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Perfect.

Thank you.

So it doesn't matter the orientation, I can just fit it any ways it drops in? Looking at the trace on the back, it looks like I need to complete the circuit path, with the inductor legs.

Pardon my ignorance, I just dont want to destroy my buddies 50 year old inductor...

Are there any advantages/changes that would affect the sound if I dropped it in in any particular place? I'm just used to things being a little more clear.

I appreciate your response, but I will wait to see what other info comes in. A little knowledge can be dangerous!

Cheers, and thanks for the swift reply!

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!

As far as I can see in the pictures, I think that U2 is placed the wrong way

That was indeed the problem, confirmed by Mammoth, and by my Carlsbad working! I originally had it in the right way, but was asked to flip it for debugging purposes, it may have been a bad chip from the get go, but I had a few TL072 CP's around, so I swapped it, and all is good!

One thing I remember from the Jargon File is that a true hacker considers troubleshooting to be a tete' a tete' with the original designer.

Lacking a schematic, emailing said designer would be my first thought.

Indeed, that is what I thought. Though I am still relatively ignorant on the maths behind solving a schematic (beyond simple things) any other kit I have bought had a schematic available, either online, or from the distributor. That being said, many have said the same things about the lack of a schematic!

A build doc with no schematic. = epic fail....

In the future, I will only be buying kits with schematics. Ths has indeed been a learning experience.

Thanks to all who have chimed in, and offered suggestions/solutions.

It is appreciated! Regards!

first off, welcome to the forum. also thanks for sticking to the tech-help guidelines.

Thank you, and it makes sense.

however, it is nearly impossible to help you without a schematic. Do you have no signal at all or do you only have dry (unaffected) signal when the effect is engaged?

I have asked the folks at Mammoth for a schematic, if available. I do have signal when the effect is bypassed, but no sound at all when it is engaged. Not even dry.

It is possible - but could also be absolutely nothing, no way to actually confirm without a schematic - that the reverb brick is on the wrong side of the pcb. Most often the square pad indicates pin 1 (it does on madbean's moodring for example), which would mean the brick is supposed to go on the back of the pcb. on the other side, your voltages (assuming your pin voltages are numbered according to the numbers indicated on the brick) are fine. Do you have any pics of builds by other people that could confirm the arrangement? again, this is only guessing without a schematic, so please do NOT desolder anything yet as it can be a big pain in the ass to desolder ICs and possibly damage them.

good luck

I originally wrote an email to Mammoth, to help with troubleshooting, and the gentleman saw the pictures I linked in this thread. He also said everything appeared to be in the right place. I'm sure that the brick being on the wrong side would have jumped out, but it is a possibility... From the PCB it looks like pin 6 (BTDR) has a square, the other pads are all circles. The numbers were taken from the brick pinouts, and they are labeled. 1 corresponds to pin one of the brick.

I do not have any pics of completed builds, but I will go looking now. If and when I get the schematic, I will post it.

Thanks again.

I bought a kit from Mammoth, the Carlsbad reverb, a unit that uses the Belton Brick BTDR2.

I completed the build 2 days ago, but the pedal isn't working.

I have built a few pedals, but I am far from complete in my knowledge of electricity. I am still learning, and hope this will be another good learning opportunity.

Here is the parts list, and build document I worked from.
https://moodysounds.com/wp-content/uploads/2014/09/carlsbad-reverb-assembly-instructions.pdf

Here are the symptoms;

The pedal has been tried in and out of the enclosure
The LED lights up, and I am getting power to the board (more on that later)
I am getting signal through on bypass, but nothing when engaged.
The switch appears to be fine, as do my Jacks and battery snap/Dc jack

Voltages read as follows;

J4- J201
G- -0.00v
S- .28v
D- 1.05v

J5- LM78L05acz
1-VOUT- 5v
2-GND- 0v
3-VIN- 9.58v

Q1-MPSA18
C- .52v
B- 0.01v
E- .34v

U2 (IC) TL072CP
1- 7.96v
2- 8.64v
3- 8.65v
4- 9.58v
5- 8.66v
6- 8.66v
7- 7.09v
8- 0v

Belton Brick BTDR-2H
1- 5v
2- 0v
3- .26v
4- 0v
5- .04
6- .04

I understand some of these numbers, and from my limited knowledge, it seems that maybe something is off with my J201, and/or MPSA18.

I do have an audio probe, and plan on throwing that at this problem later on if I can find the time. I thought I would try my luck, and post here, as I have always found it helpful to do so.

Here is a link to a few pictures of the PCB, with off board components, unboxed.
http://imgur.com/gallery/5ISB0

Feel free to offer any suggestions.

I appreciate the time and capabilities of all who chime in.

Cheers gentlemen,

You were quite right.

Thank you for the information. It is appreciated!

So I got the whole unit working, biased with a battery.

It isn't working with the Dc Jack though.

I am quite new to this, and am looking for some general debugging things I should be looking at.

My lugs on the Plastic DC jack have been shrink wrapped with the soldered wires, so there is no real chance it is a short between the ground and +9V.

What are some things I can check for? As it seems that there is 0V going to the board with the DC jack. No LED light up either.

Any help is appreciated!

Thanks guys and gals!