The Carl Martin Vintage Opto-Compressor is a compressor pedal from the Danish maker's Vintage line. Like all the Vintage pedals, it comes in a solid diecast housing with chicken-head knobs, in Carl Martin's CM color and graphics1.
It belongs to Carl Martin's Vintage series of pedals, and like all of them it comes in a solid diecast housing with chicken-head knobs and Carl Martin's own color and graphics1.
How optical compression works
An optical compressor performs gain reduction control via a light source into a photo sensitive cell. As the light source gets brighter, the photo sensitive cell sends a signal to reduce dynamic range1. In plain terms, the incoming signal drives a light, and the light's brightness tells the circuit how much to squeeze the signal, which is the character of optical compression as a design.
Controls
The pedal has four controls, each with a distinct job1:
| Control | What it does |
|---|---|
| Gain | Controls the "pre-glow" of the optical circuit; the more you turn it up, the fatter the sound |
| Attack | Takes the signal from transparent to outright total squeeze |
| Compression | Controls how hard or soft the compression is |
| Level | Controls the overall volume of the compressor |
The Gain control is the one that shapes the color of the pedal, since it drives the optical stage before compression. The Attack control sets how quickly that compression clamps down, from untouched to fully squeezed, and Level sets the output to match the rest of a rig1.
Power
The Vintage Opto-Compressor runs on 9V and has a 9V battery compartment1.
Because of the nature of compressors, Carl Martin highly recommends a regulated power supply or a large stock of batteries when using the compressor1.
Where it sits in Carl Martin's range
The Vintage Opto-Compressor sits within Carl Martin's Vintage line of pedals, which share the same solid diecast housing with chicken-head knobs, CM color and graphics1. For the wider category, see the site's page on compressor pedals.
What reviewers said
Premier Guitar's 2008 review is the published account of this pedal. Its reviewer laid out the optical circuit and the four controls, and passed along Carl Martin's own framing of the pedal: that "a short time with the Vintage Opto-Compressor will allow you to find some of those classic guitar sounds which may somehow have escaped you before"1.
Videos
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Questions
Does the Carl Martin Vintage Opto-Compressor take a 9V battery?
Yes. The pedal has a 9V battery compartment, so it can run from a battery as well as a DC supply. Because compressors are always working on the signal, Premier Guitar's review notes that Carl Martin recommends a regulated power supply or a large stock of batteries, since battery drain can be quick with this kind of circuit.
How does an optical compressor work?
An optical compressor performs gain reduction with a light source and a photo sensitive cell. As the light source gets brighter, the photo sensitive cell sends a signal to reduce dynamic range. That light-based approach is what gives optical compressors their character, and it is the circuit idea behind the Vintage Opto-Compressor.
Does the Carl Martin Vintage Opto-Compressor need a regulated power supply?
Carl Martin highly recommends a regulated power supply, or a large stock of batteries, when using the compressor. The recommendation comes from the nature of compressors, which are continuously shaping the signal, so a steady, clean supply is worth using rather than an unregulated or shared one.
What does the Gain knob do on the Carl Martin Vintage Opto-Compressor?
The Gain control adjusts the 'pre-glow' of the optical circuit. The more you turn it up, the fatter the sound becomes, so it shapes how much the optical stage is driven before the compression takes hold, working alongside the Attack, Compression and Level controls.
Sources (1)
- Carl Martin's Vintage Opto-Compressor, Premier Guitar, 2008-11-03
