The DOD 690 Chorus is a chorus unit made by DOD Electronics in the late '70s, one of the company's higher-end products of that era and, by Vintage Guitar's account, one of its more obscure. It is a chorus and vibrato box with two footswitchable speed settings, stereo outputs for two amps, and an AC power cord rather than a battery. Vintage Guitar's February 2001 review compared it directly with the Boss CE-1 and found it a close match in sound with more control over the sweep1.
Controls and footswitches
The 690 carries the usual chorus controls, width and depth of effect signal, plus a lighted power switch. What sets it apart is the footswitching: dual speed controls that can be switched on the fly, a speed select footswitch to move between the two settings, and an effect on/off switch to turn the effect on or bypass it1.
| Control | What it does |
|---|---|
| Width | Sets the width of the effect signal1 |
| Depth | Sets the depth of the effect signal1 |
| Speed one | Set for a slow, subtle effect1 |
| Speed two | Set for a faster Leslie-type vibrato1 |
| Speed select footswitch | Switches between the two speed settings1 |
| Effect on/off switch | Turns the effect on, or bypasses it1 |
| Lighted power switch | Turns the unit on and off1 |
The two-speed setup is the heart of the unit. Vintage Guitar describes keeping speed one at a slow, subtle effect and speed two at a faster speed to achieve Leslie-type vibratos, with the speed select footswitch moving between them. An LED effect light turns on and off with the speed of the oscillation of the effect, giving a visual read on the rate1.
Power and stereo outputs
The 690 is an AC-powered unit with a heavy duty three-pronged plug, so it plugs into the wall rather than running on a battery or a pedalboard supply. For outputs it offers an A output and B output for running in stereo with two amps. Vintage Guitar found the unit gives warm, rich tones, especially with two amps1.
Because the 690 runs on AC mains power through a heavy duty three-pronged plug, it does not take a battery or a standard pedal supply. Plan for an outlet where you use it.1
What reviewers said
Vintage Guitar's February 2001 review is the main published account of the 690. The reviewer summed up its sound this way:
"The 690 offers nice, widespread chorusing sounds and shimmering vibrato tones."
The same review weighed the good against the bad:
"While the unit produces shimmering chorus tones and great vibrato, it can be a bit noisy."
On how it stacks up against the Boss CE-1, the reviewer found the 690 ranks right up there in terms of sound quality, and also offers the user a few more options to control the sweep. The 690 is smaller and built just as ruggedly, and although it can usually be purchased at a significantly lower price than the CE-1, it is usually harder to find. The fast speed setting sounds very much like the CE-1's vibrato setting1.
The review also pointed to modifications: taking out the RC-4558P op-amp chips (there are two) and adding a true-bypass switch. The reviewer's verdict was that if you don't mind spending a little extra for these mods, the 690 can be a really fine unit1.
Videos
Science of Loud
9277707
Audeath
Questions
Is the DOD 690 Chorus stereo?
Yes. The unit offers an A output and a B output, intended for running in stereo with two amps. Vintage Guitar's reviewer described the chorusing as nice and widespread, with warm, rich tones especially when using two amps.
Does the DOD 690 Chorus run on a battery?
No. Vintage Guitar describes it as an AC-powered unit with a heavy duty three-pronged plug, so it draws its power from a wall outlet rather than a battery or a pedalboard power supply.
Is the DOD 690 Chorus true bypass?
Not as built. Vintage Guitar's reviewer suggested op-amp and true-bypass switch modifications, saying that if you don't mind spending a little extra for these mods, the 690 can be a really fine unit.
What chips are inside the DOD 690 Chorus?
The unit uses two RC-4558P op-amp chips. Vintage Guitar's review points to these chips and to a true-bypass switch modification as the changes that turn the 690 into a really fine unit.
How does the DOD 690 Chorus compare with the Boss CE-1?
Vintage Guitar's reviewer found the 690 ranks right up there with the CE-1 in terms of sound quality and offers more options to control the sweep. The 690 is smaller and built just as ruggedly, usually sells for a significantly lower price, but is usually harder to find. Its fast speed setting sounds very much like the CE-1's vibrato setting.
Sources (1)
- DOD 690 Chorus, Vintage Guitar magazine, 2004-10-28
