Month: November 2014

Fender Superchamp XD Line In/Mute Switch Mod

I recently did a popular mod to my Superchamp XD. I put a line/poweramp in so that you can just use the tube preamp, without any of the digital or solid state that comes before it. At the same time I also added a poweramp mute switch so I could use the line out and play when son is asleep in the house. The line in mod will also mute the speaker when a cable is plugged in, but I put the switch in as well because its easier than finding a cable and plugging it in.

Tube amps can be dangerous. Always observe tube amp safety:

Changing Batteries on a Mobee Power Bar

I used a Mobee Power Bar to save money and the environment by not needing any batteries for Apple’s Magic Track Pad. I use in plugged in all the time, meaning that I never run out.

However this does eventually kill the rechargeable batteries inside, and meant mine would keep losing the bluetooth connection and need to be re-paired. Anyway, had a thought the other day and unscrewed it and used a spudger to prize it open gently. Its basically two AAA NiMH batteries inside a AA case. I replaced the AAA with new ones, and things seem to be fine again.

Custom Neunaber ExP Controller

I recently purchased a Neunaber Slate pedal for the amazing Wet Reverb effect. However all the v2 of their stereo pedal range support up to 4 effects, with 2 presets per effect. They make an external controller to control this, but its a little too big for my Pedal Train Mini. You can see a demo in the video below:

Update July 2015:
Anders Jepsen has provided some updated information if you have issues with switch:
avaliable to download here.

Update March 2016:
For those of you that have visited before, I now have a new improved circuit that just uses a SPST which means you can use soft touch switches :) It’s also much more stable when switch and shouldn’t have the random/glitchy issues that some have experienced.

Update July 2017:
I’ve since built a new ExP that ads an expression output, but still fits in the mini enclousre below. I also managed to change the hardwired Cat-5 cable for a panel mount socket. See pictures below.

Links:
Neunaber Slate: http://neunaber.net/collections/pedals/products/slate-stereo-effect-pedal-v2
ExP Controller: http://neunaber.net/collections/pedals/products/exp
ExP Specification: https://docs.google.com/document/d/1dtP4e3Sp2izZ9LJ1SC9TPAYDjfYPpU8mbfK4Lh-GG54
4024 Datasheet:
https://media.digikey.com/pdf/Data%20Sheets/ST%20Microelectronics%20PDFS/HCF4024B.pdf

This is the most recent circuit I’ve used with has a switch bounce filter which allows the use of SPST soft touch footswitches:

Neunaber-ExP-spst

The first incarnation used a SPDT switch for the clock:

Q1 Q0 Effect LED
0 0 4 (off)
0 1 3 Green
1 0 2 Red
1 1 1 Orange

Notes:
– Neunaber don’t cover warranty for custom ExP controllers, I can’t be held responsible if you break your pedal.
– While my pedal works, I’m not sure if I drew out the circuit exactly like I made it :P
– While I’ve used a counter so that I can cycle through the effects with a single momentary switch, the same could be achieved with 2 latching switches or a rotary encoder: http://www.fk-industrie.de/en/produktkatalog/P/D/E/A/27.html
– I’ve used an up counter which cycles the effects in reverse 4-3-2-1. Use a down counter if you want to go the right way.
– When the counter sets the effect inputs to high, it also turns on the LEDs.
– I used a two color LED for L1 and L2. Mine had a common cathode, some others you buy have a common anode and may need to be connected to the +3.3V rail, with the cathodes connected to Q0 and Q1.
– Power is provided through the ExP port, I’ve just labeled the rails for clarity.
– Since the supply is 3.3V, you need a HCF logic chip (Not HCT which is minimum 5V).
– I wired the RJ45 cable directly into the box to save space, but there are some nice panel mount sockets around.
– I’ve drawn a switches only circuit here: http://jameslow.com/2014/12/01/custom-neunaber-exp-3-switches/

Components:
Counter: http://www.maplin.co.uk/p/4024-cmos-logic-hcfhef-qx13p
2 Color LED: http://www.maplin.co.uk/p/5mm-multi-colour-led-yh75s
Panel Mount RJ45: http://www.gtcontact.com/Ethernet-RJ45-Plastic-Screw-Panel-DIP90.html