9700 Series Modules, current flows
9744 CV Source
9748 Balanced Modulator
9751 Noise Source
9753 Envelope Follower
The MIDI2CV8 is the power supply for the complement of modules in the P9700S (9710, 9720, & 9730). It has the same four-wire DC power connection points (+, G, SG, -) as the other modules and power jumps from one module to the next with the basic modules having two connection areas for accepting the power and passing it on through. The minimum Amp rating of the 12V AC transformer used with the MIDI2CV8 is 1A (1000mA). 1200 to 1500 mA is even better. MIDI2CV8 uses a voltage-doubling rectifier for unloaded, dual-polarity 18VDC supplies. With the 1A transformer to the MIDI2CV8 and the load of the other three modules in a P9700S the DC passed along is about 16V. The modules take this unregulated DC power and on-board regulate it to twelve volt supplies. The supplies from the MIDI2CV8 are at their limit on the 1A transformer -- with more Amps, more power can be tapped, but the FR-7 chassis is full. If you are planning an expander system in an FR-7, it is best to have a second power supply.
The first and second-generation 9700 series modules can operate from regulated fifteen volt power supplies; however, for the best results, the first modules in the series should have the power supply input coupling resistors bypassed or replaced with wire.
For the most power in an FR-7, the 9771-15 is recommended. It provides up to 600mA on the positive and negative 15V DC supplies. It has 12 power connection areas and this is useful with the second generation 9700 series modules which only have a single DC connection area (each module wires back to the supply rather than the pass-thru arrangement on the first generation modules). It occupies one of the ten single FR-7 spaces.
The 9770R-15, also a regulated, dual-polarity fifteen volt DC supply, can be mounted in the mounting ear area of the FR-7 chassis when fitted to the FR-PWP option, leaving all ten single spaces available across the front of the FR-7. With the 16VAC/800mA transformers we presently include wiht the 9770R-15, it is good for up to about 300mA per supply -- plenty for a system of 9700 series modules and in most instances, a mix including other brands too. There are only six power connection points on this supply, so power connector wiring must be doubled-up or, a piece of 0.1" spaced strip-board used to extend the taps.