SSlmixed.com Forum

Tech discussion => 4K,6K,8K Series => Topic started by: Megaphon on April 30, 2020, 06:39:19 PM

Title: Channel dynamics sidechain HPF modification
Post by: Megaphon on April 30, 2020, 06:39:19 PM

Hi everyone!

Now in Corona times I decided to recap one of my SSLs, only because I suddenly found myself with lots of spare time. This console wasn't really in need of a recap at all but I'm now upgrading it with 105 degree caps and doubling or tripling their capacitances to make this console more future proof and with a better low frequency response than it ever had. Today I also took the opportunity to try out some different cap values for a permanent HPF modification of the channel dynamics sidechain. This was simply accomplished by replacing the C1 cap (10uF) on the dynamics card with a small Wima MKS2. The result is a 6dB/oct filter which I think will be steep enough to make a useful difference although the standard on board HPF is a lot steeper with its 15dB/oct. The examined cap values were 470nF, 330nF, 220nF, 150nF, 100nF and 68nF. You can see the resulting filter curves in the attached graph. For reference I also added a graph of the on board HPF behaviour when put in the dynamics sidechain. This far I haven't done any practical listening tests so we'll see which value I finally choose to install. A good guess is that I go with the 220nF with its -3dB point at 55Hz. I just wanted to share this here in case there are someone else here who are considering this kind of mod.

/Ulf

Title: Re: Channel dynamics sidechain HPF modification
Post by: Matt Sartori on April 30, 2020, 07:22:21 PM

amazing tests!!!!
thank you  for sharing!  :)

Matt Sartori

Title: Re: Channel dynamics sidechain HPF modification
Post by: oyanliz on April 30, 2020, 08:06:32 PM

Thanks!! Great info!!

Oihan

Title: Re: Channel dynamics sidechain HPF modification
Post by: marcmozart on April 30, 2020, 10:03:37 PM

Very cool - might make the channel comps more useful!