why don't we make a SSL channel compressor clone?

[pietro_moog]

thanks.
i'm looking for alpha pots libraries.
i can't find ground icon searching the word "ground", do you remember where it is or have a suggestions for searching?


and guys,
this comp seems to have just 2 attack settings, slow and fast.
i don't understand the schematics here, it seems connected to the release..

 

[phishman13]

according to documentation on these units, one attack setting is an adaptive auto attack ranging from 3 to 30ms.  The fast attack switch changes that to a fixed 3ms attack time (i've read 1ms in other places too).

 

[pietro_moog]

cool.
so, what do i have to do?  i don't understand how pots are written in the schematics.
there's a dotted line connecting the both side of the dual pots,is that a sign to mark they are the same pots?

and, there's a line connecting the attack switch to the release pot. that's my problem now.

another thing: there's plenty of white hollow numbered dots on the schematics. what are them?

 

[signalflow]

Click on the "Add Part" symbol look under the "supply" library and select a ground icon that best suits you.

if you use the search function try searching for GND.  But if you use the directions above you will not only find the ground
symbols but you'll also have a good idea of what parts you have in your library.

-Casey

 

[pietro_moog]

cool, thanks.

NB.
if someone is expecting me to deliver a working PCB is so wrong.
i'm a noob, and i'm really not sure of what i'm doing.
i'm just trying to copy the schematics in eagle, but i'm not so good.

i'm just doing it because the guy on the second post made me realize i don't have to ask others.
 

 

[signalflow]

This book helped me when I started messin around with eagle, I am by no means an expert now but I definitely know more than when I started.

http://www.amazon.com/Build-Your-Printed-Circuit-Board/dp/007142783X/ref=sr_1_5?ie=UTF8&s=books&qid=1265505306&sr=1-5

You might also try and search for "eagle" here in the forum  if I remember right there is a post which links to some very helpful tutorials.

Good Luck,

-Casey

 

[phishman13]

On the duality, the release knob was also a push switch that toggled the attack mode, and the pot changed the release speed, all in one control.  So my guess is that you don't have to link them like the schematic shows.  That's just how they did it.  You could use a separate toggle switch or whatever to switch the attack, and then a regular pot for the release.  So for your purposes, just act like the dotted line connecting the two doesn't even exist.

 

[pietro_moog]

thanks guys.
my schematics in eagle is almost done.
it misses power supply, balanced input and output
power supply is my weakest point.
i'll ask stuff tomorrow


quick question:
i see "TP1", "TP2" near ad536 and "TP3" near the output. what is this stuff?

 

[Biasrocks]

quick question:
i see "TP1", "TP2" near ad536 and "TP3" near the output. what is this stuff?

These are test points, you need to provide a pad for them.

I've been studying the schematic.

There are a number of parts that are obsolete that we need replacements for.

CA234 Quad Opamp, 1S44 Diodes, AAZ17 Germanium Diode.

I couldn't find any specs on the CA234 quad, what's a good substitute for this guy?

Looks like it's mostly a utility opamp, used in the side chain and LED driver.

There are also 2 10K Lin Dual pots we need to account for, these shouldn't be to difficult.

Mark

 

[helterbelter]

thanks guys.
my schematics in eagle is almost done.
it misses power supply, balanced input and output
power supply is my weakest point.
i'll ask stuff tomorrow

Awesome dude !
IMHO, leave out the powersupply. There are plenty seperate powersupplies that can be used (like a partly stuffed 9k powersupply for instance). When you'd like to build a 2 channel or 4 channel unit, you'll need only one PSU anyway.

onboard balanced in and outputs are very convenient though. As well as a led meterdriver for GR (in case that's not included yet)....

Wicked......

 

[Moby]

my schematics in eagle is almost done.

Great. Count on me for some help with Eagle and possibly PCB manufacturing but right now I'm really bussy with few studio projects. Anyway just keep on  
I use 4K channel for drums and guitars, hard to be beaten, so few more racked will be great  

 

[Biasrocks]

thanks guys.
my schematics in eagle is almost done.
it misses power supply, balanced input and output
power supply is my weakest point.
i'll ask stuff tomorrow

onboard balanced in and outputs are very convenient though. As well as a led meterdriver for GR (in case that's not included yet)....

Wicked......

This project needs a triple supply, +/-5v, +/-15v, +/-18v.

Mark

 

[phishman13]

That's why there is that psu section at the bottom of the schem.  You need those components so that you can feed the board a +/-18v supply and then it splits that into the +/-15v and +/-5v on the board.  So yeah, don't ADD any psu components, but what is shown on the schem is there to make life very easy, so keep those.  This way we can use the ssl9k psu w/o the 48v rail and not have to worry about 3 bipolar supplies.

 

[pietro_moog]

hi guys
i don't understand, do all the hollow white points are test point, or just the "TP" points?

 

[pietro_moog]

i'm giving names to the components and checking a bit.
i didn't find the right symbols for diodes and transistors in eagle, so i used what seemed to me common size components for now.

i still wonder what numbered white hollow points are (are they test points too?)
and why half ad536j is not wired?

what is P11 "out" near the release pot of the expander?

can i cut the section of dyn send & return  near t4 pin5,6,7 in the schematics? i think so, but i'm not sure.

i still have to do power supplies rail.

last thing: where i find a micro symbol on a mc keyboard?

 

[phishman13]

the hollow points are the points that go to the connector on the card to plug into the console.  Basically like the card edge connector on api 500 cards.  I guess not all of them will be used, some will be connected together, such as the main input, and the sidechain input (not exactly sure they get DIRECTLY connected together, but i think the pdf posted a few days ago shows how all the modules get connected together within the strip, so that may help.) so those points will need some examination.

 

[pietro_moog]

hi guys.
weekend is over, i'm back to study.

tonight i'll check the circuit again and make the power supplies.

where do i connect the sidechain input?

 

[Biasrocks]

where do i connect the sidechain input?

It should normally be connected to AUDIO IN, but you will need to provide a switch for external side chain insert which will go to a connector (1/4-inch TRS) on the back of the unit.

Mark

 

[barclaycon]

I caught up with this thread late so forgive me if some of my points have already been covered.
I actually made 4 x SSL gates in the 80's for use in a Scamp rack.
I used the original Aphex VCA design and copied the actual SSL PCB layout.
Still use them to this day.

Here's a few reasons why a DIY version would be difficult. The pots used are a bit tricky - 250k log with pull switch for example. I used pots culled from various SSL spares kits (i.e. original Clarostat types).
To do a DIY project you might have to get pots custom made.
The RMS chip that they used was very expensive even then - I'm not sure it's even available now.
I did look into the possibility of using the THAT's RMS chip - especially as they do a combined RMS converter and VCA with opamp on one chip, but I didn't devote that much time to it.

If someone does decide to get this project going then it would certainly be worthwhile because it is a fantastic design which sounds great. It might even suit a 500 series module.

 

[strangeandbouncy]

HI Barclaycon,


  or we could just use a pot AND a switch, more real-estate, but much cheaper. If you built just a comp without the exp/gate, then there shouldn't be too much problem in a 500 series, I reckon. SSL Exp/Gates are very usable, and predictable on drums especially, but for me, gating is fine digitally. It is the comp that sets my heart a-pumpin' . . . I definately would love to be able to do both in a 500 series rack module, but I guess there are always gonna be compromises to be made.


    Kindest regards,


    ANdyP