Boss CE2 clone mods questions

[vinceg]

I built this fantastic pedal and I read about some mods to modify depth intensity and rate speed. Someone says to increase C22 cap for intensity mod and decrease C19 cap for speed mod. Other say to decrease R38 for intensity mod and decrease R32 or change to 1Mohm pot for speed mod. I'm confused, what is the best?

Also, about the VR3 trim, is it a bias trim? What is it for?

Thanks in advance for your reply

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

[Elijah-Baley]

I'm building the CE-2 in these days, I just completed the board.
If you add to C22 another cap (47pF could be ok, but you can try some other value) you can encrease the value and get more intensity. Work fine. You could use a switch for the two modes.
If you want just one mode, the more intense one, it's enough to replace the stock 47pf with a 100pF (or try other value around it).

For the speed, I still didn't try it, maybe I'll do today. But you can try it, too.
Reduce C19 100nF to 68nF to encrease the speed.
Or:
Reduce R32 1M to 470k or 560k. For another speed pot you can try to connect a 47k resistor with a 1M pot.

You set the trimpot until you get a noiseless and a not distortion sound. It should be pretty easy.

[vinceg]

So change resistors value is alternative to change cap?

[Mark Hammer]

C22 does indeed set the delay range of the unit.  Note, however, that the filtering in the unit is set to minimize noise AND maintain widest usable bandwidth.  Increasing the delay range via C22 too much will result in more audible clock noise, since you won't have adjusted the filtering to compensate.

Personally, I vote for decreasing C22 a bit for something closer the the overlap between chorus and flanging, and only a modest increase.  So, use 36 or 39pf instead of 47pf, and use a 3-position toggle to add in 10pf or 22pf to the 36/39 value for stock and a little thicker than stock.  The difference in ranges will not be huge, but will be noticeable and useful.

[Elijah-Baley]

I have to say in another kind of chorus, the Zombie, I got much noise with the intensity mode than in the CE-2, and I got ticking in any mode if I set Deptch and Speed very high.

But now, I built my CE-2 circuit planning an anti-ticking mod, and I have to say that I can't hear any noticeble tickinga and the effect sounds noiselss enough. And it is still out of the box!

Then, yes, the intensity mode encrease the noise, but not too much, in my case. Make some experiment, like Mark Hammer said.

[vinceg]

I agree with you about experiment but I get confused with what Mark said. For increase lightly deepth I have to increase or decrease C22?

[Elijah-Baley]

[...]
If you want just one mode, the more intense one, it's enough to replace the stock 47pf with a 100pF (or try other value around it).
[...]

Substantially increase.
The stock cap is 47pF.
If you want just one option you could replace the stock cap with an higher value like 56pF, 68pF, 82pF. I'd say 100pF at max. To get more depth.
If you want the stock option + the intensity mode (more depth) you could use the 47pF and add through a switch another cap, like 30pF or 39pF or 47pF at max.

Or you could use a cap smaller than the stock cap, as Mark says, and get a lower depth: for example a 33pF as basic value, then you can add another cap like a 15pF to get the closer than you can to the stock value (33pF + 15pF = 48pF). And using a three way switch you can add a third cap as a 33pF cap, getting 33pF + 33pF = 66pF.

I hope it is more clear, now.

[vinceg]

Yes, I understand now. Thanks

[Mark Hammer]

Again, I repeat my caution that the lowpass filtering on the delay path is set to reject/minimize clock noise produced at the longest delay (remember that longer delays are produced by means of a slower/lower clock frequency).  If one shifts the delay range considerably, especially longer, then you may be asking the clock to go slower than the filtering is intended to block, and the clock noise may become annoyingly audible.

Some delay lines in past have used an approach to filtering that changed the lowpass cutoff frequency along with the delay time, so that the best balance between bandwidth (treble response in this case) and noise-prevention was achieved.  But this chorus, as good as it is, uses only fixed filtering.  So the filtering is either ideal for striking that balance...or it isn't.  If you only increase the value of C22 (whether via a single cap or a combined pair of them) a bit, then the odds are pretty good that the filtering will be remain good enough to keep it a quiet pedal.  If you increase the C22 value too much (and I think doubling it with 100pf may be risky), then the filtering may be unable to keep clock noise low enough.

So go ahead and experiment.  Just be careful not to ask more of the pedal than it can deliver

[vinceg]

Again, I repeat my caution that the lowpass filtering on the delay path is set to reject/minimize clock noise produced at the longest delay (remember that longer delays are produced by means of a slower/lower clock frequency).  If one shifts the delay range considerably, especially longer, then you may be asking the clock to go slower than the filtering is intended to block, and the clock noise may become annoyingly audible.

Some delay lines in past have used an approach to filtering that changed the lowpass cutoff frequency along with the delay time, so that the best balance between bandwidth (treble response in this case) and noise-prevention was achieved.  But this chorus, as good as it is, uses only fixed filtering.  So the filtering is either ideal for striking that balance...or it isn't.  If you only increase the value of C22 (whether via a single cap or a combined pair of them) a bit, then the odds are pretty good that the filtering will be remain good enough to keep it a quiet pedal.  If you increase the C22 value too much (and I think doubling it with 100pf may be risky), then the filtering may be unable to keep clock noise low enough.

So go ahead and experiment.  Just be careful not to ask more of the pedal than it can deliver

Now it is very clear. I'm sorry I did not understand before but I'm just a simple amteur not expert. Perhaps, I'll add only 20pF to C22, I'll see.

Instead, can you explain me what the level mod does? I would very much like to have something like this

https://www.nemphasis.com/en/products/liquid-mind-analog-chorus.html

It has a Color control but I do not understand what it does

[Mark Hammer]

No need to apologize.  It's my job to make it understandable, not your job to struggle.

Listening to the samples they provide, it appears that the Color control does something like what my suggested mod does, although its adjust delay time in continuous fashion, rather than with fixed changes.

Take a listen to the 1st and 3rd samples on their site.  They both have the same speed and depth settings, but differ in color.  You can hear the first sample sounds a little thicker and darker.  That comes from increasing the range of delay-times covered.  The 3rd sample uses a shorter range of delay times.  By "longer" and "shorter", I mean something like 5-12msec vs 3-9msec.  I have no idea what delay times are used by the Liquid Mind or CE-2, but that's what longer vs shorter delay times would mean.  Increasing the value of C22 produces longer times.

[vinceg]

Instead, what the level mod does?

[Elijah-Baley]

The Level is a cool adding, the CE-2B (bass version) has it.
That is the "level" of the effect. At min no effect, at max full effect. You can adfust the amount of the effect, light or heavy.

Mark, do you have idea how add a Color pot in the CE-2?

[Fender3D]

The Level is a cool adding, the CE-2B (bass version) has it.
That is the "level" of the effect. At min no effect, at max full effect. You can adfust the amount of the effect, light or heavy.

Mark, do you have idea how add a Color pot in the CE-2?

make R38=47K and add a 220K pot in series with it

[vinceg]

The Level is a cool adding, the CE-2B (bass version) has it.
That is the "level" of the effect. At min no effect, at max full effect. You can adfust the amount of the effect, light or heavy.

Mark, do you have idea how add a Color pot in the CE-2?

make R38=47K and add a 220K pot in series with it

Without change C22 cap?

[Elijah-Baley]

Well, I guess there's no need to change also C22 if you change the delay through that resistor, unless you don' want calibrate the amount of the deep.

Anyway, cool mod, thanks! This was new for me.
But this time I wil not use it. Maybe next time.

I'm excluding the Bass/Guitar switch because I can't hear any noticeble difference.
The intensity switch, yes, I'm including, and even the Chorus/Vibe switch, though I don't like the Vibe effect as well in the Zombie Chorus.

Before to put in the box and make the off board wiring, I'd like to know the last thing. I noticed a bit loss volume in the Vibe mode, and I read about a mod to avoid this volume loss.
R22 - 47k -> 22k
R24 - 47k -> 56k
I tried and myabe it goes a bit better, but I'm wondering if it has some effect to the stock chorus sound or on the overall volume. I can't test the bypass volume because the circuit is still without the switch. So before mess it up I would likd to know all this.
Thanks!

[Fender3D]

Without change C22 cap?

It won't be a huge change in clock freq...
at least not as big as subbing the cap.

Just follow Mark's advice, I don't know how loud you play, but for me, on stage, clock noise is really annoying...

As a rule of thumb, if you double clock cap, double or raise filters caps value too...

[vinceg]

Without change C22 cap?

It won't be a huge change in clock freq...
at least not as big as subbing the cap.

Just follow Mark's advice, I don't know how loud you play, but for me, on stage, clock noise is really annoying...

As a rule of thumb, if you double clock cap, double or raise filters caps value too...

I mean if for color mod is need change C22...

[Mark Hammer]

The Level is a cool adding, the CE-2B (bass version) has it.
That is the "level" of the effect. At min no effect, at max full effect. You can adfust the amount of the effect, light or heavy.

Mark, do you have idea how add a Color pot in the CE-2?

One of the complaints I sometimes hear from people about chorus pedals is that they find the effect to strong, and would like it subtler.  The Level control (which might be called Mix in some other pedals) blends in the amount of wet/delay signal.  In some pedals, it simply allows you to reduce the wet level.  In other pedals it allows you to go from 100% wet to 100% dry, and various proportions in between.

For bass players, in particular, the "pitch wobble" of a strong chorus effect is problematic.  Bass notes need to have a clear and stable pitch, because the rest of the band is depending on it.  So chorus pedals oriented towards bass players will often do a few things to reduce that problem:
1) they will include a Level/mix control
2) they will aim for a range of shorter delay times that will have less effect in the range of note fundamentals
3) they may include filtering that only applies the chorus effect above the note fundamentals

So  bass players will get the "swirl" and coloration of chorus, but not in a way that makes it harder for the other musicians to tell what note the bass player is picking.

When I make a chorus, I always include a switch to select delay range, another to cut the bass from the delay signal, and a pot to adjust the wet level, from a 50/50 blend to as low as 20% wet (no real advantage to going below that).

[Elijah-Baley]

[...]
So  bass players will get the "swirl" and coloration of chorus, but not in a way that makes it harder for the other musicians to tell what note the bass player is picking.

When I make a chorus, I always include a switch to select delay range, another to cut the bass from the delay signal, and a pot to adjust the wet level, from a 50/50 blend to as low as 20% wet (no real advantage to going below that).

In the CE-2 there's C14 33nF (guitar version), while in the CE-2B this cap is 12nF, I guess to cut the bass you mentioned, Mark. I really can't hear the difference.
Indeed, there are some demos with Boss CE-2 and Boss CE-2B with guitar, indistinguishable. And maybe the same thing with a bass.