Yes, Mata is correct. SSL wired the multitrack returns from DL's 11 and 12 (and on larger consoles, 13 and even 14) to the patchbay row C which is Multitrack returns (1/2 normalled to line inputs on row D). Row C was then hardwired,
without linking the screens, to row J (also multitrack returns) which got 1/2 normalled down to the tape monitor inputs below on row K. If these letters mean nothing to you, look at the patchbay or DL wiring cable idents. This labelling should match the patchbay row unless some wiring goes elsewhere in the console like the 651 .
The original idea was that you could swop the signal paths around to both the small and large faders with the multitrack returns going to both line and tape monitor inputs to suit your requirements. You could record to a multitrack using the mic and line inputs on the large faders and monitor the sound in the Control Room via the small faders (or the other way round if you wanted more or less fader adjustment for either function). When you were mixing and maybe adding a few overdubs, the large faders went to the computer mix with the small faders being used for just monitoring the overdubs.
A few decades later and we find the use of the SSL console is changing as more sounds can be processed outside of the console (within DAW systems) and more and more inputs need, and can be, brought into the mix system, now almost defaulting to ProTools, at the last moment unless you require the SSL eq, dynamics and effects and cue routing.
With the original SSL patchbay wiring, you can patch inputs to send them elsewhere but, they will
still go to their original input as well unless you plug a dummy jack into either line inputs or the tape mon inputs as these are 1/2 normalled from both C and J rows of Multitrack returns.
However, you can change the internal wiring. It is feasible to separate the link between row C and J and wire the monitor feeds directly from some new different DL's (or hardwire them) if required. This will then create an extra (up to or more than) 48 or so inputs directly to the tape monitor inputs. The downside is that you cannot link them back to the line input feeds from the multi returns unless you cross patch them individually (using up loads of patch cords again).
To Summarise: Unless you separate the link between C and J you have the same multi returns going to both line and tape monitors unless you separate them on the channel I think! By using the existing patchbay wiring, you can plug other inputs into the tape monitor inputs but these would use a lot of patch cords if you are prepared to pay for the cost of these and use them
each time you need them, possibly in the same place most of the time!
If you separate the link between C and J, you can wire your other inputs directly to J. If you wish to plug these into the line inputs instead via row C, you have to use patch cords again to do this.
Bear in mind that I'm a wiring guy (and a drummer!). I worked at SSL for 7 years from 1980 and recorded and engineered several mixes on one at the original Acorn SSL studio so, you people have much more knowledge than me regarding how to use the console. Most of my comments above, apart from the wiring aspect, are based on past experience some 30 years ago so, excuse me if I have got anything wrong!
I'll think about this wiring idea some more and put a post on the forum with some drawings at some point after I first post more thoughts regarding patchbays and DL's.
Hope this helps from Jim Lassen (
www.profcon.co.uk). PS: I prepared this reply several days ago when I initially saw the question so, sorry for the delay in posting. PPS: No studio user ever finishes their last patchbay as a studio is
never finished!!!