HI
i recently got this SSI passive summing mixer, 8 channels with a Melcor 1731 DOA makeup gain output. there are some mods I would like to do with it, but first I'd like to get it functioning as it should stock before I mess with it.
For 1 thing, the panners are all dying, they use these Ohmite 10k type AB panning potentiometers, its a double pot, with one for left and one for right, I don't see any slugging resistors, but there is a significant drop in level when at center, and thre signal cuts out randomly when turning the panner, so I'd like to replace them, maybe with a single center dent pot,. can anyone recommend a pot that would be compatible? I believe the input transformers are wired for 4k input impedance and 600ohms output to the channel gain pot( is 600 ohm), and they seem to work fine.
there is no master gain, but I do notice that there is a difference in level between the left and right channels, but there are no trim resistors in the master section, so I was wondering if I can add one, or replace a certain resistor with a trim pot resistor. I cant figure out the value of the feedback resistor, the 1st color is a cream colored bar, it says 1k under where both feedback resistors are but they are not. also there is a 47k resistor tied between the Trim of the 1731 and the V+, and a 320uf 6.4v cap between the output of the DOA and the output. the input from the 1k buss resistors go to the negative input of the DOA, and the positive input is tied to the COM and then to ground, i'm assuming then that the black is the HI out and the red the LO? ive attached a couple photos for reference, any help I'd appreciate it. thanks!
i recently got this SSI passive summing mixer, 8 channels with a Melcor 1731 DOA makeup gain output. there are some mods I would like to do with it, but first I'd like to get it functioning as it should stock before I mess with it.
For 1 thing, the panners are all dying, they use these Ohmite 10k type AB panning potentiometers, its a double pot, with one for left and one for right, I don't see any slugging resistors, but there is a significant drop in level when at center, and thre signal cuts out randomly when turning the panner, so I'd like to replace them, maybe with a single center dent pot,. can anyone recommend a pot that would be compatible? I believe the input transformers are wired for 4k input impedance and 600ohms output to the channel gain pot( is 600 ohm), and they seem to work fine.
there is no master gain, but I do notice that there is a difference in level between the left and right channels, but there are no trim resistors in the master section, so I was wondering if I can add one, or replace a certain resistor with a trim pot resistor. I cant figure out the value of the feedback resistor, the 1st color is a cream colored bar, it says 1k under where both feedback resistors are but they are not. also there is a 47k resistor tied between the Trim of the 1731 and the V+, and a 320uf 6.4v cap between the output of the DOA and the output. the input from the 1k buss resistors go to the negative input of the DOA, and the positive input is tied to the COM and then to ground, i'm assuming then that the black is the HI out and the red the LO? ive attached a couple photos for reference, any help I'd appreciate it. thanks!