Weird "pop" coming from my wah...

Started by soulboogaloo, November 30, 2011, 02:28:31 AM

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soulboogaloo

Hi there,

I happened to mod my Maestro wah. First, I replaced the old switch to a 3PDT and everything was ok. Then, I added a LED, and now I get some terrible pops when hitting the switch on and off.
Do you know how I could avoid that?
Thanks a lot, and sorry for this rookie question!!!

wesman26

http://www.diystompboxes.com/wiki/index.php?title=Frequently_Asked_Questions_(DIY_FAQ)#POPS
Better explanation than I can give.

Personally I would say get rid of the LED, but it's your choice.

--Wes

soulboogaloo

Thanks mate, I'm going to check that out!
If possible, I would prefer to keep the LED, I'm tired of playing with the pedal switched on whereas I don't want to, and wonder why my sound's so weird!!!

wesman26

Not a problem.  Keep us posted if you get it fixed.

Welcome to the forum and happy soldering.

--Wes

ayayay!

Depending on your 3PDT wiring layout, my guess is you've got the Neg leg of your LED soldered on the 3PDT to where the ground should be.  Reverse them and see what happens. 
The people who work for a living are now outnumbered by those who vote for a living.

soulboogaloo

Thank you all for the reply, guys!
Tonight I first had a look at the Wiki Wes indicated me : one possible explanation was the dust and funk on the stereo plug, therefore I swapped it for a brand new one, but nope...
Then I tried to reverse the LED, as Ayayay suggested, but no... and actually that is quite logical : when I reversed the LED, it didn't light anymore, of course, that's all...

This is the 3rd time I'm modding a wah (1st a Crybaby, then a Coloursound, and now this one), but that's the 1st time I happen to get weird pops like that..
The Maestro is a bit special, because when the wah is not on, it works as a volume pedal. Do you think it could be an explanation?


wesman26

What's the specific model?  From your description it sounds like a Maestro Boomer 2 volume/wah.  Also do you think you could share a picture of your 3pdt setup?

--Wes

soupbone

#7
Quote from: soulboogaloo on November 30, 2011, 05:49:15 PM
Thank you all for the reply, guys!
Tonight I first had a look at the Wiki Wes indicated me : one possible explanation was the dust and funk on the stereo plug, therefore I swapped it for a brand new one, but nope...
Then I tried to reverse the LED, as Ayayay suggested, but no... and actually that is quite logical : when I reversed the LED, it didn't light anymore, of course, that's all...

This is the 3rd time I'm modding a wah (1st a Crybaby, then a Coloursound, and now this one), but that's the 1st time I happen to get weird pops like that..
The Maestro is a bit special, because when the wah is not on, it works as a volume pedal. Do you think it could be an explanation?


This is from Analoman's site;(scroll down a little bit and he talks about using a 3pdt switch)   Popping sound when effect is switched
My effect with DPDT switch makes a "popping" sound when I switch it in and out. How can I quiet this down?

This is caused by a change in levels between the effect BYPASS and ON modes. According to Geoffrey Teese (Teese Real McCoy wahs- the best wahs available) You can fix this by adding a 1 MegaOhm tie-down resistor on the circuit board. You need to add it between the INPUT and ground. Do not add it at the jacks, but on the circuit board. On the VOX V-847 this can be done on the back of the circuit board on the multi-pin connector. On the newest crybaby wah you should not have this problem as they use a buffer which even does away with the need for the true bypass mod.

Note that most wahs are microphonic and some of the popping is unavoidable. The noise is the sound of the mechanical switch clicking, amplified by the inductor on the circuit board. Try tapping on the board with a pen to see how microphonic yours is (the wah should be ON).

Alternate wiring to reduce popping on some pedals

Many pedals will make a POPPING sound when the effect is clicked on or off after installing a true bypass switch. This can be minimized by an alternate switching method which grounds the input of the circuit board when the effect is OFF. This type of wiring was used on many old fuzzfaces.

You need to add a GROUND WIRE to the switch, to lug 3. This can be attached to one of the ground lugs on a nearby jack. The INPUT JACK wire will run to lug 1 and also be jumpered to lug 6 in order to short it out to lug 3 when the switch is OFF. Lug 2 now goes "TO" the board. Lugs 4 and 5 are the same as the standard wiring : lug 4 is "FROM" the board and lug 5 is to the output jack :

input jack--1   4---From board
            \
To board----2 \ 5---Output Jack
              \
To ground---3   6  Jumper from 1 to 6


or if you are using the more common 3PDT switch, make the
lugs horizontal lines as below for correct switching:

_  _  _    1  4  7   Use the same connections as above.
_  _  _    2  5  8   you can use 7 8 and 9 for LED.
_  _  _    3  6  9   7 will be connected to 8 when ON, run LED there.


Last night somebody told me that the battery is being drained even when the effect is off and in bypass mode. He said that the input jack can be modified to correct this. is this true? can you add this mod? if so and it is reasonable price, let me know and go ahead and do it and i'll send you the extra bucks.

The battery is being drained only when a cord is plugged into the input jack, even when it is "off". You don't want the battery off when the effect is off as when you step on it to turn it on you will have a dead effect until the capacitors charge up. The current draw is quite small, a good alkaline battery will last a long time in a wah. When the wah starts sounding weak, you will have plenty of time to change the battery before it goes dead.

So you are best off with the true bypass mod and the standard battery connection, just unplug the input cord when you are not using it to conserve batteries.

In the pedal full down position, the wah is extremely trebly and kinda harsh. I know this is due to the circuit itself. Is there anything i can do to get less of the trebly harsh sound. I'm a sweet tone guy. Can I rotate the teese pot a notch or two so when the pedal is pushed all the way it doesn't go all the way to the extreme treble zone?

Yes - that will do the trick. Easier though is to unscrew the plastic thing that pushes the straight gear thing against the gear on the pot (looks like a wire tie down) and then re-index to the next gear on the pot. Keep trying until you get the right gear (trial and error).

Will this work or will the bass direction bottom out? Know what I mean?

A few teeth on the gear should not bottom it out but it may. After tightening down the screw, turn the pedal by hand too the extremes of up and down and see of the pot tries to move at either end of the movement. If it does then it is bottoming out. If so, you should adjust it so as not to bottom out.

Alternatively, without having to open the pedal you could stick a bump stop under the existing bump stop at the toe of the pedal. You can get a little stick-on rubber pad at radio shack (they are also the same as Electro Harmonix feet!).


soulboogaloo

I hadn't time so far to take pics of the inside, I'll do it tonight!
To answer the question, yes, this is a Maestro Boomer 2!
I can precise 2 things :
- for now, I haven't rewired the pedal to true bypass. Just swapped the original switch for a 3PDT.
- When I take the LED out, everything is ok, I mean no plop anymore

I'm gonna try to true bypass the pedal and check if it makes it better
Gonna try the 1M resistor trick as well...

Cheers!

soupbone

Quote from: soulboogaloo on December 02, 2011, 05:38:33 AM
I hadn't time so far to take pics of the inside, I'll do it tonight!
To answer the question, yes, this is a Maestro Boomer 2!
I can precise 2 things :
- for now, I haven't rewired the pedal to true bypass. Just swapped the original switch for a 3PDT.
- When I take the LED out, everything is ok, I mean no plop anymore

I'm gonna try to true bypass the pedal and check if it makes it better
Gonna try the 1M resistor trick as well...

Cheers!
Right on