Diamond Pedals Diamond Comp/EQ

The Diamond Comp/EQ is a compressor pedal with a built-in EQ section, made by Diamond Pedals. It builds on the circuit architecture of the company's original "yellow box" Diamond compressor, adding a Mids boost/cut control, an Attack switch, custom spec'd opto-isolators and modern, quiet switching¹. Diamond describes it as "a mastering solution for your effects chain," combining optical compression with a hi-fi inspired, center-detent active tilt EQ¹.

The Attack switch is the pedal's main tonal lever. Diamond says it "allows you to go from the signature ultra-snappy Diamond comp style all the way to softer transparent compression"¹, so the same box can cover pronounced country-style squish or a gentler leveling effect. The tilt EQ then shapes the overall frequency balance, and the Mids control adds or cuts a specific mid band on top of that.

What it is and what it does

The Comp/EQ pairs two functions in one box: optical compression and an active EQ. Diamond calls the compression "silky smooth, natural optical compression," meaning the gain-reduction element is a light-dependent component rather than a VCA, the approach used in classic studio optical compressors⁴⁵. The EQ side is a tilt design with a center detent: turn the knob one way and highs are emphasized against lows, the other way and the balance shifts back, with the detent giving a flat setting you can feel by hand⁶.

On top of the tilt EQ, the newer Comp/EQ adds a Mids boost/cut control that the original yellow box did not have, along with the Attack switch and custom spec'd opto-isolators¹. The audio path is all analog, using Burr-Brown components¹.

Controls and connections

Input impedance is greater than 1MΩ and output impedance is under 10KΩ¹, figures that matter if you are placing it after high-impedance sources like vintage fuzz pedals, where a low input impedance would load down the signal.

Power and bypass

The Comp/EQ runs on 9 to 18 VDC through a 2.1 mm barrel jack with a negative tip, drawing 22mA at 9V¹. That means a standard 9V center-negative pedalboard supply is all it needs, and the 22mA draw is light enough that it is easy to accommodate on a shared supply. The pedal uses relay based true bypass switching¹, so the signal path is out of the circuit entirely when the pedal is disengaged.

From the yellow box to the Comp/EQ and its editions

Diamond Pedals says "there are few compressors that are more sought after than our yellow box Diamond"¹, and the Comp/EQ is the next-generation version of that circuit, maintaining the classic architecture while increasing range and functionality². Alongside the standard Comp/EQ, the pedal comes in several editions:

• Limited Maple Leaf Edition: a limited run of the Comp/EQ "clad in red and white, proudly wearing the maple leaf," with the same Mids control, Attack switch, Burr-Brown analog path, relay true bypass and 9-18V operation⁶.
• Surf Green Comp/EQ: the same next-generation circuit in a Surf Green finish, with top-mounted jacks and the same power, bypass and warranty specs⁷.
• Bass Comp/EQ: a bass-tuned version, covered below.

The bass version

There is a dedicated Diamond Bass Comp/EQ for bass players. It augments the original bass-tuned yellow box design with the same additions as the guitar version, including the Mids boost/cut control⁵. Its Mid EQ is centered at 500 Hz with plus or minus 10 dB of boost or cut⁸, a frequency range aimed at the low-mid area where bass tone shaping usually matters most. It shares the all analog Burr-Brown audio path, relay true bypass, 9-18 VDC operation, 22mA current draw and Canadian build of the guitar version⁵. A Custom Black with Gray finish variant also exists⁹. If you play bass, see the bass pedals overview for where it fits among other options.

Where it is made and warranty

Every Diamond pedal is designed and built entirely in the company's own shop in Montreal, Quebec³, a point the Maple Leaf edition celebrates directly. Diamond describes the full process in-house: "Every single Diamond pedal is designed, machined, powder-coated, UV printed, assembled, tested and packed entirely in our shop"⁴.

All Diamond products purchased through the diamondpedals.com website or authorized dealers carry a three-year warranty against failure resulting from defective parts or faulty workmanship¹⁶⁷. The warranty applies to the original owner only, is not transferable, and terminates three years after the owner receives the product. The owner pays shipping both ways, and the warranty is void if the pedal is tampered with, modified, abused, misused, repaired by an unauthorized third party, damaged through not following the operating instructions, or powered improperly⁸.

Price

The Comp/EQ lists at $249.00 USD on Diamond's own site¹. UK pricing has been reported differently at different times: £249 ERP in 2023¹⁰, and $259.00 / £235.00 / 275.00€ in May 2025¹¹. 00 USD listing as the current reference.

Videos

Click to load

Click to load

Click to load

Questions