stickjam
Well-known member
I'm looking at modifying an AV receiver to add balanced I/O inserts on the 5.1 signals between the preamp and power amp (before volume control)
The signal chain for each channel is conceived (in order) as follows:
- existing receiver preamp switching circuit providing 200mV signal
- *Send Level shift (gain?)
- BurrBrown/TI DRV134 Balanced Driver
- DB25 connector
- Tascam DA88 snake to TRS fan
- 6 balanced console channel line inputs (0dBu=0.775V +30dBu MAX)
- 6 balanced console monitor sends
- another TRS fan-to-DA88 snake
- another DB25 connector
- BurrBrown/TI INA134 Input device
- *Return level shift (attenuation?)
- existing receiver volume control/power amp expecting 200mV
The idea is to interface to the console through true balanced interconnects. Theoretically the receiver could also be essentially restored to its original operation by strapping the two DB25's together.
Knowing all the above, can the required Send and Return level shifts (*) be reasonably calculated? If so, what would they be? If not, what else would one need to know?
Thanks
--Bob
The signal chain for each channel is conceived (in order) as follows:
- existing receiver preamp switching circuit providing 200mV signal
- *Send Level shift (gain?)
- BurrBrown/TI DRV134 Balanced Driver
- DB25 connector
- Tascam DA88 snake to TRS fan
- 6 balanced console channel line inputs (0dBu=0.775V +30dBu MAX)
- 6 balanced console monitor sends
- another TRS fan-to-DA88 snake
- another DB25 connector
- BurrBrown/TI INA134 Input device
- *Return level shift (attenuation?)
- existing receiver volume control/power amp expecting 200mV
The idea is to interface to the console through true balanced interconnects. Theoretically the receiver could also be essentially restored to its original operation by strapping the two DB25's together.
Knowing all the above, can the required Send and Return level shifts (*) be reasonably calculated? If so, what would they be? If not, what else would one need to know?
Thanks
--Bob