chorus question

[Kipper4]

Ok so I built both the Tonepad Heladito-02 and the corrral chorus.
At the moment i'm liking the Corrral best. Why?
to my ears it is more jangly and the modulation seems brighter and more present.
Question.
How do I make the heladito modulation more like the Corrrals?
Heres what i'm thinking. Its just a matter of swapping some caps. Maybe the 33nf and 470pf between the input buffer  and Q1.
Or the 10nf in the output buffer feedback loop. I suspect its too late in the circuit to make a differance with this solution however.
Any suggestions would be welcome here

Question 2
Can I do an intensity mod on the small clone like the one on the Corrral by removing the 150pf (pin1 of cd4047) modding it like the corrral with two caps in parrallel ? Or will it mess with the clock or worse still not work?

Thanks
Rich


links to the projects


http://www.tonepad.com/getFile.asp?id=101   Corrral chorus

http://www.tonepad.com/getFile.asp?id=97     Heladito (Small clone)

[Fender3D]

Hi Rich,

I don't quite understand what you mean by

modulation seems brighter and more present

,
because there are some design solution involved.
I mean:
the modulation ratio: 4047 has a higher ratio (delay max/delay min) than MN3101
the clock freq.: Corrral's 47p (C22) should give a lower minimum delay than Heladito's 150p

The LP filters Q1+its resistors and caps and Q2 provide clock filtering. You could try other values, but you'll get additional noise, too. since clock is different

the 10n (AND the 6k8 resistor) in the feedback loop, just de-emphasize what's emphasized by the IC1a 10n + 6k8
filter cell and should be kept the same for a proper linear response

[Mark Hammer]

There are two major factors that dictate the tone of a chorus.  One is the filtering applied, and the other is the delay range produced.  Simply shifting the delay range from, say, 2-8msec, up to 3-12msec, can make a heckuva difference in tone.  So do feel free to play with the value of the 150pf cap, and move the delay range around.

In terms of filtering, I can't work out where the corner frequencies are, but both the CE-2 and Small Clone have 3 poles of lowpass before and 3 poles of lowpass after the BBD.  They also both implement what I like to call "the poor man's Dolby": pre-emphasis and de-emphasis.  The pre-/de-emphasis ideally should have no impact on tone, because it is a complementary circuit, designed to balance out.  The corner frequency of the lowpass filtering is somewhat tied to the delay range (the longer the delay time, the lower you have to roll off), and hence correlated with the resulting tone.

[Kipper4]

Thanks for the clarification guys.
I'm gonna spend a little more time getting to know them. Find their strengths and weaknesses.
They're clearly two very different beasts.
I might just try doing the effect pot mod on the CE2 as suggested in the other thread before I mess with the filters.
Messing with the bias on the ce2 improved it more to my liking.
Given that I mostly play rhythmn I'll try to tweak it a little.
I'll look into the different delay times in circuit too. Time to get the data sheets out.
I'll report back later.
The help is appreciated.