I have been scetching out a few possible designs for a DOA based preamp for mid-side tracking. I have read the other posts which all seem to have the 3 signals at equal levels and non-adjustable. My need came about after trying to track M-S guitar overdubs in my DAW(PT). The problem is that I need to flip the phase and bus route the signal and there is enough latency to be noticeable.
That said, I am trying to map out the best way to deal with the Side signals that I need to split. It seems that Y cable to 2 preamps would be OK for a makeshift solution, but I want to do this properly wtihout extra loading on XFMRS.
I am basing this on a simple 312 type circuit
my rough ideas are the following:
I need 2 outputs with one signal having opposite polarity.
1. XFMR to noninverting opamp and inverting opamp:
-This may be the best way but I am not sure if it would load the input XFMR too much(although the secondary will be terminated with 150K).
2. XFMR splitter XFMR secondary + to Left opamp and XFMR secondary - to Right opamp -both opamps are non-inverting.
-The problem here is that to use 75101APC type I yould need to have 2 transformers on the input. eg the 75101 feeding the 1:1:1
3. XFMR> Opamp split to L out and inverting opamp for R
-I would rather not have caps in the path or use a servo bias circuit.
These are the basic building blocks -a bunch of other compenents are not shown obviously.
That said, I am trying to map out the best way to deal with the Side signals that I need to split. It seems that Y cable to 2 preamps would be OK for a makeshift solution, but I want to do this properly wtihout extra loading on XFMRS.
I am basing this on a simple 312 type circuit
my rough ideas are the following:
I need 2 outputs with one signal having opposite polarity.
1. XFMR to noninverting opamp and inverting opamp:
-This may be the best way but I am not sure if it would load the input XFMR too much(although the secondary will be terminated with 150K).
2. XFMR splitter XFMR secondary + to Left opamp and XFMR secondary - to Right opamp -both opamps are non-inverting.
-The problem here is that to use 75101APC type I yould need to have 2 transformers on the input. eg the 75101 feeding the 1:1:1
3. XFMR> Opamp split to L out and inverting opamp for R
-I would rather not have caps in the path or use a servo bias circuit.
These are the basic building blocks -a bunch of other compenents are not shown obviously.