Had a great time at DIY swap this year. The turn out was small. I managed to sell about 7 boxes. The Fuzz Faces were popular and went fast, they sounded great which may have helped. Also sold a tone Bender and a few other things.
My wife made me the most awesome bento box for lunch you can see in the picture below.
For some reason I thought it would be fun to build a guitar, from scratch. And, after a lot of self reflection and deep introspection, I’ve come to the conclusion that it is! Of course I have had to rationalize away all of the time and expense, but that’s another conversation.
Here’s a few pictures. There are two guitars and some wood to make a third. The first is a slightly modified outline from a Gibson Melody Maker. Which will either have three single coil pick ups, or two P90 types. The second is an LP Jr outline with a Telecaster style bridge and pick up arrangement. The two blocks of wood are alder for a third guitar. I’m in the process of trying to join these into a body blank.
Some years ago I bought some PCB for various synthesizer modules. I thought I would design some panels and build a few new modules. This is a first draft of a panel for Ken Stone’s Wave Multiplier CGS29. I have the first version. http://www.cgs.synth.net/modules/cgs29_wave_multiplier_v1.html
Millenium problesm all solved with the help of R.G. Who kindly pointed out that I probably didn’t have a path to ground on the out put of the effect. Which was exactly right.
After having the Millennium work so well on the SHO, I decided to add one to a Fuzz Face. This Fuzz Face is the First DIY guitar effect I had built. It was built around 2000. Back in the “olden” days it was hard to get 3PDT switches. I seem to remember buying a Fulltone labeled switch from Small Bear, that cost about $13 at the time! So the carling switch was the say to go for DIY.
This is really Joe Gagan’s Easy Face, which is essentially a Fuzz with variable input cap and Si Q1. This thing sounds pretty good, though I think when I first built it I didn’t get it. Now days I like a lot.
The problems with adding LED to this Fuzz Face is that the circuit is Positive Ground. Nothing a quick Google search can’t solve these days, Of course all paths lead back to the DIYStompbox forum where I found a simple solution using a PNP-2N3906.
Managed to get this working in less than an hour. I used 10K current limiting resistor with and a super bright Blue LED. The Bezel is from Mammoth Electronics. I like these bezels the little stopper is made of rubber and fits into the bezel well.
This has two booster in series in side. First is a NPN Range Master followed by a Sparkle Boost. The idea was Joe Gore’s. The two booster work well together. They each have their own flavor, and together get a good over driven sound.
The Range Master side sports a variable input cap. So this effect is a variable range boost, that goes from full range boost to treble boost. The other knob is gain.
The Sparkle Boost is a JFET boost by Andrew Carrol. This is a circuit that would make a good building block for a lot of projects. The First knob is gain the other is volume.
I built this over a year ago, and had originally omitted LED indicators. After playing this with the “band” LEDs were a necessity. The Range Master got a Blue on and the Sparkle Boost got an orange. The switches were 3PDT, and so already had the extra pole. The bigger problem here was drilling the box.
I decided to place the knobs on the side of the box. The reasoning being to avoid hitting them with your foot, and provide more real-estate for foot switches. After some use I find this makes the knows hard to read. Might be best to place them on top. Really the settings can all be done by ear. There seems to to also be some peace of mid to be able to look down and read the knobs without testing.
And of course the last mod would be the DC jack. Originally Joe had suggested this, and it wasn’t on my radar, so the build left a few things out. At this stage with everything assembled, the only place for the DC jack is between the knobs. Which is not a bad spot, but poses a potential awkwardness with DC plugs that have a 90 degree connector, like my One Spot. Should still work, and it will give me another excuse to update this blog.
I built this last week, see the previous post. Everything seemed fine on the bench. Today i gave it a test with the “band”. Seems like it is not working quite right. The LED lights when the effect is on. But, when the effect is off the light slowly turns on over a few minutes. Turning the effect on and off again resets the light. Not sure what is going, need to read the documentation over at GEOFX a few more times.
This is one of those things that has been around for a long time. Back in the olden days when the 3PDT switch was hard to get and cost as much as all of the other parts that went into a box. There was a need for a status LED that could be operated from a DPDT type switch.
Then there was the 3PDT revolution. The blue switches became cheap and plentiful. I had bought a few of the Carling DPDT switches before the revolution. Still having these around I threw one into an SHO clone. I figured I wouldn’t need an LED. Over time I found myself using this more often than anything else. I had built another with a 3PDT and an LED, but I gave this to a friend. You can’t let your friends run around using your products without and LED? They will start saying things to people like: “this thing is great, just wish it had an LED…”
So anyway, I finally decided I’d put an LED in my SHO, and of course I don’t have a 3PDT on hand! Which of course brings us back to the Millennium Bypass. I had never tried this before. I found a Vero layout, 4 by 5, on DIYStompboxes. Built the whole thing in 15 minutes. Worked like a charm!
The box I had was not originally designed for an LED. So I found some empty space and drilled a hole. I mounted the tiny circuit board from the LED, which was attached to the bezel.
I used a bezel from mammoth electronics. These look like many of the other chrome bezels of similar style. What’s nice about these is they have rubber, rather than plastic, plug to hold the LED in. This makes a nice tight fit and doesn’t leave you thinking it might come loose.
(Note sure what happened, but all of the pictures above seem to have imported upside down?)
Sounds like something from an old Bugs Bunny cartoon:
Though it might have appeared in a Warner Bros. production it could have easily added to a sound track.
This is the Snarling Dogs Mold Spore Psycho-Scumatic wah. We’ll call it the Mold Spore from here on out. It is a combination wah and ring modulator. Yep, you read that right, wah plus ring modulation.
For those of you who are not familiar with ring modulation a short description is in order.
Ring modulation, also known as balanced modulation, is a process that combines two signals using a mathematical function. The two signals are the input, your instrument, and the carrier frequency. The carrier frequency, in the case of the Mold spore wah, is an audio frequency generated inside the device. The mathematical function is the sum and the difference.
For example, imagine you played the note A 440hz and the internal carrier frequency is 600hz. Feed these both into the ring modulation circuit and it outputs:
1040 (440+600)
160 (440-600)
Generally speaking, this produces a non-musical tonal relationships. The classic sample of ring modulation you may be familiar with is the voice of the Daleks on Dr. Who.
The Mold Spore wah, not only provides typical wah sounds, it also provides ring modulation sounds and it allows you to control the carrier frequency with the treadle. You can actually have the wah and ring going at the same time and control both with the treadle, neat!
The Mold Spore wah sports several controls.
- Range, with three settings, White Room, Voodoo and Shaft. This sets the range of the wah effect.
- Preamp, which acts as a boost.
- Mix, mixes the source with the ring mod sound.
- Frequency, sets the carrier frequency.
There are two push button switches:
- Range, which sets the range of the carrier frequency to either a higher or lower frequency.
- Control which allows the treadle to control the carrier frequency or not.
The enclosure and general structure is pretty well made, very solid. The whole package is heavy and feels very solid.
Inside the wiring and soldering leaves a little to be desired. I’ve had the thing for some years and it still works, but have had to repair it a few times.
Recently, I broke it out for fun, and the ring mod was not working. After opening the box I noticed one of the chips had a hole, which looked to be burned from the inside out.
The chip was a MAX1044, this is a charge pump. The ring mod section probably requires +9V and -9V. The charge pump generates -9V from the regular +9V supply. This allows the mold spore to run off a standard +9V supply.
These chips also cost $2 to $5 ouch! Luckily I had a few in the parts bin. This particular chip was installed in a socket, where the other chips are soldered to the board, which suggests they had problems with this chip, or at list anticipating trouble. This made it easy to replace.
Anyway, I replaced the MAX1044 and the thing fired up immediately. He ring modulator working in all of its sonic glory. Of course the suspicion of something going wrong was in the back of mind. A quick check did not detect any chips showing any signs of over heating.
The Mold Spore runs off a 9V battery, but the charge probably drains the battery pretty fast. best to run this one from a power supply.
Sounds
The wah alone is a very usable. The three settings provide a lot of choice, though I find myself using White Room most often.
The boost is a nice added bonus. I wouldn’t use it just for the boost alone.
The ring modulation is not an effect you will find yourself using often if it all. Then again if you’re in the mood to make dissonant noises it could be just the thing you’re looking for.
As explained above the effect is based on a non-musical function. In general this is true. There are times when the ring mod will produce musically interesting tones. Being able to control the carrier frequency with your foot allows you to ”tune” the effect as you play. Admittedly his is not as easy as playing the wah by itself. The addition of treadle control of the carrier adds a significant dimension to the ring modulation effect.
The ring mod can also produce interesting and musical sounds if he carrier is tuned to a pitch that produces musical tones around a tonal center.
These ideas give you two strategies to using the ring mod. Tune the carrier with your foot, or tune the carrier to a note central to a musical phrase or section.
The ability to control both the wah and the carrier frequency with treadle at the same time adds another dimension. Using the wah with the ring mod works best when tuning the frequency of the carrier and not controlling the carrier frequency with the treadle. Then again controlling both with the treadle sounds pretty crazy.
The wah works well with other effects. I get great sounds putting fuzz before the effect. This creates a really synthy sound with a octave down type fuzz. We’re talking MXR Blue Box type effects.
The Mold Spore’s sounds are both capable and unique. The ability to control the carrier frequency with the treadle adds new dimension to the ring modulator.
Obviously it would be great if a schematic would lay itself out. Eagle and other applications have included Autorouters, that do just this, for years. In the case of Eagle this was a feature you had to pay for. Until recently, well recently in years. Of course the computer in this case can not do a better job than a human brain. That said it can do the job much faster.
Rock Box!
I was talking to a friend about distortion boxes and the Box of Rock came up. Which got me thinking, I’d never heard one before, and Z Vex always makes good stuff. I found a schematic in the usual place. It looked like a pretty easy build.
The Box is basically two pedals in series, a distortion followed by a booster. The Box has two foot switches, The first switch engages the distortion and the second engages the booster. The controls for the distortion are Gain, Tone and Volume. The booster adds a fourth knob, Gain/Boost.
The distortion section is made of three BS170 MOSFet stages. The first stage is a SHO followed by a Marshall style high pass filter made of a 470p cap and a 470K resistor in parallel. Then come two more BS170s configured gains of approximately 51 and 15.
Next is a BMP style tone stack followed by an extra low pass filter. The low pass filter is exactly the same as used in the BSIAB II. The BSIAB II also uses the same Marshall style, 470p and 470K, high pass filter between the first two stages.
The B of R includes an SHO booster on the output. I had one of these built already so i decided not to build the stock B of R and instead build just the distortion section. I figure I can place my SHO or any other booster after it for different sounds.