Author Topic: old ssl (1979) alignment  (Read 9501 times)

christiancarvin

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old ssl (1979) alignment
« on: October 07, 2013, 08:52:17 PM »
Hi everyone! (Excuse my poor English writing!)

I own an ssl 4040E build in 1979.
I'm trying to align each module of the desk.
I've downloaded the 611 I/O module calibration.
The problem is that it concerns 82E291 input cards and 82E13 cards.
My desk is fitted with 82E01 (no VR)
and 82E14 (2 VR)
http://cjoint.com/13oc/CJfjiLiU8Yl.htm
As you can see on the picture there are 2 VR on VCA card. One is a 60k trim pot (fix the reference value) and 500k trim pot (adj offset: what is that for?)
the main problem is that 2 faders give different levels with the same level input....I don't how to fix that.
If you have any suggestion....Thanks!
« Last Edit: October 07, 2013, 08:55:34 PM by christiancarvin »

marcmozart

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Re: old ssl (1979) alignment
« Reply #1 on: October 07, 2013, 10:37:01 PM »
Hi Christian,
welcome at the forum! Your E-Series must be a very early one. Would be great to see more posts from you and perhaps some pictures of the console!

I have a G so can't really help. My guess is that the second Trim is to the trim the VCA for minimum distortion. I would just turn it and see what happens. You can mark the setting with a pen so that you can return to it.
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christiancarvin

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Re: old ssl (1979) alignment
« Reply #2 on: October 08, 2013, 07:33:10 AM »
Thanks for reply!

So here is the console:
http://cjoint.com/?CJiiAF8XpGJ

Quote
My guess is that the second Trim is to the trim the VCA for minimum distortion
I have already tried that but nothing changed...Maybe I didn't turn the VR enough...

I'm going to make a topic on the desk repairs...I'm learning it on my own so I will need help!

sintech

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Re: old ssl (1979) alignment
« Reply #3 on: October 08, 2013, 09:05:42 AM »
Hi Christian, the line up for the 14 card is going to be pretty much the same for the 13 card, really only the VCA type differed.

As a ballpark, you can flip your VU's into 'VCA to Meters' with all your faders sat on 0dB, and get an idea if anythings wildly off.

VCA Card 82E13 (Non-Ultimation only)
Set the console to Record status and press the channel FLIP and DIRECT buttons. With +14dB applied to the Line Input, measure at the Group Output and adjust VR3 for +14dB output with the large (VCA) fader set at 0dB. Measure this output again for fader settings of +10, -10, and -20dB. Adjust VR2 (dB/V adjustment) to correct or evenly distribute any measured error.
Set the fader to 0dB and, using a distortion meter, adjust the Symmetry present VR1 for minimum distortion.

sintech

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Re: old ssl (1979) alignment
« Reply #4 on: October 08, 2013, 09:07:48 AM »
Best to leave the Distortion trim alone, you really need a Distortion meter for it to make any sense.

christiancarvin

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Re: old ssl (1979) alignment
« Reply #5 on: October 08, 2013, 10:12:55 AM »
Thanks for replies guys!

Quote
As a ballpark, you can flip your VU's into 'VCA to Meters' with all your faders sat on 0dB, and get an idea if anythings wildly off.
It's a real mess here! even with fader down there are some VUs up...I think that is the trouble...How can I fix that?

sintech

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Re: old ssl (1979) alignment
« Reply #6 on: October 08, 2013, 10:58:23 AM »
Hi, if the meters all the way over and don't indicate any fader movement, it could be the lack of VCA voltage +5v rail from the VCA card. This can be checked with a multimeter. 

0v = fader fully up

Also:

Bad connections: at the fader/fader bus card (unplug the small ribbon/ swap the fader from a working channel)

Reseating the module in the bucket.

Bad fader, dirty faders.


christiancarvin

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Re: old ssl (1979) alignment
« Reply #7 on: October 08, 2013, 10:59:34 AM »
They move with faders moving.
But the values are all different....

sintech

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Re: old ssl (1979) alignment
« Reply #8 on: October 08, 2013, 11:07:14 AM »
Thats good.

With the channel on an extender, you should be able to trim the 14 card so 0 on the fader = 0VU

You can also monitor a tone going through the module, set at unity, and meter that on the LF and RF VU's

You should get things pretty good with this method.

All the faders have a tolerance, and normally numbered so they stay in the same position.. maybe things got moved around in a move.
 


christiancarvin

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Re: old ssl (1979) alignment
« Reply #9 on: October 08, 2013, 11:36:54 AM »
Quote
With the channel on an extender, you should be able to trim the 14 card so 0 on the fader = 0VU
I've done it for two modules.
The problem is: If I have 0dB on two faders and 0dBVU on LF et RF and I put faders at - 10dB I'm going to have -10dBVU for one and -14dBVU for the other.

sintech

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Re: old ssl (1979) alignment
« Reply #10 on: October 08, 2013, 11:46:16 AM »
Yeah, better to get the audio right.. and not the VCA to meters. Is there enough adjustment to get the two channels equal? To match in pairs 1-2, 3-4 and so on.

christiancarvin

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Re: old ssl (1979) alignment
« Reply #11 on: October 08, 2013, 11:50:17 AM »
If there were I didn't find them...just this 60k trimpot on the vca card
make it good just for one value...

sintech

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Re: old ssl (1979) alignment
« Reply #12 on: October 08, 2013, 12:19:16 PM »
Hi, on the schematic here, the 500k is marked Adj. offset, and the other is unmarked. Don't have any other info regarding the 14 card.

If you put the channel on the extender, switch to VCA to Meter, one trimmer (most likely the 60K) will move the meter up and down, increasing/decreasing the output of the VCA by the same amount.

I've lined channels up like this with good results in the past.
« Last Edit: October 08, 2013, 12:20:59 PM by sintech »

christiancarvin

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Re: old ssl (1979) alignment
« Reply #13 on: October 08, 2013, 12:27:23 PM »
This is what I've done on two modules with the 60k trimpot...it makes a good pair for one value but when you decrease the two faders exactly the same way values are not the same anymore....
(Sorry for my English and thanks for your replies!...)

sintech

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Re: old ssl (1979) alignment
« Reply #14 on: October 08, 2013, 12:31:15 PM »
Hi ok, so what your saying is it also effects the Fader Law. Could it be the two trim pots are interactive?