Boss CE-2 Chorus/Vibrato Mod

[beedoola]

Is this the same mod as the "Pedal doctor" does?

http://pedaldoctor.com/BossCE2.html

[Boba7]

Hi!

Sorry for replying to such an old thread, but I just did the vibrato mod to a CE2b, following Joe Krammer's second message, and it works!

However, there is an audible pop when switched on/off in vibrato mode. Is there anything I can do for that?

Many thanks to whoever's interested or has any idea!

[Joe Kramer]

Hi!

Sorry for replying to such an old thread, but I just did the vibrato mod to a CE2b, following Joe Krammer's second message, and it works!

However, there is an audible pop when switched on/off in vibrato mode. Is there anything I can do for that?

Many thanks to whoever's interested or has any idea!

You brought me out of the woodwork. 

Haven't looked at this mod for a long time, but here's a possible fix for the pop.  See where you've cut the traces and put the switch in between?  Try jumpering across the cut with something like a 2.2M resistor.  That should be big enough to block the dry signal when the switch is open, yet keep the DC level constant enough so that a difference doesn't build up and cause a pop when closing.  If you still hear dry signal with a 2.2M resistor, try something even bigger.  Hope that helps. . . . 



 

[Boba7]

Thanks so much for the quick answer!
I'm gonna try that tomorrow, if I can find the right resistor, I'll let you know how it goes! 

I cant believe I got such a quick answer ten years after the thread was started!

Planning on experimenting with the diodes/resistor wave shaper later too!

[karbomusic]

Thanks so much for the quick answer!


I cant believe I got such a quick answer ten years after the thread was started!

Joe's good like that and a heck of a smart guy too!

[Joe Kramer]

Hi guys!  The internet is sort of like transcendental technology--it's easy to be everywhere at once.     

Definitely keep us posted as to whether that fix works. . . .

[Boba7]

Hey it works!

So I ended up putting resistors in series cause I didn't have a 2.2M. I put 2x1M and a 47k in series. There's no pop although you can still hear the change in sound, like a split second of silence when it's switching, but that's totally fine.

Also the vibrato mode was a bit quiet, so I changed R22 which on the CE2B is in series with the E. Level pot. I put 22 and 10 so 32k total instead of 47k, and doing so got unity gain in vibrato mode.

I could add a switch with an additional cap to get more bass in vibrato mod but I don't really mind, and C14 is already 0.33 cause I changed it to CE2 specs.

So I have my vibrato/chorus switch next to the power jack, and it sounds great!

Maybe I'll get into the wave shaping thing later today.

Many many thanks for your help!

[Boba7]

Wave shaping done!

Once again thanks to you Joe Kramer (http://www.diystompboxes.com/smfforum/index.php?topic=57655.0)
I used 2 leds and a slightly bigger resistor and it works well. It's not a pure sine wave but enough to my ears! I didn't put it on a switch cause I don't think I'd want to go back to triangle. We'll see.

[Joe Kramer]

Ah, excellent, glad this worked out for you!   

About the slight gap when switching: what you're hearing is the time delay between the dry signal and the BBD signal, probably between 10-20 milliseconds.   One way around that would be to shorten the delay time of the BBD, but doing that would affect the chorus sound.  The other way might be to slow down the timing of the flip-flop switching, so that there's a small crossover between dry and wet.

I've never actually tried this, but you might be able to tweak the switching timing of the CE-2.  Take a look at C28 here: 

http://www.hobby-hour.com/electronics/s/schematics/ce2b-bass-chorus-schematic.png

Assuming you already duplicated this cap on the dry leg of your circuit, try increasing the value of C28 and the cap you added to slow the switching down a bit.  I'd start with .056uF first and then keep going up until it sounded right.  Also,  possibly, increasing both C24/C25 might slow down the switching action, but others on the forum will probably have better firsthand knowledge of this than I do.

Hope that helps. . . .

[Boba7]

Interesting, I might try it. For now I'm really satisfied with the mod, and the switch doesn't bother me. But if I end up putting a bass switch, I'll look into it!

I got the CE2B for 35€ shipped, bought the fromel kit (first diy mod I did) and now with this vibrato mod, it's becoming a truly amazing pedal for quite cheap.

I'll let you know if I change the caps.

[Boba7]

So I tried changing the value of C28 and its equivalent in vibrato mode, but it didn't change much. But really it's fine like that, I even used the pedal for an acoustic gig a couple nights ago with no problem!

For the wave shaping, I used a smaller resistor, not a bigger one, I think it's a 22k. The leds are 2 small red ones. It works fine!

What I'm gonna do is use a DPDT for the vibrato switch, so that the same switch can add a .01uf cap in parallel with C14 (.033uf in the CE2) to keep a little more bass only in vibrato mode.

And I'm gonna use a simple switch to select triangle/sine wave.

I'm really happy with these mods, thanks again!

[Joe Kramer]

Hey, thanks for the update.  As I say, I hadn't actually tried tinkering with the switching timing, but I'm glad you at least investigated a bit. 

Anyway, nice work on your build/mods, and happy vibe-ing!

[Mark Hammer]

Hey Joe.  Nice to see you back here. 

[Joe Kramer]

Hi Mark, nice to see you too.  

I pop in and lurk occasionally, but there are so many knowledgeable and quick answers here nowadays, it seems I hardly have anything to add.  Nevertheless, this forum feels more like home to me than any other on the webs.

Fond memories of auditioning pedals late into the night, interesting nerd-talk on guitar pick-ups and whatnot, Noah's not-so-authentic bagels, and missing my plane out of Berkeley.  Last I corresponded with P. Ruud, he was still teaching at . . . Brown, was it?  Can't even recall now. Haven't heard from him in years.

Sincerely hope all is fine and well with you.

[Ben N]

Cool thread. Does this essentially turn a CE-2 into a VB-2?

[Boba7]

Ben> yes it does, exactly! Except no latching and rising option, but I dont care for them. And contrary to the VB2 you can get triangle/sine on a switch if you want.

I feel sine is perfect for vibrato but prefer triangle for chorus.

Also I think I changed a cap to get a deeper effect, which probably helps for the sinewave option. I'll look into it when I'm home.
It's an easy mod, I'm glad I found this thread!

[Boba7]

Isn't it cute now?
Ah ah ok I'm out of here...

The vibrato / chorus switch allows for more bass to come through when in vibrato (added a .01 cap in series with .033 C14. Could be bigger in order to use vibrato with a bass)

The sine / triangle switch simply disconnects the wave shaping leds/resistor network from pin 7 on the PCB.

And the added dot next to the E. Level pot indicates the original CE2 mix position (=pot fully clockwise on the CE2B). Now with E. Level fully clockwise, there's unity gain between vibrato on and off, so in chorus mode, it's a bit louder, hence the dot to remember the right chorus position (R22 is now 32k instead of 47k).

Thanks again for all the information!