# 1967 Maestro BG-1 Boomerang wah repair



## fernieite (Oct 30, 2006)

Hi Guys,

I've got a 1967 Maestro BG-1 wah coming in the mail. It seems to be all original besides the replacement Joe Gagan BG-1/BG-2 pot. However, I understand that it's not working properly.

Apparently, according to the previous owner - "there is very limited wah sweep". "The wah is sweeping very high only"

Do you think it could just be a matter of a dead cap, transistor or resistor?

Thanks a lot.


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## Scottone (Feb 10, 2006)

try adjusting where the pot is in it's rotation (turn it more counterclockwise). Good first step...doesn't cost anything


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## Scottone (Feb 10, 2006)

Scottone said:


> try adjusting where the pot is in it's rotation (turn it more counterclockwise). Good first step...doesn't cost anything


sorry, I think it's more clockwise. Try it both ways


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## mhammer (Nov 30, 2007)

Ditto. Rack (the long flat part) and pinion (the round toothed part on the pot shaft) systems that rotate pot shafts only rotate them *part *of the way, the reason being that forcing the pot wiper past its normal stopping point with one's whole body weight would likely irreparably damage the pot. So all such pedals leave a few gear-teeth's worth of spare space at each end of the pinion rotation. In other words, it is usually set up to only cover maybe 60-65% of its total possible "free" rotation. In this instance - and I'm guessing, here - the Gagan pot may have been installed too many teeth over to one end.

The good news is that, once the parts (rack, specifically) are loosened a bit on the inside, you can plug your guitar in and twiddle the pot shaft until you find a range you like. Set it to the desired toe-down position, press the treadle down, seat the rack up against the pinion and tighten the screw that holds it. Just make sure you have two or more pinion teeth of slack when in the toe-down position.


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## Scottone (Feb 10, 2006)

mhammer said:


> Ditto. Rack (the long flat part) and pinion (the round toothed part on the pot shaft) systems that rotate pot shafts only rotate them *part *of the way, the reason being that forcing the pot wiper past its normal stopping point with one's whole body weight would likely irreparably damage the pot. So all such pedals leave a few gear-teeth's worth of spare space at each end of the pinion rotation. In other words, it is usually set up to only cover maybe 60-65% of its total possible "free" rotation. In this instance - and I'm guessing, here - the Gagan pot may have been installed too many teeth over to one end.
> 
> The good news is that, once the parts (rack, specifically) are loosened a bit on the inside, you can plug your guitar in and twiddle the pot shaft until you find a range you like. Set it to the desired toe-down position, press the treadle down, seat the rack up against the pinion and tighten the screw that holds it. Just make sure you have two or more pinion teeth of slack when in the toe-down position.


Yep, this is what I meant 

Also, clean up the crappy soldering job on the replacement pot while you're in there.


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## fernieite (Oct 30, 2006)

Thanks guys! I hadn't thought of that. I'll check it out once it gets here.


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## mhammer (Nov 30, 2007)

I'll just note that most wahs will have a sort of pressure pad on the underside of the foot treadle, such that you can press down to actuate the stompswitch without much noise. Over time the pressure pad can get compressed or dry out and shrink a bit (if it's rubber). The solution is to loosen the nuts holding the switch to the chassis and raise the switch a smidgen or two, then retighten the nuts.

It's always a matter of personal preference how to adjust them. Some folks use their wah a little more aggressively and need a stompswitch that doesn't easily get actuated, while others like to be able to hit bypass or engage easily without having to press extra hard. Adjusting the switch height appropriately can achieve either of these.


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## toby2 (Dec 2, 2006)

Make sure it is a 25K linear pot assembly


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## greco (Jul 15, 2007)

Following with interest. Please keep us updated.
Hope it is an easy fix.


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## fernieite (Oct 30, 2006)

toby2 said:


> Make sure it is a 25K linear pot assembly


It has the Gagan BG-1 replacement pot. Seems to be the best replacement available.








gagan pot for maestro boomerang wah , BG-1, BG-2 replacement | Reverb


NOTE #1 !!!!!! ~~~ See ****essential note**** at middle of page . Not returnable, no warranty. this part is provided as a service out of our love for wahs, we do not make any profit on these.Note # 2. install tips and instruction, including video are listed throughout ...




reverb.com


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## tonewoody (Mar 29, 2017)

My guess is that the pot was installed too high in the slot, limiting the length of travel.

Loosen off the nut on the pot and shift the pot lower ( towards the bottom of the pedal).


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## fernieite (Oct 30, 2006)

*Update:* I think the pot is working alright and i have it adjusted properly now, but the wah doesn't have much volume and it's pretty noisy/hissy.

It seems to be making a nice wah sound through the full range of the pot, but it's very weak and there's a fair amount of hiss going on...

I have it at my tech's place right now. Hopefully it's something simple.


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## player99 (Sep 5, 2019)




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## player99 (Sep 5, 2019)

Your wah has the black label, which makes it the rare first year version.


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## fernieite (Oct 30, 2006)

Another update: Derek, my tech, replaced one of the resistors that had drifted off spec considerably. He also found out that one of the transistors was bad.
I'm waiting on getting a replacement now. 👍





P-2356 transistor for Maestro Boomerang Wah


Thanks Mozz! Looks like some other guy was looking for a replacement too... https://www.diystompboxes.com/smfforum/index.php?topic=121168.0




www.freestompboxes.org


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## fernieite (Oct 30, 2006)

Scratch that! 

Turns out it only needed 2 resistors replaced. One was out of spec, and made the output weak; and another which contributed to the hiss.

I should be picking it up later today!


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## mhammer (Nov 30, 2007)

I don't know how a resistor drifts off-spec, but confusion aside, congrats.


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## fernieite (Oct 30, 2006)

Yeah, apparently the original 68k resistor was measuring 84k, and the 120 resistor was noisy, causing the hiss.
It sounds great now!


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## tonewoody (Mar 29, 2017)

mhammer said:


> I don't know how a resistor drifts off-spec, but confusion aside, congrats.


"mojo drift"....

Congrats ferniete!


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