Author Topic: How to recap a SL611 Channel Input/Output Module (SSL 4K/6K/8K E/G-Series)  (Read 29182 times)

marcmozart

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(This first post should have all the info needed as I kept updating it - I was clueless when I first posted this but really got into recapping now)

Q: Which caps to change? (I understand they are numbered in the schematics which helps)
A: "You only need to change the Electrolytic caps, typically these channels have masses of: 100uF/10v, 10uF/50v and 220uF/25v just buy 1000's of these. Then smaller quantities of odd values 1.5uF and 6.8uF and others depending on board revs. It's better to look at the cards, to make the bill of materials rather than the schematics, changing 'like for like'" (thx sintech)

Note by author: The 291 G-Series Channel Amp and 292 G-Series EQ use 100u 25v and 220u 6v "Non Polarized" Electrolytic Capacitors. The G-Series Group Amp has a 10u 16v "Non Polarized" Cap. There's also either a 10uF or 100uF non-polarized cap on both the original and MK II G-Series Film Pan-Card.

I've created a bill of materials for both the Channels and the Centre Section.
http://forum.sslmixed.com/index.php?topic=308.0

Q: How do I read the values of the caps in the schematic?
A: see above, check the values used on your cards rather than relying on the schematics; capacitors with values lower than 1uF are NOT Electrolytic, but Film- or Ceramic-Type and do usually not need replacement. If you see Caps in the Schematic with values in the pF or nF-range, those are not Electrolytic Caps. (Film- and Ceramic-Caps do not really age compared to the Electrolytic Caps)

Q: What caps to get? Where to buy?
A: For the polar capacitors, Panasonic FC, FM and FR Series are very popular for audio and have very high specs. FR is the latest and has the highest specs, FM is an updated version of the FCs with better specs, but not all values are available. The polar ones have to be replaced with the + and - pointing in the correct directions. The capacitors have a marking for the negative - on one side. The PCBs usually (but not always) have markings as well, showing where the positive + side has to go.
For the non-polar capacitors, Nichicon Muse ES have been recommended by multible sources. These are marketed as special "High End" Audio Capacitors.
Mouser.com is a great source for all of these - they ship worldwide. Just type "Panasonic FR Capacitors" or "Nichicon Muse ES" on their website. You save A LOT of money by buying in volume (100 of each value, or at least 10).

Check sintech's post - makes recapping look easy ;)
http://forum.sslmixed.com/index.php?topic=8.msg794#msg794

Quick overview - these are the main cards on the 611
82E291 - Channel Amps Card (G-Series)
82E241 - Channel Amplifier Card (later E-Series)
82E292 - Parametric Equaliser and Filter Card ("pink G-Series EQ")
82E242 - Parametric Equaliser and Filter Card ("black G-Series EQ")
82E10 - Dynamics Section
82E13 - VCA Card
82E294 - Group Amplifier Card (G-Series)
82E281 - Film Panning Mk2 Card (G-Series)
+ Logic Card + (optional) TR Cards

Details may vary, this is taken from the 4000 G / G+ Service Manual. Link here:
http://forum.sslmixed.com/index.php?topic=292.0

Quick example for dummies (like me) - Dynamics Card 82E10

1. Look at the photo below showing the Dynamics Card. Those blue "round cylinders with silver top" are the Electrolytic Capacitors (there's an orange one as well). I counted 13 of those on the card.

2. Look at the second screenshot below which says C1 10u 35V. This is how an Electrolytic Capacitor looks like in the schematic. You can see it is a polarized cap, it's value is 10uF, the voltage rating is 35V. C1 is the number of the Capacitor in the schematic. The PCB does in most cases also show this number and the "+ side".
Make sure to replace with a capacitor that has the same voltage rating (35V) of higher (e.g. 50V). Getting higher rated caps neither improves or hurts anything, but higher rated caps are more expensive and physically bigger (sometimes too big to fit on the PCB).

3. Now look at the entire schematic and find those capacitors. Capacitors with values lower than 1uF are NOT Electrolytic Capacitors, they usually don't need replacemant.
I found exactly 13 (polarized) Electrolytic Capacitors, the same number I counted on the photo.
Here are the values of those:
C1 10u 35V
C3 100u 25V
C4 3u3 50V
C5 3u3 50V
C6 22u 25V
C9 6u8 75V
C13 220u 25V
C14 220u 25V
C16 3u3 50V
C17 10u 35V
C18 3u3 50V
C19 10u 35V
C20 10u 35V

For example, 3u3 means 3,3uF (micro Farad).

This card also has a non-polarised Capacitor, but it's not an Electrolytic Cap, so no need for action.
C10 2u2


As mentioned by sintech, confirm the values in the schematic with the ones on your particular board.
« Last Edit: March 16, 2014, 12:38:36 PM by marcmozart »
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sintech

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You only need to change the Electrolytic caps, typically these channels have masses of: 100uF/10v, 10uF/50v and 220uF/25v just buy 1000's of these :-)


Then smaller quantities of odd values1.5uF and 6.8uF and others depending on board revs. It's better to look at the cards, to make the BOM rather than the schematics, changing 'like for like'


My 611 re-cap box :-)

Artur D'Assumpção

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Respect! :D


marcmozart

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Re: Recapping the SSL 611 / Red Dubiliers + Volt Rating
« Reply #3 on: March 23, 2013, 08:53:32 AM »
Thanks!!! Can you elaborate on the volt rating? 10v, 50v, 25v... do I get an advantage/disadvantage by using higher rated caps?
I see you're using the red Dubiliers sold here:
http://www.audiomaintenance.com/acatalog/radial_capacitors.html

I heard these are a favorite of Rupert Neve, any specific reason you went for these? They seem reasonably priced  :)

Anybody up for a group-buy of these to get prices down?

One more question: why only change the Electrolytic Caps? Do the other types of Caps not age?

You only need to change the Electrolytic caps, typically these channels have masses of: 100uF/10v, 10uF/50v and 220uF/25v just buy 1000's of these :-)


Then smaller quantities of odd values1.5uF and 6.8uF and others depending on board revs. It's better to look at the cards, to make the BOM rather than the schematics, changing 'like for like'


My 611 re-cap box :-)
1992 SSL 4048 G-Series
Mix Engineer Blog
http://www.mixedbymarcmozart.com

sintech

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Hi Marc,

Went for the red Dubiliers, as it's a quality cap, and AML have all the correct values.

In 1982 SSL used 100uF/3v caps, so the 10v is three times higher than it needs to be, in the same sized package. Physical size has to  be a consideration.

Lot of other place just won't stock a 10v cap, it's too low rated in 2013

marcmozart

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Excellent, thanks a million! I'll edit my initial post with your info, so we get everything in one place.

Hi Marc,

Went for the red Dubiliers, as it's a quality cap, and AML have all the correct values.

In 1982 SSL used 100uF/3v caps, so the 10v is three times higher than it needs to be, in the same sized package. Physical size has to  be a consideration.

Lot of other place just won't stock a 10v cap, it's too low rated in 2013
1992 SSL 4048 G-Series
Mix Engineer Blog
http://www.mixedbymarcmozart.com

marcmozart

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Re: Recapping the SL 611 Channel Input/Output Module (SSL 4K/6K/8K E/G-Series)
« Reply #6 on: November 10, 2013, 08:06:35 PM »
Voilà, recapped G-Series Group Card!

The green bipolar caps are Nichicon Muse ES, the polars are Panasonic FR or FC (for values where FR wasn't available).



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