Distortion (based on Electra) build issues

[zrod13107]

Hi

I'm a new member and new to pedal building. Thanks for the forum!

I just completed a build based on the Small Bear Electronics Ursa Minor distortion circuit.
http://diy.smallbearelec.com/HowTos/Bre ... aMinor.htm
http://diy.smallbearelec.com/Projects/U ... aMinor.htm

I completed the breadboard build and liked the sound of the two main options a) using a Darlington pair of transistors, and b) asymmetric diodes using an Si b2b with a Ge + Si. In fact, I liked it so much I decided to do a full pedal build.

Shipping costs to Australia made ordering the dedicated PCB and enclosure uneconomical, so I designed my own perfboard layout and 1590B enclosure (also my first time for both). The pedal powers on using either battery or DC in, but alas no sound when activated (I do have sound in bypass).

I thought the best place to start is to seek a validation of my layout. I've added photos of the basic Small Bear schematic/PCB layout, and my custom layout. The schematic doesn't show the mods, but there is some more detail in third diagram.

Would anyone care to provide some feedback on my layout please - I accept it could have been more efficient, but I really just want to know if it replicates the schematic/PCB??

Thanks in anticipation... Rod

Perfboard layout

Schematic/PCB

Options

[mauman]

Welcome to the forum!

I don't see anything amiss with your vero drawing. Next step would be for you to post some photos here, of the front and back of your assembled vero board, and maybe we can see something that's not quite right. The usual suspects include transistor pinouts, solder bridges between two traces, a trace-cut that's not quite cut, and less-than-perfect solder joints.

If it were me, I'd probably replace VR2 with a fixed-value resistor, once you get the bias tweaked to your liking.

[zrod13107]

Thanks Mauman! I’m on the road for a couple of days and will post at the earliest opportunity.

I’ll also take a look at the fixed resistor. To me it doesn’t make sense having a set and forget pot, and I found the best sound came from a bias setting of 4.5v