The Carl Martin Ottawa Vintage Optical Envelope filter is a compact modulation pedal, an envelope filter in the auto-wah family: it sweeps a filter automatically in response to your playing dynamics rather than waiting on a foot treadle. Guitar World reports that it aims to deliver psych-inspired auto-pilot wah sounds, ranging from '60s psych sounds to '70s disco tones1. It belongs to the broader family of filter pedals, which also take in wah-wah pedals and their relatives.
How it works and what it does
An envelope filter responds to the shape of your signal: play harder and the filter opens further, which is what produces the automatic wah character. The Ottawa does this with what Premier Guitar's review of the related Optical Envelope Filter describes as an analog optical circuit: "you can manipulate the wave envelope with an analog optical circuit"2. As that review puts it, "Add this control parameter to a filter and you get an optical envelope filter"2.
Controls and filter modes
The Ottawa keeps its control set small, which is typical of the design.
| Control | What it does |
|---|---|
| Mode switch | HP, BP and LP, High Pass, Band Pass and Low Pass, aiming to deliver a holistic library of wah sounds1 |
| Tone | Tweaks the high cut filter1 |
| Level | Sets the pedal's volume1 |
The three filter positions change the character of the sweep considerably. Guitar World notes that "The Low Pass setting also means the pedal can be used with a [bass guitar]"1, which widens the pedal beyond six-string use.
Where it came from
The Ottawa is a beefed-up version of Carl Martin's pre-existing Optical Envelope Filter1, an envelope filter pedal that Premier Guitar reviewed and found that "Carl Martin's new envelope filter works brilliantly on this account"2. That earlier pedal carried a street price of $135 in the Premier Guitar review2.
No official US price had been confirmed for the Ottawa at the time of its September 2021 announcement, according to Guitar World1.
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Questions
Can you use the Carl Martin Ottawa with a bass guitar?
Yes. According to Guitar World, the Low Pass setting means the pedal can be used with a bass guitar as well as guitar. The Ottawa's three-position filter switch covers High Pass, Band Pass and Low Pass, and the Low Pass mode in particular suits the lower range of a bass.
What filter modes does the Carl Martin Ottawa have?
The Ottawa has a three-position selector switch with HP, BP and LP settings, standing for High Pass, Band Pass and Low Pass. Guitar World reports that these three modes aim to deliver a holistic library of wah sounds, from tighter high-passed sweeps to the fuller low-pass response that works with bass.
What does the tone knob do on the Carl Martin Ottawa?
Guitar World explains that the Tone and Level knobs are responsible for tweaking the high cut filter and the pedal's volume, respectively. In other words, Tone shapes how much high end the filter removes, while Level sets the overall output of the pedal.
Is the Carl Martin Ottawa an auto-wah?
Yes, in effect. Guitar World describes the Ottawa as an envelope filter, or auto-wah, pedal that aims to deliver psych-inspired auto-pilot wah sounds. Instead of a foot-operated treadle, an envelope filter sweeps the filter automatically in response to how hard you play.
What is the US price of the Carl Martin Ottawa?
No official US price had been confirmed at the time of the Ottawa's September 2021 announcement, according to Guitar World. For reference, Premier Guitar's review of the earlier Carl Martin Optical Envelope Filter listed a street price of $135.
Sources (2)
- Carl Martin debuts streamlined Ottawa Vintage Optical Envelope filter pedal, Guitar World, 2021-09-22
- Carl Martin Optical Envelope Filter Pedal Review, Premier Guitar, 2012-05-02
