BJFE / BearFoot fx Guitar Effects Community

Nicks PCB is the same layout that will be ordered with some very minor changes. Part values will not be listed on the PCB, instead the part location on the shcematic will be referenced. There are a number of reasons for doing this.

1. It teaches you the proper way to populate a PCB and will help you to learn how to read a schematic. BJ wants this to be an educational process.
2. If you want to change a value in the schematic you need to know where it is on the PCB.
3. You will be able to troubleshoot the PCB againt the schematic.

I have changed some of the trace thicknesses and will most likely make the holes for the 4001 diodes bigger as the leads are pretty thick. The PCB work is Nicks, I just dressed it up a bit

In order to help you prepare for your build here are some suggestions for the pots and toggle switch, you will also need jacks, a way to power this, an enclousre and an LED. These are from Mouser but you can also get the rest of the parts from Small Bear, PedalPartsPlus.com etc.

Mouser #: 313-1500F-50K
Mfr. #: RV16AF-10-15S1-A50K
Desc.: 16mm Carbon Potentiometers Audio Screwdvr 50K Solder Lugs
RoHS: RoHS Compliant

Mouser #: 313-1000F-1M
Mfr. #: RV16AF-10-15R1-B1M
Desc.: 16mm Carbon Potentiometers Linear B1M
RoHS: RoHS Compliant

Mouser #: 313-1000F-100K
Mfr. #: RV16AF-10-15R1-B100K
Desc.: 16mm Carbon Potentiometers Linear B100K
RoHS: RoHS Compliant

Mouser #: 108-1MD3T1B1M1QE-EVX
Mfr. #: 108-1MD3T1B1M1QE-EVX
Desc.: Miniature Toggle Switches SWITCH TOGGLE DPDT
RoHS: RoHS Compliant By Exemption

Question:

If you don't want the clipping options, what do you do?

Hey John -

Got the boards today, thanks. I have a few questions regarding component spacing. To the best of my knowledge, T1 through T4 are all TO-39 style transistors and the silk screen legend on the PCB appears to be for TO-92 transistors. There's a fair amount of size difference between the two and I was wondering if this project has changed to a Si based fuzz and I just missed the announcement. Also the BOM calls for LED 2 and LED 3 to be 5mm standard diffused but the silk screen legend looks like they would be 3mm and in a dry fitting of the parts, two 5mm placed side by side do not sit flush on the PCB. Are we good to sub 3mm red LED's for 5mm's? Thanks for the time and info.

Scott

The way Nick drew the PCB he spaced it for TO-92, you will also need to be mindful of the pin positions, make sure the collector and base are lined up with your transistor correctly. I had the same problem with the spacing on T1 and T2 where I used some 2n1306 germainium trannies and I mounted them to the underside of the board to make them fit. I have 3mm led's in mine as well but I thought about doing 5mm on top and one on bottom. When I made the kits up I did switch to Si trannies in TO-92's and 3mm diffused LED's

If you dont want the clipping options then don't install D2, D3, D4, D5, Led2 or Led3 then bridge the two top hole and the center hole of the DPDT swithch.

I found these at Mouser this morning. They may make mounting the trannies a little easier.

Mouser PN 610-PN2907A is a cross reference match for the 2N2905A in a TO-92 package.
Mouser PN 512-TN2219A is a cross reference match for the 2N2219A in a TO-226 package.

As for their sound...

thanks for that post BMF - those are actually the parts I included with the kits for everyone that ordered parts kits with their boards.

...any hints or suggestions for making the pedal more suited to a bass guitar?
Is it possible to switch out certain components with different ratings for a lower range? If so, which ones?

thanks,
-tf

Shoot.... had a better reply typed out, and the internet ate it.

I'm a long way from an expert, but here's some of the things I've read a bit about, used in other circuits, and was going to try on this project. Life's been to busy for me to breadboard it, so this is only my speculation for the pedal I was going to try and tweak for bass. Either solder the parts in and sub them out as you try it, or socket them in and its a little easier to play with the values.

The 150pF capacitor between the two transistors... I think that increasing it should filter the highs out a bit, but I could have that backwards. I had thought about increasing that, leaving off the tone control, and putting in a different pot instead for a different control.

C1... Theoretically, increasing this value increases the bass going into the circuit. I don't know if this is calculated to let most audible frequencies through, but it could make a difference. It might not be a noticible increase in lows, as much as the nature of the distortion as different frequencies are clipped.

I've read that increasing the 10uF caps to the ground might increase the lows, but I think I've seen it debated if there's actually an audible difference after 10 or 20uF... Couldn't hurt to try though, and I've seen some bass fuzz schematics that have up to 100uF in a similar position.

There's other possibilities to try, but these are three easy ones. Just try and play around with the values if you can... it gives you an idea how the parts effect the sound.

Can anyone share the Mouser part number for the 9 volt jack to use on the case?

jakeddy wrote:Can anyone share the Mouser part number for the 9 volt jack to use on the case?

See if the one you want is on this page;
http://www.mouser.com/catalog/635/1091.pdf

There's quite a choice.