Build Your Own Clone Message Board

Hi All,

I’ve just completed the flanger pedal, version 1.0. The pedal works fine, I.e. the LED works, the effect engages and all the knobs work. The only issue is that when the regen knob is set at 10 o’clock or above the pedal makes a loud whistling sound that gets really extreme the more the knob is turned clockwise. The effect is engaged and does seem to be flanging and not just a chorus sound. I have put in the 1k resistor instead of the 47k resistor as per the instructions. I’ve attached pics of the top and bottom of the PCB. Hopefully they are clear enough.

Cheers

Oops. Pics too small. I’ll try again...

What’s that missing component just below the regen circuit?


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That's a blank spot left there for modifications.

Have you tried dialing in the trimpot? I don't have this pedal, but sometimes these clock-based modulation effects can whistle if the trimpot is set too high.

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Scott

My band, Austin Hollow

The next thing I would check is your resistor placement. It is a little hard to do this from your photos because not all the resistors are shown, and because the photo is not quite in bright, sharp focus. If you retake the photos, bring the circuit board into better lighting, such as a dining room table or even outdoors.

Be especially wary of resistors with the same value and a different multiplier, e.g. 1k vs. 10k vs. 100k. Notice how they only have one color band difference, making it easy to mix them up. Someone else may be able to see them better than I do, but if you're anxious to make some progress, that's something you can double check yourself.

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Scott

My band, Austin Hollow

Your soldering looks like you didn't have your iron hot enough and/or didn't hold the iron to the PCB long enough. You don't have very much flow through when looking at the top of the PCB. If you had a cold solder joint at R10, R9, R22, D1, D2, or in any of the low pass filters, that would have an effect on the overall signal level, which could cause the regeneration to be overly sensitive.

You should go back and reflow all your solder joints. Add just a tiny amount of fresh solder to each. Take the ICs out of their sockets. The PCB and all the other components will be able to withstand plenty of heat.

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*patience is a virtue*

Please do not PM me. email is prefered. keith@buildyourownclone.com

More details on that process here: viewtopic.php?f=9&t=52188

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“My favorite programming language is SOLDER” - Bob Pease (RIP)

My Website * My Musical Gear * My DIY Pedals: Pg.1 - Pg.2

Thanks all. I’ve fiddled with the trim pot but it really only engages the effect and not much else. I will try the resoldering option this weekend and see how that goes... will check the resisters too though I was triple checking them as I put them in... cheers

So I’ve checked all the resisters and they are all correct in terms of placement/values. I’ve resoldered everything on the PCB and made the iron nice and hot, so should be all good?

Unfortunately haven’t solved the issue though. Still have whistling (bird) noise when I turn the regen knob past around 10 o’clock. It is worse in differential mode. I think the ICs are okay as I’ve tried some spares in it and it seems the same...

Any further advice is appreciated...

Will try post better pictures soon too... but have noticed that I have a 47nK film capacitor in the bottom left of the PCB, which should be a 4n7... unless that means the same thing in electronics?

Here is the top of the PCB

No, these are not the same. (4n7 is 4.7k.) I don't have time to look at the rest of the board right now, but definitely check all the capacitors to make sure you didn't mix up the placement of two caps. If that's the only one that's wrong, you may have received the wrong value—rare, but it happens. In that case, you can request a free replacement, although I'm betting a person who has spare ICs lying around also has spare capacitors.

_________________
Scott

My band, Austin Hollow

That incorrect capacitor seemed to be the problem. Replaced it with the 4n7 one and now the pedal is working properly! Woohoo!

Thanks for all the help and suggestions everyone!