Cloning the Rare Boss CE-1 Chorus... Well... Kinda!

There are certain vintage pedals which are much harder to clone today than they were once upon a time. Among these are chorus pedals, flangers, phasers, and basically anything that relied on a specific integrated circuit to do the heavy lifting in terms of audio signal modification. While Moore's Law has continued unabated for over a half century, and despite the fact that modern semiconductors consist of  literally over 100 billion transistors on a single processor die, certain integrated circuits go completely out of production and ultimately become exceedingly rare. 

One pedal design I've always wanted to clone is the Boss CE-1 Chorus Ensemble, largely because (I'm sure you'll be shocked) Alex Lifeson used one at one point. However, there hasn't been a decent DIY clone out there - largely because the original uses obsolete Panasonic MN3002 BBD chip, and these are getting increasingly hard to find. PastFX has a clone of the original they've sold for years, but even after cornering the market on MN3002 chips, they're running out. As such they're released a version of the pedal using the more common MN3007 chip. Because of the rarity of the required chips, the MN3002 version runs about $350 US while the MN3007 version clocks in just north of $200 US.

None of this, however, helps the DIY pedal builder. Because of the rarity of the original MN3002 chips, there were no clones of the CE-1 out there that I could find. I did actually find an image trace of the original circuit board, but as I couldn't find any MN3002 chips. However, this year Lectric-FX released a PCB which is "heavily inspired by" the Boss CE-1, but uses the MN3007 chip (which is still manufactured in clone form by Xvive - so it is much easier to get ahold of!) called the Karaoke Chorus. While I find the name a little cringeworthy, it was my only option to try and get something like a Boss CE-1 on my board, so I decided to give it a whirl!

The Lectric-FX board is a little different in a lot of respects. First off it uses all 1/8W resistors - largely for space considerations - and the recommended BOM used Tayda as a source for the 1% metal film 1/8W resistors. The leads all seemed a little thin, and honestly if I end up building another one, I think I'll probably go to higher quality 1/4W 3.2mm or 3.4mm length resistors. Otherwise the components are fairly standard for most of my builds - WIMA / KEMET film capacitors, Nichicon electrolytic capacitors, etc. There are several ICs, including the aforementioned MN3007, which I just happened to find an original of at my FLES (Favorite Local Electronics Store).

There is no daughter board for the 3PDT switch, so it has to be hand wired. The audio input and output wires are on the north end of the board and trace around the outside to shorter wires that then attach to the stomp switch. There are two LED's - one for the chorus / vibrato rate and one for the bypass. On the original one of the indicator lights is tied to the clipping level, but that doesn't appear to be the case with the clone.

For the enclosure, I've decided to stop doing "interim" enclosures and start going straight to enclosures like I'd want to use going forward for all of my builds. Some will be a mix of licensed art (Adobe stock and other), but some, like this one and the Dimetrodon Distortion, will feature unique and original art by my wife who is painting up several dinosaurs in the style of marginalia found in medieval illuminated manuscripts. At this point she's done about nine of them, with I think three more in progress.

In terms of the sound of the pedal, because it's controls are a little different than the original, you have to dial in the sound a bit differently. That being said, when it is set to Chorus mode, I'm able to get sounds just like the CE-1 demos I've seen online - including taking it straight to "seasick" mode if you crank the depth and rate. I'm still struggling with the Vibrato mode (and the mixed mode, which is also an option on this pedal). It's not that I don't think it is working properly, it seems to be just fine based on what I've heard, it's just I'm struggling to figure out when I'd use it. That being said, if I throw a compressed signal into this Chorus, I can get a nearly perfect Rush "Time Stand Still" sound, and honestly, that's one of the places I wanted to go with this pedal anyway!