SSlmixed.com Forum
Tech discussion => 4K,6K,8K Series => Topic started by: StarF666 on March 13, 2015, 06:26:45 AM
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Hello Everybody,
this is kind of an official introducionary post. The reason is, our desk is finally with us. My name is Martin, I'm 34 years old, got a MA in computer science and my guitar skills got me somehow in the music business. The studio and hence the SSL I'm talking about belong to a very close friend of mine. The SSL is kind of a lifetime dream of him and we finally make it come true.
As we are (like probably anybody else) on a budget, we could not affor to get a fully serviced console and decided to do most of the work ourselfes. We did that with his last two desks as well (a vintage ACE and a 72-channel D&R Triton, which will be for sale soon) and also some MCI multitracks.
After I mailed most of the known dealers in Europe no one had something to offer. I was after the desks on ebay in Frankfurt and Toulouse. The Michael Stockdale of AES pro audio London came up with an offer: 1985 40 channel E-series ex Maida Vale studio 3 w/ plasma meters. The price was good enough to buy it without further inspection and we liked the history of the desk. We went to London on monday in a 30 hour trip and got it now in a seperate room in the studio to fix it up. It was allegedly serviced until about a year ago and sat unused since then. It was pretty dusty but otherwise in a pretty good condition.
With it came:
- two power supplies (one faulty), changeover unit, power cables
- computer with G+ drives and psu
- spare channel
- service manuals for console and computer, computer manual, console specification sheet
It has quite a few BBC mods:
- EDAC varicon connectors instead of DL
- TB control, status buttons and some more control stuff paralleled to producers desk
- custom BBC main VU panel
- custom BBC 682 with 3x 2-track remote and varispeed
- custom BBC 682 headphone amp with source selector
- no video screen in center section
and some more. It will need some time to get through all the mods. Some have already been removed like a 28 channel submixer, which was in there at some point.
As I said, the desk is in a seperate room now, all channels, bargraphs and center section removed. We started blowing the dust out, cleaning the frame and removing some of the annoying BBC stuff.
I am writing all this in the hope for some help from this great community. I've read through a lot of topics already and I hope I can help others with some of the things I discover on the journey. I'll enjoy every question and all the support of you.
I just realized, I've got not photo of the desk complete so I'll attach one of the frame and one of the channels.
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Hi Martin,
Welcome to the family! You must be thrilled with the new project! Give it a lot of love, pay attention to details, and I am sure in the end you'll get a console for years to come by. It won't be an easy road, but we're a family and if you need anything I am sure any one of us will jump right in to help.
You should check you console, I know of some ex-BBC consoles which were custom ordered with transformers on the channel input cards. Those rock for tracking! ;)
Good luck and have fun! \o/
PS: does this console comes with TR? :D
Cheers,
Artur
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Hi Martin, looks like a great project. More pics please :-)
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Thank you. Yes it has the Jensen transformers in the inputs, brown EQ and TR. More pictures will follow as we make progress (and I find time to spend with the desk).
The SSL is in quite good condition. It seems the console has really been serviced till a year ago. It has at some point been recapped (at least partly). The circuit boards and ribbon cables are also in good condition. Only the patchbay looks a little abused.
One thing we want to change before putting it in the control room is to add 8 additional channels. We have a spare bucket and want to put the bus cards from that into the producer desk. As we have only a 40 channel patch bay, we will wire patch points to an extra patch row. Do we have to think about anything else? Does anybody see a problem with that?
Another thing, that puzzles me, is the wiring of the 120 pin EDAC connectors. I don't know what connections are on which connector and how the pins on the connector are wired. Maybe someone has a clue? Any best practice how to find out (besides using a DMM)?
We also ordered an Atomic S1 power supply. Does anybody use one of these? We won't turn it on with the old supplies. The original PSUs/changeover might be up for sale (one has the power transistors missing)
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Hi Martin,
man that's super awesome! You will love those channel inputs, special for tracking! I know of some G+ consoles which were factory for customized for BBC like your E and they rock! :)
If you have any doubts regarding recapping you better off by recapping it all. What you can do is get a channel which you know isn't in good conditions and recap it bottom up and re-calibrate it. After this, run a frequency response measurement and compare with others. If results are that better, you got yourself a reason to recap the channels! ;)
Remember that bad chap caps, although the might seem to be performing correctly (sound wise), can be in many situations for weird and sporadic malfunctions, such as logic mistriggering.
Cheers,
Artur
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the other suggestion would be to get the desk up and running before you do any additions or modifications to it. Can save a world of time running in circles.
looking at the "inside" of the EDAC connectors should give you a clue on layout as they will have individual cables landing, and you will know the pinning layout that was used. (+/-/S) Then its "just" a matter of finding where one of them goes and the rest will start to fall into place.
Cheers
Alan
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Do you have the manuals dossiers of the console correct?
You should have a system manual, that goes through all the wiring (patching) and customization for your specific console. This is not the console service manual nor the computer service manual. It's a 3rd thinner dossier that SSL provided and had all the specifics of your console (purchase order, parts list, etc.). This is because of the customer requests which could be specific from console to console.
Cheers,
Artur
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I've got a quite thin document titled "System specification". I attached a photo (been on tour the last days, hotel bar lecture). It contains all the mods and the custom patchbay rows. I'll guess I'll be able to figure things out.
And here is a little status update:
The frame has been cleaned now and we've got a plan for the new studio wiring. We added the bus cards for another 8 channels to the producer desk and are prepairing their wiring. Will make photos tomorrow. Can't wait to get the new power supply and power up the center section and a test channel.
5 channels are missing their 82E13 (knew that when buying). I'll have to find them used or might go with some from CML (thanks for the offer). One of the edge connectors on the lower bus card in the producer desk (from a spare bucket) is broken. Still trying to find that one. Apart from that I'm trying to find an ultrasonic cleaner for the switch cards. Has anybody experience with the cheaper models? Or should I try to rent a professional one?
Cheers,
Martin
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Hi, I've got a spare Lower bus card for an E series.
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Just want to give you a little status update. We have prepared the producers desk bucket for the additional 8 channels. We had to relocate the plasma motherboard a bit and will install a frame to make room under the bus cards for the connector panel. The panel will hold computer ribbons and the power supply cable. All audio connections will be on the other side under the patchbay. Speaking of, we removed all patchbays and are currently trying to get through the snake nest to configure it to our needs. We have to rearrange some of the EDAC connectors (no DLs for the BBC) and have just received the tools to do so. Still waiting for the Atomic to power it up. Meanwhile we started removing the switches from the channels to give them some ultrasonic cleaning. It seems to help especially with the routing switches. The knobs and switch caps will get a bath though we are still arguing, should we put them into the washing maschine or the dish wascher.
There are also a few questions that came up through the last days.
First, there are different type of capacitors throughout the console. I know, that some have been replaced at some point. There are a lot of the orange ones, some kinda dark blueish and some in "british racing green". Among the photos I attached you'll find one of a channel with all kinds on different boards (preamp, dynamics, vca). Can anyone shine a light, which ones are most probably factory original and which one might be changed? It's mostly out of curiosity , I know I better recap but I will start with the center section.
Then we have removed an eurorack under the producer desk which had, besides some custom switching electronics, fitted several "dual switching/buffer card 82E148". As far as I can tell, these were used to disrtibute certain signals throughout the (BBC) studio. Am I right that these were used to balance signals and bring them to the right level/impedance? What else do these cards do? Any idea what I can do with them?
As I mentioned earlier in this thread, the desk had two custom BBC 682 panels fitted. On one, there are two switches labeled "A-H solo inhibit" and "25-32 solo inhibit" (see attached picture). Do they provide some kind of "solo isolate" for those buckets? I wasn't yet able to figure out, where the cables go. Any ideas? As I have lots of switches to spare, I thought I could install this for every bucket or at least reassign one of the switches to another bucket.
As always, any help is appreciated. Thank you.
Cheers,
Martin
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"A-H solo inhibit" and "25-32 solo inhibit" Make either side of the centre 24 channels of the 4040 configuration solo safe for FX returns. They'll just have cut traces on the motherboards that are linked via the switch in question.
The Orange cap's are original, these tended to weep a grey residue just around the legs, and contaminate the solder joint, through to the other side of the board. If you flip.. look for a slight ring around the solder joint.
The Green caps are "Muse" caps.. maybe the best cap, these are not original.
Blue caps took over from the 'Orange cap' period.. and most likely original.
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Thank you. Great info on the caps. The solo inhibit seems to work like I expected. Is this the same mechanism as the "solo isolate" on the Gs (though not "per channel")? I will have a deeper look at how they really did it and see, if I'll rearrange or expand it.
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If you're going through that minute detail, and stating that you have original caps on an 80s console I would just go through and recap the entire console. That would not only improve overall sound, but spare you to future headaches.
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It is planned to recap it completely but I will have to do it step by step. The plan is to get all the wiring sorted out, then, when the power supply is ready, start with the center section, add one channel per bucket and up until it's running. Then recap center seciont and after that gradually recap the channels one by one. I hope the Atomic has enough range to dial in the right voltages for every stage.
Does anyone have some info on the 82E148? It's also listed in the G service manual that's available in this forum's manual section.
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Just be aware that many logic problems come from bad-behaving capacitors. Capacitors not-totally-faulty, but working out of spec can mess with logic boot and you experience several random weird problems. Capacitors from the 80s will be for certain out of spec, since these would only last 8-10 years.
Cheers,
Artur
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Just a little update as it seems a little quiet around the forum. Hope you're all busy with exciting projects.
Cleaning of the channels goes on. Ultrasonic cleaning on the switches brings out some dirt. The E channels look very nice after cleaning. Anybody knows where to get the colored caps on the pots for a reasonable price? Meanwhile I started work on the patchbay. We got all the tooling for the EDAC connectors and have just started rearranging the connections for our new studio wiring. Still trying to get EDAC plugs, Jim might help but is very busy atm.
Also bought a soldering/desoldering station which is great. Might bring back the fun to soldering and I might fix my Tweed Twin finally.
Still trying to find more information on the 82E148 cards and what they are good for.
If only the new power supply would finally arrive. Just can't wait to fire it up but would rather do that with all the protection candy of the Atomic.
Edit: Sorry, I forgot to resize the images, they are quite big. I'll do better next time.
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The Atomic is ready to go, Ian will contact you today. Thanks! N
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Great news. Thank you.
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Those per-bucket solo defeat mods are wired to the bucket backplane pcb,
they cut the traces near the S3E ribbon and put them there. And yes the
atomic will go down to 18.5 with the center section and 1 module. Cheers
it will ship today! N
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I take it you are now up and testing with the Atomic?
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Almost. I wanted to fire up the center section on Tuesday but we had enough man power to work on the patchbay. I will probably test it tomorrow. The colors of the wires on the 19-way power Bicc differ a little from the service manual. I have to carefully sort this out. I don't have a white cable for example but 4 red ones. So I have to double check, where all the wires go. And then I pledge for mercy and the genius of your protection circiut. ;)
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What do you need to sort out? Are you having to build power cables?
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No, I have the power cables. But the bucket with the panel where the power connector is mounted, was removed and therefore all internal wiring. I have to connect the wires from the internal power loom back to the 19-way Bicc connector on the panel. So I know 3 red wires to B,C,D, but I have 4 of them. I guess one of them should be white and inserted to E. I also have no yellow wires but all green ones for 0V. I'm just worried because of the different current ratings on the white +20V. I guess the one with the lower (5A) current rating goes through the bargraph motherboard. I'll check where all the wires go and am pretty sure, I can figure it out. I will post once we got something running. The S1 and the power brick look great.
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Oh no! Fun, we have rewired some of those, I would double check everything on the other side, like at
the bucket edge connectors, also the the + audio and + logic get connected together at the breakers.
Another note, they have the +265 on one connector and the -265 in the other (M and N) I presume
to make it harder to kill yourself. May the force be with you. N
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And they reference the 265 off the Logic - for some god awful reason, it made the Atomic a
a nightmare in the beginning.
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Well, they were in there and it worked. I just have to figure out, where everything belongs. There are some wires labeled B and I'm pretty sure these are the ones going to the bargraph board. I will sort out the rest tomorrow. Does anybody exactly know what the E pin on the B2 connector is for?
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The 'White Wire' is not well documented, apart from Jim's power wiring scheme, available in the 'Technical Manuals & Documentation' section...
But from memory white is the +18v console end feed back to the power supply to act as the +6v ground to make the logic
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Yup, that's where that connection is made, in the early stages of the Atomic development
our logic voltage meter did not kick on until connected to the desk, but that did not
end up working because of the protection circuit, I get a lot of questions regarding
what the hell that voltage actually is because they call it 6, 7, 11 and 13 in the manual.
So we made our meter just read the actual logic psu because that is the number they
use in the manual to calibrate. It confused the hell out of me about 15 years ago.
I would like to know why they did it that way to begin with and the fact that the 250
is also tied to the logic is bizarre to me. N
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Yeah, the power supply maths is done at the console end, guess from a service point of view it's easier to have individual rails.
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It's been a while since the last update. We were busy with work and had not too much time for the SSL. Nonetheless we made some progress. The patchbay is almost finished. We prepared everything for our eight extra channels in the producer bucket, which got its bus cards and wiring installed. We also received our Atomic S1 and it was great to bring power to the desk for the first time (only with center section and two channels). It took me a day to figure out the wiring and grounding scheme and though the Atomic has great protection circuits I triple checked everything.
After everything was up (and I fixed a fault with the logic voltage wiring) I had to troubleshoot some things. The oscillator wasn't working (missing +18V from the status lock switch) and I had to repair the MD talk back switch. The logic board seems fine and status switching works. The master fader didn't work and I was very embarrassed to find out, I had forgotten to bypass the computer. Unfortunately none of the monitor outs is working.
This is what I'm going to investigate next. By then, the rest of the team will have finished the patch bay. After that we will take care of the plasma mainboard and install channels, faders and plasmas to see, what's working and what's left to fix. Meanwhile I'm trying to get some EDACs (no DLs for us) for the studio connections from Jim but he's pretty busy atm. I'll attach a pic of the current test setup.
If anybody is interested: The SSL power supply is for sale. I've got the changeover, one working unit and one with the transistors removed and the large capacitors marked "faulty". We will most probably sell the computer as well but I will try to make it work first.
Feel free to chime in. Any ideas on the non working monitor outputs are welcome.
Martin
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Things are going well at the moment. We finished the patch bay and will soon start with the new studio wiring. Still need some EDACs and Jim seems busy. The problem with the monitor outs solved itsself (like a lot of problems lately). This time playing around with the monitor cuts suddenly made the outputs come alive one after another. I think all those logic circuits and relays just need some juice again. And I will at some point replace capacitors on the logic boards. But for now all switches and logic dependend functions just work.
We also fired up the Atomic plasma brick and the plasma mainboard. We've got at least one working plasma meter ::) But I have to check the grounds one more time as I get a weird noise on all audio paths once the plasma mainboard gets power. Luckily I found a grouding scheme in the docs. BTW: What is the "common" way to set levels with plasmas? I can switch them from group to tape but there doesn't seem any way to monitor the inputs. Maybe I should RTFM.
Lastly we fired up the computer. We don't really plan to use it but who knows. Might be fun to use it with our two MCIs 2".
So while we will start to get the studio ready for the SSL I will start to check the audio paths. I got my oscilloscope and a true RMS multimeter ready. Any hint on a good free or shareware software spectrum analyzer/measurement software?
That's all for today.
Greetings,
Martin
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Looking very clean! ;)
Use the computer! It rocks, once you start messing with the SSL mixing system you'll understand why it was a success! ;)
Btw, the new "SSLMixed" computer will support your keyboard! ;)
Cheers,
Artur
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Great to hear about the keyboard support. As I said, we might keep the computer to use it with our tape recorders.
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Noise with the Atomic brick? You must have a problem elsewhere. We have plenty out there with
zero issues including Kilmister on this forum. Remember the HV for plasma is referenced to the logic
rail which is referenced to the audio rail, so I imagine if anything in the new power wiring is
a little off, noise havoc could happen. The build is looking great!
I'm sure we can get to the bottom of it. N
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Thanks Norman. I'm sure it ain't a problem with the power brick. It's probably something with the power wiring or maybe something on the plasma motherboard.
Didn't have time to investigate this further. We had a very odd problem and I don't know if anybody is aware of it but on older Es the switch cards for dynamics and EQ are a little different. When cleaning the channels, my partner simply removed all switch cards and the switch caps and then randomly reassembled them. I had a burning input amplifier a week ago but did not find anything, guessed a failing op amp. Then the other day another burning input amplifier. I had put in a few channels and realized that some were not working. After some checking I found the 2A fuses on the failing channel mainboards where gone (at least one per channel). We traced it down to the switch cards. In certain positions they shortened +20V to ground. My partner was very embarrassed. Maybe I should make a thread somewhere to warn other users?
We checked all channels and put in most of them. Still have problems with some but it starts to look like a 4k.
Norman, I know your video for the alignment procedure (math ist math). I'm a little confused anyway. What should the voltages read on the center section? I guess 18.5V vor +/- rails. And where should I measure the logic voltage (and this is the one I really don't know where to set).
Once I'll be back on the plasmas, your help is very welcome.
Greetings,
Martin
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18v or 18.5v on the audio rails (your call it really makes no difference, but some swear by 18.5) Then 6.5v,
Between the +18v audio and the 11v (sometime called 13v, welcome to ssl land!) logic rail. Cheers! N
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Thank you. I will stay at 18V for now. I have to switch parts of the desk on and off as long as we are working on it and with 18V voltage can swing a little. Might go for 18.5V once it's in its final parking position.
The monitor outs are still not working properly. They put out a very quiet signal altthough it doesn't sound distorted or anything. I'll take care of this next. Then I'll go over the power cabling once more to get the plasmas working.
Sill looking for some audio measurement software to check some signals. I now have some test speakers at the main outs and it doesn't sound like it's missing something. But I know the capacitors on the input modules (and probably the other channel modules) are a bit below spec. The center section looks like it has been recapped at some point. All values are to spec and it has different capacitors all over the place.
We also installed the faders. Some VCAs seem to have some noise, but only one seems to be really bad. We'll need some new VCA cards anyway.
Oh and I tried Total Recall... it's awesome! :D
Stay tuned
Martin
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If your metal work is in good shape, the module should lock into the up position and you don't need a piece of plywood to keep the module up. Probably just pull up a little more.
Cheers
Alan
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Thank you Allan. Unfortunately, the mechanism is worn out and does not lock up reliably. We tried to fix it but it's not really secure. That's why the plywood.
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Just a short update. Spend another day finding the problem with the monitor outs. Somebody replaced R78 (the 10 ohms "fuse" resistor) on the logic card (82E24) with a 1,5k resistor) wich dropped negative supply to almost 0V. Don't know how anything on that board could have worked. Got the mini LS output working now. Main monitor outs and switching the monitor matrix to "quad" still doesn't work (it switches but no sound at any monitor out). Will start over bughunting on the 24 and 22 cards now. But it's nice to listen to the SSL sound while working on it. :)
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Hi,
I don't know if you're already doing this but I though it would be nice just to put it out there:
I will suggest you to bug hunt using a technique taught by my buddy Norman and which proved to be very effective in these cases. Use a guitar amp and a guitar cable, place the - on the console frame (for ground) and probe with the + side. You can find by just "hearing" where the sound eventually stops! ;) - CAUTION: put very low volume on the guitar amp! ;)
You can use this to probe the backplane of the 651 and then in the faulty card.
I hope it helps! ;)
Cheers,
Artur
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Or a scope or any audio analyzer, a amp works in a pinch, a cap and resistor in line is also a good idea. N
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Thanks for the advice. I have a scope here which I use for these things. I have another problem which distracts me from the monitor outs. I keep burning R15 on the channel input cards and I just can't find what's faulty. It happens after I switch the console on but not every time. Mostly after the desk was out for several days but sometimes just for the night. It's always the current limiting resistor in the negative line and sometimes it also kills the 2A fuse on the channel motherboard. It only happens on startup. I'm currently checking the 82E21 card in the center section. When I switch on the SSL it's both in mix and record status simultaneously and I usually switch it to one status and flip them a bit to make sure mix and record bus are in a defined state. Dunno if the two things are connected and I really can't get down to why the input cards keep burning. it's mostly just one card failing on startup. And somedays the desk just works fine. It drives me nuts.
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Hi,
Im new to the forum today (found it while doing some of my own personal research) I've previously been on the prodigy pro/group diy forums for years.
I saw the title of this thread and had to come and have a look, I'm actually an Engineer at Maida Vale looking after the studio's and although I've only been there for about 6 months I've been in other parts of the BBC for 7 years one of the main reasons I moved to MV was to get my teeth into the SSL's before they are all gone and deal with music recording studios rather than the Radio and TV studios i used to look after.
Right now we have two 9000J's and although i was not around in the days of your 4K we might still have some info knocking around if there's anything specific you need i can find out.
I know for certain one of my colleagues who used to look after your desk so i can direct any questions to him on your behalf anyway great to see what you have done so far and good luck with the project!
Neil
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Welcome Neil!
I'm actually an Engineer at Maida Vale looking after the studio's
Neil
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Thanks Marc !
I also have my own Frankenstein SSL 5000 that I've been working on for years 12 stereo (that I'll be adding more to) channels of input modules with filters and EQ's and 3 imo modules as mix busses (with the intention of adding a bus comp built into one imo.
It's been in storage for a few years now as I moved my own studio part way through the build and I haven't got it back out yet, it was all documented over at the group DIY forum but when I get some more progress I'll post it on this forum too.
I also have 2 channels worth of 4k 02 eq's and dynamics cards that I intended to rack up but never got to that I'll be starting soon too.
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Welcome Neil! It's always good to know a family member is joining in! we are growing day by day! ;)
\o/\o/
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Welcome Neil! It's always good to know a family member is joining in! we are growing day by day! ;)
\o/\o/
Thanks ! :)
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Wow, this is awesome. Welcome Neil. I think it's great to have someone from the BBC here as there are quite a few BBC desks around. Of course we would be interested in every little detail you could gather about our console. I'd like to take a photo of the two custom modules in our centre section once I'm back at the studio next week. Maybe you could shine some light on their functionality. I don't suppose there is any documentation left? And of course it would be nice to know some history of our 4KE, for example from when to when it was at Maida Vale at where did it go from there and what was done on it. Feel free to PM me or just reply to this thread. It might be of interest to others. This is great. Thank you.
Martin
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Hi,
Yes I can probably help identify those modules so by all means upload some photos,
There is some documentation for the 4000/6000's but its not for the MV3 desk so I'm presuming that all went with the sale of the desk originally, what I do have is for another studio which would have been very similar - and I have quite a lot so I think I'll scan it all into electronic format and host it on my webspace if possible and link to it here so please be patient.
Of course let me know if there are particular areas you are missing documentation and I'll look into that first.
I also have a lot of 5000 documentation so I'll do the same for that.
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Well, it's really been a while but besides a lot of touring we continued work on MV3. While my friend and studio owner prepared all the new studio wiring (thanks to Jim for prvoviding the EDAC connectors), sold the D&R Triton (which was a great desk on its own, we have another frame with a few channels in our mastering suite) and prepared the control room (new racks and cabling) I spent most of my time hunting the fault which caused the fuse resistors on the channel inputs to burn while powering on the console.
It was a PITA and in the end it was something really simple (as it is most of the time). First I realised there where two input versions using Jensen transformers. Our desk has 82E01 cards which use a very simple mic amp design using just one 5534. There is another version (82E001, spot the difference) using a two stage mic input. The BBC had an additional HF filter added right after the transformer. It's a 100pF capacitor that is connected to ground. Due to the board layout this connection is made using a simple wire bridge. This wire corroded over time and damaged the protecting laquer of the board. Because the bridge linked the capacitor to ground this caused a short of the negative supply rail (which was the line going under the bridge). This only happened on startup thanks to the very powerful Atomic power supply (which is really great to have). Well, to be sure we removed the link and the capacitor (I guess the BBC wanted to prevent any HF signals getting in the way) and the link and we had no burning resistors any more. I'm happy we finally found the fault as this was a show stopper but it took so much time and prevented me from taking care of other problems. At this point thanks to Andy for selling us a channel extender which really helped.
Anyway, last sunday the SSL moved from the room where we did most of the restauration work to it's final parking posistion in the control room. We had to remove one wall but everything went really well. We added plasmas and those fired up nicely (powered by the Atomic plasma power brick). The monitor section is still not working but I connected a pair of NS10 and brought a couple of tracks from the DAW to the board and we played around with it for about two hours. Then one side of the quad bus stereo outs stopped working (there is only a very low, distorted signal). I think the mix amp cards are ok as chaning them around does nothing. I think the problem is on the 25 card and fixing this is my next task. I think I'll try the guitar amp probing method as my scope has a bad hair day for a month now. Then I still have to fix the monitor outs and I think the 24 card has some issues. PFL only wents out when the LF monitor cut is pressed. I'm sorry I have to be rude but WTF?
Well, it's really been a while but besides a lot of touring we continued work on MV3. While my friend and studio owner prepared all the new studio wiring (thanks to Jim for prvoviding the EDAC connectors), sold the D&R Triton (which was a great desk on its own, we have another frame with a few channels in our mastering suite) and prepared the control room (new racks and cabling) I spent most of my time hunting the fault which caused the fuse resistors on the channel inputs to burn while powering on the console.
It was a PITA and in the end it was something really simple (as it is most of the time). First I realised there where two input versions using Jensen transformers. Our desk has 82E01 cards which use a very simple mic amp design using just one 5534. There is another version (82E001, spot the difference) using a two stage mic input. The BBC had an additional HF filter added right after the transformer. It's a 100pF capacitor that is connected to ground. Due to the board layout this connection is made using a simple wire bridge. This wire corroded over time and damaged the protecting laquer of the board. Because the bridge linked the capacitor to ground this caused a short of the negative supply rail (which was the line going under the bridge). This only happened on startup thanks to the very powerful Atomic power supply (which is really great to have). Well, to be sure we removed the link and the capacitor (I guess the BBC wanted to prevent any HF signals getting in the way) and the link and we had no burning resistors any more. I'm happy we finally found the fault as this was a show stopper but it took so much time and prevented me from taking care of other problems. :-\
At this point thanks to Andy for selling us a channel extender which really helped.
Anyway, last sunday the SSL moved from the room where we did most of the restauration work to it's final parking posistion in the control room. We had to remove one wall but everything went really well. We added plasmas and those fired up nicely (powered by the Atomic plasma power brick). The monitor section is still not working but I connected a pair of NS10 and brought a couple of tracks from the DAW to the board and we played around with it for about two hours. Then one side of the quad bus stereo outs stopped working (there is only a very low, distorted signal). I think the mix amp cards are ok as chaning them around does nothing. I think the problem is on the 25 card and fixing this is my next task. I think I'll try the guitar amp probing method as my scope has a bad hair day for a month now. Then I still have to fix the monitor outs and I think the 24 card has some issues. PFL only wents out when the LF monitor cut is pressed. I'm sorry I have to be rude but WTF? :o
I'll post some details of the custom BBC panels for Neil in a minute. For those stopping reading here, have a nice summer. 8)
Greetings, :)
Martin
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Ok, took me more than a minute. I'll attach photos of the two custom BBC panels and the custom BBC main meters. Neil, I hope this helps. If you could get any info or even schematics for some of this, it would be awesome. Especially panel 1 is a mystery. On panel 2 I wonder what the buttons labeled "EMX RING", "AUX RM RING", "EMX ANS" and "AUX RM ANS" once did. And I'd be still interested in some history of the desk when it was at MV3.
Tomorrow I'll be back at the studio taking care about the 25 and 24 cards. Any hints what to inspect closely on these cards? Any caps, ICs or op amps in particular?
Did I mention the studio is downstairs and has temperatures like it had air condition? We've got 35°C (95°F) outside which is quite hot for around here. Have a nice summer.
Greetings,
Martin
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Just realized, I forgot to attach the photos :o
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Ok, one more photo. This time it's the back of our 24 card. We had a lot of strange behavior on our center section. For example AFL only went off, when LF was cut. I could not find any faults on the 24 card but after I inspected the backside, I found that the insulation of the resistors that are placed there went bad and caused a short. After we took care of that everything was fine. Is there a place on this forum where this hint might be easier to find for others? This, like the problem with the corroded bridges on our input cards, might be a problem with more of the older cards and desks that have been stored in warehouses or other not so comfortable places.
Further had to replace the transistor (TR10) for the dim function. Only thing still not working in the center section are the monitor outs. Main and mini are always mono, even when switched to stereo and have no sound on quad. Might be another transistor gone bad. Main outs have little to no sound on RF, might be the large volume pot. Have to take care about these things first, then I'll move on to the channels. Some of the VCA boards make noise. Any hints on this?
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We had some oxidation or corrosion in the solder joints on the 24 card which produced all kinds of issues. So maybe try to resolder the ones that look bad.
Sent from my iPhone using Tapatalk
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Doing our first recording session on it. Mostly guitar overdubs for 2 days now. Had a burning EQ board on one channel after 12 hours, probably another corroded solder joint and some HF noise/tone on one channel that went away with power cycling / floating the channel. Day two went with zero problems. Mic pres sound great and just listening to the mix bus doing it's job is plain fun. Really need to take care of the noisy VCA boards (any hint where to start? read about faulty regulators) and order replacements for the missing ones (in contact with CML) to get the working channel count up. And I have to calibrate/align the channels (got a MOTU 828mk2 and some audio measurement software ready for that, hope that's ok).
We still can't use the plasmas though, we get noise on the quad bus once the plasma power supply is switched on, especially through the mic pres. Gotta check the plasma mainboard. Any ideas? Filtering?
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Hi,
You are doing an awesome job! I am very impressed with the commitment to get your baby working... and as it shows, it needs looots of love! ;)
After finding all faults are you planning to go through a full recap? That will improve greatly the sound and overall stability of the electronics.
Thanks for logging everything and sharing with us! ;)
CHeers,
Artur
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Thank you very much, Artur. I think it's the least thing to say thank you to everybody on this forum by logging everything for others who might want to do the same thing. And yes, it still needs some love. The desk was rather cheap and we knew from the beginning we would have to put a lot of work in it. And we're still confident it was the right thing in our situation. We learned so much about it and now we feel really connected to it. And now we are already using it and it's really great feeling that all our work was really worth it.
For the recap thing: As far as I can see, a lot of the caps have already been changed at some point. The only caps I checked with lower than spec capacitance are on the channel input cards. In the long run I plan to recap the whole desk but this will be a long term thing after we got everything else working. First will be the input cards (82E01 in our case). I'm going to recap one or two cards and see, how big the improvement is. 22-26 cards in the center section all look very good cap-wise. Or am I fooled by the good capacitance readouts?
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In my experience, recapping channels entirely makes a huge difference to the overall reliability of the console. Obviously the best thing is to start with channels that have obvious faults or a reduced frequency response, but the more channels I've completely recapped on my console, the less "random" issues came up.
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as a generic approach, I start with the monitor section. You will be judging everything thru that, it should be as clean and well off as possible, then you can compare things in the board and not have as much masking of problems as you may otherwise have.
Then I like to do the center section as 1) everything goers thru it, and 2) it has less parts!
Then channels, etc.
reality often makes other choices necessary.
Cheers
Alan
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That is of course 100% correct. Luckily, my own console had completely new G+ cards in the centre section when I bought it.
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I would categorize that as yet one more instance of reality rearing its head...... in a good way!
:-)
Cheers
Alan
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Should I recap even though the caps show their full value on my DMM? The channel input cards are the only ones that have the orange caps on and are missing up to 30% of their printed value and the extreme cases. I'll get to play around with some analyzer software this week and see what the bass response looks like. The desk sounds very good nonetheless.
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Hi,
As a rule I would recap the center section completely no matter what. (an exception to the rule is if you know it was definitely fully recapped in the previous 5 years)
Regarding your channels, I would plan for a full recap also (check my exception). What I would do in your place, if you have doubts, just do a full frequency sweep analysis in one channel strip. Fully recap that only one and measure again. Check if there was a big improvement in frequency response.
Of course if you're having erratic channel strip problems with the electronics overall you should do this no matter what. Remember that caps are not only for the audio chain, but also for the overall electronics behavior. Sometimes off-spec capacitors can trigger a myriad of random problems not easy to troubleshoot.
Do you know if your console what fully recapped in the recent years? Sometimes techs put a small stamp on the electronics with the year.
Cheers,
Artur
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I also had the plan of recapping one channel and measure the result. I'll go this way. The desk is running now and besides some small problems (faulty switches and two EQ cards) everything is working fine and I have no hurry with the recap as there are a still some other little things to fix. I doubt the console has been recapped in the very last years but it wasn't really used in these years. And it sounds good. I think recapping one channel completely and comparing it is the way to go. If this makes a significant difference it's a no brainer. I already have new caps for this ready. Just have to find the time. Recapping the center section is also on our todo list. But for now we are really happy for what we got for our money.
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Just my 2 cents, recapping the center section should be top priority before channels. Specially if you're not certain when a last recap was done, if it ever was. This will save you lots of problems, specially if you now start using it regularly, problems will appear with usage and heat.
In the other side of the coin, center section is much easier to recap it being so modular. :D
Good luck!
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Any hint is appreciated. Thank you all. I'll keep you updated, of course.
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Time for an update. Desk is running and sounding gorgeous. We're trying to fix all the small things on our list step by step. While calibrating the VCA boards I did frequency response measurements on all channels and they are all very good. If these are the original caps they didn't see much action since 95 or they just hold up very good. I will do this with the center section as well but the important cards look recapped and it's just sounding so good. We got a few replacement VCA (13) cards from CML and they are as good as the originals.
I finally got the monitor section running. T2 on the 24 card was faulty and kept the whole monitor section in mono. And a 5534 on the 22 card had to be replaced to get the quad monitor outs running.
At this point a short detent: I already had a replacement 24 card ready. It came from ebay, seems to be a very early on whith tantal caps. I checked it, put it in and it shorted immediately with some nice fireworks of course. Anyway it provided T2 for the original card.
The main outs we're off about 1,5dB, we switched the 26 cards until LF and RF had the same levels and will look into the other two cards sometime soon. Any ideas how to correct this?
I got myself an early christmas present and ordered a new oscilloscope (Hameg/R&S HMO1002) which should be with me anytime soon. It should help following/measuring signals throughout the circuit. Only two things in the center section not working now: Listen mic and the meters. Meters are out because we accidently cut the cables (going through distribution amps in the producers desk, we removed everything from there for our channel extension early in the process and now focus the consequences ;) ).
And we got ourselfes a better ultrasonic cleaner. The desk did not look really dirty but we had some trouble with wire bridges corroding/shorting through to the traces. Maybe the desk was in some not so dry environment for some time where it collected moisture and dust on the cards. Anyway the ultrasonic bath really helps cleaning it and we are very happy with the results. Cards going through it look like new.
That's it for now. Still looking for channels to bring it up to 48.
Greetings,
Martin
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...
That's it for now. Still looking for channels to bring it up to 48.
Greetings,
Martin
have you tried the usual suspects like Funky Junk London or recycle audio or AES pro audio?
Mattia.
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Yep but nobody has anything in stock right now. Might have to wait a little.
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Hi,
Sorry looks like ive missed a lot and got a lot of reading to do to catch up, i thought my topic subscription would email me when there were replies in this thread but thats obviously not working!
I had a quick look at your pictures of the custom BBC panels, in case you were wondering:
RM means Ringmain which is an internal broadcast distribution system within the BBC of all BBC station outputs so for example you are working in a Radio1 studio and you want to check you are making it on air etc, or if you are in one studio and going to contribute to another studio's program you can listen before you go live.
EMX is an internal emergency direct telephone system to BBC master control rooms if you need to contact them if you are experiencing a problem and need them to do something about it.
The meters are standard BBC spec PPM peak meters whcih were a requirement on all BBC gear until last year.
The varispeed and transport are remote tape machine controls.
Feel free to ask any questions if you havent already and i'll reply and read through all the other posts asap.
Neil
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You have been busy...