james low

I’m a big fan of the Fishman Aura Spectrum DI. If you don’t have something like the Taylor Expression system on your acoustic, it can vastly improve your plugged in sound, particularly for live situations. If you have a piezo on an electric or slimline guitar, it does the same, but because of the more “neutral” sound, I’ve found you can use it to give you all sorts of different acoustic sounds. Fender even do this with their Acoustasonic Tele.

Since using it to give multiple sounds on an acoustic guitar, something I’ve wanted to be able to do is switch presets with a footswitch. I had a look at the circuit and figured out a straight forward way to do this. Warning: This will void your warranty and I am not responsible for any damage to your pedal.

UPDATE Feb 2015:
I now recommend wiring up both sides of the DPDT switch and wiring to pins 3/4 instead of pins 1/2. The reason for this is that it puts on the “preset” slots at the end (13-16), and means you only loose 4 slots. This makes more sense to me because I set the presets all the same (my main sound) and that set an alternative on the dial. If you like to set up pairs of sounds with a different preset on each one, then use my original mod of just soldering a single side of the DPDT to pin 1.

Update Oct 2024:
I’ve found a 3PDT switch that fits if you sand down the sides a bit. This means you only lose 2 preset slots 15/16 rather than 4. Switch is here:
https://lovemyswitches.com/taiway-3pdt-latched-foot-switch-low-profile-solder-lugs/

How I did it:

1. Use pliers to remove the ring around the anti-feedback switch. The anti-feedback switch is a momentary switch and we need a latching one.

2. Use hex keys to remove the base of the pedal, and remove the battery clip as you do.

3. Locate the rear of the anti-feedback switch and remove the clip for that too.

4. VERY CAREFULLY use a sharp craft knife or scalpel to cut down each side of the switch to remove the plastic washer that stops you removing it. I found if I bent the switch to one side while I did this it made it easier. I’ve owned two versions of the Fishman Aura DI, and the older ones didn’t have this, so you could just remove the switch, if you do you’re lucky, this step took me a couple of hours!

5. Insert the new switch, I used some rubber washers to space it. Alpha’s small DPDT footswitches fit, and appear to be the same as what Fishman are using. They’re available on eBay: http://www.ebay.co.uk/itm/131175360378

6. Connect one pin of the switch to the 2nd pin of the 16 position rotary encoder (bit 1), and another pin to ground.
– There are multiple ground points, use the one that’s easiest, but I used the ground for the rotary encoder.
– From left to right the pins of the rotary encoder are: Input, bit 1, bit 2, bit 3, bit 4

How it works:
The 16 way preset switch is basically a rotary encoder counting from 0-15 in binary. As it counts, it connects each of the 4-bits to ground. We’ve connected the switch to bit 1, which means that it will increase any of the off positions (in binary even) by 1. So it will switch between preset 1 and 2, or preset 3 and 4, 5 and 6, etc. If you are on an even position (in binary odd), bit 1 is already grounded so the switch does nothing, i.e. positions 2,4,6,8 won’t be switched.

Notes:
– The original Aura Imaging Blender seems to have had preset footswitches built in:
http://www.fishman.com/product/aura-imaging-blender-discontinued

– If you could get access to the other side of the PCB, you could disconnect the input to the rotary encoder and switch that. This would give you a better switching system, where you always switched between preset 1, and what you had set on the preset dial. I didn’t feel confident disassembling things that much though, so elected for the simpler system.

– Here’s a list of my favourite Fishman Aura patches:
https://docs.google.com/spreadsheets/d/1FN8WMgKAJQHMKjTJkxhZzQQYS5DTSRZGXKffRXjX6PA

Update:
i) I just found that Catswhisker Pickups #5 with in their S-Bucker pickups:
http://www.catswhiskerpickups.co.uk/humbucker.html I’ve ordered one and will do a demo soon.

ii) Dean Zelinsky guitars just announced their SideKick pickup which aims to be a “true single coil”: https://deanzelinsky.com/sidekick-pickup

iii) Rautia Guitars Toast-O-Caster, Single-Bucker and Bar-O-Caster pickups look interesting too:
http://www.rautiaguitars.net/toast-o-caster.html
http://www.rautiaguitars.net/singlebucker.html
http://www.rautiaguitars.net/bar-o-caster.html

iv) I’ve seen some people put two single coils or a sustainer in humbucker slot. Another option might be two put a true single coil (or even a noiseless single coil) and a mini humbucker in a single coil slot:
http://www.tdpri.com/forum/tele-home-depot/413620-4th-july-caster-8.html#post5425950

Recently been interested in changing the neck pickup on my guitar to a humbucker that has a coil tap that doesn’t seem to have such a large drop in volume. There seem to be a few different ways to do this:

1) Seymour Duncan and Dimarzio

Seymour Duncan seem to be have experimenting with this for a while. They had their Stag-Mag which is a humbucker made of two true single coils and The P-Rails which is a single/P-90/humbucker all in one:
http://www.seymourduncan.com/blog/the-tone-garage/how-to-get-more-from-your-humbucker-coil-split/

Dimarzio had their DP157 Multibuckers which where two of their rails pickups in one. While both rails where humbucking, one was designed to sound like a humbucker, the other a single coil. Dimarzio discontinued it, and when I emailed to ask why they said “the parts used for it are no longer available”, I’m not sure why that should be in our technologically advanced age, but maybe its because of a legal dispute or something.

Dimarzio also have the bluesbucker which is an interesting humcancelling, but coil splittable P-90 in a humbucker:
http://www.dimarzio.com/pickups/humbuckers/bluesbucker

2) Mismatched coils

Lindy Fralin have their Unbucker pickup which has two heavily mismatched coils. When its coil split, it then has a higher output coil than a humbucker that is just split in half. It sounds pretty good, the disadvantage is that you don’t have full hum cancelling in humbucker mode:

3) Asymmetric coil tapping

Asymmetric coil tapping, doesn’t split the pickup in half like a coil split, it takes one coil and then a few extra winds from the other coil. The disadvantage here is that you don’t have a true single coil anymore:
http://www.geminipickups.co.uk/coil_taps_31.html

4) Partical coil cancellation

Similar to the above, some people just put a resistor across one of the coils:
http://www.musicradar.com/news/guitars/50-steps-to-better-electric-guitar-tone-528489/39

5) Add extra coils to single coil

Finally, this is an idea I had, how I think it should work though is mismatched coils like the Unbucker so that the coil split has more than half the winds, but also a coil tap of the overwound coil when in humbucking mode so that the coils are matched again and you get a proper humbucking tone and hum cancellation. I think it can still be done with a 4 conductor cable, but the connection points would be different than a standard one. Something like:

-------------------------- Single coil hot
       |    1.5K     |
Coil 1 ------------------- Humbucking hot
       |     4K      |
-------------------------- Single coil ground
Coil 2 |     4K      |
-------------------------- Humbucking ground

How it would work is that when you want a single coil you would connect the extra windings on coil 1 and use the middle point between the coils as ground. For Humbucking you would coil tap coil 1 it had the same number of winds as coil 2 and use the humbucking ground. In this example in humbucker mode you get an 8K true humbucker. In single coil you get 5.5K true single.

I also found out PRS are doing something similar, but I can’t say its exactly the same:

I recently bought a Fender Blues Jr. with Billm mods. I wanted a Hammond 1590H footswitch to fit on my pedalboard.

The Blues Jr. footswitch circuit has a 15V signal that is connected to switch the fat switch. Billm suggests that you could use a LED and resistor and then bypass it so that the LED is on when the fat switch is off. However other companies offer a footswitch with an LED that is on when the fatswitch is engaged. I did some testing and I found that, at least with the Blues Jr. III, even with the LED and resistor in the circuit it still switches, so you can just break the circuit to turn it off. I think I calculated that an 800ohm resistor was about right.

Here’s a picture with the LED indicating the fat switch is on:

I wrote a previous post about my custom Neunaber ExP controller that uses a counter to switch between the 4 effects with just a single button.

3 Switches
I’ve had a few requests about how to do it with just switches. I’ve drawn up a circuit, but don’t have time to build it, so I can’t be 100% sure it will work.

Notes:
– Neunaber don’t cover warranty for custom ExP controllers, I can’t be held responsible if you break your pedal.
– If you only want 2 effects, you can leave off the 3rd LED and switch
– The logic of the switching in this configuration is more like 2 banks of 2 effects with 2 presets each. Switch 3 selects between bank 1 (effects 1/2) and bank 2 (effects (3/4). Switch 2 selects between either effect 1 and 2 or effect 3 and 4 depending on the position of switch 3.

Common Anode
Another variation depends on the the type of multi-colored LED you use. Some have common cathodes, some have common anodes. You have to connect the common pin to the rail, and the individual coloured pins to E0/E1 because connecting the common pin would join E0 to E1 which you don’t want to do.

This also changes which colors indicate which effect:

I recently did a popular mod to my Superchamp XD. I put a line/poweramp in so that you can just use the tube poweramp, 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:

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:

The first incarnation used a SPDT switch for the clock:

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

I recently built a bypass looper into a Hammond 1590H pedal enclosure so I was doing some research into this. If you wanted to use jacks, and not have the LED, I realised you could use insert cables and fit two stereo switchcraft jacks and one of the small 13mm x 13mm DPDT footswitches that are avaliable.

I really miss my M-Audio Fasttrack 8R. M-Audio/Midiman had the most stable drivers and best customer support, until they were bought by Avid, and the sold again, decimating one of the best value midi/audio interface companies.

I sold the Fasttrack to downsize, but also because the drivers were becoming less and less stable on newer versions of Mac OS, and it became impossible to contact Avid without paying for support. I bought a Apogee ONE, but the Mic did’t compare to my old Rode NT1, and I missed being able to do 2 mics, or 2 lines at the same time.

I’m about to sell my ONE and get a PreSonus Audiobox iTwo (it wasn’t out when I got my ONE). I was trying to figure out if it would work with Garageband on the iPad for mobile recording, since in all the marketing they push their own app. I contacted their sales and go this reply:

“You can use Garageband; you’re not limited to just our recording app, no.

Conversely, there are people who bought our PreSonus Capture iOS app and use the built-in mic or other 3rd party audio interface on their iPad to track stuff when they’re out an about… so our software app isn’t limited to just work with our iOnes/iTwos.”

I also eventually aw that right at the bottom of the features they have a comment that it works with other apps on the iPad:
http://www.presonus.com/products/AudioBox-i-Series/features

Update:
I sold an Apogee ONE for iPad because it would cause crashes on waking from sleep. I was going to get the iTwo interface, but decided on the Audiobox USB because it was cheaper. Unfortunately that interface doesn’t work with the iPad (unlike the Audiobox VSL 22). It gives the “device uses too much power” even when plugged in through a powered USB hub or one of these dual USB power cables and removing the power pin going to the iPad: