HELP, JEN 60's Cry Baby Wah PCB Component Placement; Inductor

Started by seagurt, February 13, 2017, 03:42:03 PM

Previous topic - Next topic

seagurt

I have also posted this thread on Madbeans site.

I have an old school Cry Baby Wah (JEN Italy, 60's,) that a buddy asked me to look at. The board is damaged in places, the traces have lifted at points, and silver trace has been applied, to to make sure the effect indeed works (been more than 20 years apparently.) and it does, and sounds beautiful.

I was asked to re board the components, and so I bought a PCB from Tonepad.
http://smallbear-electronics.mybigcommerce.com/pcb-tonepad-wah-wah/

All the components seem to match, except there is an additional 100kQ trim pot (Bias I presume, or tonal width?) and I dont know how/which way to install the inductor. Its a red Fasel, and it appears to have 2 legs (all I can see) but the board has 8 different spots where the inductor is supposed to seat (from what I can tell, I may be totally off.)

I don't want to solder, and de solder components, especially a Red Fasel from 67...

Would anyone here know which way I am supposed to install this inductor, or do I need another variant because the standard component housing has changed so much in the last while. I am ready to modify the existing inductor if I need to in order to make it fit.

Here are some pictures of the original wah board, components, and such, as well as the new PCB I wish to use.


Apologies if the images dont appear, I'm still trying to figure that part out. I tried to add them as an attachment, but the files were too large.

Thanks for all the help, it is appreciated!
Those who know the least will always know it the loudest.

Long's Law

thermionix

There are multiple inductor mounting holes to accomodate a variety of inductors with different pin spacing.  It doesn't matter which way you install yours as long as one pin goes to each trace (top and bottom).  There is no polarity.  The 100k trimmer is a "Q" control.  The earliest wahs used a 100k resistor there, later ones used a 33k.  Some people like values in between.  I used to have an adjustment there in my wah, but after I found a pot with a taper I like, I found that I preferred 33k.  That's the value you've heard most on recordings all your life, as the 100k wasn't used for long, maybe a couple years.

thermionix

I should add, the Jen you're restoring may be old enough to have used the 100k "Q" resistor.  If you're moving the original components over from the original PCB, then just go with that.  Ignore the trimmer and use the original resistor.  Also, some wah inductors have 4 pins, but only two are active, the other two are just to help secure it to the board.  That's why you see the square pattern there.  But you said the Fasel only has two pins, so just one to each trace and you're good.  Hope that makes sense.

seagurt

Quote from: thermionix on February 13, 2017, 04:23:49 PM
I should add, the Jen you're restoring may be old enough to have used the 100k "Q" resistor.  If you're moving the original components over from the original PCB, then just go with that.  Ignore the trimmer and use the original resistor.  Also, some wah inductors have 4 pins, but only two are active, the other two are just to help secure it to the board.  That's why you see the square pattern there.  But you said the Fasel only has two pins, so just one to each trace and you're good.  Hope that makes sense.

You are indeed correct, it uses the 100K resistor, I'm throwing the 100k variable trimpot in to adjust to taste. The resistor measured 112.5, and if the variable resistor doesn't sound good, I'll throw the original one back in.

Thanks to all!
Those who know the least will always know it the loudest.

Long's Law

duck_arse

seagurt - for the address you posted:

http://imgur.com/gallery/CEpT0

you need to post that between the tags provided by pushing on the button. no images will show in the thread, but we can visit your bukket over at imgur via that link [which has no image extension].

if you want to include an image, click instead on mona (she likes it) and insert the seperate address imgur provides for each of your images [each of which will end with an image-type extension]. (you need to right click or hover over three dots or something at imgur, I can do it when I'm in-logged there, but can't remember the process to tell.)

or you can right-click the image at imgur, and choose "copy image address", and paste that into mona's waiting embrace. when you have managed the images, click the "Preview" button next to the post button, and check your images are not YUGE! and then add something like height=300 in the opening img tag. there is a sub-board called testing, you can go there and mess about with your method/technique, till you get it working, and we are not allowed to say rude things to you in there.

can you counts to 34.

thermionix

I see a 33K on the JEN board there.  That's almost certainly the Q resistor.  The 100k on the board is another part of the circuit.  Doesn't really matter since you're using the trimmer.  But 33k will get the "original" sound of the pedal.