Remote Wah – Putting it all Together

Assembling the enclosure and inserting the circuit boards is the easy part.  A few holes are drilled, and some standoffs and washers employed:

The smaller satellite board on the right contains the optocoupler and related circuitry which attaches to the XLR jack.   This isolates the footpedal from the rest of the audio circuit – no audio travels through the expression pedal cable.  The rest of the wiring goes pretty fast, too:

Here is a closeup of the V847 Wah board:

I modded it with a couple of trimpots to control the “Q” factor and the gain on Q1.  I also switched out the inductor for an old Crybaby inductor, as I preferred the sound on it.

The front jacks are normalled to the rear jacks, so if nothing is inserted in the front, the signal will pass through to the rear jacks:

Now we are ready to rock…

Remote Wah Enclosure

Even though the wah circuit is not that large, in this case the goal was to make the unit look like Edge’s, which has a black 1RU rack box enclosing it. I settled on using an off-the-shelf Lansing enclosure Graybox, which comes in many depths and is available in a nice black anodized finish. Based on the photos, I designed a panel with holes for 1/4″ audio, a power indicator LED, and and XLR jack for the expression pedal.

I don’t have an fancy milling or machining tools, so I printed out some full sized patterns from the drawing, and used them to mark the front (and back panels) for drilling with a drill press.

The labels were made using a P-Touch printer.

Remote/Rack Wah – Getting Started

The basis for this project comes from R.G. Keen’s wonderful article The Technology of Wah Pedals found at his GEOFEX website. It the article he explains how the pedal for a wah circuit can be positioned remotely from the audio using an LED and Light Dependent Resistor:

So it’s a relatively simple matter to disconnect the pot from the circuit and implement the alternate circuit using a 3 conductor cable (XLR or TRS) and an expression pedal. I use the Boss FV300L since I have one sitting around (and b/c Edge has one too of course…) In place of the LED/LDR pair R.G. describes, I think it’s easier just to use an off-the-shelf NSL-32 optocoupler.

The first step was to build a very rough prototype with some spare jacks and scrap sheet metal parts, to make sure the concept would work. I usually do this for pedal experiments:

Edge’s rack wah is a Vox V847 but I happened to have an old Crybaby board lying around, so I used that instead. The circuits are virtually identical. Next was to attach the FV300L with a mic cable give the wah a test drive. (Note: This also required a cable splitter from TRS to two mono cables) Here I used it for a cover of “The Fly”:

Once I was confident the prototype worked as I hoped, it was time to design a nice box for it…

Edge Effects Settings Lookup

The Early Years: 1977 to 1983

The Classic Era: 1984 to 1990

The Awesome 1990′s

2000′s U2

This is a new section of the site I’m working on, which is very much inspired by the website gilmourish.com (which I am a big fan of).

I’ll be adding settings, tips, and other suggestions that I think will be helpful in trying to duplicate Edge’s tones with your own setup.

You’ll be able to click on the album thumbnails and this will take you to a page listing songs and suggested effects settings.

(Yes, I am biased in favor or 1990′s U2… That should be obvious. )

What project would YOU like to see?

I’ve added a poll, to see what might be interesting to work on next…

Thanks for voting!

Dave

SDD-3KP Has made it into the Guitar Effects Database

I just saw this today and though it was really cool! :

http://www.effectsdatabase.com/model/dtsaudio/sdd3kp

They have even archived pics of Version 1 and Version 2.

Now Accepting Deposits to Reserve an FA-2 Pedal

I try to keep this site more informational vs. commercial, but I do sometimes receive a lot of emails with price inquiries which can crowd my email inbox. So, in the interest of streamlining things I’m trying something new to see if it works out better for everyone. Here’s the pricing info on the FA-2 pedals: I’m now accepting a limited number of deposits (of $100 USD) from those who want to reserve a pedal in the upcoming FA-2 build. I’m expecting these to be completed in the December/January timeframe. The total price is not set in stone yet, but will be very close to $175 without the footswitch, and $200 for the version with the footswitch, plus shipping.

Also, as an experiment, I’m trying out the use of Paypal buttons to see if this makes things more convenient for everybody who wants to place a reservation.

Deposit to Reserve an FA-2 pedal without Footswitch (Traditional Style):

Deposit to Reserve an FA-2 pedal with added Footswitch:

Bear with me as this is very much in “beta” mode. However, if this works out well for people, I may set up a separate web shop in the future for those who want to purchase pedals.

Thanks!
Dave

Building a Remote/Rack Wah Like Edge’s

A fun little custom project, coming soon…The plan here is to copy The Edge’s rack wah.

DTS SDD-3KP Pedals Now Available in Japan

For those in Japan interested in purchasing an SDD-3KP pedal, good news:  a limited quantity are now available through an authorized dealer, Musette Japan Co., Ltd.

http://www.musette-japan.com/

http://rush.sub.jp/musette/archives/gear/dts/index.html

Dave

Korg A3 Jack Maintenance and Replacement

The Korg A3 is now famous as being one of the main effect boxes used during the Achtung Baby and Zooropa sessions.   With the 20th anniversary of Achtung Baby fast approaching (hard to believe!) these old units are definitely showing their age.  One of the most common problems they have is a tendency to develop loose solder joints which at the rear input and output jacks.  This is because the Jalco 16PJ500/16PJ509 jacks are attached to the circuit board in a rather flimsy way – they are soldered to the board, but there is no nut used on the rear panel for strain relief.  Eventually, after plugging in and unplugging phone plugs many time, and/or moving your A3 around in a rack to various venues and rehearsals, etc., those old connections break.  You can wiggle the phono plugs and it doesn’t give you a good feeling.  The result is that your A3 eventually cuts out on you.  (For some reason, usually this happens sometime after soundcheck when things seem to be working fine but right before you play Mysterious Ways…).   Don’t feel too bad – Sometimes bad stuff like this happens to the Edge, too… (“Edge, did someone break your funky thing?”)

A good way eliminate this problem and to make the A3 more rugged is to replace those Jalco Jacks with something you can mount to the rear panel using a nut, and then connect wires to the circuit board.  This way there is no more stress on the circuit board from the weight of a heavy 1/4″ phono plug.  The space to do this in is not very big, however.  The most convenient jacks I’ve found for this (so far) are the Neutrik Slim Jacks.

They are made for PCB mounting applications, but that’s OK.  The soldering pins are big enough for you to solder a wire to.

Here’s a friend’s A3 I did some work on, with the original Jalco jacks visible:

The next step is to carefully desolder them.  I use desoldering pump to do this and its has been a problem.  Sometimes it helps to add fresh solder (with its flux) when desoldering old solder.  Here’s the board with the jacks removed:

Now one can position the news jacks to see how they will fit:

As you can see it will be a tight fit next to those inductors/ ferrite beads.  One of them has to be turned on it’s side. Because of space constraints,  I’m not going to replace the “Direct Out” jack (it’s rather useless).

Now solder some wires to the jacks. I’m using 22AWG wire here:

Then solder the wires to the board:

To keep it simple, the ground wiring (black wire) is only connected to the board in one place.

Here are the old leftover jacks after being removed (By the way if you need to buy these, you can get them at Mouser.com. They are part number 16PJ500 or 16PJ509 under the brand name Kobiconn):

Finally, here’s a view of the back after everything is put back in it’s place. Don’t worry about the open hole – there’s an easy fix for that…

You can get little plastic plugs at the hardware store which will pop into place and fill the empty hole in the rear panel.  ( It would have been better if I had found a black one, but it’s only going to be at the back of the rack…):

Now this A3 is going back home, and hopefully it’s wild flanger sounds will make it’s owner comfortably “Numb” for many more years to come…