Boss CE-1 ticking problem.

[coxy46]

I have acquired a boss ce-1 off ebay. The seller said it was working fine. It's a US two pin model, I am in the UK and bought a UK - US two pin converter. When the vibrato on it is fine, but when I use the chorus it ticks along with the chorus. (i.e controlled by the intensity pot). I did a search on this forum and it seemed that a bad electrolytic capacitor would be the cause. So I have just replaced them all. And no luck. Can anyone advise me on further possible ideas of how to solve the problem.
Cheers
Coxy46

[coxy46]

just replaced most of the green mylar capacitors and still no luck, only a few more to go, so will finish off in the morning.
The sound I desribed as ticking, it is possibly better described as clicking as well. And sounds very similar to the sound that a flashing led can sometines make on numerous diy pedasl, it's that kind of click. I.e when it lights up it emits a thump.

[343 Salty Beans]

In DIY pedals such as the Trem Lune, putting a 100uF electrolytic cap from V+ to ground can take care of that.

A ticking problem solver: it's for the trem lune, but it should be applicable to most LFOs.

http://commonsound.org/fud/index.php?t=msg&th=408&start=0&S=34a574e97bdabaab7c08f25f1cf036e8

[cjlectronics]

I've worked on a few of these.  They can be tricky.  One of the repairs I remember was a high pitched squeal in the output.  It turned out that one of the 2SK30A was not turning off fully. The JFET was bad.  I replaced it and it fixed it.  However, this does not sound like this is your problem.

What I would do first is deep clean or replace the chorus pot.  I would suspect the mechanical parts first.

[George Giblet]

If I had to guess I say it's LFO related.  In vibrato mode the LFO operates as a sine generator, which are generally free from producing click problems.  The LFO circuit is completely in chorus mode.  In chorus mode the LFO operates as a triangle generator.

No answers only ideas:

There's two obvious points where the noise could come from.  The first is the electrolutic caps: C44, C45, and possibly C4 and C10.  Alternatively it could be related to the chorus pot wiring.  The signals on the chorus pot have the sharp square-wave edges on them and these could be getting into the audio signal paths.  That would point to the cable 10 on the intensity pot (I would expect cable 18 to be more troublesome).   It could also be the LED wiring.  Route these cable away from the PCB/audio cables  and see if it improves things.

Another remote possibility is to check the signal to the LED ckt (R58, R60, C33 and Q13).  If C33 or Q13 aren't right some of the tick signal could be getting into the audio by modulation of Q13.  Perhaps even check S3.

[coxy46]

Thanks guys.
The problem has been found. When i move the intesity pot away from the other pots the click goes away. Going to see if using shielded wire helps, if not I will have to move the pot elsewhere within my custom enclosure.

[Peter Davidoff]

Hi,

Go to Marc Hammer's page and read his notes about Zombie Chorus! I hope this will help!

Succsess!

Peter

[Peter Davidoff]

Sorry,

Hi is Mark not Marc! A great guy!

Peter