Ridge farm boiler

[pucho812]

schematic request,  por favor

 

[ruairioflaherty]

I've never seen that schematic in the wild, I tend to add pretty much everything of interest to my local archive.

Apparently it's based (closely?) on the SSL talkback mic compressor.

 

[[silent:arts]]

Found this on my computer, unknown source and quality.

 

[Rob Flinn]

Try asking POM, I believe he designed it http://pomaudiodesign.com/ .

If you're trying to clone it he probably won't be massively helpful I'm guessing.

 

[RuudNL]

I think there is an error in the schematic, the line from the rectifier shouldn't be connected to the junction of the 22 K and the capacitor, but (probvably through a 1 M. resistor), to the gate of the FET.
Also the 4n7 at the non-inverting OpAmp doesn't seem a good idea.
And there should be a capacitor between the rectifier circuit and the gate of the FET (to hold the rectified DC) , probably with attack/release resistors.

 

[pucho812]

Well I have a unit I can reverse engineer should I need to.  Having a schematic makes it easier to read the diode values.  when working repair. That schematic matches closely to what I have including the ssm2142.

 

[Michael Tibes]

isn't that thing based on the ssl talkback compressor?

Michael

 

[pucho812]

Not sure but it does squash the audio.  Thinking of swapping the ssm2142 for drv134's and see if things improve.  It's good now but you never know.

 

[ruairioflaherty]

Thinking of swapping the ssm2142 for drv134's and see if things improve.  It's good now but you never know.

From the SSM data sheet..

"The input of the SSM2142 should be driven directly by an operational amplifier or buffer offering low source impedance and low noise."

And from the DRV data sheet..

"The DRV134 input should be driven by a low impedance source such as an op amp or buffer."

Surely the non ideal circuit implementation will swamp any differences?  Especially in a circuit deliberately designed to pump and distort?