Caesar Chorus EQ modifications

[calculuscore96]

Both Caesar's I have built are very close to the Julia, but retain slightly less bass and low mids than the Julia. Could just be combined tolerances, but I want to beef up the effect signal. I know that in a CE-2 schematic the two 100pf caps function as low pass filters, should I decrease/increase the corresponding 100pf caps in the Caesar? Anybody know what other key parts might be most responsible for sculpting the eq? Thinking about just socketing some stuff

 

[Stickman393]

Good read on the CE-2 circuit, which the Julia clearly was based off of.

ElectroSmash - Boss CE-2 Analysis

Chorus Effect,Architecture,Circuit, Achematic,Layout,Components Part List,JFET Bypass Switch, Power Supply,Boss ACA vs. PSA Power Supply Adapters,Input Buffer,Input Impedance,Pre-De Emphasis Filters,Shelving Filters with Operational Amplifiers,Inverting O

www.electrosmash.com

You'll be able to plug component values into the equations there to see how changing individual components can affect the frequency cutoff and gain of each filter.

Those little 100pf caps don't appear to be the best place to focus your attention, if I'm reading this article correctly. Parallel paths where one is equal to zero...I might not be totally wrapping my head around this. Maybe someone else can chime in

But, the pre-emphasis filter can be tweaked by adjusting R9, S10, R11, & C4. Increase C4 alone, and you shift the frequency curve a bit lower, boosting and shelving from a little further down. But the pre emphasis and de-emphasis filters are meant to cancel each other out in this scenario. You might be able to get some results by shifting the de-emphasis filter range down a bit...couldn't tell ya.

Honestly, I'm curious what would happen if you bumped R16 up a bit in the anti-aliasing filter. That would certainly feed more low end into the BBD...but how much would actually make a difference? Shoot, I dunno.

First time engaging with the math here...learning like everyone else.

 

[keevohn]

Digging this back up to see if the OP was able to beef up the bass in the Caesar at all. I find that my build also cuts bass in a noticeable way, especially when it's on full wet / vibrato mode.

 

[eh là bas ma]

Delyks made a CE-2 pcb with a CE-2b specs toggle to change the bass response.

2nd Chorale PCB - delyk PCBs

www.delykpcb.com

This "W BASS" toggle adds a 22n (C16) to a 12n cap before the Effect Level control.

Not sure if this can be applied in the Julia, i just thought that this mod is simple enough to be worth a try.