Boss CE-1 Chorus Build

[jakebrown5]

Hi all, first post here at MEF....

I've been wanting to build my own CE-1 for a while now, because it seems there just aren't any pedals out there that can replicate its warm, unique sound. So I did some digging around and found what seems to be the ONLY schematic of the CE-1 on the internet.

http://www.mif.pg.gda.pl/homepages/t...es/bossCE1.jpg

I only have a moderate knowledge of electronics, and I have built a small MXR phaser before.

First of all, does anybody know where I can find a better quality schematic? I've been using a PCB editor to make a layout from it, but there are many values that I just can't make out.

To those of you that know more about how these types of circuits work, what transistors do I use for the JFET's (Q11, Q12, and Q13)? Can I improve the power supply by using adjustable voltage regulators set to +13, -13, +14, and -14 volts? Finally, can I get rid of some elements in the schematic to make it true bypass switching, and can I remove the Vibrato section?

Thanks, Jake

[magna1]

Ce-1

Hi Jake, it would certainly be cool i'm sure to build a ce-1, as well as pretty damn impressive! But if your looking more simply for the sonic joy's of playing one, check out the Retro-sonic CE-1. If you havent already. This guy spent years with the circuit and has cooked it down to a normal compact sized pedal! Has eliminated the funky input loading thing, added tru-bypass etc. and retained pretty much everything else. I still own my original CE-1 i bought in 76 when they came out, and was a bit skeptical on how close he could have come in cloning the depth, and warmth of mine. Wow, i'm blown by it!! It's as close as you could hope for with out it literaly being one. And overall its better, because of the lack of the aforementioned problems with the oldie. Yes if you get super isoteric, one could MAYBE pick out a slight difference, but youd have to be a basement wanker in total isolation. Not my world. On stage it is WAY close enough, and way smaller than the tank! = a dream come tru! For my taste, its the best chorus on the market! Best of luck

[Mark Hammer]

I don't know if it is the "best" on the market, but as someone who has often "nursed" the builder Tim Larwill through many of the changes in that particular product (read: long conversations about the pros and cons of design changes he worked out on his own), I have to concur it is VERY well thought out, and tries to capture what people liked about the original without the things they disliked.

The original was really more tailored towards keyboard players trying to nail a Leslie speaker thing (hence the too-low input impedance, which was actually bang on for a keyboard line-out). Tim's is tailored towards guitar explicitly.

The most recent issue of the Retro-Sonic incorporates a custom-made power regulator chip so that the user can plug in a 9VDC Boss-style wallwart and get the +/-15V. The custom chip freed up enough space that Tim could finally install a second output jack for stereo, something missing on the earlier versions he produced. Over the summer, we were privileged enough to bring it to a Sheryl Crow soundcheck for Peter Stroud to try out. While Stroud was not ready to give up his Moolon chorus, he was very impressed with the Retro-Sonic.

If what you want is simple,then you might want to try out making the Corrral CE-2 clone project over at www.tonepad.com. It is an excellent quiet and trouble-free pedal, plus the parts are easily available, and the layout is nice and compact. I enjoy mine.

[jakebrown5]

The Retrosonic clone does sound great, but the reason I want to build my own is because of the experience, as well as the huge cost difference.

I asked for a schematic from Tim @ Retrosonic, but he understandably doesn't want to give away his secrets. He does say, though, that the circuit is the same. So now its down to whichever one I can build easiest.

[Mark Hammer]

Tim's reluctance is not just because he doesn't want to lose his "trade secrets" but also because the pedal is under constant evolution. I have to hand it to Tim. He is always incorporating client feedback and looking for ways to bring out the best in the original with small changes here and there.

Since the powering requirements (+/-15VDC) impose a certain burden and risk on those who attempt to build their own CE-1, this is one more reason why I recommend going for a CE-2 clone using the Tonepad layout. It is a relatively trivial matter to turn that little 2-knobber into a very powerful tonal beast, complete with alternate switch-selectable speeds, vibrato option, separate vibrato and chorus speeds, etc, etc. It sounds VERY good, and is directly compatible with guitar, which the original CE-1 wasn't. Finally, unles you are prepared to play one in stereo, then I personally find not special advantage to the CE-1 over the CE-2. As for experiential learning, a CE-2 build does not come up short in that department at all.

If you go to the diystompboxes forum ( http://www.diystompboxes.com/smfforum/index.php ), you'l be able to find all sorts of assitance from those who have built one.

[jakebrown5]

Well for different reasons I've decided to stick with my initial idea of replicating the original CE-1 circuit....EXCEPT:

-I want to use a modern power supply.
-I want to remove the vibrato section.
-I want to remove the LED's and all switching devices.


So I was wondering if someone could help me with these questions that arose:

-Can I use a standard +/-15 voltage for it? The original says +/-14V (and +/-13V for IC-1).....increasing the voltage will just give it more headroom right?

-To remove the vibrato section, can I remove the one half of IC-4 and the Rate and Depth pots? The goal here is to not alter the chorus section tonally.

-By leaving out the switching and LED parts, can I remove Q8, Q9, Q11, Q13, and Q14?

-I've found all the NOS parts needed to build this, except for Q5 and Q6.....what are suitable replacement transistors for Q3-Q6?


Again, I only have a moderate understanding of electronics. Just thought maybe someone out there that knows this stuff would be willing to work this out with me.