[build] Steffen's GSSL High Pass Filter Documentation

This thread contains all the documentation needed to get Steffen's high pass filter incorporated into the GSSL. For purchasing boards check the Black Market.

1. Sidechain Highpass Schematic

2. Sidechain Highpass Parts List

3. Sidechain Highpass Hookup Instructions
The GND point on the filter PCB needs to be taken to the chassis star ground.

4. Switch wiring:
The PCB matches the schematic, but here's a verbal description as well. The SW point on the PCB goes to the switch pole. Then points 1-6 on the PCB go to the corresponding switch position. Position 1 won't produce any filtering; position 2 will roll of the least low end; position 5 will roll of the most low end; position 6 is the external sidechain.

If possible, could this thread be added to GSSL META... thanks.

..Added to Gssl meta..

Thanks Jakob:

I read the description in the META. It said something about this being thrust type-tilting filter. This is simply a buffered high-pass with variable gain. I think this is different from the thrust circuit, but I could be wrong.

I'll correct that..

Forgive me for being thick
But I was soldering this up last night
For the elctrolytics - the BOM says 10uf and 47uf - but the schematic says 2 x 47uf
Am I going mad?

[quote author="uk03878"]Forgive me for being thick
But I was soldering this up last night
For the elctrolytics - the BOM says 10uf and 47uf - but the schematic says 2 x 47uf
Am I going mad?[/quote]

Next stage has 10k impedance, both will work fine.

The last position of the switch must be labeled "sidechain filter off" or "sidechain filter bypass" instead of "sidechain off".

Someone brought this to my attention last week. Sorry for the confusion. But as Michael stated, both will work fine. I will change C8 on the schematic to read 10uF.

No problems greg - I'll keep my 2 x 47ufs in there...

Thanks for the boards!
I love those through plated hole thingies - still gives me a chuckle when I solder one side and turn it over and there is a nice bit of solder on the other (little things and little minds)

Hi,

i was searching for a link to Steffens (EQ) Homepage the Link from Gyraf was not actuell!

Can Anyone help me?

Nice Day

Dennis :roll:

Hey Greg,
I've got a few of your boards, and will soon implement it to some of my comps. I unfortunately don't have the frontpanel realstate for a rotary and its label, so I decided to go with a simple toggle switch. Maybe a 3P, so I can have an off position as well as 2 different freq.
My questions is:
On your experience with this circuitry, which 2 freq did you find more usefull??
I know its pretty easy to try them out, but I figured I could start with suggested values.

Forgot to mention that intended use is for Drums and Mix.

Thanks
Gil

hi:

A believe a simple toggle will only give you 2 positions, OFF and one frequency, even with 3 poles. Only one pole is needed, and having extras wouldn't help us here. But I usually either use the 60Hz position or the 200Hz position, kind of a low and a low-mid filter.

Hope this helps.

if you are just going for a hipass filter in the sidechain without external input, you might be able to just switch in a cap (or two for two positions).

I am still not sure if I should get the PCBs for hi-pass from our Greg or just make it without them. It will not look so nice but ... can someone post some nice detailed picture of the soldered PCB for Stephen's high pass filter?

I will most probably end up with Thrust + Stephens filter. :grin:

http://www.groupdiy.com/index.php?topic=13315

Hey Greg,
I actually meant a 3T switch.
But your 60hz and 200hz recomendations is what I was looking for.
I'll look through the schem and layout again and see what parts I actually don't need to stuff for this.
Thanks
Gil

Keep in mind that the high pass is first order, so the corner frequency is very broad. At the 60Hz setting, it's definitely rolling off a good bit above 60Hz. But those frequencies worked well for me. On a drum buss, the 60Hz allowed to "hit" the drums a bit harder without getting that pump on the kit drum. Also, I like slow attack and fast release with the SSL on drums.

hey greg,
sorry if this is really a stupid question, but i couldn't find an answer with the search function. so here's my question...
is there a calibration procedure for the RV1 (threshold sensitivity) for your sidechain hi-pass filter boards?
thanks a bunch.
-grant

No, there's no set threshold calibration. It's really just a set to taste pot. What I did was use the compressor a good bit, then set my typical compression threshold to around 12 o'clock. I felt this gave me a much better range.

If you want it to be same as stock, set the pot to 11K. Or you could also just build the PCB, send it a test tone, and tweak the pot until unity is achieved.

cool thanks so much greg! :thumb:
-grant

[quote author="Madman"]Hi,

i was searching for a link to Steffens (EQ) Homepage the Link from Gyraf was not actuell!

Can Anyone help me?

Nice Day

Dennis :roll:[/quote]


http://www.diygallery.de/DIYsites/index.html

greetz, steff