Silver Shark (Grant?)
Me again, I've just seen an earlier post from you about an earth wire connected to input 1 on the patchbay. Along with some of the other patchbays with SSL (but not user option wiring), this wire is probably a green 7, 16 or 32/0.2 tech grounding wire and should go to the end of the two copper bars in the block by the tech ground point hanging out at the console connector panel. It is an SSL internal signal ground wire and not directly related to the studio installation.
There you will (or should) also see a bunch of other green wires from the other patchbays all screwed into the copper block. The patchbays, having metal front panels, are screwed to the frame which, in itself, is technical ground but the green wire soldered to one of the patchbay jack screen positions (any one of the 48 or 56, it doesn't matter which) is actually a hardwired ground to the copper block, even though the patchbay is screwed into the frame as well. The patchbay screens are shorted to the frame and the green wire, via the copper block, also ends up shorted to the frame and goes to the 0BA (M6) technical grounding point.
The mic panels are a separate issue as I tried to explain in my last post but I'll clarify the whole signal path again.
1 All studio mic leads have their grounds connected both ends.
2 All studio wallbox wiring also has screens connected at the wallbox AND at the DL end.
3 From the DL, the balanced twin screen cables go to the patchbays and the individual screens are connected to the bantam jacks.
4 In this case, the mic lines (they should really be called mic sources in my view as they are not a line signal!) are fully normalled down from row A to B (just the hot and cold, not the screen on any patchbay).
5 Row B (which is NOT individually screened at the patchbay end) takes the signal to the upper buscard Bicc B (which is screened).
6 So, from the mic right through (via wallboxes and DL's) to the patchbay row A (mic lines!), the screen is fully connected.
7 The individual mic screens go to the patchbay on row A. This is screwed into the console frame (which becomes part of the technical ground). Also, the green wire, as an extra measure, ensures the patchbay screens get taken to the copper block which ends up being screwed to the frame as well, creating one big happy tech earth ideally!
8 The SSL internal wires from row B (mic inputs) are unscreened at the patch end but ARE screened at the 6 way Bicc end.
9 From the Bicc end, they hit the upper buscard and that has a 50/0.25 white wire (SSL couldn't get the same size wire in green at the time and stuck to white!!!) linked to one of the copper bars (one was for mix earths and the other for power earths) for each section of 8 channels.
10 The two copper bars come together at the end and are screwed to the frame (see point 7).
11 The idea was that the SSL console would be the hub of ALL of the studio technical screens before going off to a studio technical earth position, ideally just before the main earthing stake or point.
So, let the console grounding design do it's job and connect ALL the screens right through from the mic to the console patchbay. Effects and multitrack stuff could be different as they are bi-directional and there is a risk of ground loops but the one way mic circuit (with associated phantom powering) especially needs the signal ground connected to work properly and not cause injury or death!
To address your point, connect the loose green wire to the copper block with the others which may be there (it should be a similar length).
I think your 48v problem lies with screens being dropped at the wallbox or DL's, hence no phantom power as it needs the screen connected throughout, as detailed above, to make it work (and be safe). If someone has dropped a mic screen between the mic and patchbay, they should be ... (I can't say as it's too rude!).
Hope this helps and sorry for all the detail. I have prepared a comprehensive schematic of the SSL power and ground wiring with help from Sintech and others on this forum and will send it to Mattia for inclusion soon.
Also, Sintech (Andy H) visited me today and suggested I PM you regarding other wiring issues you may have so I will do that now.
Finally, why I am doing this shxt on a Friday night when I should be out begging as usual?
That's it, I'll shut up now people. This should hopefully earn me another 63 positive Karma points (I'm trying to catch up with Andy ... no chance really!).
Regards from Jim Lassen (
www.profcon.co.uk). Also on
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