mac
Well-known member
Can anyone identify the console that the channel strips may be from in the attached photos?
Problem is no-one can seem to identify them, so no schematic, and few clues to go on.
Each input channel has phantom and phase switch followed by rotary gain pot, EQ stage, FB and Echo sends then finally Pan, Solo and Ch switches, Pan pot, Sends Buttons and a 100mm fader. There are six ML748CS ic’s on board each input channel strip and a mic input tranny which has “MSC 1829 PMT\7710” written on it.
No other markings or identification.
So far I have spent several hours with a DMM tracing the circuits that relate to each of the connectors on the bottom edge of the PCB where it obviously sat in the input slots of the console. Also, have started to make a collection of schematics from other desks from the late 70’s early 80’s to see if I could start to see similarities in the circuits from which to make some assumptions about the pin outs on my strips (have noted some similarities in parts of the circuits from a Series 20 Cetec input channel schematic).
The goal obviously being to try to determine how to commence making connections to bench test these strips, and ultimately rack them up once I am happy with them.
I have a rather poor attempt at a sketch attached which is as far as I have gotten with my detective work. I realise that it isn’t a proper circuit diagram and probably won’t make sense to all knowledgeable folks around here – as stated I am still learning how these things go together, (and how to draw circuit diagrams). If you can see anything obvious in terms of pins which would likely be inputs, ground, power feeds etc that would be appreciated.
I started with all the easy and obvious stuff like 48v phantom feed to the switch, grounds on all the pots, sends and group assign feeds from the switches. What really has me scratching my head is pins 1-3 as they tangle with the mic input tranny (which I also have no info on).
I am assuming that a second power feed like maybe 15v+ and 15v- comes onto the board at some point, but this isnt obvious to me yet. I cant locate a datasheet for a ML748CS, however I did locate a modern "replacement" IC for the ML748CS which is a NTE975. This chips datasheet identifies pin 7 as V (+) 15v.
Any insights would be appreciated.
Cheers, Mac.
;D
Problem is no-one can seem to identify them, so no schematic, and few clues to go on.
Each input channel has phantom and phase switch followed by rotary gain pot, EQ stage, FB and Echo sends then finally Pan, Solo and Ch switches, Pan pot, Sends Buttons and a 100mm fader. There are six ML748CS ic’s on board each input channel strip and a mic input tranny which has “MSC 1829 PMT\7710” written on it.
No other markings or identification.
So far I have spent several hours with a DMM tracing the circuits that relate to each of the connectors on the bottom edge of the PCB where it obviously sat in the input slots of the console. Also, have started to make a collection of schematics from other desks from the late 70’s early 80’s to see if I could start to see similarities in the circuits from which to make some assumptions about the pin outs on my strips (have noted some similarities in parts of the circuits from a Series 20 Cetec input channel schematic).
The goal obviously being to try to determine how to commence making connections to bench test these strips, and ultimately rack them up once I am happy with them.
I have a rather poor attempt at a sketch attached which is as far as I have gotten with my detective work. I realise that it isn’t a proper circuit diagram and probably won’t make sense to all knowledgeable folks around here – as stated I am still learning how these things go together, (and how to draw circuit diagrams). If you can see anything obvious in terms of pins which would likely be inputs, ground, power feeds etc that would be appreciated.
I started with all the easy and obvious stuff like 48v phantom feed to the switch, grounds on all the pots, sends and group assign feeds from the switches. What really has me scratching my head is pins 1-3 as they tangle with the mic input tranny (which I also have no info on).
I am assuming that a second power feed like maybe 15v+ and 15v- comes onto the board at some point, but this isnt obvious to me yet. I cant locate a datasheet for a ML748CS, however I did locate a modern "replacement" IC for the ML748CS which is a NTE975. This chips datasheet identifies pin 7 as V (+) 15v.
Any insights would be appreciated.
Cheers, Mac.
;D