COMP-1 | Bass Player (September 2003)

DEMETER COMP-1 COMPULATOR REVIEW

 

Demeter Compulator and Electro-Harmonix Black Finger

 

Originally intended to control and limit a signal's dynamic range, compressors are also used to give bass a thicker, richer, and sweeter tone. The Demeter Compulator and Electro-Harmonix Black Finger utilize similar optical technology as the venerable Teletronix LA-2A, one of the most popular studio compressors of all time - especially for bass. The oft-copied LA-2A derives its sound from a quirky optical attenuator, four vacuum tubes, and special impedance-matching input and output transformers. While the LA-2A's tubes and transformers contribute significantly to its sound, most compressor connoisseurs believe the optical attenuator's unique attack and release characteristics are largely responsible for its enduring sonic magic. The LA-2A sets a high standard for musical compression, and its highly regarded reputation is largely responsible for the current interest in optical compressors.

 

Demeter Compulator

 

Like the LA-2A, the easy-to-use Demeter Compulator has two main controls: compress and volume. The Compulator can be optimized for low-output passive pickups or high-output active electronics thanks to its recessed input gain trim-pot, but you'll need a tiny screwdriver for the job. Its 9-volt battery, solid-state circuitry, and LED opto-coupler are housed in a rugged heavy-steel box. A blue LED illuminates when the pedal is on, but I like seeing an LED that illuminates when the compressor engages. (Designer James Demeter responds: "I tried including an LED to show when the pedal is compressing, but with a 9-volt-battery power supply as opposed to an AC adapter, the additional circuitry added unacceptable noise.")

 

At modest compression settings, the Compulator sounds detailed and transparent, with a fast attack and a smooth and graceful release. Cranking up the compress knob and input gain and can produce more dramatic squashes and swells - great for enhancing fretless mwah. On gigs and recordings, the Compulator always sounded sweet and well mannered. It's nearly impossible to abuse this pedal. In fact, the Demeter can sound so well mannered that it becomes more conspicuous in its absence; you don't realize how much it's contributing until you turn it off. You'll want to leave it on all the time. The Demeter Compulator's sound is truly first class.

 

Electro-Harmonix Black Finger

 

Back in the '70s, Electro-Harmonix was one of the first companies to develop a stompbox-style compressor. Out of production for many years, this solid-state design was also called the Black Finger, but its circuit and controls were completely different from those of the current Black Finger. The new tube-driven Black Finger sports a pair of Russian-made Electro-Harmonix 12AX7EH tubes. (Electro-Harmonix's parent company, New Sensor, is one of the largest importers of Russian tubes.) The tubes operate from a full 300-volt power supply and are protected by a black "roll bar" that's bolted to the aluminum box.

 

The Black Finger's pre-gain knob controls the input level, and at higher settings, it can provide mildly overdriven textures. The compress knob controls - you guessed it - the amount of compression, while an LED's light changes intensity as it tracks the amount of gain reduction. The post-gain knob controls the output level. Pretty straightforward so far, but here's where it gets interesting: You can choose between the Black Finger's two opto devices. The lamp-driven opto-coupler is intended to provide a slower attack time with reduced high-frequency compression, while the fast-acting LED provides more evenly balanced compression for more fidelity-conscious applications.

 

The Black Finger's sqsh/norm switch provides additional compression. In sqsh mode, the amount of compression is increased dramatically and the attack becomes longer and more "squashed." This produces a significant drop in volume when switching from norm mode, but this lost gain can be recovered by increasing the post-gain level.

 

Electro-Harmonix has a decades-long reputation for making some of the wildest-sounding effects imaginable, but in norm and led modes, the Black Finger is capable of surprisingly transparent tones. Switching to lamp mode and increasing the compression adds more tube-flavored bloom for thick-booty tone that sits well in the track; we got a great Old School sound with a Fender Precision. But if you're really into high-cholesterol tone, switch to sqsh mode for some over-the-top, greasy goodness. You can also add tube-amp-style grind by cranking the pre-gain knob. If you're into experimenting and exploring a wide range of compression colors and textures, you'll get a big kick out of the Black Finger.

 

Pick Your Poison

 

Both the Demeter Compulator and the Electro-Harmonix Black Finger are capable of admirably transparent tones. If you're seeking an easy-to-use, set-and-forget compressor, you'll be sweetening your tracks in no time with the easy-to-tweak, great-sounding Demeter Compulator. If you don't mind spending a bit more time experimenting with sounds and you're looking for something a little out of the ordinary, you may not be able to resist the Electro-Harmonix Black Finger's unusual controls and flexibility.

 

Tech Spec

 

Optical compressors have an internal light source that glows brighter as the input level increases. This light source shines onto an adjacent Light Dependent Resistor (LDR); the LDR's resistance varies with the light's intensity. This varying resistance controls the compression like an automatic volume knob. The term "optical compressor" refers to these two optically coupled components - a light source and a light sensor.

 

Demeter Compulator

 

Input impedance: 1M ohm
Electronics: Two LF353 dual JFET op-amp integrated circuits with an LED light source
Controls: compress and volume knobs, plus screwdriver-adjusted miniature input gain trim pot
Power source: 9-volt battery or AC adapter
Dimensions: 43/4" x 23/4" x 21/4"
Weight: 1 lb
Made in: U.S.A.
List price: $249
Warranty: One year limited

 

Electro-Harmonix Black Finger

 

Input impedance: 82k ohm
Electronics: Two 12AX7EH tubes; one TL074 quad JFET op-amp integrated circuit controlling selectable lamp or LED light sources
Controls: pre-gain, compress, and post-gain knobs, plus lamp/led and sqsh/norm switches
Power source: 12-volt AC adapter only (provided)
Dimensions: 71/2" x 43/4" x 31/4"
Weight: 1 lb, 8 oz
Made in: U.S.A.
List price: $298
Warranty: One year limited