PHASE MKII

So as I've said before, I'm currently working on a new version of the phase pedal described in one of my previous posts. 

Whenever I complete a build I'm always filled with a great feeling of accomplishment, but afterwards it's natural to assess your creation and see how you could've done it better. So after spending a while sat on my breadboard, I deduced some changes I'd like to make and set out to do that. 

The first thing I immediately wanted to change was that I wanted a PCB instead of the Vero board I used for the first one. Vero board is great, but I think once you go past a certain size, it's not worth the trouble. I spent a long time laying down short jumpers across the pads and used a ridiculous amount of solder. It was my first attempt at Vero and maybe my last.

For the PCB I used Freeware Eagle Light Edition.
Eagle's one of those programs that looks scary but is actually really easy to use. The free Eagle Light has three basic limitations.

- The useable board area is 100mm x 80mm
- Only two layers
- The schematic editor can only create one sheet
 
Luckily, I very much doubt anyone using Eagle for DIY pedals will ever have much trouble with these, except for very large boards. This board reached the maximum allowed width, but any wider and it wouldn't have fit in the box anyway.

I've also re-designed the front panel and incorporated the depth knob as part of the preset switching. For me this is important, because at faster speeds the phase is much more pronounced. Also, having the controls totally isolated from each other is why we use presets in the first place. Using a global depth control wasn't what I originally wanted, but because I opt for all analogue switching in the first circuit, I really limited myself. After researching electronic switching I've been able to get more from one pole of a switch. Here are some diagrams to explain the methods used in the first and second pedal. 

Note: the 2PDT switch shown in the PHASE MK2 photo represents the electronic switching.

I've also changed the output stage incorporating an internal mix control. This is taken from BYOC's Phase Royal but rather than using it externally, I've got it inside so I can fine tune the 50/50 mix and leave it set. I've also altered the input and output stages with slightly larger capacitors than before. I'm also going to be working towards replacing the 2n5952 jfets used as they're becoming increasingly harder to source. 

Tomorrow I'll be picking up the PCB! Expect more posts of the PCB design and hopefully my first fully documented build log. Here's a preliminary shot of the template and thanks for reading!