Author Topic: Small Clone "warmth" Mods  (Read 553 times)

DJPsychic

Small Clone "warmth" Mods
« on: March 07, 2021, 02:42:19 PM »
What mods can be done to improve a (non-vintage) EHX Small Clones "warmth"? I recently did the depth switch mod as well as a trimpot for volume and really digging the pedal, but it's just a little on the bright side.

Maybe I've been comparing it to the ultimate Analogman Mini-Chorus, but I'd like to get the SC closer to that.

Any help is always appreciated guys, thanks!

Mark Hammer

Re: Small Clone "warmth" Mods
« Reply #1 on: March 07, 2021, 03:52:01 PM »
What do you mean by "warmth"?

DJPsychic

Re: Small Clone "warmth" Mods
« Reply #2 on: March 07, 2021, 04:12:35 PM »
What do you mean by "warmth"?

Soften some of the harsher high end freqs of the effect?

Improve on some of the tinny characteristics of the tone, making it warmer and more lush sounding?
« Last Edit: March 07, 2021, 04:39:42 PM by DJPsychic »

Mark Hammer

Re: Small Clone "warmth" Mods
« Reply #3 on: March 07, 2021, 06:14:19 PM »
On the output of the BBD, there is a 10k resistor with a 4700pf cap to ground from that resistor.  That provides a rolloff starting just over 3.3khz.  It's not the only lowpass filtering, but is easy to do calculations for and also to get at (I'm assuming this is not a surface-mount board).  Tack on a 1000-1500pf cap to the pads where the 4700pf cap is, to increase the total combined capacitance and lower the frequency where the rolloff begins.

Not sure if this will get what you want, but it will be easy to do and easily reversible.

DJPsychic

Re: Small Clone "warmth" Mods
« Reply #4 on: March 07, 2021, 06:36:57 PM »
On the output of the BBD, there is a 10k resistor with a 4700pf cap to ground from that resistor.  That provides a rolloff starting just over 3.3khz.  It's not the only lowpass filtering, but is easy to do calculations for and also to get at (I'm assuming this is not a surface-mount board).  Tack on a 1000-1500pf cap to the pads where the 4700pf cap is, to increase the total combined capacitance and lower the frequency where the rolloff begins.

Not sure if this will get what you want, but it will be easy to do and easily reversible.

Awesome thank you!

 It is not SMD, it's a green board older Reissue I think (red LED)

When you say tack the cap to the "pads" do you mean solder it to the "underside" of the board, directly on the same joints as the 4700pf?

Mark Hammer

Re: Small Clone "warmth" Mods
« Reply #5 on: March 07, 2021, 07:05:10 PM »
Yes.  You probably have room, providing the added cap is small enough.  This way you don't have to remove anything and can simply unsolder the cap if it doesn't do what you want.

DJPsychic

Re: Small Clone "warmth" Mods
« Reply #6 on: March 07, 2021, 09:06:25 PM »
Yes.  You probably have room, providing the added cap is small enough.  This way you don't have to remove anything and can simply unsolder the cap if it doesn't do what you want.

Excellent thank you so much. I'll give it a try in the morning  :)

DJPsychic

Re: Small Clone "warmth" Mods
« Reply #7 on: March 09, 2021, 07:31:51 AM »
Kind of off topic (don't want to start another "depth mod" thread)....

But I used the suggested 10k pot for the depth pot. If Increase pot to say 50-100k, will I be able to get "more" depth? or is the effect maxed out at 10k...

Mark Hammer

Re: Small Clone "warmth" Mods
« Reply #8 on: March 09, 2021, 07:54:26 AM »
At max depth, the wiper of the pot, and the 39k/10uf junction as well, is tied directly to the output of the LFO, with precious little difference due to whether the other 10k...or 50k...or 100k of any depth pot going to ground.  As the Depth pot is turned down from max, consider the portion of the pot from LFO out to wiper, as being in series with the 39k resistance, as well as forming a sort of lowpass filter in combination with the 10uf cap.  That lowpass filter adds some smoothness and a bit of lag to faster LFO speeds.  But the portion of pot resistance, in series with the 39k, drops the current feeding the 4047.  I don't know enough about such matters to know whether that would deleteriously affect the sweep.

But the short answer to your question is No, upping the value of the Depth pot will not increase the degree of depth attainable.

ElectricDruid

Re: Small Clone "warmth" Mods
« Reply #9 on: March 09, 2021, 08:06:21 AM »
+1 agree with Mark. The depth pot is used as a voltage divider so changing its value doesn't change the situation. There are some secondary effects that might alter, which Mark mentioned, but just thinking about the depth, no, makes no difference.

DJPsychic

Re: Small Clone "warmth" Mods
« Reply #10 on: March 09, 2021, 01:47:32 PM »
Thank you guys. It would be interesting to attempt to get more "depth" from the LFO (If that's what were talking about. More of a musician/hobbyist than an engineer :) ) I'll probably leave it alone for the time being
 
Concerning my original question and wanting more "warmth", I've actually come to like the more shimmery and brighter character of the Small Clone. I'll still try the cap Mark recommended, but The more I live with it the more I'm starting to enjoy the SC for what it is

Mark Hammer

Re: Small Clone "warmth" Mods
« Reply #11 on: March 09, 2021, 06:47:55 PM »
The time-delay range is partly set by the 150pf cap in the CD4047 clock circuit.  Reducing its value moves you to the zone where flanging starts to turn into chorus and chorus starts to turn into flanging, perfect for emulating slow Leslie speakers.  A value of 68-82pf will take you there.  Alternatively, increasing the cap value produces more delay time for a "thicker" sounding chorus.  Note that, as delay range increases, the same Depth settings will yield a "boingier" sound that you'd need to dial back a bit.

Sesh

Re: Small Clone "warmth" Mods
« Reply #12 on: March 10, 2021, 05:55:45 AM »
Check out the schematic of the VFE CHoral Reef, it's a Small Clone on steroids. Might be some mods you can apply as well: https://www.madbeanpedals.com/projects/_folders/VFE/pdf/VFE_ChoralReef.pdf

DJPsychic

Re: Small Clone "warmth" Mods
« Reply #13 on: March 10, 2021, 06:26:49 AM »
Awesome stuff thank you both. Definitely targeting a "thicker" chorus if anything.

I may open up my analogman at some point and see what kind of magic sauce mike uses.


ElectricDruid

Re: Small Clone "warmth" Mods
« Reply #14 on: March 10, 2021, 09:45:26 AM »
I may open up my analogman at some point and see what kind of magic sauce mike uses.

Oooh, be sure to report back!! Always interested to see/hear about stuff like that.

POTL

Re: Small Clone "warmth" Mods
« Reply #15 on: March 12, 2021, 03:40:25 PM »
Paralleling the BOSS CE-2, which is considered a warm chorus, I would make 2 mods. 1) Installed 100p capacitors in the negative feedback of the op amp, at the input and output filters. 2) Reduce the value of the 150p capacitor to 100p or 47p (the capacitor found on the CD4047), this should shorten the delay time and make the modulation less noticeable. Disclaimer, I have not tested these mods, but these are the most obvious deviations from the BOSS circuit. Maybe the problem lies in the CD4047 watch, I definitely don't like modulation with this watch, EHX DMM, Small Clone, Analogman Chorus, Tortuga Martini, Coppersound Polaris Chorus, Ada Flanger. I haven't experimented with changing clocks yet, but from the ready-made effects I definitely prefer MXR (CD4013), BOSS / DOD original clock.