Author Topic: multiple problems with SSL 4056 - Troubleshooting  (Read 919 times)

Tony White 28

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multiple problems with SSL 4056 - Troubleshooting
« on: July 02, 2018, 05:13:20 AM »
Hey there everybody!

So I own a 1987 SSL 4056 E Series Console which i've been running pretty seemlessly for several months now and of course it's about that time for parts to start giving out and little quirks to start popping up. Below I have a list of issues that I am currently troubleshooting and I thought it might be productive to throw this list up on and see if there is any tech heads out there that can impart a little wisdom that might help me work through these problems quicker and save me the hours of research ad tinkering that I have before me. So thank you in advance to anybody out there that can lend a hand!!

1. Rythmic "Tapping" noise in quad buss:

so this is my biggest problem and the one that has stumped me the most. After several hours of use a popping, thumping or tapping sound starts appearing on all four outputs of the console's quad buss going to the monitors. This thumping noise is low frequency (The pitch never changes either) and happens at regularly spaced intervals. Upon shutting the console down; allowing it an hour to cool and then turning it back on the thumping actually goes away until several more hours later when it appears again leading me to believe it has something to do with a component overheating. The thumping is not happening in any of the individual channels in either the Channel or Monitor path and i have confirmed this by floating each channel one at a time which disconnects the channel from the quad buss. Not a single channel seems to be contributing to the sound and with all channels floated the sound continues. We can also visually note the thumping/tapping happening in the quad buss meters so we know it is in the console not the monitors and it is also apparant in the quad compressor meter. When the Control Room Level Pot is down the thumping is not audible but it can still be seen in both the quad meters and quad compressor meter. Alternatively; when the Master VCA fader is down the tapping can no longer be seen in ANY of the meters. It does not seem to matter which output of the console I am using (FR,FL,BR,BL, and Mini) as all of them are connected to the quad buss. I cleaned the Master VCA but this did not seem to help. I have been informed that this could be an issue with a bad IC Chip/Off Amp somewhere in the center section of the console. My only plan of attack at the moment is to identify which logic cards in the center section are feeding the quad compressor after the channels and then locate the IC Chips on those cards and start testing them to find a bad one. The problem also does not seem to be connected to the Echo sends, Cue Sends, External source selector, AFL or SLS systems as i have eliminated all of these systems with zero change in my problem. If anyone out there has any further info or a bright idea that may help me further identify the possible cause of this problem that would be very much appreciated as i currently have a crap ton of IC chips i need to test and i'm not even sure if that is where my effort needs to be directed.

2. I also seem to have a pretty nasty noise floor happening in my console again on the monitor path. The noise floor is inaudible when proper gain staging is used but with the control room level pot and master VCA both cranked it is extremely audible. The sound is a good old fashioned fizziness with random crackles and pops and at times even seems to fluctuate similiar to the sound of tuning a radio. I'm not hearing any actual talking or picking up any obvious signals like an actual radio frequency; the sound just seems to fluctuate randomly as if you were skipping through radio channels. I thought this may be some kind of grounding issue so i went through and checked all ground connections to the copper bar running through my console and then attached this ground bar to an 8ft. copper rod that i hammered into the ground beneath the console. The setup seems to meet grounding specs outlined in the manual but did little next to nothing to help the noise floor leading me to believe it must be a whole lotta noisy components contributing to the problem. I feel like i may have confirmed this as i noticed the noise floor drops when all of the console's echo send volume pots, and all the channel's line level input pots are turned all the way down. My question is how do i remove the noise from these pots? is going through the console and cleaning each pot my only solution to dropping the noise floor? And is there any other factor that may be contributing to the noise floor other than noisy components and improper grounding? Any ideas are welcome!

3. So there are 4 warning light on the top of the center section of the Console. These LEDs are there to indicate that power is indeed getting to the very end of all 4 power rails running through the console. The indicators are marked: +20v and -20v for the 20 volt power rails; +48 for the phantom power rail and +11 for the logic rail. Last week the LED for the +11 rail did not turn on which is VERY bad! however; upon pulling the center section and testing the actual +11 power rail at literally every point provided from the output of the PSU (an Atomic) to the end of the power cables to the input of the +11v circuit running through the center section to the very end of the +11v circuit which connects to the LED, I found that the console is getting damn near perfect voltage to the rail itself. Okay; so i figured the LED just went out. So i replaced it and it did not work. So again i replaced it but this time tested the LED first to insure it was a good bulb. it was so i replaced it and again it did not light up. So right now my power indicator is telling me that there is something wrong with my +11v rail yet from the very start to the very end of the power rail i am getting perfect readings and at this point i have used numerous LEDs not a single one of which is turning on. All i can think is maybe the wire leads from the end of the +11 rail that go to the LED somehow got disconnected from the rail or the wires got smashed or cut. I'm going to trace these wires but in the meantime i just though i'd ask if anybody out there has experienced similar problems are may have run into this Oddity with their own console before?

4. And Lastly I am currently on the market for the following parts which all seem to be very hard to find so if anybody out there knows where i could source these components that would be extremely helpful!! The components i need to replace are:

1x SSL E series Conrol Room Level Knob (Not the actual potentiometer just the plastic gray knob itself. It looks as though someone in the studio turned the knob to hard and now the thing turns past it's orginial stopping points)

any replacement button tops for the Channel strip's VCA Faders' CUT and SOLO buttons. I have about a dozen of these plastic tops that ran away and would like to know where i can buy some replacement peices.

and I also have about 8 channels that came without any EQ cards in them. The card in question is a 82E242 parametric Equalizer card for SSL E116 channel strips.

Anyways like i said thank you for any help you guys can give me on any of these matters! Have a great rest of your day guys!



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Re: multiple problems with SSL 4056 - Troubleshooting
« Reply #1 on: July 02, 2018, 05:34:49 PM »
1) seems to be a) pre master fader, B) post channels. That points to either the summing busses, or I believe the master VCA is in that path. As it does all channels equally from what I read of your description, I would suspect something like the control voltage for the VCA being unstable or noisy. Patch around the VCA and see if the noise is gone.

2) you should not have those sounds in the noise floor. It is time consumptive, but you have to start tracking them down individually, starting with the monitor by itself and going backwards. The patchbay is your friend.

Funky Junk?? for your parts

Alan Garren
Waltzing Bear Audio


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Re: multiple problems with SSL 4056 - Troubleshooting
« Reply #2 on: July 12, 2018, 08:01:45 PM »
Like the bear says, the patch bay is your friend try patching around the 26 cards
coming out of the pre vca going back in post vca (on master VCA). If the problem
seems like it is on the 26 cards it is probably capacitor related (like 95% of the time)
Or on the control voltage to the vca via the 27 card you could look at it with a scope.


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Re: multiple problems with SSL 4056 - Troubleshooting
« Reply #3 on: July 13, 2018, 08:51:25 AM »
Where are you ?
I'm qualified engineer, and I can help you


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Re: multiple problems with SSL 4056 - Troubleshooting
« Reply #4 on: July 20, 2018, 01:43:10 AM »

I was just about to post about the First issue you're having.

It just started a few days ago... Almost sounds like someone tapping on a microphone.. but faint, Low frequencies. Visible on the quad meters, not terribly audible but is annoying and makes the quad bus unusable.

Currently im using the Disk input and patching from output 1-2 of my Daw to External in.

Its definitely in the master section. Not in a channel.

Just had my console recapped... so.. im guessing not caps.. or less than likely caps. . .

If you find a solution please let me know.. im calling my tech tonight. Was gonnna post about it first but it seems hes to get a call now... :)

If i figure it out, ill post for ya.



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Re: multiple problems with SSL 4056 - Troubleshooting
« Reply #5 on: July 22, 2018, 03:08:11 AM »

A couple things.

Whats the temp/humidity in your studio? Bad or good?

second, have you looked at the 27 or 25 cards yet? I think its the 27 that feeds the voltages to the 26 or the 25 that does... off the top of my head, but whatever one that does, may be a bad IC on it dumping bad voltage.

Long and the short of it, my issue went away... with the cooler temp of the room. We had used window open air for a day or two and it was humid. System didnt like that at all.. closed the space up and turned on the AC. no issues...

If it comes back again. i was told that it was voltage motorboating from the 27 or 25 card.

Will look if we end up with this issue again... Luckily i have spare centre cards for those slots!