance/feedback behaviour and two other required adjustments
(balance/symmetrical clipping and clock feedthrough). Four trimming
potentiometers have to be readjusted (clock offset, max. feedback,
balance/clipping, clock feedthrough). An oscilloscope and frequency meter is
recommended but one could try the adjustments even by trial and error. An
appendix is planned for the A-188-1 manual that describes the adjustments
and how to change a circuit (different cases and pin numbers).

Best wishes
Dieter Doepfer