Speck Electronics Xtramix - Manual (Page 41)

Simply connect an Effects or Auxiliary send from the external mixer to
the Sum In Jack of any of the eight Xtramix send channels. While it
makes sense, for the sake of continuity, to keep the Effects Send
numbers matched (#1 of the external mixer to the Sum In point of #1 on
the Xtramix, etc.) it is certainly not necessary.
Once the Sum In connection is made, then connect the input of any
effects device to the Xtramix Effects Send Jack. It may take some
experimentation to determine the best settings for each of the Effects
Send Master (Trim) Controls. Try to achieve a situation where an
Effects Send Control on any given input channel needs to be set between
twelve and two o'clock to achieve a healthy effects device input level.
Each Effects Return provides two discrete balanced 1/4" TRS
connectors for connection from the outputs of a left/right stereo effects
device.
Typically, this input is used to connect the left output of a stereo effects
device. When an effects return is operated in the stereo mode, the left
input is assignable to the four odd subgroups; 1, 3, 5, 7, (see Effects
Return Assign Switches on the front panel)
Typically, this input is utilized to connect the right output of a stereo
effects device. When an effects return is operated in the stereo mode,
the right input is assignable to the four even subgroups; 2, 4, 6, 8 (see
Effects Return Assign Switches on the front panel)
When using a single output effects unit, connect its output to either the
left or right Effects Return Input and set the effects return channel for
mono operation (see effects return Mono Switch on the front panel).
Each Bus/Subgroup feed has a separate balanced 1/4" TRS connector.
The Subgroup Feed provides a low impedance source for connection to
the input of a multitrack analog, digital, or hard disk recorder.
Each Subgroup Feed is capable of driving three high impedance
bridging inputs without any loading effects. This means that Subgroup
Feed #1 could connect to tape inputs 1, 9, and 17, and Subgroup Feed
#2 could connect to tape inputs 2, 10, and 18, etc. The Subgroup Feed
may also connect to the line inputs of a recording console.
Effects Return
Connections
36
8. Left Return Input Jack
Assign Subgroup
Connections
10. Assign Subgroup Feed Jack
9. Right Return Input Jack
Chapter 4 Operation Section