Possible fix for tremuls lune popping?

[chromesphere]

Hi everyone,

I think i may have found a way of getting rid of the popping in the tremulus lune ive read some people are getting (tonepad build reports to be specific).  As the reports suggested the popping happens at 'extreme settings' for me more specifically when the depth or spacing dials are on full.  I think i may have the answer.

When i first hooked up the un-enclosed circuit, everything sounded good.  No real problems.  Because there was light in the room though, the depth on full wouldn't produce complete silence when up full as the signal dropped.  I put a small box over the circuit and noticed the 'popping' or 'ticking' people have complained about started as previously mentioned (extreme settings).  Remove the box, back to normal.  Turn my study light off, ticking straight away.  So i figured maybe the resistance of the LDR is getting too high? The 'pop' is followed by a noise that sounds sort of like the circuit is off.  Anyway, long story short, tacked on a 100k trimpot (tried other values, 100k was the best for me) onto the back of the LDR (in parrellel) to limit the LDR to a max of 100k.  Adjusted the trimpot to a point where the guitar signal is quiet but the popping noise hasnt startedm around 80k approx.  Oh, just one warning, be careful not to turn the trimpot to zero ohms...unless you enjoy being deafened!  

Had the popping problem with both tremulus lune boards i made, this method of limiting the LDR resistance worked for both.

Just thought i would share my discovery with you guys, If your having the same problem, give it a try, might fix your problem too!

Oh yeah and thanks Pete Moore for posting the parellel resistor / LDR idea in my other LDR thread.  This idea prompted me to try it. cheers!
CS

[rousejeremy]

Try a 100Uf cap between +9v and ground.

[Hides-His-Eyes]

Try a 100Uf cap between +9v and ground.

When I had one on the breadboard I tried a 220u across the rails and it didn't fix the problem.

[rousejeremy]

Well, I know it works with the Tonepad layout and the vero layout that's around here somewhere. I've built three Tremulus Lunes and 2 of them had the LFO ticking when the trimpot was set just so. There's also the 1nf cap across the volume pot which can be added to the 100uF cap across +9v and ground.

[chromesphere]

Hi rousejeremy, Thanks for the suggestion.  It's ok though, the LDR trimpot fixed it for me.

EDIT: forgot to mention.  My popping was happening, pretty well anywhere the trimpot is set to.  Well you know, until the volume has dissappeared altogether

Hides-his-eyes, give the trimpot a go!  Might fix it!  Just play around with different values.  I found mine started at about 80k for one tremulus and around 100k for the other.
CS

[darron]

having the switch turn the LFO part off while on bypass should stop it too... dunno why it was never designed that way. i assume you only get the pop when you turn it on.

[chromesphere]

Hi Darron,

The pop occurs in the effect, when the tremolo falls (too low), it will pop, goes silent, the guitar signal comes back again as the tremolo effect rises, then it falls again *pop*, goes silent, the effect comes back, etc etc.  This only happens on 'extreme settings' and i assume its because the dark resistance of the LDR gets too high and, sort of, switches the entire circuit, or one of the IC's causing the effect to pop...thats my, electronics noob, assessment of the problem anyway.  Limiting the LDR resistance to below 100k fixed it for me.

CS

[darron]

i'm glad you worked it out too....

are you sure that's a pop and not a tick (: hehe

some LDRs goes way past 10m on dark resistance too.... might be a good note for people with different LDRs

[chromesphere]

ahhhh....a tick that sounds like a pop? Ok, yeah i think technically its a tick...

You are correct, this one also goes past 10m in a short amount of time. I was discussing this in another thread i created a few days ago.  Turns out it was a problem!

CS

[therecordingart]

Mine did the same thing, but once I got the trimpot dialed in it stopped. It was when I had the effect louder than the source that I got the ticking. I know this sounds weird, but what type of trimmer are you using? I can't dial in one of these to save my life:



Every single one of this type that I've tried is either open, full resistance, or maybe a little something in between. Maybe I just suck?

[chromesphere]

Hi therecordingart,

No thats the same as mine, and i agree, they are very hard to adjust...maybe that was the problem after all...?

CS

[therecordingart]

Hi therecordingart,

No thats the same as mine, and i agree, they are very hard to adjust...maybe that was the problem after all...?

CS

Doesn't hurt to try.

[rousejeremy]

The Tonepad instructions say to use a 25k trimpot, but 100k may be needed depending on the LDR used.

[chromesphere]

Well there you go....so maybe attaching the 100k trim in parrarel with the LDR has a similar affect to using the 100k trim?  Oh well, its done now :-)

Hopefully this thread helps anyone else with this issue....in a...round about manner 

CS

[therecordingart]

Well there you go....so maybe attaching the 100k trim in parrarel with the LDR has a similar affect to using the 100k trim?  Oh well, its done now :-)

Hopefully this thread helps anyone else with this issue....in a...round about manner 

CS

Sweet. It's an awesome pedal! It does mild to insane and everything in between.