The Discomfort Designs Spectrum Overdrive is a hand-wired mid-gain overdrive box that Pedal of the Day places "in the family of hard-clipping [distortions]"1. It is built on the circuit of the 1981 Inventions DRV, an overdrive and distortion pedal, and Pedal of the Day's later review of another Discomfort Designs pedal refers to it as "their 1981 DRV-inspired Spectrum Overdrive"2.
What it does to your sound
Pedal of the Day describes the Spectrum as covering "a wide range of dirt tones, from slightly dirty boost to a brutally gorgeous distortion, and all kinds of in-between"1. The reviewer's verdict on the circuit's response: "The awesome result is a spacious headroom that gives life and energy to low and mid gain settings."1
Because the clipping is hard rather than soft, it sits on the distortion side of the overdrive family rather than alongside soft-clipping designs like a Tube Screamer. For a sense of how the two approaches differ, see the comparison of the Boss SD-1 and Ibanez TS9, both soft-clipping overdrive pedals, against the distortion pedals family the Spectrum is described as belonging to1.
Controls
| Control | What it does |
|---|---|
| Distortion | Sets the drive amount; Pedal of the Day calls its range "inspirational" and says it "works hand-in-hand with the Cut control"1 |
| Cut | A wide-sweeping low pass filter that shapes the pedal's top end1 |
The 1981 DRV circuit and the charge pump
The DRV the Spectrum is based on is an overdrive and distortion pedal from 1981 Inventions3. One feature Pedal of the Day highlights on the Spectrum is its power arrangement: "an internal charge pump, taking a standard 9V power supply and doubling the voltage"1. The pedal runs from a standard 9V supply; the charge pump raises the voltage internally before it reaches the circuit1.
On the DRV circuit, the independent technical analysis at Tagboard Effects notes a detail relevant to anyone building or servicing this kind of circuit: the charge pump chip must be the 'S' variety, for example a 1044scpa, because "the chips without the 'S' will emit a high pitched noise"4.
The Spectrum is hand wired with high quality parts in a heavy-duty 1590 BB enclosure1.
Videos
Pedal of the Day
StorehouseSilo
Questions
What circuit is the Discomfort Designs Spectrum Overdrive based on?
Pedal of the Day describes the Spectrum as a 1981 DRV-inspired design. The DRV, made by 1981 Inventions, is an overdrive and distortion pedal, and the Spectrum takes that circuit as its starting point while adding its own controls and an internal charge pump.
What does the Cut control do on the Spectrum Overdrive?
Cut is a wide-sweeping low pass filter. Pedal of the Day notes that it works hand-in-hand with the Distortion control, so you shape the amount of drive and the top end of the pedal's response together rather than treating them as separate settings.
What does the internal charge pump do?
The Spectrum has an internal charge pump that takes a standard 9V power supply and doubles the voltage inside the pedal. Higher internal voltage generally means more headroom for the clipping stages to work with.
Is the Spectrum Overdrive hard-clipping or soft-clipping?
Pedal of the Day places the Spectrum in the family of hard-clipping distortions. It is described as a hand-wired mid-gain overdrive box, so the clipping happens in a hard-clipping arrangement rather than the soft-clipping style found in many overdrives.
Sources (4)
- Discomfort Designs Spectrum Overdrive, Pedal of the Day, 2021-04-17
- Discomfort Designs Glow Cloud Toxic Delay Device, Pedal of the Day, 2021-05-14
- 1981 Inventions DRV Overdrive Distortion, Pedal of the Day, 2018-09-28
- Guitar FX Layouts: 1981 Inventions DRV, tagboardeffects.blogspot.com, 2019-07-04