User manual

2
0 - Combinations of features for the TR-606, TR-808 and TB-303
This is an additional modification I can install in a Devil Fish modified TB-303 or in a TR-
606. A similar system can be installed in the TR-808, with the switches aligned vertically on
the left side of the machine, with their toggles moving left-to-right.
This manual describes the Dynamic Bank/Channel Switching variants of the 32 Bank
Memory System, which I started installing in February 2014. Please see the Devil Fish page
for a separate manual describing the basic 32 Bank Memory System as I have been
installing it since April 1999. From the early 1980s I also installed memory systems with
4, 16, 21 or 32 banks, with completely different controls.
In the context of the TB-303 Devil Fish and the modified TR-606 and TR-808, the term
“Dynamic Bank/Channel Switching (DBCS)” refers to several combinations of
modifications, as explained in the following paragraphs and table.
For the TR-606 it refers to “Dynamic Bank Switching” in which two input sockets, two
approximately +1.15 volt detector circuits with two LEDs are used to potentially invert two
of the five memory bank address bits generated by the toggleswitches and pushbutton. The
input sockets, LEDs and switches look much the same as those in the picture above, which is
for the TB-303.
For the TR-808 it refers to “Dynamic Bank Switching” in which two or four input sockets,
two or four approximately +1.15 volt detector circuits (with two or four LEDs) are used to
potentially invert two or four of the five address bits generated by the toggleswitches and
pushbutton.
For the TB-303 Devil Fish without the MIDI In and Out system, the same is true as of
the TR-606: the term refers to “Dynamic Bank Switching” in which two input sockets, two
approximately +1.15 volt detector circuits (with two LEDs) are used to potentially invert two
of the five memory bank address bits generated by the toggleswitches and pushbutton. This
is true for the TB-303 Devil Fish with or without MIDI In. Only the MIDI In and Out
system supports Dynamic Bank/Channel Switching – which includes the ability to
dynamically switch MIDI In channels for Notes.
For the TB-303 Devil Fish WITH the MIDI In and Out system, the term refers to
“Dynamic Bank and MIDI In Channel Switching” in which two input sockets, two
approximately +1.15 volt detector circuits (with two LEDs) are used to potentially invert two
of the five memory bank address bits generated by the toggleswitches and pushbutton. The
potentially inverted bits from these switches are also used by the MIDI In and Out system to
switch between four contiguous MIDI In channels for reception of Notes. In addition, the
two input sockets can have their default contacts (which drive the output of the socket if
nothing is plugged into it) with bits which result from MIDI In (on Channel 15 or 16) Note
and/or Control Change messages. This means that in addition to using the toggleswitches to
control memory bank or MIDI In Channel, and the potential use of one or both Audio/CV
Input sockets to invert two of the bits, it is possible, when not using one or both of these
input sockets, to have the detector circuits and their LEDs and bit inversion circuits driven
by bits derived from MIDI In Note and/or Control Change messages received on Channel 15
or 16. This is the complete Dynamic Bank/Channel System – and all the MIDI aspects of it
are described in the MIDI In and Out System User Manual.
On the next page is a table of the possible scenarios involving a 32 Bank Memory system,
with an indication of whether the manual you are reading now, or some other manual, is the
best source of information. The “Installation” numbers “
TB-303-x ” refer to various