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

[barclaycon]

Well the fact is Andy, from a circuitry point of view, if you've done the RMS converter and the VCA it's not much more to add the gate to the compressor.
It's just a little bit of control circuitry to the VCA.
If you could find miniature pots it would all fit on a 500 front plate.
It's what? - 6 pots and about 4 switches (if you include a sidechain switch). It's just a matter of finding small 250k log dual. 25k lin dual etc. etc. I mean the Clarostat ones are fantastic, but imagine how much they'd cost to DIY-ers! The display is fairly small too.
I think the fly in the ointment is the RMS chip. I just had a quick look on the web for the AD536 and noticed that prices for NOS units are about 50 Euro's a piece.
Like I say, a bit of redesign perhaps using the THAT4301 might be the way to go - but it's finding the time and inclination!
Oh and by the way, I'd take the SSL analogue gates over any digital gate anytime.
Even the Waves SSL plugins don't sound that great from the point of view of the gating.
(I think they've done a great job on the EQ but to me the dynamics aren't as good as their analogue counterpart).

 

[pietro_moog]

power supplies done, i have to connect them and rationalize.

barclaycon, do you work for SSL? you are making this very hard..
you can find ad536a at digikey, at a fair price.
it seems to me that comp release pot is mono. you can find mono 250k SPDT pot at banzai music for about 3€..
if we change rms chip the comp won't react the same way, so it will not be a SSL channel comp..
i'd like this to be an affordable good copy, not a cheap crappy copy..

i'm just making the schematics in Eagle, not the pcb for now..
so, for the 500 s. compressor and all the small problems, we'll see then..

let's keep it simple..

 

[peterc]

I am contemplating a 500 series version of this but without the expander/gate & simpler hardware like separate switches.

Peter

 

[strangeandbouncy]

Hi PeterC


    How can we help you in your contemplation?  ;D


      I am sure that there'll be plenty of take-up for just that!


            Kindest regards,


              ANdyP


     

 

[peterc]

Hi PeterC

   How can we help you in your contemplation?  Grin

An extra 4 hours n the day would suit me down to the ground

Question: the wiper of the Comp release pot is shown as going to 0V, while all the other connections to ground are shown as  a short 45 degree angle line... Is this the same point? Have I missed something? I couldnt find another point marked 0V

THx
Petr

 

[barclaycon]

Re

barclaycon, do you work for SSL? you are making this very hard..

Pietro - calma... I'm not trying to put you off!
Based on my experience of having built a few of these, I just thought I would point out that you might have some difficulties with a few of the parts. And the fact that I had contemplated designing a version using the THAT4301 chip.
I don't think it would sound fundamentally different with a different RMS chip. Just a matter of juggling the parameters to suit.
Anyway, I hope your design turns out well.
Buona fortuna.

 

[phishman13]

PeterC,

How can I urge you to INCLUDE the gate/expander?  As barclaycon said, better than digital!  I love the comp, but I also love the fact that they are the total package with both, and you don't have to worry about compressing a bunch and not being able to gate b/c of that, it feeds both the same signal and processes separately.  I love that!  PLEASE please please include it!  ;D ;D ;D

(persuasive enough? haha, also like barclaycon said not much extra circuitry to add.)

Thanks for whatever you choose to do!

 

[strangeandbouncy]

Hi.


  Woah! Hold on a minuet, guys . . . .

  true, not much extra circuitry, but a lot of front panel real-estate to accommodate pots/switches, and if 51x/500 series is a goal then . . . . not possible without switchpots of dubious cost/availability. Also, don't forget release pot for exp/gate is a mixed dual pot . . .



  original question was about comp clone . . . . . no mention of exp/gate.


  why not do two modules, one comp, one exp/gate? Or, separate module could link the control circuitry to common vca on one or other board? or do double width module?


  or a fully loaded version for a 1u rack with all da bells and whistles?


  you can't please everyone, but if you try, you will fall  between two stools.


  take a leaf from barclaycon. He only did the exp/gate, and that is in a Scamp rack, with a much bigger pcb possibility, and (probably) more faceplate surface area. And, he had original, surplus SSL switchpots at his disposal. I also think that the exp/gate rules, especially when building a live drum mix in a hurry, but it is the comp that has the sound for me. I still argue that the gate can be achieved digitally, or with a seperate 500 series module ;D


  just some food for thought,



      ANdy-PleaseMakeThisHappen!-P


ps double width is sounding more and more appealing right now . . . .


pps I wish I had the skills, and/or the time to do something practical here to help out. I will be very grateful for whatever I get!!!!

 

[barclaycon]

take a leaf from barclaycon. He only did the exp/gate, and that is in a Scamp rack

Ah, no.
Sorry to correct you there Andy, but my modules were the full-featured thing: Compressor and gate.
6 pots, 2 push switches & a toggle for key input.

I could post some pictures if anyone is interested.

 

[strangeandbouncy]

Hi Barclaycon,


  one thousand pardons, but I was quoting you earlier when you only mentioned gate  . . . sorry to be a pedant! I personally would LOVE to see some piccies when you get some time.


  6 pots still ain't gonna(cheeply/easily) fit on a 51x/500 series panel, switched or unswitched by my reckoning, but I don't want to appear a naysayer!



  Anyhows, enough semantics!



        Kindest regards,



          ANdyP

 

[strangeandbouncy]

Just to split more hairs,


  the reason why I am more than happy to gate in the digital domain is the ability to automate all the functions in real time - sure helps with drummers of dubious consistency, not to mention songs of great dynamic range, you know, "he rails on the high-hat like it'd some guy raped his sister, yet hits the toms like a pussy"( is it ok to quote da MixerMan?) . . . . This flexibility trumps any sound advantages in my book. it is very easy to automate/ride the input and output of any inserted analogue compressor to achieve some consistency. This, however, will not be effective on a gate! You also raise the spillage, which is obviously higher in loud passages, especially metalwork,  so, I often prefer to separate the two. best of both worlds, you might say. I totally get the advantage of one vca/two functions, but I cannot automate an analogue gate(yet!), let alone an SSL gate . . . Also, you cannot gate the compressed signal, or compress the gated signal, since they are in parallel, - obvious ad- and dis-advantages both ways.


    But thank heavens we are all different! A little careful planning might make a one-size-fits-all project. Cheeper, not-so-tiny pots will certainly increase the accessibility factor, but hey! perhaps I shouldn't be such a socialist cheapskate . . . .



  Kindest regards,



    ANdyP

 

[phishman13]

that's why i DONT want a 500 size board.  i know its the newest fad here since some extremely badass people just made it affordable.  A serious accomplishment that I couldn't even DREAM of knowing how to do, those guys should be proud (and sure they are).    I personally don't have one, nor see one in my future anytime soon.  I know I can "rack" 500 series modules, but for me, if you can't fit it all on there, then its not the same thing.  I feel like it is truly a complete package, the dynamics module, not a compressor and gate.  I have no need to gate a compressed signal, since that usually doesn't work as well due to the smaller dynamic range, and the way they parallel the s/c you basically ARE compressing the gated signal.  I don't really see the difference... and plug-in gates just don't do it for me.  BUT I do understand everyone has their own workflow.  I have a hell of a time adapting to other people's and I'm sure they would to mine too!

So, I am at the mercy of what most people want here, so it seems like i am on my own in wanting a 1u rack pcb of both gate and comp.  Maybe once the final schematic gets nailed down in software, it can be shared, and we can go in a couple directions.  I have the ability and software to design my own pcb, so that sounds like my best bet.

oh well.

 

[pietro_moog]

my schematics in eagle are done. i just have to connect the power rails of ics.
but i have a lot of questions about the circuit.
i'm going to sleep, i need a few hours before going back to study.
tomorrow night i'll ask some stuff

 

[pietro_moog]

guys, the schematics are done, i'll take a few days to check it, and then i'd appreciate if someone other would check it to.
we can replace CA324 (schematics says CA234, but i've seen a few pics of a 82L10 board and they are CA324 ) with LM324, they
are about 0.2€ each and largely available

i have a lot of questions:
-i used that 1240 and 1640 for input and output, but i'm not sure of what i've done..  however, do i have to connect them to +/-15v rails?
-the icon of that 2181 has no V in and V out, how can i connect them? (i can connect the pin on the pcb design,is that the way to proceed?)
-same question as PeterC about 0v on the release pot of comp.
-why ad536j is  +15v / -18v?
-what is "P11 out" near 250k log expander release pot? and why a leg of this pot is not connected to anything? it seems to go on ground, but it misses the oblique line..
-why negative rails of T3 and T4 should be connected between R18 and C20 on the power supply (near 79L15), and not to the -15V rail?

 

[pietro_moog]

i think wee need a replacement for the 1S44 diodes

 

[pietro_moog]

the pcb is a freaking mess..

 

[pietro_moog]

oh my god.
the diodes and the pads i choose are really too big, i have to change them.
can someone suggest me a normal diode for size and a common pad size?
thanks

 

[barclaycon]

These are the SSL channel modules that I built in 1988:

http://picasaweb.google.com/barclaycon/ScampSSL#5436356933475651330

http://picasaweb.google.com/barclaycon/ScampSSL#5436356922824479010

Martyn

 

[pietro_moog]

those are really really cool!!

now we know you're not working for SSL!
BTW are you italian, or of italian descent?

what diode did you use at time?

 

[Rob Flinn]

Martyn

Did you ever do any similar green modules that might have been the SSL eq ??  Your modules remind me of an SSL eq module that someone from Peckham tried to sell me a few years ago that was in the same green colour, possibly for a scamp rack ?