Channel Backplanes for the ToolMod Mixing Console

ToolMod analog Mixing Console
Channel Backplanes

The backplanes are the best possible compromse between cost of the console frame and cost of external wiring. The different versions of the backplanes are adpated to mono or stereo channels with or without patch bay. Multilayer pcbs with ground planes maintain high crosstalk. The design of the backplane considers the availability of standard multicore cables and uses common connectors and pinouts.

Four version are available. The 8-channel backplanes are adapted to mono and inline modules while the 4-channel backplanes are adapted to stereo modules. 8-channel and 4-channel backplanes are available with two different configurations of the insert connectors. Version 1 is designed for system without patch bay. The insert I/Os are available on TRS connectors. The patch bay version use 25-pin D-subs connectors with 'Tascam' pinout for the inserts. 8 insert outputs are combined on one D-sub and 8 insert inputs are available on a second one.

All versions come with 9-pin D-sub connectors per channel for external meters. All TRS and XLR connected are gold plated versions, brand Neutrik.

Connector Panels | Channel Panels | Channel Backplanes | Master Connector Panel

8 Channel Backplanes
The image above shows the 8-channel backplane with inserts on TRS; the image below shows the patch bay version with inserts on D-Subs. Both version use female XLR connectors for the 'Mic' input and the 'Line' input. All D-subs use 'Tascam' pinout; the TRS connectors are balanced with + on tip, - on ring, and ground on sleeve. XLR connectors use international pinout with + on 2, - on 3, and ground on 1. The design of the 8-channel backplanes breaks out the 'Tape' inputs of the 8 channels to a 25-pin D-Sub. Connecting to the d/a outputs of a DAW will require a standard 25-pin, 8 core cable, which is available at reasonable cost. The channel outputs are combined on a second D-sub. The cable from the console to the a/d converter input of the DAW uses the same principle and requires another standard multicore.

Apart from the insert connectors, the patch bay version is identical. Instead of the TRS connectors, 4 25-pin D-subs are used for 8 x Insert Out A, 8 x Insert In A, 8 x Insert Out B, and 8 x Insert in B. Connecting the inserts to a patchbay using standard multicores is possible. These D-subs also use the standard 'Tascam' pinout.

Backplane for 8 input channels, patch bay version

4 Channel Backplanes
The 4-channel backplanes are designed for stereo Channels. While mono or inline modules are usually connected to one DAW input and output per channel, stereo channels need 2 DAW sends and returns. When using many stereo channels that are used for stereo outputs and inputs of the DAW, the breakout shema of the 8-channel backplanes is not suited well. Both versions of the 4-channel backplane use 1 25-pin D-sub for the DAW return and another one for the DAW send; however, the 8 tracks on each D-sub are connected to four channels instead of 8. The tracks 1 and 2 a connected to the left and right inputs of the first channel slot, tracks 3 and 4 to left and right of the second channel slot, and so on.

Since stereo input modules don't have mic and line inputs, there are no additional XLR's. The TRS versions is shown above. The 2 insert I/O's per channel are available on 4 TRS jacks per slot. The image below shows the patch bay version with 2 additional 25-pin d-Subs for the inserts. One d-Sub is used for the 4 stereo insert outputs and the other one for 4 stereo insert inputs.