SSL Balanced buss mod - question for SSL tech's

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Livingroom

Member
Joined
Jun 5, 2004
Messages
19
Location
Oslo
We are installing a few new buckets of channels in our ssl G 4040 and need to do the balanced buss mod on some of the new buss boards.
Anyone know how this is done and what number motherboards/bussboards need to have them done? Do the channel 611's need to be modded too?
Some detailed info about this "coat hanger mod" as I understand it's referred to would be greatly appreciated.
Ssltech/Keith I bet you know all about this one :green:
 
I have all the factory docs on this, there is quite a bit to it (a full 1" ring binder). Keith & I did this to a 6K together, enlisting several helpers it took around a week to do a 48 input console, with leaving out the PFL mod (very difficult to get to). If you can come up with the balanced buss mother boards it will be much easier. Is the rest of the console allready fully balanced buss?
 
Yep.

I also did it to a 4K back in Liverpool about 15 years ago.

ALL of the 611 modules need to be modified, and ALL of the lower buss cards need to be replaced. The cue send summing amps, the quad (or stereo on a 6k) buss summing amps need to be modified, and there's also a few other choice cuts to do.

The noise difference is modest I think... definately beter, but NOT earth shattering. If you don't have hum issues, you may be better advised not doing it, but if you have bus hum issues, it can be beneficial.

There is no improvement in the signal, only noise. -If you don't have oise, you'd be mad to undertake it. -Hw many channels in your frame?

Keith
 
The new console is a 4040G with E master section upgraded to G specs. The frame is 40 with buss cards numbered: 82E245-H586 lower bus and 82E266-B785 upper bus. I'm epanding it to 56 with new metalwork/buckets and buss cards. I also have an old 1981 E here for parts.
My plan is to use all 40 of the new G channels and adding 16 of my old brown eq E channels filling up the 56 frame.
I was recommended by a tech to do the mod as 56 channels probably would be noisier and there might be a case the buss cards wouldn't match.
Peter Duncan is sending me 2 sets of new buss boards and they are G, so I won't be able to use the E channels in them without the mod right?
When I insert the G series channels into the E I get funny things happening on the aux sends.
 
[quote author="Livingroom"]When I insert the G series channels into the E I get funny things happening on the aux sends.[/quote]

Yes, you will.... you turn one up and odd, lower signal levels start appearing on other busses, 'out-of-phase' and seemingly randomly associated...

So you first need to determing what mods are present in the base console modules, there may be AFL mods etc...

Then you need to make sure that you're adding the SAME revision of lower buss cards on the extension section.

Then you need to perform the "coat-hanger" modifications to the older ("brown-EQ") modules... Notice that the black, stiff wire (looks a bit like the stuff that wire-coat-hangers are made from.. hence the name) -that sits on top of the 611 motherboard and runs underneath the daughter cards- will be different on the new and old cards.

The newer (split-ground) modules will have:

1) Different ground 'coat-hanger' layouts
2) A little "ladder of about five resistors standing upright and joined together at the upper end, near the upper buss card edge connector pins
3) A cut in the really thick PCB trace, near the resistor "ladder"
4) usually a small jumper in the same area, which allows you to 'bridge' the PCB ground trace cut, for using the modules in split-ground installations, without ruining the grounding scheme.

You WILL need full documentation to do the mod, missing a SINGLE step on any ONE module will mess up the whole console whenever that module is inserted.

-But it's not that tough though, just needs some patience.

I can probably help out, and I'd be happy to do whatever I can... -specially if there are any juicy spares left over in that '81 center section! :wink:

Keith
 
Hi and thanks guys.

You are as always very helpful and I can indeed confirm that all the new channels in the new console has the resistor ladder at one side of the upper card, a few cuts in the pcb on both edges and a jumper installed on the upper edge of the lower bus card going into what I understand is a coat hanger wire.

Ill post again as soon as I recieve the new buss cards from mr. Duncan and gather some more info. Keith I would really appreciate some tips and when I disassemble my old master buss I'll keep you in mind. Was there anything in particular you were looking for? :sam:
 
Heh... I'm sure you've already got plans for the Sifam Buss compressor meter... :wink: but there may be other things that I could really use, like the phase meter driver board (and meter, poss?)

I recommend that you keep most of -or all of- the center section cards from the 82E20 to the 82E33, but in some cases they're duplicated (like the LF, RF, LB and RB VCA cards, so you can keep one or more of those and use the rest to make an outboard SSL buss comp, or desolder them to use as spares for the 82E13 channel VCA cards.

Of course, if you don't want the meter... :wink:

I think that the talkback cards you can probably also convert into outboard "crush" compressors, there should be two of them (is that the '30 or the '33 card? -I forget.) and you don't necessarily need to keep spares of that card if you don't have the return-talkback listen-mics wired (for studio-to-control-room communication) on your existing console -many studios don't wire them- since your console already has two of them, and you may only be using one (for control-room-to-studio communication.)

But apart from that, keep one of everything for yourself, -unless of course you already HAVE a spare one of everything!!!

If you have a spare Total-Recall ribbon cable harness for a module, that would be VERY useful, as I have amodule here with a bad one, and I don't want to spend big money on a replacement, seeing as so many people are parting-out modules for the EQ cards, the Dynamics cards etc, and tossing the ribbon harnesses... I usually only hear about that AFTER they've thrown them out, so I thought that I'd mention it in case you are about to do the same... :green:

Keith
 
Ok Keith. I'll get in touch when I get all the parts together. Tha old meters are PPM's btw so integrated phase meter in that one. I actually like them better than the VU ones.
Nielsk would it be possible to do a scan of the docs? I'll gladly pay you for the trouble.
 
as I do not have a scanner, maybe have one, Keith? Let me know what docs you have & I will get you anything that's missing, (I still have the color copy of the balanced buss lower card we made) and we can see about sending the whole set.
 
That would have been a great help guys, scan or photo :grin: . I can try to get in touch with SSL but I thought I'd try here first. I have also sendt a mail to George Gilbert hwo was one of SSL's chief engineers in the 4000 era and I'm sure he has some info on the revisions of the buss boards.
Keith I was a little quick in my last mail as my old PPM's does not have a separate phase meter driver board. Im sure I can find some other stuff you may me insterested in after the dissection :thumb:
 
Neils,

I have a sheet-feed scanner which I'd be delighted to use to make pdfs from anything else that you may need.

George Gilbert is a great guy, he's with Pro-Serv audio at the moment I think. -Last year he managed to repair two cards for me: an intermittent SMPTE card and a keyboard/VDU card. They have both worked flawlessy ever since, and I highly recommend that you contact him if you ever need anything for the console. He remembers me and my colleague Peter from something over 20 years ago, and he's a top man.

Actually, I like PPMs too... maybe we can work something out! :wink:
-Whatever... let's get your questions sorted out first.

Neils, if you are round this way, let me know and I can scan whatever you need... likewise if you have any scanning needs in the future, it's faster, cheaper and probably even easier than Kinkos. Oh, and I just got a tracking number for your Dolby jig... should be here by about Tuesday, I reckon.

Hey, Livingroom, when you say PPMs do you mean plasmas or mechanical blackface-PPMs? -There was someone here who was looking to buy a bunch of Plasma tubes the other week... now that there's no new supplier that I know of, plasma tubes might be worth a LOT of money... don't throw any away! -Of course if it's mechanical PPMs, they're worthless... just send them to me, and I'll 'dispose' of them for you... :wink:

Keith
 
Just recieved the 2 extra channel bays from mr. Duncan today and the buss boards are the same revision as the ones I already have. So the thing I'm looking at now is modding 16 611E's from 1981 to work without crosstalk in the new balanced bus cards holding 40 balanced 611 G's. I've noticed the difference in layout on the E's and G's module mother boards and I've seen a jumper set to balanced on the 40 G's. I now have to mod the old ones with more wire, cutting a few traces and adding the jumper to use them in the new buss boards right?
I'm sure I can try to copy the wiring in the new 611 but if you could describe the basic procedure I would be very happy :cool:
Keith, I'll have some spares left over from this (mainly old eq, 1537 vca channel comp cards and some jensen trafo mic/line cards) and would be willing to trade for a scan or a detailed description of the procedure :sam: :green:
 
WHERE EXACTLY ARE YOU GUYS GETTING YOUR SSL PARTS THE REASON IASK IS BECAUSE I HAVE 8 SSL 4000 MODULES AND I AM LOOKING TO ADD MORE IN THE FUTURE PROBABLY LIKE 32 MORE TO MAKE A CONSOLE WHERE WOULD YOU GET THE MAIN CENTER SECTION AND ALL OTHER PARTS LIKE THAT
 
THANX FOR THE QUICK REPLY, WHAT EXACTLY GOES IN TO TRYING TO MAKE ONE OF THE CONSOLE WHAT PARTS WOULD I ABSOLUTELY NEED TO BUY TO START BUILDING THE CONSOLE?
 
Please, turn off your caps-lock, this pisses many people off here.

To answer your question : Better think again before you start such an endeavor. You'll need more than what you can think of at forehand, I'm sure. I started doing a 5000 console, by just a few modules. 5 years later I'm close to completion, but it'll never be ready, and I spent loads and loads of euros, and loads and loads of time to it. I don't know the ins and outs of a 4k console, but the IR/TR stuff of the 5k is... well....  daunting, to say the least. In hindsight I'd rather have built a 51x console. Less hassle, and it costs about the same, but then you can choose what stuff you put in.

But back to the 4k : I'm absolutely sure it costs less to buy a used 4k, than to collect modules, strips, PSU stuff, interfaces, and so on. The strips that you already have : Rack them, and use them !
 
Hey Keith, the SSlMixed forum sent me over here.. Looking for some more info on the "Coat Hanger" mod.. I have a non "coat angered" 6K-E and  I've bought the G Lower buss cards to replace my old E cards,  just need some more info what I need to change on the channel cards.
Any input would help,
Thanks,
Vance Powell
[email protected]

SSLtech said:
Yes, you will.... you turn one up and odd, lower signal levels start appearing on other busses, 'out-of-phase' and seemingly randomly associated...

So you first need to determing what mods are present in the base console modules, there may be AFL mods etc...

Then you need to make sure that you're adding the SAME revision of lower buss cards on the extension section.

Then you need to perform the "coat-hanger" modifications to the older ("brown-EQ") modules... Notice that the black, stiff wire (looks a bit like the stuff that wire-coat-hangers are made from.. hence the name) -that sits on top of the 611 motherboard and runs underneath the daughter cards- will be different on the new and old cards.

The newer (split-ground) modules will have:

1) Different ground 'coat-hanger' layouts
2) A little "ladder of about five resistors standing upright and joined together at the upper end, near the upper buss card edge connector pins
3) A cut in the really thick PCB trace, near the resistor "ladder"
4) usually a small jumper in the same area, which allows you to 'bridge' the PCB ground trace cut, for using the modules in split-ground installations, without ruining the grounding scheme.

You WILL need full documentation to do the mod, missing a SINGLE step on any ONE module will mess up the whole console whenever that module is inserted.

-But it's not that tough though, just needs some patience.

I can probably help out, and I'd be happy to do whatever I can... -specially if there are any juicy spares left over in that '81 center section! :wink:

Keith
 
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