zamproject
Well-known member
- Joined
- May 11, 2010
- Messages
- 1,630
Hi
Usual maintenance routine for my Studer 289, where I take notes of minor issues and repair all at once about twice a year
I have 2 stereo plasma meter (that can be routed direct from the quad master line out or from the monitoring section with access to all other I/O)
The input circuit simulate a Vu response ballistic (there is a version with PPM)
I have a dead secondary trafo at one input, same as neutrik NTL1, about 1k1/1k3 DC and 10H each side, but I don't have spare any more and the price get crazy, about twice what I remember last time I buy some...
In other hand I have a meter module from a 963 (cannibalized long time ago for the small Vu galvanometers) also with input trafo 1:1, in a RM 6 or 8 footprint. they measure about 54Ω/66Ω DC and 2H each side.
I try to substitute them and got -3dB at about 70Hz where the original trafo is flat in the circuit.
I then short the 1k resistor (R203) at first inverting buffer/ref level adjust, like in the 963 schemo, and fr response is now fine with that.
So I’m tempted to keep this mod…
Any advice regarding that ? what about load difference as primary DCR are unmatched from LR now, more than 20%, especially if I route the meter from master line out ?
In practice I usually don’t load the master out with the meter when printing a mix, but monitor the feedback from the DAW (AD/DA), but still a concern to me (if there is one)
Both schemo attached
Usual maintenance routine for my Studer 289, where I take notes of minor issues and repair all at once about twice a year
I have 2 stereo plasma meter (that can be routed direct from the quad master line out or from the monitoring section with access to all other I/O)
The input circuit simulate a Vu response ballistic (there is a version with PPM)
I have a dead secondary trafo at one input, same as neutrik NTL1, about 1k1/1k3 DC and 10H each side, but I don't have spare any more and the price get crazy, about twice what I remember last time I buy some...
In other hand I have a meter module from a 963 (cannibalized long time ago for the small Vu galvanometers) also with input trafo 1:1, in a RM 6 or 8 footprint. they measure about 54Ω/66Ω DC and 2H each side.
I try to substitute them and got -3dB at about 70Hz where the original trafo is flat in the circuit.
I then short the 1k resistor (R203) at first inverting buffer/ref level adjust, like in the 963 schemo, and fr response is now fine with that.
So I’m tempted to keep this mod…
Any advice regarding that ? what about load difference as primary DCR are unmatched from LR now, more than 20%, especially if I route the meter from master line out ?
In practice I usually don’t load the master out with the meter when printing a mix, but monitor the feedback from the DAW (AD/DA), but still a concern to me (if there is one)
Both schemo attached
