Thursday, July 24, 2008

Adding pre-amplifier outputs to an Onkyo Receiver

I bought an Onkyo TX-SR505 receiver and really like it. It has a lot of good features, will drive 4 ohm speakers (despite what the manual says), and accepts a variety of signal inputs. However, there is one missing feature that I would really like to have: pre-amplifier outputs. This would allow the use of an external amplifier and additional signal-chain devices (such as a graphic equalizer). I feel strongly that room compensation with a graphic EQ is important, but that is a topic for another post.

I opened the cover on the TX SR505, and eventually found a convenient place to tap into the pre-amp signals. I used some short lengths of shielded cable to connect three newly-added RCA jacks to three points on the main audio board. Note that the cable shield is only connected to the metal receiver case at one end. I think the photos will explain everything better than I could in words, so take a look.

1 comment:

  1. hi there,after I had made ​​the same wiring on the Onkyo as you(tx sr505) and i make it as a pre-amp,there is no problem(really love it).but when it is(the pre-out)connected to the active subwoofer, the left speaker(in a 10-20minutes later)will sound strange as there short circuit(crackling sound).my question,is this adding pre-out only for the pre-amp?or mean no main speaker attach to the onkyo?sorry my bad english.