HEAR Tech. Hub Mod

[sr1200]

Problem:  Trying to use the AUX input on the hearback mixer for talk back, but they are NOISY (almost sounds like a bad ground).  Tried numerous cables and different mixers... same story on all of them.  That 1/8" jack is sketchy to begin with.

Solution: I'd like to either mod my hub (older model) so i can inject a signal into the 1-2 inputs for talk back. Was thinking of just drilling out the back panel to add a 1/4" TRS and wiring it up through a pair of 10k resistors to the existing db25 input.  Any problems doing this (should the resistors NOT be 10k?  The passive summing box i built years ago used them though im not sure the theory behind that choice). 
OR
Would it be better to not hack up the original box and make a little break out box that did the same thing.  Looking to keep noise to a minimum and thought that this option might be prone to added noise since there'd be more connections and cables to deal with.

alternate suggestions welcome. Thanks in advance!

 

[mjrippe]

Get in touch with the folks at Hear.  They are a small company and very open to finding solutions for studio owners.

 

[sr1200]

Was able to figure it out.  There were via's on the board right before the "THAT" op-amps i was able to inject the talk back signal into.  Adding the resistors created an interesting issue where if I had the talk back plugged in, it would ONLY be the talk back input and if unplugged would be the regular incoming signal.  I omitted the resistors and works fine.