DOD 210 FET Preamp

Got a little simple boost/preamp for your Thursday. Should be a pretty easy fit in a 1590A. J113 alternatives would be J201, 2N5457, and probably a couple other JFETs that are obsolete. 😑

DOD FX91 Bass Overdrive

Always need more bass effects, right? This was one of the first bass ODs to have a clean blend. Should be an easy fit in a 1590B. Here's the schematic for reference.

DOD Carcosa

Happy Fuzz Friday, everybody! Here's a new fuzz circuit from DOD. It's a cascaded transistor design offering a wide range of tones with tons of output. Should be an easy fit in a 1590B.

DOD 230 Optical Noise Gate

Not a lot out there on this one. It's a optical noise gate DOD produced in the late 70s and works best at the beginning of your signal chain. The original had a very strange way of bypass switching, but I've omitted this as your true-bypass method of choice is probably much superior. Originals used a VTL5C2, but experiment with LED and LDR combos, and possibly the value of the resistor feeding the LED (10k right above the LDR and Q1).

The Drivestortion Project

I really enjoyed making the Big Muff Project file a couple months ago and thought it would be fun to make a similar project based on the MXR Distortion +/DOD OD250 circuit (in an attempt to combine the 2 names I call this project the Drivestortion). This circuit was also cloned by other pedal manufacturers (apparently this was the Timmy of the 70s), so the project provides component values for a couple of these as well. Let's start with the schematic:

This is the basic circuit for several versions of the DOD OD250, the MXR Distortion +, the Ross Distortion, and the DeArmond Square Wave, just to name a few. The only difference between all these is differing component values (and sometimes not even that). The component names from the above schematic follow those in the layout drawing below.

For a full BOM for 6 different versions of this circuit, download the linked file below. In addition to the BOM, it contains scaled transfers for etching your own circuit board and a scaled drilling template for building the effect into a Hammond 1590B enclosure.

Effects Layouts' Drivestortion Project

DOD FX25 Envelope Filter

The FX25 was initially produced by DOD in the early 80s and is an OTA-based envelope filter/auto-wah. It's a fairly tweakable and you can find various mods on other sites, but this is for the stock layout. The original switching circuitry has been removed, so you can use true-bypass. An LM1458 is listed in the layout below, but just about any dual op-amp should work there (TL072, NE5532, JRC4558, etc.), so if you get a little distortion, try a different op-amp.

Update Aug. 10, 2016:

I've fixed the layout as per NapAlpha and Eduardo's comments below. Thanks for catching that guys. Sorry it took me so long to make the fix.

DOD 280 Compressor

The DOD 280 was DOD's first compression pedal made in the late '70s through the '80s. A great sounding compressor, this fairly simple circuit uses an LDR and LED combination (in the form of a VTL5C2) to compress the signal. This one's laid out for on board right angle PCB pots, mounted from the solder side as per usual). I've added polarity protection and power filtering, as well as an input pull down resistor. You can use a VTL5C9 or CLM6000, or a good ol' 1M dark resistance LDR and an LED in heat shrink in place of the original VTL5C2.

DOD Studio BiFET Preamp 410

The original DOD units had "balanced" XLR output as well as the normal 1/4" jack and no footswitch. This has been adapted for stompbox use and could work well with acoustic guitar.

DOD FX55 Distortion (2-knob version)

Last post of 2014. Happy New Year, everybody!

Here's the early 80s DOD FX55 Distortion, without the original switching circuit so you can wire it for true bypass. The original used a TL062 dual op-amp, but the 2nd half of it wasn't in the signal path all, so I went with the single TL061. The off-board wiring pads aren't as neat as I'd like, but I wanted it to fit in a 1590a.

You could fairly easily use this same layout to make the DOD FX50 overdrive with the following mods:

• Change the 1k resistor to 4.7k
• Change the 3.9M resistor to 1M
• Place a 1n capacitor between lugs 1 and 3 on the Level pot

DOD Overdrive 250 Grey Spec

Here's the grey spec DOD Overdrive 250 that fits in a 1590a enclosure. You could also build a yellow spec 250 or the MXR Distortion + with this layout. Just compare the schematics and value swaps.