Soft Latch Relay Bypass Daughterboard

[12th June 2014 - perf version added]

I've wanted to do a layout for this one for a while, but it fell by the wayside as the board will just be too big to fit in a 1590B which I use the majority of the time.  But there are a few builds I want to do now using 125B or 1590BB boxes and so this may now come in handy for me.

The idea is that you can use a SPST momentary stomp which are much nicer to use than the 3PDT stomps with no clunking, one stomp will energise the relay coil, the next stomp will de-energise it and it cycles like that.

With a footprint around 40mm x 30mm this may just about fit at the bottom of a 125B and my intention is to velcro it to that lower side so it's in the right vicinity but leaving plenty of room for the stomp.

I've got some 9V and some 12V relays, both of which should work fine with a 9V supply, but check the pull-in voltage of the ones you want to use.   These look like they'll be fine:

http://www.rapidonline.com/electronic-components/g5v-2-12dc-dpco-pcb-relay-2a-12vdc-60-4446

and these are the stomps I will be using:

http://www.ebay.co.uk/itm/290619513732

So it won't be the cheapest bypass method but nice to do for certain "best builds".

Thanks to Paul from paulinthelab for the circuit.

And something unusual for this site, but if you want to keep the size to a minimum then perf may be a good option.  This version also grounds the board input during bypass, and note that I have done this with 1/8W resistors in mind.

Buzzaround-Alike

Hello new and old friends! On this day AD, we have some exciting news. I, Miro have been dubbed as thee second-in-rank-admin to help Mark around on the blog. Many of you already know me from various post threads :) Anyway. I've started to draw layouts some time ago and we thought we might give a go for these too. My layouts look a bit different  and there is a reason for that. I have been using Linux as my only operating system for last 8 years and the software version Mark uses, well, doesn't work too well on Linux/Java. Comments are open, so please let us know if you think this is a bad move :)

As a tryout for Miro's layouts, we have Mictester's Burns Buzzaround-Alike. Description from Mictester:


The legendary Burns Buzzaround was a slightly unusual germanium fuzz that achieved its (undeserved) reputation for two reasons - some great guitarists used them, and they are virtually unobtainable. The original consisted of two stages - a two-transistor amplifier and a distortion stage that could have both the amount of signal sent to it and the bias point adjusted by external controls. The third control was a crude tone control which fed the output. Originally, the output was unbuffered, and the leads and amplifier following would load the unit, and the top end would be rolled off, and often the tone control would have little effect. 

The first stage in the sound-alike is just a high input impedance op-amp gain stage. You may wish to increase the gain by increasing the value of the feedback resistor, but it sounds pretty good as shown. In the original, the first stage didn't really have much effect on the sound - it just amplified it enough to drive the following stage into conduction. 

The heart of the beast is the germanium transistor stage. Apart from using an NPN transistor, this remains true to the original (why screw up a classic?), and still gives a wide range of sounds from the thin toppy fuzz beloved of sixties bands through to gated spluttery farts, with smooth warm distortion sounds in between!

The final stage is just a buffer - it isolates the tone circuit from the outside world, and allows a full range of control from muffled to glass-shattering!

Depressed

Yesterday:

Today:

Better get back to layouts then because there's going to be no more sunbathing! :o)

PCB - DPDT Daughter Board with Millenium Bypass

(originally posted on freestompboxes.org)

I thought I'd share this little project with everyone as I'm sure a few other people would be interested in it. Just to paint the picture I really hate two things about building effects, firstly the clunky and sometimes unreliable 3PDT switches, and secondly (and most annoyingly) the offboard wiring. I reckon I'd have built considerably more if the thought of offboard wiring hadn't put me off doing something so many times. So here in the UK we have an online electronics supplier called Rapid Electronics and they sell some DPDT switches which have a much nicer action than the usual 3PDT, you literally only need to step on it lightly to switch over and there is no clunk, and as an added bonus they're really cheap and readily available:

http://www.rapidonline.com/Electronic-Components/Foot-switches-79208/

They're currently £1.69 each if you buy 10 or more, but the price has gone up and I only paid about £1.12 each when I bought a stash a while ago.

I'd seen some of the daughter board layouts on here for the 3PDT which looked excellent, so I asked Eric (Mr G on FSB) if he'd mind doing one for a DPDT switch and with onboard millenium bypass components and the good man that he is, he happily obliged.

Here's the boards, and the first build I'm using them for:

The first thing that struck me was how much neater the thing ends up compared to my usual builds! :) The second thing that struck me is that offboard wiring really isn't an issue now, I actually enjoyed it for the first time ever. All the connections are there including separate ground connections for the input and output sockets which just makes it a breeze.

Anyway thanks Eric for the excellent layout and here's the PDF containing the PCB artwork for printing:

Millenium Bypass