Why no ballanced ins on G SSL sidechain? New pcb...

[intellijel]

I have seen the SideChain HPF circuit (e.g. the oen that Greg made PCBs for) and the plans for adding the external sidechain.

Maybe I missed soemthing, but how come no one is using ballanced inputs?
On one of the DIY pages, the builder ntoed that he copied the ballanced i/o circuityr fromt he other parts of the SSL to add to the side chain input.

I am thinking about making a new PCB (which I will share)

On this PCB would be the following:

1. Relays for bypass and SC in/out
2. Power supply for the relay coils
3. Ballanced inputs for side chain In
4. Side chain HPF
5. ballanced outputs for side chain out

Perhaps #1 and #2 should be seperate boards?

I would also seeke permission from the deisgners of the HPF to add it to this PCB.

I would also design a one layer board so that DIYers like myself can make the boards at home.

thoughts?

cheers,
intellijel

 

[matthias]

why should the in/out connection of the sidechain circuit be balanced??
you will never hear this signal...

and why do you think is an in/out for the sc so important if you have a lowcut for the sc-signal..??

mat

 

[[silent:arts]]

[quote author="matthias"]why should the in/out connection of the sidechain circuit be balanced??
you will never hear this signal...[/quote]

Oh, you WILL hear it if there is any hum or other crap in your sidechain signal.

 

[Greg]

Are you specifically talking about balanced inputs/outputs for the external sidechain? This is not a bad idea.

But for the filter part, the signal in the sidechain is not a differential signal, so I'm effectively putting the high pass right into the sidechain signal path, with only has one signal... ie unbalanced, non-differential. I hope this makes sense.

 

[intellijel]

I am talking specifically about external side chain signals.

The HPF circuit can be used as is for the internally generated SC signal (which is unbalanced). But if you intergrate the HPF in such a way that you have the option of internal or external SC IN, then the external SC would ideally be converted from ballanced to unballanced. The best idea is to just copy the ballanced in/out circuitry already used on the GSSL.

If you do not do this for the external SC, then it would be a half-legged signal signal (3db lower) and it may be noisy.

cheers,
Intellijel