In my quest to create my ideal portable pedalboard I've decided a Morley Mini Volume pedal is perfect for adding volume functionality to the finished product. The idea is to just use the circuitry in a new enclosure so as to avoid unnecessary routing and cabling. I had lofty goals of completing some projects for work and on our house today, but unfortunately I feel like I'm about to die, so I'll do something that requires less effort and decipher the schematic. First thing's first, tear it apart:
It's a very simply constructed pedal. It's not even a fully enclosed box or cast aluminum or steel as many are, but rather a formed piece of sheet steel with a bottom cover. Four screws hold the bottom in place. After removing the screws it's easiest to remove the battery cover and reach inside to pull the base off. It's a very tight fit, so it takes more force than I was initially comfortable with, but nothing broke, so I was good.
The wide open space of an optical volume pedal. From the factory
it featured a foam battery holder and 9V terminal. I tore them
out the first time I opened it since I always power it with a
9VDC power supply.
The next step is to remove the outer nuts from the in/out jacks and the nuts that hold the pcb in place. A socket or wrench for both are necessary unless you're too lazy to walk across the room to the workbench so you just grab a pair of pliers and go to town. That works too. Then with a little bit of finesse and some prying on the case you can remove the entire PCB in one piece.
Evidently in order to save money on production costs Morley uses the same board for all their mini pedals. They offer a volume/wah combo, as well as a dedicated wah. This PCB has two sets of LED/photovoltaic sensor combos, although only one is in use. Once I discovered this I started formulating how to incorporate a switch onto the body of the new enclosure that would allow me to switch between acoustic and electric volume. Basically in position 1 the acoustic would be full volume while the electric is controlled through the top bank of LED/photovoltaic sensor, and in position 2 the electric would be at 0 volume while the acoustic is controlled by the lower bank of LED/photovoltaic sensor. This will allow me to start at 0 volume on both signals, fade the acoustic in to full volume, hit the switch, and then have the electric. If I decide to have the option of fading the electric in I will need another switch that would mute it while I move the pedal back to the 0 position, then reengaged the signal and fade up. I'm not sure that's an option I'll want to use because of the amount of space needed to add two more switches on the final enclosure. Regardless of what I decide, there are two sets of LEDs:
They shine through these slots and illuminate the photovoltaic sensors. A lot of reviewers online complain that this pedal is either all on or all off. This is because of the design of the holes. They're shaped similar to a hammer, a long skinny 'handle' and a large open 'head. When the 'head is in front of the LED, all the light is allowed through, where the 'handle' section limits the amount of light. I'm thinking that this could be remedied by tapering the opening more and then adding a small piece of translucent tape. I'm not unpleased with the control of the unit, so I will not mess with any of it unless I find myself frustrated with it, or am really, really bored one day.
The circuitry of the volume pedal is insanely simple. Below left is the top (pedal side) of the board, and below right is the bottom side:
In it's simplest explanation, the LED is constantly powered by either battery or a 9VDC power supply (when the pedal is powered on, through the switching input jack). The ground is common for both input and output jacks, as well as the LEDs. The tip (hot) side of the input jack runs to one side of the photovoltaic sensor while the tip of the output runs to the other. The amount of light that reaches the sensors adjusts the amount of signal that passes through from 0-100%. As I said earlier, the second pair of LED/sensor is unused. Here is the schematic I drew up to help get it all clear in my mind:
Now don't focus too much on the wildly beautiful hand drawings that make up this little beauty, because you'll miss out on all the wealth of information it has to offer. What it lacks in complexity it makes up in simple straight forward information. If you'll notice that I've already noted where I intend to steal the signal to send to and and receive from the iRig Stomp. This was originally penned when I intended to just house the guts from the iRig in the enclosure of the Morley. Since I intend to house it all in one enclosure, there will be no need to grab the signal from the input of the Morley since I will simply rout straight from the input jack of the enclosure to the iRig, and then from the output of the iRig to the side of the jumper leading to the sensor. The only reason I will use the jumper is simply because it will be easier to solder there than elsewhere. If I decide to add the switching option for the acoustic signal I will just jumper on the in/out to the bottom photovoltaic sensor and use either a 3PDT or 4PDT switch to handle the signal routing.
Hopefully the coming weeks as I mull over the final product I'll be able to find a few more ideas/shortcuts to make the whole thing work a little better or more polished. Anyway, this is a teardown and reverse engineering of a very simple little volume pedal. I'm hoping that you'll find the confidence/desire to tear into some of your stuff and make it a little more perfect for you...
I love my iOS devices. There was a time I didn't. About the time that the iPhone 3G was becoming available, I was up for an upgrade. I looked into every smart phone that was offered at the time, but each one fell short. I finally realized that the only thing stopping me from getting the iPhone was the fact that it was an iPhone. I was so afraid of falling into the stereotype of Apple fanboy that I avoided their products like the plague. I then realized that mentality was just as short sighted and stupid as those who only purchased Apple products. I now use my iPhone 4 for more tasks than I would have ever imagined and my iPad (which I thought was completely absurd at it's release) is an essential part of both my music making, my other businesses, and my everyday life. I even recently caved and bought a MacBook Pro after my water cooler in my desktop PC exploded while we were on vacation.
So I've loved the idea for years of incorporating the processing power for digital music of the iOS devices into not just recording, but live performances. There have been several products released over the past few years that are pretty incredible, but always left me feeling like there was a big part missing. The initial offering for guitar interfaces (the IK Multimedia iRig, Peavey AmpKit, etc.) were all astonishing in their reproduction of sounds, but always left me with that stupid little 1/8" headphone jack for output. Not at all useful if I wanted to run into a PA.
Griffin Technology previewed the Stompbox a while back and I thought I was sold, but again I was left with what felt really cheap and awkward for interfacing with a PA. A few even managed to incorporate a 1/4" jack, but the impedance was always wrong.
Digitech debuted the iPB10 to accept the iPad and although it was an incredibly cool concept, it's $400 price point coupled with the fact that you must dedicated a device costing at least $500 puts it's minimum cost at just shy of $1,000. Really? A grand for some digital effects?
I watched devices come and go and although I'm still pretty excited to check out Mackie's DL1608, I'm not sure I'll be able to afford it.
Then I saw a preview for the IK Multimedia iRig Stomp. It contained an upgraded circuitry from the iRig (which received less than stellar reviews from most users, though I suspect that was more a result of their software and less the hardware), but was packaged in a stompbox format and included a pre-amp, headphone jack, and not one, but two 1/4" line level outputs. It seemed like I'd found my answer. Then it was a waiting game. I watched as my favorite retailers promised ship date after ship date. I waited and waited. Marked them in my calendar, and then waited some more.
It's important to understand why I want the iRig stomp to work so badly. I run a strange setup for my guitars. A few years back I added a D-TAR Wavelength pickup to my Taylor T5 in order to be able to run dual outputs, an acoustic signal, and an electric simultaneously. I often perform alone and I wanted the added depth of sound of running the twin signals. I started with a little box and added one here and there until I ended up with this:
I then needed a way to transport it, so I came up with the set up you see on the left. It was just a spare suitcase we had with custom inserts I designed to hold all of my other accessories I needed on the road. The pedalboard consisted of a Zoom A2.1u for the acoustic signal, a Zoom G2.1u and a DaneElectro Fish & Chips for the electric side, a couple of signal routing pedals I built, a tuner, and a TC Helicon Voicetone Harmony G for vocal affects. It was a nice little setup, but I wanted a few other things. The empty space on the board was intended for a Boss RC-20xl. Then Boss released the RC-30 and I bought one. I quickly discovered that the looping capabilities were severely limited by the two available footswitches and needed a second interface. Boss's offerings were sufficient, but I wanted to choose when to rout my electric signal through the looper, so I designed another pedal to fill my needs. That presented a problem. I was out of room. Then I decided I needed a TC Helicon Voicetone Correct XT, and I was REALLY out of room. So I built this:
And I love it. It does so many things. I love explaining it to people. I love playing through it. I love watching all the pretty flashing lights when I plug it in. What I don't love is carrying it. Fully loaded in it's box it weighs just over 150lbs. It BARELY fits in the trunk of my car. I designed it to fit, but didn't count on it weighing so much. It's great when I'm traveling through the summers and playing for 3 or more days at the same venue. It's not great for setting up to play a 7 song set in a church service. It's too much. It's too heavy. It's too flashy. I want something that gives me most of the functionality, but much less bulk and weight. Enter the iRig Stomp.
After months of waiting, I finally ordered one of the first available and received it a few weeks ago. I sat down with it, plugged it in and marveled at how horrible the sounds coming from it were. I then did a little bit of reading, discarded the Amplitube software and downloaded Peavey's AmpKit, and I was in love. After about $20 worth of app purchases, I had the sounds I wanted, both from the acoustic side and electric. So now I needed two, and two iPhones (I can steal my wife's on stage right?), and I needed to be able to control the volume of the electric so I can fade it in and out depending on the song.
My main rig has a Morley Mini Volume pedal on it. It's so compact for a volume pedal at about 6 3/4" x 4 1/2" compared to an average size of 10" x 6" for full size volumes. I decided that two iRig Stomps, another signal switcher, and a Morley Mini Volume would fit the bill. I could put it all on a board about 7" x 10" and have about 60% of the functionality of my main rig, but at a fraction of the size and weight.
I can't leave well enough alone. my brother-in-law needed help moving the in/out jacks on his Morley Mini Volume, so I tore into mine to see what I could find. I found that there was a ton of space in there, possible even enough to fit the internals from the iRig Stomp into (I had, of course, opened mine up as soon as I received it to inspect the guts). I started working on the layout and was shortly led to the conclusion that I could, within a larger enclosure, fit all the components for all four of the desired pedals. The design of the Morley lends itself very well to alternate placement. I will show all of this in more detail in future posts as I go through the build. If I cut out all the cabling necessary to rout the signal chain through the 4 pedals, I save enough money to pay for the enclosure. I found several boxes from Hammond Manufacturing that would work, but I think I've decided to build my own out of sheet metal. Regardless, here is the mockup:
Notice I have labeled a midi jack on the back side. That will be my interface with another box I will build that will house/mount/power/interface with the two iPhones. Basically I will use any 8-pin din connector and corresponding cable I can find.
It's just a theory at this point, and will likely undergo massive changes before completion. I still need about $150 to buy the rest of the components and since I do all my music experimentation with our 'extra' money, It'll be a while before that happens, but please check back from time to time to see how things are or aren't progressing.
I own a Taylor T5 that I've added a D-TAR Wavelength pickup to. I play through a custom board that I built that accommodates both the acoustic signal from the D-TAR and the electric signal from the T5 electronics. Here's an overview of the board on youtube:
And the followup with the new signal chain and interface for the RC-30:
We traveled for 7 weeks this summer on a tour leading worship for camps and missions groups and I spent a lot of time in DADGAD tuning on my T5. From time to time I would need to go back to standard tuning for a song or two which required me to either retune, or play my acoustic which is a Dean Exotica Andes. Although I love that acoustic and have had many good years out of it (it was my first guitar) it just sounds and feels so bad compared to my T5 (when amplified). So I decided I needed another dual output guitar that played as easily as the T5, and still sounded as good. I considered buying another T5, but didn't have the money. I considered a Godin LGXT, but didn't have the money. I considered an Anderson Crowdster, but didn't have the money. It seemed that there was a common thread at work here. I started looking at lower budget guitars and decided that my options there were not only very limited, but the quality seemed lacking also. The Godin A6 crossed my mind, but I just didn't feel good about it.
Then I remembered my Epi G400 sitting at home and the L.R. Baggs T-Bridge I'd seen at Stewart MacDonald and I had my plan. The Epi was a used guitar I bought from the local mega music center. I had received a $100 gift card for credit card rewards, and they were asking $198 for it. It was used, well, more like pre-purchased, because it still had the factory plastic on the pick-guard and back electronics cover. I paid $114 and walked out feeling like I'd gotten a deal. I took it home and did a thorough setup on it. I took it to a gig and let my lead guitarist play it. He offered me $300. Over the course of a few months I had several different players offer me anywhere from $250-$500 for that little SG. It's my experience that Epiphones are great guitars for beginners and hobbyists, but every so often you run across one that's incredible. This was one of those guitars. So I decided to chop it up.
I started researching and found no information from anyone who had done a T-Bridge install on an SG, so I decided after I'd started the process that I would do a writeup myself. That's why the pictures start a little late in the process. Here we go:
In the case after leaving the store:
The first step was to open the package and all the contents, which I don't have a picture of.
Next I removed the pick-guard, back electronics cover, bridge and knobs. The first volume knob was broken when I bought the guitar:
So I knew I was going to need something to remove the rest without breaking them. I purchased the knob remover from Stewart MacDonald for $8. Definitely worth it.
Removing the knobs is very straight forward and easy with the remover. Just slide the ring up, slip the tabs under the edge of the knob:
Slide the ring down:
And lift up to remove the knob:
The new bridge came with new threaded posts and threaded inserts for the body. I had assumed that one of a few things would be true: either the new T-Bridge would drop directly down over the old posts, the new threaded posts would be the same size and thread as the old threaded posts, or the inserts for the new posts would be the same size as the old inserts. None of these were true. The new posts were much smaller in diameter than the old ones, which prevented the T-Bridge from mounting on the old posts. The threads on the new treaded posts were tiny compared to the old ones, which prevented them from threading into the old threaded inserts in the body. The new Threaded inserts were tiny compared to the old, so if I had removed the old, I would have been left with very big holes and very small inserts. The instructions that were included were nothing more than a warning that the T-Bridge should only be installed by a trained professional and a wiring diagram for the summing board. I was pretty quickly at a loss until I noticed that the O.D. of the new threaded inserts was only slightly smaller than the I.D. of the old threaded inserts. I have no idea if it was designed this way or not, but I know I was faced with a decision. I could hammer the new inserts into the old ones and know there was no turning back, or go for a much more drastic approach and remove the old ones, fill the holes, drill new holes, then press the new inserts in. I went for the quick and risky option. (This whole process was before I had decided to chronicle the process, so I apologize for the lack of pictures.) They fit right in:
Closer detail:
Size comparison between the old threaded posts and the new:
It's important to know that I had already measured and compare the spacing of the posts of the new bridge verses the old. I knew that the spacing would work out when I made the decision to press the new inserts into the old inserts.
It was now time to drill the hole for the wires from the piezo pickups in the T-Bridge. Each pickup has it's own wire, so there are 6 wires in total. I decided to drill the hole directly below the center of the bridge to minimize the visual impact of the new bridge and hopefully hide everything.
The posts were spaced at 2 15/16" between centers, which gave me a center of 1 15/32":
Halfway between the 7/16" and the 1/2" mark is 15/32"...ish:
I then measured to the center of the bridge posts from the edge of the pickup cavity (which I had removed) and matched the center mark at 11/16":
It's important to use the right tools on something like this. A bradpoint bit is a drill bit designed for use in wood. It has a sharp point (hence it's name), but it also has raised cutting edges to ensure sharp cutting surfaces for the wood fibers. A standard point tip drill bit is made for metal and though it will work for drilling wood, a brad point gives a straighter, cleaner hole:
After cutting through the finish and top veneer, I angled the bit towards the pickup cavity. A pretty steep angle is necessary to help the wires feed without kinking or too many sharp bends as they have very thin insulation:
Using my finger to show the approximate depth of the hole. I was actually slightly below the bottom edge of the pickup cavity at this point, but was already at the sharpest angle I could manage without having the hole show beyond the edge of the bridge:
I then drill from the inside of the pickup cavity out towards the hole I just drilled down from below the bridge and met the hole under the surface of the face:
Next I dressed the 6 wires through the hole 1 at a time until they were all 6 directed below the bridge and into the pickup cavity:
Pulled the wires through the hole as I pushed the bridge down onto the threaded posts:
A couple of closeups detailing the wire routing:
Next I routed the 6 acoustic pickups wires through the hole the magnetic pickup wire was wired into the main electronics cavity accessible from the back:
The view from the electronics cavity with all 6 Piezo wires routed:
WebRep
currentVote
noRating
noWeight
Some views of the face of the guitar with the humbucker back in place and the bridge mounted:
Now it was time to start installing the volume knob for the acoustic bridge, and the jack. The T-Bridge kit comes with a stereo jack and wiring instruction for wiring both pickups through the stereo jack. I had two problems with this installation: 1st - I hate that the jack sticks out the front of an SG. I know it's the way they're made and the way that they're supposed to look, but I don't like it. 2nd - even though I could have used a stereo to dual mono cable my T5 is set up to use a dual mono cable and I don't want to have to switch cables to switch guitars, or convert the T5 to stereo jack since both it's electronics systems are active systems and use stereo jacks for switching on the electronics already. So I decided to just use the old hole from the jack for the volume pot that came with the T-Bridge and add two jacks on the bottom of the guitar using LP style jack plates. It was slightly more work this way, but it suited my needs better. First I needed to remove the jack and prep the hole for the pot:
The original jack and all it's simplicity:
The hole that was used for the jack, that will soon be used for the Volume pot for the T-Bridge:
The O.D. of the jack was slightly smaller than the O.D. of the volume pot, so I needed to drill it out:
Because there was an existing hole I used a standard tip 3/8" drill bit to enlarge the hole:
The bit measured slightly less than .375" which is 3/8", but because of the way a drill bit walks a little bit I knew it would be sufficiently sized for the volume pot:
I started with the bit as centered as it would get itself because of the taper on the tip. I started with the bit out of the hole to keep it from tearing up the finish any more than was necessary:
The hole after being drilled:
A test fit of the volume pot:
A detail of the finish right around the hole. I expected the brittle nature of the finish to have some tear out and fortunately it wasn't so much that the washer, nut, and knob wouldn't cover it:
If you'll notice the the new volume pot for the T-Bridge does not fit flush into the old depressed section for the jack:
I could have taken a chisel or dremel to the inside of the cavity and made it a little larger, but in order to preserve the looks of the flat black cavity and frankly because it was much easier I decided to take the pot itself to the shop and hit it with the belt sander to knock off the excess of the board that was hitting inside:
Here's what the pot looked after a touch on the belt sander:
Installed from the backside, and front:
And with the nut installed. Notice the finish tear out is already covered up:
Now the next step was strictly optional for me. The old jack was slightly taller than the other jacks that I had. I decided that to keep the protrusion on the outside of the jackplate to a minimum I would go with the new jacks for both the acoustic and electric. A detail of the differences in height:
These are the jackplates I ordered from Stewmac.com (Stewart MacDonald). They're made for Les Paul style guitars, but I hoped I'd be able to make them work on the SG:
A dry fit of the jack into the plate:
The plan was to drill a hole big enough for the entire jack to fit through and let the plate cover any imperfection, so I measure it and the jack was just slightly smaller than .750, which it 3/4":
This is the mockup of the two jacks made by placing the jackplates in position and marking their centers with a pencil:
This is a 3/4' brand point bit. It's hard to grasp the scale of it unless you look at the neck of the guitar that's also in the picture. It's a big chunk of steel and works fairly well, unfortunately, it's a little wild to use and has a tendency to walk a little bit. This is unacceptable on such a project requiring such precision:
Instead of the giant brad point, I went with a forstner bit. A forstner is useful for drilling into uneven surfaces or when you need a precise hole. It has a sharp center point to start and then sharp cutting edges all around the diameter. The straight surfaces help to hold it straight in the hole:
The next few pictures show the progress of drilling with a forstner. It's a messy ordeal. I did most of this project on my guitar bench instead of in the shop so I enlisted my oldest son to hold the shop vac and capture all the sawdust after a bit:
All that work and now the jack won't fit it. The sections of board keep it from fitting smoothly into the hole. Unfortunately you can't just grab the next size forstner and size it up like you can with a standard drill bit:
I could have sanded or filed out the interior of the hole until it was large enough, but I chose to go back to the belt sander:
It fit now, so I drilled the other hole:
And now I had a new problem. The contour fit on one of the jack plates, but the body of the SG was just too flat for the second jack. I could have just gone with it and left a little bit of a gap, but I wanted it to fit a little better:
I put the jack plate inside of the nearest magazine and them put it in the bench vise to flatten it out:
It took a few tires and a lot of force, bit I managed to get it flattened out enough. Here's a comparison to the other one. I forgot to take a picture from the other angle, but it sits flat on the contour now:
It was now time to solder everything in place before mounting the jack plates. The soldering included the summing board for the piezo wires, the volume pot, and both jacks. In order to protect the body of the guitar I used the box that it shipped in to cover it: and the summing board:
Setup for soldering with flux and solder:
The first wire soldered on the positive side:
The negative (shield) side of the first wire:
2 wires done:
4 wires done:
All 6 piezo wires done, plus the 7th which takes the summed signal to the pot:
I forgot to take a picture of the shielding process which involved covering all the contacts with an insulator, and then soldering a copper shield over the top. I then wrapped it all with electrical tape to keep the shielding on the wires (which was bare metal) from shorting any of the other connections in the electronics cavity:
The shield of the wire serves as the negative side, so it is soldered on to the casing of the pot, which will be joined with the rest of the ground signal in the electronics cavity:
A jumper is soldered from the existing pots to the new one to carry a universal ground:
Two jumpers soldered on to the acoustic jack:
The old lead wire from the electrics magnetic pickups is soldered on to the new jack:
The hot lead from the acoustic jack is attached to the far right terminal on the pot:
Each jack is dressed and ready to install in the jackplates. I chose to put the acoustic on the top jack (when holding the guitar to play) since my T5 is set up the same way:
Each jack (starting with the electric) is then held in place, predrilled, and screwed down. One corner is predrilled and then a screw is put in. The opposite corner is next with the same process. Finally the other two screws are predrilled and put in place. The process is repeated for the second jack plate:
The finished electronics cavity just needs to be dressed and closed up:
A couple pictures of the finished volume pot and jacks, as well as the bridge and overall project:
It still needed to be strung and setup. I have finished all of that process and I must say I am completely in love. With just a little bit of processing (either through my A2.1u, or now through my iRig Stomp and the Peavey AmpKit App) you can get very bright and clean acoustic tones from the T-Bridge. The knobs allow for on the fly blending of signals into two signals on a P.A. or into my board as I intend. I will post a follow up in the next few days with more pictures of the final setup as well as a video of the guitar in action. I hope this will serve as a help should you be looking to make your SG sound like a J200.
The next step is to remove the outer nuts from the in/out jacks and the nuts that hold the pcb in place. A socket or wrench for both are necessary unless you're too lazy to walk across the room to the workbench so you just grab a pair of pliers and go to town. That works too. Then with a little bit of finesse and some prying on the case you can remove the entire PCB in one piece. 
