Archive for March, 2012

Digital Reverb (Accutronics BTDR-2H)

First of all, let me say this. I love my amp. It has great tone, and breaks up at a friendly volume level. But it lacks one thing that I rely on to cover up my (many) mistakes: Reverb. I didn’t want to just build another pedal. I wanted this project to be a special one. As I keep reverb turned on 85% of the time I thought instead of building a pedal (that would take up valuable board space) why not build a little unit to sit on top of my amp. Influenced by the lovely Fender tube-based spring units that sit on top of your amp I set out to create my own little op amp and digital circuit.

I purchased an Accutronics BTDR-2H digi-log reverb from a friend from over the pond and the rest of the parts from local suppliers. I based my design off a vero layout found at Sabrotone.com. While his design was originally designed for the BTDR-1 Brick, I was able to modify it with help from the brick’s designer, Brian Neunaber. Brian was a fantastic help and answered my E-mail within one hour (very impressive to say the least).  As I was using a DPDT toggle for the switch I used a Millenium 2 bypass wiring to enable the use of an LED.

Accutronics BTDR-2H Vero

Red text shows the correct pinout for the BTDR-2H rever brick.

Since it was going to be sitting on my amp I wanted it to have more of a visual impact and instead of using a small enclosure I decided to go big with a Hammond 1590T die-cast box.  This left me with plenty of workspace and I had no problems fitting all the components nice and neat. Here’s what it looked like when I was just finishing up with the heatshrinking and cable management and such.

You’ll see I used sockets on the reverb module. These bricks come in Short, Medium, and Long decay models. I’m using a Long decay module, as, well, like I said, I like reverb.

Remember when I said I wanted this build to be epic? Well to really test my patience I decided to cover the enclosure with Tweed tolex, much like vintage fender amps. I purchased a small amount of the authentic material (I found out that many of the suppliers online sell a vinyl simulated tweed – Do not want) and began measuring and cutting. I won’t post a tutorial here, but one of the most difficult parts is making sure that thepattern in the corners line up just right. I somewhat suceeded in this, but hey, it was my first try.

After doing a bit of research I decided on coating the tweed with several thin coats of Minwax Polyshades Honey Pine. This is a stain/poly mix that will protect while it stains. I used 4 coats and wetsanded afterwards. I wasn’t too particular about getting exactly even coats as I wanted this reverb to look like it’s been through years of gigs and tours. Here’s the final result. I really should have taken more pictures of the process…

It fits nicely on top of my small 5F1 clone, and sounds beautiful, with no digital artifacts or loss of volume. I was surprised that this quality of sound was available from a small digital circuit with just a few ICs and parts. For anyone looking to build a reverb, those little bricks are highly reccomended.

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Modified EA Tremolo (Runoffgroove)

Today we’re going to look at a perfboard layout for one of the more popular DIY Tremolos out there. Originally published in Electronics Australia magazine this tremolo can be found as the basis for many boutique and DIY Tremolo pedals. For this build I decided to try the layout posted at runoffgroove.com. Working with perfboard is a little bit different than working with Vero board. It requires a bit more planning (in my opinion) and you have to be confident with your soldering capabilities. Anyways, here’s the layout I used.

As I rarely use perfboard I was happy when the pedal fired up the first time I plugged it in. One of the nice modifications to this layout is that the LED pulsates with the tempo of the effect. I added an additional LED just to show status (on/off) as the rate LED stays on regardless of the pedal’s operation. The board fits nicely into a Hammond 1590B box. I chose not to add a battery jack as I rarely use batteries in my setup. It’s not my cleanest wiring job, but it’s far from my messiest.

Finally, here’s the finished enclosure. I used rattle cans for the basecoats, and while cost effective, it is a far inferior finish than powdercoating the enclosure. I couldn’t think of a clever name for this build so I chose to leave the image as is.

It’s a great little pedal. The volume control is a great addition as I’ve found that some trems have a slight volume loss when engaged. As well, with the depth control at zero and the volume at 11 this pedal doubles as a decent clean boost. Bonus! I’ll have a few interesting posts coming up in the next few weeks, so stay tuned!

Lovepedal Woodrow (Electra Distortion)

Today we’re going to look at a Tweed-amp-in-a-box pedal called the Lovepedal Woodrow. It’s based off of the Electra Distortion circuit, which you can see below.

As you can see, it’s a simple one transistor design that uses two diodes for clipping. The original circuit calls for a silicon 1N4148 diode and a germanium 1N34A diode. But as you all may know there are countless options for clipping diodes, and this is a great circuit to experiment with (Once again, sockets are your friend). And here’s the vero layout I used.

Lovepedal Woodrow Vero

Socket those diodes!

The Lovepedal Woodrow is one of the many Lovepedal designs based off of the Electra circuit, but has several component changes. It was designed to emulate the tone of a cranked Fender 5E3 Tweed Deluxe amp. While I don’t think the pedal matches that description accurately, it does have some tweedy characteristics and is a great OD pedal that works with your amp to get that ragged glorious tweed tone.

Anyways, back to diodes. By adding sockets to the veroboard changing diodes is a snap. I tried out 1N914 (1N4148 is very similar) silicons, BAT 46 schottky, 1N4001 rectifier, 1N60 and 1N34A germaniums, and several different types of LEDs.

Some of the diodes used in my Lovepedal Woodrow

After spending an afternoon testing out diodes and watching hockey I decided that I preferred a silicon germanium combo (1N914 and 1N34A) and that BAT46 and LEDs really do not mesh with this circuit. It’s funny how the pedal took around 90 minutes to build and I spent far more time tweaking it with different diodes. Here’s a gutshot for those interested.

It’s a nice clean build that would even fit into a 1590A enclosure. Finally, for the graphics and pedal design I wanted to keep it clean and nice and tidy (much like the insides!) Using my high tech paint studio (unheated garage and rattle cans) I used silver hammertone paint. Originally I planned on using a graphic of Gordie Howe from the Simpsons (internet high five if you get the reference) but alas I finally decided on just adding my name at the bottom. A stupidly bright blue LED completes the pedal. As for naming it I think the Woody Laboratories Woody would be a little bit odd, so we’ll just call it Tweed.

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