I am considering attempting to upgrade the balanced inputs/microphone preamp board on my Digidesign 003 Rack.
They are for channels 1-4 and are based upon TL074.
There is an existing "well known" and easy modification by Blacklion Audio which replaces the TL074 with OPA4134 and also upgrades to Nichicon FW capacitors. I might make my own version of the upgrade with Panasonic FM capacitors, Nichicon UES (green) and OPA4134.
Based upon the linked listening test I think the OPA4134 is a great choice especially with the feedback on Digi 003 racks that were upgraded: ULTIMATE OPAMP SHOOTOUT... Where you get to decide.
Before deciding I was wondering if there were any recommendations for suitable very high quality balanced preamplifier designs that I might consider.
In my box of available parts I have tested (distortion and noise) and verified OPA4134 and LM4562 along with various BC series low noise transistors as well as tested (in my 60 dB LNA) generic 2SB737 and original Rohm 2SD786. The generic 2SB737 appear to be good and are the lowest noise that I have tried so far at the input of my LNA.
The Digidesign 003 is pretty modular in the sense that the input board for channels 1-4 is separate from all the other boards and has nice 0.1" header connections for the balanced inputs and outputs for each channel. So it would be reasonable for me to design a new PCB. The input headers go to the balanced connectors on the back and the outputs go to the A/D/A board with the CS5361. Or I could go the easy route with just OPA4134 and Panasonic FM swaps.
They are for channels 1-4 and are based upon TL074.
There is an existing "well known" and easy modification by Blacklion Audio which replaces the TL074 with OPA4134 and also upgrades to Nichicon FW capacitors. I might make my own version of the upgrade with Panasonic FM capacitors, Nichicon UES (green) and OPA4134.
Based upon the linked listening test I think the OPA4134 is a great choice especially with the feedback on Digi 003 racks that were upgraded: ULTIMATE OPAMP SHOOTOUT... Where you get to decide.
Before deciding I was wondering if there were any recommendations for suitable very high quality balanced preamplifier designs that I might consider.
In my box of available parts I have tested (distortion and noise) and verified OPA4134 and LM4562 along with various BC series low noise transistors as well as tested (in my 60 dB LNA) generic 2SB737 and original Rohm 2SD786. The generic 2SB737 appear to be good and are the lowest noise that I have tried so far at the input of my LNA.
The Digidesign 003 is pretty modular in the sense that the input board for channels 1-4 is separate from all the other boards and has nice 0.1" header connections for the balanced inputs and outputs for each channel. So it would be reasonable for me to design a new PCB. The input headers go to the balanced connectors on the back and the outputs go to the A/D/A board with the CS5361. Or I could go the easy route with just OPA4134 and Panasonic FM swaps.