SSL "Talkback" Listen Compressor

[substitute]

Is Jensen slow also?  I'm still waiting on some cinemags fromearly december.  Maybe mouser etc. has something cheap that would work for testing purposes?

It's funny I mere hours after I posted the cinemags showed up.

 

[Mylithra]

http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMv0IfuNuy2LUQ0m87amfyq2Dj7UeeLO0fc%3d
http://mouser.com/Search/ProductDetail.aspx?qs=sGAEpiMZZMv0IfuNuy2LUaR7iCoLh1pOFtNuWG6Few8%3d

Should work for testing purposes. Probably wont sound too good.
They carry 3 others by Hammond but would take them min 2 weeks to get them.

 

[geetar_king]

im looking into the JLM14s. i try to stay away from mouser because I'm in canada and customs charges when ordering from mouser are ridiculous for some reason.

 

[Ptownkid]

im looking into the JLM14s. i try to stay away from mouser because I'm in canada and customs chargers when ordering from mouser are ridiculous for some reason.

It's because they are shipped from the states and ship fedex ground. I stick with digikey, electrosonic, and newark.

 

[geetar_king]

yep its brutal.  i try to get everything through digikey or locally.

 

[geetar_king]

Specs for original Sowter 3811f transformer:

 

[shabtek]

does that xfmr ratio spec look funny to anyone else?

edit: Z=turns squared ...1:4 turns squared =1:16 Z ; 600 ohm primary times 16 =9600 ohms = 600:9600=1:4 turns=wtf=u see?

600:5000 Z=1:2.8____ turns no?

 

[rascalseven]

I've got one of these that I'd like to try with this circuit.

http://www.edcorusa.com/products/transformers/mx/mx5cs.html

It's a 1:5 not 1:4, but I suspect it'll be more than good enough for this, and it's pcb mounted as well.

JC

 

[geetar_king]

i see what you are saying shabtek. don't know, thats what sowter gave me from their data sheet.  600 / 10k would make more sense hey?

edit: checked with sowter and they sent me another data sheet with 600 / 10k  haha...

 

[geetar_king]

10K pot on the input opamp thats an audio pot right? looks like the input is set up for 10X gain. i guess an audio pot makes sense there.

is the bias pot linear 10K? i guess i could look at the 1176 bias

 

[geetar_king]

I took a bunch of pictures of the original SSL card. Also scanned in the bottom of the card so you can see the traces.  There's actually a few traces on the top (component-side) of the board for power to the opamps.

This is a zip file (~40MB) : http://www.4shared.com/file/89016725/489f2af7/SSL_Talkback_Images.html

I'm working on building a layout right now. The board will be mono and power will be taken from an external power board. I'm setting it up with two Omron relays that will reverse the routing of the input transformer for using 1:4 mic or 4:1 line inputs.

Also talked to rascalseven who is interested in making up a layout too.  I'll post more info as I go. I'd like to test out my layout before I post it here probably

;D cheers

 

[geetar_king]

Also, the SSL Talkback schematic on nrgrecording's website shows C16 as 100uF/10V and the card I have actually has a 10uF/35V cap there instead. That is the only minor discrepancy with the schematic I have found so far.

 

[Whoops]

Great stuff!!!

Have you tried to wire the original board to see how it performs?

 

[geetar_king]

Nope. I dont have a power board made up for it yet. I'll have to make one up when I make up the DIY board anyways, so I could probably try it out then.

 

[geetar_king]

The LMC-1 free talkback plugin released by SSL has a LESS/MORE compression control on it:

From what I understand, would this be the same control as the 10k trimpot on the FET?

I'm trying to decide whether or not to pull the 10k trimpot control out to the front panel so it can be adjusted.

 

[joe-electro]

That trimpot most likely sets the bias for the FET and therefore shouldn't be on the front panel.  A less/more control would most likely be placed at the input to the control amp that develops the control voltage for the FET.

---Joe

The LMC-1 free talkback plugin released by SSL has a LESS/MORE compression control on it:

From what I understand, would this be the same control as the 10k trimpot on the FET?

I'm trying to decide whether or not to pull the 10k trimpot control out to the front panel so it can be adjusted.

 

[livingnote]

*oooo* boing!

Yah, do keep up with this. That's one cool little audio widget to have dongling around - if I can be of any help, just say so. If Volker gets any wacky ideas maybe he can come over for an etching party

 

[geetar_king]

I'm almost done a board layout for the project. I wanna go through it and double check everything first and maybe test it out. Should have it up fairly soon though.... we'll see. I've done it up with two relays to switch around the input txr for having a 1:4 mic input or 4:1 line


-->>  Anyone know about the LESS/MORE control? I think its the control on the zener bias.

 

[livingnote]

Oh great What software are you working in?

 

[Whoops]

any SSL gurus around, to help on the Less/More pot?