Boss CE 1 volume pot mod

[Fenderbender]

Hi there,

Just wondering whether any of you know about the CE 1 pedal level pot mod. Just bought one recently and as I had read the pedal is very sensitive to a guitar signal and if the level pot is turned past low settings signal clipping occurs in a nasty way. The level pot on the CE 1 controls the entire volume of your rig too. I now have it setup quite well and theres not a big problem more fine tuning would be nice though.

I replaced the existing 50k pot with a 500k one and it made little difference although the 500k pot was old.

Has anyone here done this mod with success??

and

Does it make any difference whether the pots in your guitar are 250k and if they are should a 250k pot be put in the CE 1??

Any other suggestions on using this pedal would be great, I love the sound but would just like to improve the dry signal.

thanks,

Andy

[Mark Hammer]

The original/stock pot tends to load down the input and loses bandwidth and clarity as a result.  On the other hand, its value appears to play a role in achieving effect/bypass volume balance.  Insomuch as the CE-1 was an effect aimed more at those wishing to mimic rotating speakers with keyboards, it anticipated hot low-impedance signals being fed to it, such that a 50k pot for attenuating such signals was appropriate.  The goal, then, is to make the CE-1 suit guitars better.

Increasing the pot value will load down the guitar less, though the benefit disappears if you feed the CE-1 with an already hi-in/low-out buffer, rather than directly from the guitar.  As they normally do, higher value pots will preserve more of the guitar's signal, so 250k will be better than 100k or 50k and 500k will be "better" than any of these.

At the same time, as my buddy who makes CE-1 clones has found out, incorporating the higher value pot can also pose a threat to clean processing precisely because it DOES preserve input signal.  You might find that you need to keep the level control set well below max most of the time to avoid clipping, in which case the advantage afforded by the pot change tends to disappear, doesn't it?

The best advice would be to stick a compressor in front of your CE-1, set for light compression.  This has two functions.  First, the CE-1 is not set up to handle hot signals very well, so limiting peaks is helpul to achieving a clean chorus sound.  Second, the compressor will almost necessarily have a much lower output impedance than your guitar, making the 50k pot on the CE-1 perfectly acceptable.

Funny, isn't it?  We are so accustomed to pedals that are designed to anticipate guitar signals, and worst-case scenarios, that when we stumble across a pedal that is optimized for a different type of signal, everything falls apart.

[Fenderbender]

Cheers for that, yeah it is a funny pedal, but does have a great sound, I use it after a few other pedals and this seems to have minimised the clipping and if I set the volume pot to about 11 o clock on the low input switch the overall volume loss compared to normal running is not that big its about 1 notch on my clean volume difference. The sound is suprisingly clear and low noise considering how old it is, the only slight issue now is that I like to drive the preamp tubes to break up and beyond on my clean channel volume so having the CE 1 in there just reduces the break up slightly due to the reduced signal, but I reckon I'll live with it, you can't have vintage stuff with all the modern perks!!

thanks for the help,

Andy

[Mark Hammer]

My buddy and I have had many discussions about optimizing the S/N ratio on this beast.  If you look at the schematic ( http://www.geocities.com/CollegePark/Library/1355/BossCE1.gif ), you'll see that there is a passive attenuator on the output formed by R52/R51 (in the upper right hand corner).  Their values are 3.3k and 4.7k.  That's some big kinda signal reduction if you ask me. Try swapping a 6.8k or even 8.2k in there for the 4.7k part, and see if it helps with the speaker breakup thing a bit.

[Fenderbender]

sweet stuff man, I'm kinda reluctant to mess with it loads in case I screw it up, plus I've only just started building pedals and modding them. I got my CE 1 for around $150 which is a bargain and they're damn difficult to find in working order at that price, so I'd I#'d hate to fry the thing! But I'll check out the schematic, as I said I've got it working almost like any other pedal apart from the slight signal drop, I love the sound though, I thought it was hyped but its just so smooth wouldn't say its the warmest as everyone says it is but just dam smooth, best chorus I;ve heard, but it does take up some serious real estate on my board. :-)

[Mark Hammer]

Sell it on e-bay and buy yourself one of my buddy's!    It only takes up the space of a 1590BB.

[Dirk_Hendrik]

I did this pot-conversion yesterday. In the recent past I had 2 CE-1's in for repair. In case of the first one I was kind of of amazed about the fuss over this pedal as I found in not really an inspiring chorus. After this I learnt about this conversion and found it already done in the 2nd. When I bought one last thursrday it took me a while to realize that the dullness was indeed that pot-thing again. 500K works terrific.