Project – Power Conditioner

Here is the power conditioner I built.

The enclosure is a Bud CN-6702 from Mouser.  Paint is a botched Rustoleum hammered spray. I wanted it to be white, so I bought a can of their ivory hammered paint. It was junk. No hide ability, no hammering. It was like a blotchy transparent metallic white. I painted over it with one coat of the paint I used for my input and output buffers, and decided it was good enough.

This mounts on the underside of my board. There are two superbright white LEDs to show it is powered up, and provide some cool under-board lighting without creating glare.

There are two identical regulator circuits. My goal with that was to spread the load and the heat dissipation. I also thought that if I have two digital pedals that conflict and make power supply noise, I could put them on different regulators and hopefully stop the noise.

As a result, I am sure the filtering is overkill– I used a 1-Watt 3R resistor, two 470uF in parallel, and some ceramic caps on the input of each regulator, and 100uF and some ceramic caps on the outputof each regulator.

You might notice the diode inserted between the regulator pin connected that is supposed to be connected straight to ground, and ground. This is a little trick that lifts the voltage by the Vf of the diode. This way, my power supply puts out about 9.6V, or roughly a brand new 9V battery. This gives me a little bit of headroom, so I can use an R-C filter at the input of each of my pedals, and not worry too much about the voltage falling below 9V.

If you can’t tell, the power in my house is very noisy… heh.

Here are the project files. Included is an ExpressPCB Schematic and PCB file, along with a PDF ready-to-transfer image. Power Conditioner – Schematic, PCB, Toner Transfer [ZIP]

Questions? Comments? Criticism? Compliments?

Project – Output Buffer

Here is the out buffer I built. It is a standard non-inverting IC buffer.

The enclosure is a Bud CN-6702 from Mouser.  No LED, no bypass, but there is room in the enclosure for both if you decide to build one. Paint is Rustoleum hammered spray. I think it came out pretty good for my first hammered finish.

I am sure this will somehow be labeled as a Klon buffer, but it really isn’t. I did copy the two output resistors, but that is it. The rest is Opamp 101. Instead of the standard TL-072, I used a TLE-2072, which is an “Excalibur Low-Noise High-Speed” version of the TL-072, whatever that means. Any dual will work fine. I used the spare half of the opamp to buffer the bias voltage, and beefed up the power filtering. Other than that, it is pretty standard.

Here are the project files. Included is an ExpressPCB Schematic and PCB file, along with a PDF ready-to-transfer image. IC Buffer – Schematic, PCB, Toner Transfer [ZIP]

Questions? Comments? Criticism? Compliments?

Project: Input Buffer

Here is the input buffer I built. It is based on the Cornish buffer, with some additional power filtering and some minor part substitutions.

The enclosure is a Bud CN-6702 from Mouser.  No LED, no bypass, but there is room in the enclosure for both if you decide to build one. Paint is Rustoleum hammered spray. I think it came out pretty good for my first hammered finish.

I actually thought I had all the parts for this build, but it turns out I did not. I was short a couple of odd value resistors, so I made my own. Here’s a little tip. Let’s say you need a 7.5k resistor, and all you have is a 6.8k resistor. Grab yourself a small file, and start filing a spot in the middle of the 6.8k resistor. Once you break through the enamel, you will hit the actual resistor. Connect your multimeter’s test leads, and continue filing until you reach the value you need. When finished, cover the filed spot with clear nail polish. Works like a charm!

Here are the project files. Included is an ExpressPCB Schematic and PCB file, along with a PDF ready-to-transfer image. BJT Buffer – Schematic, PCB, Toner Transfer [ZIP]

Questions? Comments? Criticism? Compliments?

Three completed projects – Power conditioner, Input Buffer, Output Buffer

I will be posting about three completed projects today. They were all designed to integrate into my pedal board.

The first one is a power conditioner. It is a dual non-isolated regulated supply. I built this mainly to consolidate my power needs down to one box and one switch. I do plan on building an isolated supply in the future, but that won’t be happening for quite some time.

The second one is an input buffer. It is based on the Cornish buffer (bootstrapped BJT w/ filtering), but with more aggressive power filtering and some component substitutions.

The third one is an output buffer. It is a simple IC buffer, but I guess some people call it a Klon buffer. I fail to see how tacking a couple of resistors onto the end of one of an IC circuit that is so simple that even I understand it. Regardless, more power filtering, some component changes, and a higher end opamp.

My theory behind the buffers is that I am looking for consistency. I want my guitar to always see the same impedance, and my amp to always see the same impedance. I have built so many pedals at this point that there is no telling which pedal will be first in the chain, and which will be last in the chain, or how they will react with whatever guitar/amp combo I decide to play. I want my guitars, effects, and amps to work together in a predictable fashion.

I’ll be posting pictures of the completed builds, along with ExpressPCB schematic and PCB files, along with PDFs of ready-to-transfer images.

More to come!

Tap Tempo Tremolo – Build and History

Well, I finally did it. I built a tap tempo tremolo! It has been a long time coming.

I am going to first show off my build, and then give a little bit of history on the whole line of DIY (and some commercial) tap tempo tremolos, from my perspective.

What I have made is a Tap Tempo Tremolo based around a board I got from Taylor over at MusicPCB.com. It is built into a repurposed Akai Variwah enclosure.

The top middle knob, the toggle switch, and the treadle work together. When the switch is in the Up position, the treadle controls the Speed, and the top middle knob controls the Wave Distort. When the switch is Down, the treadle controls the Wave Distort, and the top middle knob controls the Speed. Of course, you can also tap out a speed with the Tempo switch.

The treadle uses the potentiometer from the Variwah, which is some sort of a custom dual gang pot. It is setup so that it is matched perfectly to the range for the treadle mechanism. Both gangs are linear. When I was testing, I found that the treadle’s linear taper was great for the Wave Distort function– the middle of the treadle was the center. For the speed, though, the fast portion was bunched up in the last few degrees of the treadle. I ended up paralleling a trimpot with one of the gangs of the pot, and adjusted the taper to my liking.

The Shape and Multiple controls are rotary switches. I never liked the idea of using a potentiometer for these settings. Rotary switches are accurate, with no guesswork involved.

The plates are regular ol’ copper clad from Tayda, treated with liver of sulfur. The switch plate and the the treadle plate are secured to the enclosure with JB Weld. It was a bit of a challenge to get the switch plate bent to the contour of the enclosure, but it came out okay. The knobs eventually will be switched out to something nicer, or at least something that matches.

I wanted to do something unique for the LED arrangement. I used a CMOS IC to buffer and filter the PWM from the TAPLFO. The signal is sent to an LM3914 IC, but is first adjusted from 0-5V to a range that works well with the LM3914. It took a lot of trial and error, but the 10 LEDs light up in time with the effect. Those LEDs, and the indicator LED, backlight the plate, and it looks really cool.

This was a very difficult build, requiring a lot of planning and a lot of detail work. It was challenging and fun, but I am glad it is done.

And now, a bit of history on DIY Tap Tempo Tremolos.

Sometime back in 2008, when I was just getting into effects, I started researching tremolos for a multi-effects board I planned on building. In my research, I found the Tremulus Lune. I could understand how the audio path worked, but the LFO was beyond my knowledge.

Around the same time, I found the VCLFO. It is a microprocessor-based LFO created by Tom from Electric Druid. I could understand the VCLFO– feed it values between 0 and 5V, and it alters the waveshape it outputs. I decided to hack them together.

I had no clue how to burn Tom’s code to a PIC, so I enlisted a friend of mine Ed for advice. He is a senior electrical engineer at a big company back in Illinois, and has been a huge help in my quest for electronics knowledge. He often points me in the right direction so I can learn whatever it is I want to learn, but in this case, he offered to burn the PICs for me.

We all know the adage when trying to get something: Cheap, Fast, Right– Pick Two. In this case, it was cheap and right. After months of polite nudging, Ed assigned the burning of my LFO chips to a junior engineer at his company, who burned me five of them.

I did a ton of research while waiting for the chips, and started breadboarding as soon as I got them. I ended up with a design that almost worked. I had one little problem, and Tom helped me out through email. I also was concerned that running multiple LEDs off of the PIC could exceed the PIC’s maximum current, so Ed scratched the transistor buffer on a napkin while he was here on vacation.

I finished my design and released it to the public in June of 2009. People seemed to like it, but I don’t think anyone built one. That’s ok, though, because Tom liked it. He thought my use of a photocell to clean the PWM was simple and elegant. He asked to use my schematic for the VCLFO Tremolo Application Note, and I, of course, agreed.

Some time passed, and Tom posted over at DIYSB that he had started working on a tap tempo version of his VCLFO. I jumped in to the development topic, of course, being the only person who had used the original VCLFO. Tom was great about the development, and incorporated pretty much every suggestion from the community. The community even pitched in on some of the coding (Wave Distort was implemented by Chris Saffi, if I recall the name correctly). Tom eventually released the TAPLFO, and a ready to go tremolo schematic that pretty much matches my original VCLFO schematic. It was so cool!

Some time passed, and Taylor over at DIYSB started a topic to build a tap tempo tremolo. Several ideas were proposed, but the end decision was to use the TAPLFO. One of the key factors was that it was open source and free to use. It didn’t hurt that there was already a completed schematic.

Taylor designed his board, and made an arrangement with Tom to sell them with TAPLFO chips. He released his board (still available), and also the Iron Ether Cygnet (discontinued, I think). At one point, he was worried about using my design for a commercial project, but I think it is great that I played a part in the evolution of tap tempo tremolos.

The TAPLFO has gone on to find its way into a bunch of commercial tremolos, including the Catalinbread Semaphore, and a bunch who I suspect are using the TAPLFO without Tom’s permission.

In parallel to all of that, I had at some point sent a crystal and one of the five VCLFO chips that Ed had made for me to Rick (Frequencycentral), across the pond in the UK. Rick was heavily into phaser development at the time, and I thought he might have some fun with the VCLFO and phasers.

Rick sat on the chip for a while, but when he started using it, great things resulted. Rick has been using (I think) both the VCLFO and TAPLFO to make synth modules. I think he is selling commercial designs and keeping with the DIY spirit by releasing his designs.

So there you have it. My little role in the history of DIY tap tempo tremolos. If you made it this far, thanks for reading!

Quick Review – Darren Riley’s Guitar and Amp Shop – Raleigh, NC

I just wanted to do a quick little review on a parts supplier I recently found– Darren Riley’s Guitar and Amp Shop in Raleigh, NC.

I was in the market for a replacement bridge for my Squier VM Jazzmaster. The stock bridge uses the threaded-type string saddles, and I have a heavy enough technique that the strings kept moving on the saddles. I found a replacement bridge– Fender # 0081239001, Bridge w/ posts Mustang Chrome.

Darren had the item at a good price, and shipping was reasonable, too. I figured it would arrive fast, since Darren’s shop is just two states away.

Darren was really helpful. I wanted to make sure the bridge would fit, so I emailed to ask if he could take two measurements for me. I emailed him at 2:09PM on a Saturday, he emailed me back with my answers less than an hour and a half later, and I placed my order about an hour and a half later. Now that is great service– I didn’t expect an answer until Monday.

He sent my order out on Monday, and it arrived today, Thursday. The item was exactly as expected, and well-packed with bubble wrap and foam peanuts. He even included a couple of picks.

Overall, everything about this order was perfect, and I will not hesitate to order from Darren when I need parts in the future– and I will need parts in the future. There are a lot of online merchants who could learn a thing or two from him.

Darren Riley’s Guitar and Amp Shop – Raleigh, NC

Fender Precision Bass Jr.

I just picked this up for Jaime from a local pawn shop. Great price, too.

Agile AL-2000: Gloss / shine removal

Here are some before and after pictures of the de-glossing / shine removal that I performed on my Agile AL-2000 Honey Sunburst Flame (Wide):

Before:

Agile AL-2000 HSBF Wide, Before De-glossing

Agile AL-2000 HSBF Wide, Before De-glossing

Agile AL-2000 HSBF Wide, Before De-glossing

Agile AL-2000 HSBF Wide, Before De-glossing

Agile AL-2000 HSBF Wide, Before De-glossing

Agile AL-2000 HSBF Wide, Before De-glossing

After:

Agile AL-2000 HSBF Wide, After De-glossing

Agile AL-2000 HSBF Wide, After De-glossing

Agile AL-2000 HSBF Wide, After De-glossing

Agile AL-2000 HSBF Wide, After De-glossing

Agile AL-2000 HSBF Wide, After De-glossing

Agile AL-2000 HSBF Wide, After De-glossing

I think it looks pretty good– much more like a wood guitar than a plastic toy. I would be happy to detail the process. If anyone is interested, just ask!

DIY Pedalboard Build Pictorial

In an earlier post, I posted some images of the DIY pedalboard that I just finished. I’m going to go into more detail here, in case anyone would like to build their own. It was really easy, inexpensive, and a lot of fun.

Materials
5x Poplar “Hobby boards”, 2.5″ x 24″ x 1/2″ (Home Depot) [<$5]
1x Poplar board, 3/4″ x 1.5″ x 69″ (Home Depot) [<$5]
3x #8 – 1.25″ wood screws, 10 pack (Home Depot) [<$3]
6x 1.5″ wood screws (already had, any wood screws around that length will do)
Formby’s Tung Oil Finish (Lowe’s) [~$5 or so]
Elmer’s wood glue (already had)
1x Velcro, Industrial strength, 2″ x 15 yards (Amazon) [$22 or so]

Tools
Electric Drill
Philips screwdriver / screwdriver bit
Drill bits to pre-drill holes for both screw types
Countersink bit (could use bigger drill bit)
Hand saw / mitre box
Random orbital sander and paper (could sand by hand)
Rags

Assembly

First, here is the SketchUp file for the project. It includes all of the wood pieces, in the proper dimensions and in the proper locations. The drawing is accurate to my build.

Pedalboard Design – Final [ZIP of SketchUp file]

As you can imagine, assembly is quite easy. The first thing I did was to assemble the supports. I cut the 3/4″ x 1.5″ board into six pieces– 3x 17.5″, and 3x 5.5″. The smaller pieces sit on top of the larger pieces, flush on one end. Each support is held together with two wood screws that are hidden underneath the two slats that make the top shelf. The screws are sunk below the surface so they don’t interfere with the slats. I used wood glue between the two pieces. Not pretty, but I used what I had.

Support components

Pre-drilled poplar support components, ready to be screwed and glued.

You’ll notice that in the image above, I have already pre-drilled the holes for the screws that secure the slats to the supports. You will have to check the SketchUp drawing for the proper spacing and layout. The slats overhang the front and back edges of the supports by 1/4″, and the screws that secure the slats are 5/8″ from the edge of the slat. I can provide exact measurements if anyone needs them.

Supports - glued and screwed

2-piece poplar pedal board supports, glued and screwed together.

Once the supports were glued and screwed together, I got to work on the slats. They come pre-cut to 24″, so I only needed to drill and countersink holes. In fact, it was so easy that I do not have any pictures of them until the pictures of the finishing process. Needless to say, you have to drill and countersink six holes in each slat, making sure they line up with the pre-drilled holes in the supports.

From there, I sanded everything using a random orbital sander. I used 220-grit paper, and it was easy work. I then quickly sanded it by hand using 400-grit paper just to get it a bit smoother. Ready to apply the finish:

Pedal board components, ready for finishing

Pedal board components, ready for finishing.

This was my first time using a tung oil finish, which apparently contains very little actual tung oil, if any at all. It was really easy. All I did was wipe it on with an old sock, like waxing a car, until it was covered. Simple.

At first, I was drying them on some styrofoam with nails poked through it, like in this shot after the first coat:

Pedal board slats with tung oil finish, first application

Pedal board slats with tung oil finish, first application.

But I realized that I needed a better solution. I used a wire coat hanger, three plastic coat hangers, and a portable wardrobe rack to hang the pieces. Here is a shot of it after putting 3 coats on the supports, and 5 coats on the slats:

Pedal board components drying on rack

Pedal board components drying on rack.

One thing to note is that between coats, you are supposed to use steel wool to take the sheen off of the finish. I used a plastic steel wool replacement that I picked up at Home Depot. It is the equivalent of fine steel wool, and worked great. It only took about a half a minute of scrubbing per board, so it was a pretty quick process.

After I had put six coats on the slats and four coats on the supports, I assembled the pedalboard. Once assembled, I put on two more coats of finish. I screwed a hook into the bottom for hanging during the final dry:

Pedalboard, assembled, final finish coat

Pedalboard, assembled, final finish coat.

I let the pedal board hang for a day. The finish was drying nicely when I, for some reason, decided to re-read the Formby’s container. It said that drying could be sped up if you used artificial light. I did some quick research, and the finish apparently polymerizes quicker under artificial light. So, in preparation for the Velcro, I placed the board under fluorescent light for two days to cure:

Finished pedal board curing

Finished pedal board curing.

From there, all I had to do was wipe the slats down with some naptha (zippo fluid), and stick on some industrial strength Velcro. I used the actual Velcro brand. Usually my thriftiness would have me buying knock off hook and loop from 3,000 miles away, but I wanted guaranteed quality.

Here is the final result:

DIY Pedal Board - Angle 1

DIY Pedal Board – Angle 1

DIY Pedal Board - Front

DIY Pedal Board – Front

DIY Pedal Board - Side

DIY Pedal Board – Side

And there you have it, my DIY pedal board. I think it turned out pretty good. At under $40, I think it was a pretty good value. I plan on building a power supply to attach underneath the top level slats, attaching a handle, and calling it complete.

It was fun to build, and seems like it will be durable for years into the future.