Keeley Electronics 30ms Double Tracker

  • By Fletcher Stewart @tonereport
  • November 12, 2015

Double Trouble Deviations

Imagine a subtle—yet infinitely versatile—modulation machine that straddles the line between chorus, flanger and slapback echo. This pedal would add movement and a mysterious backdrop behind the guitars core tone, while seamlessly slinking into the nether realms of ambience and intrigue. This shadowbox would tiptoe behind the scenes of known modulations, weaving a web between the familiars into tonal tapestries of new sonic subtleties. Add to this the ability to create polymorphic dual deviations and spread or condense them at will, and we have an idea of what the new Keeley 30ms Automatic Double Tracker is all about.

In a convoluted overlapping landscape of boutique tone tweakers, modders and noise box builders, veteran tone doctor Robert Keeley has come up with a strikingly original pedal design concept—the studio stompbox. The first in Keeley’s studio-in-a-stomper series is this mighty red-and-black twin attack. The 30ms ADT crams all the magic of Abbey Road Studios engineer Ken Townsend’s tape reel stereo treatments into a compact form factor that belies the kaleidoscope of trippy tones within. As if this wasn’t enough, Robert Keeley has even included the famous “Abbey Verb” chamber effect, modeled after the fabled Studio Two. Far out.

Triptych Out to Stereo Fields Forever

Upon unboxing, I jacked the 30ms ADT into the effects loop of my trusty dual channel clean-to-crunch machine—The Victory V30. While most folks like chorus and flange tones before dirt, I wanted to hear the full movements of these more subtle modulations, while having the built in reverb logically after the distortion. My intuition was bang-on. Even with extreme amounts of gain, the 30ms never flattened out or became too whooshy and obvious. This is perhaps due to its more subtle and unpredictable pitch deviations Keeley painstakingly fine-tuned into the control set.

Starting in Dimension mode with everything at noon, I played a clean arpeggiated cyclical riff and engaged the pedal. A pure warm halo of movement surrounded my tone that was silky without ever getting caught in the sickly chorus hairnet of sticky 80s’ stigma. Turning up the “Abbey Verb” revealed a roomy echo with some pre-delay and diffusion. This was great for an unobtrusive ambience that maintained the subtle overall approach of the pedal. Switching to the dirt channel with these same settings released a tide of Permanent Waves. This distorto-chorus was similar to vintage Alex Lifeson tone. Switching to Abbey mode revealed a more traditional chorus effect with everything at noon, so I decided to simulate a vintage tape flange by scaling the time back to 5ms and turning the rate down to a crawl. What I ended up with was a phosphorescent flange-like tone reminiscent of Metal Box-era Keith Levene. Ace. Switching to the Slapback setting and configuring the internal dipswitches for Double Track Pro mode, I bypassed the reverb in favor of full control of the two voices. I then jacked into inputs one and two of my audio interface with a TRS cable and hard panned them in my DAW sent to two Marshall plug-in emulators. I was immersed in stereo slapback glory with the two independently detuned voices simultaneously speaking in liquid tongues, wetting each side of my brain with inspiration.

What We Like: The idea of a studio-in-a-stompbox is fresh. While the Keeley 30ms ADT doesn’t offer tape saturation like the only other pedal of its ilk—Strymon’s Deco—the effected signal is filtered with warmth and garnished with an organic patina. I compared this compact stomper with my coveted ‘70s BBD chip-laden PA:CE ADT rack unit and it sounded every bit as lush without the hiss of noisy old components. I also love the Ampex tape reel box graphics, compact size and overall usability and immediacy of the control set. This is a hard one to turn off; maybe I will Velcro it atop my amp and have it permanently in the loop.


Concerns: I would rather have stereo inputs and outputs than having to whip out the TRS cable. Then, I could run the 30ms through the effects loops of two amps.

Leave a Reply

Your email address will not be published. Required fields are marked *


  1. Mark C

    Great review and I totally agree with the comments!. I remember getting a Boss DM-2 way back when they came out in 1981 and would use it as a grind/doubler instead of a slap or echo. I also got a Boss Dimension C when they first come out in 1985 and ran it stereo - loved those tones! The Keeley 30MS does all of these and more!! I gigged with mine last weekend and never turned it off! Very addicting!!! I too wish it had stereo inputs and outputs!!

  2. Eric Filsinger

    For true stereo in/out it would require two separate processors and twice the cost!

  3. Roger Cloud

    I just tried out my new 30ms for the first time, only in one configuration, and only so far with my Moog Werkstatt (I explain why below):  In Dimension Mode, with the dip switches in the stock “UP/UP” position, delay at about 26 ms, tuning at about 11 o’clock, with the Abbey reverb at around straight up noon, and level (blend) at 9 o’clock.  This yielded a subtle double tracked sound that overcame the Werkstatt’s “single VCO” sound, which was my intention as to the Werkstatt (Moog sound at cheapest price, yet with as much fatness as I could squeeze out of it).  The Werkstatt’s sound is already rich, being a Moog (I am a Moog advocate of the first order), but not as rich as if it had 2 VCOs.  Using the 30ms did the trick even more than I’d dared to hope!  But the addition of the Abbey reverb - wow!!  Switching the unit off (bypassing) was downright depressing!  I am very much looking forward to messing around with the many other possible permutations dialing up other settings, much less using the other two modes (Abbey and Slapback), but I have a suspicion that an even more realistic double-tracking effect, per se, may be achieved by having the second dip switch (and maybe even both) in the DOWN position.  This is *only* a suspicion, but it’s based on my little bit of puzzlement as to why KE calls this config “Double Tracking Pro Mode.”  This does remind me of my main issue with the 30ms, and that is that that the instructions are downright confusing.  The Introduction part of the instructions says that “n Dimension Mode, two voices are created giving you the ultimate double-tracking experience,” yet the “Explanation of Modes” says the Abbey Mode “was designed to aproximate (sic) the double tracking effect employed on legendary British studio sessions of the 60’s,” and even notes in that section that the Slapback Mode “produces an adjustable classic Slapback Delay… as well as the 2 adjustable doubled voices.  Then, they show 3 different “Example Settings in Double Track Pro Mode” for each of the 3 Modes (Dimension, Abby [sic], and Slapback) that you’re in depending on which position the central mini-switch is in.  Don’t know about you, but that sure confuses the heck out of me.  What I *think* is happening is that you can augment the core “Dimension” sound (the core DT   sound?) with an Abbey studios reverb and/or a Slapback effect, but that still doesn’t explain whether you’re getting “more” of a doubling effect if you’re “in DT Pro Mode.”  There are even more ways in which the instructions are confusing, but it would only add to the confusion to try to explain them (like how you use the included TRS splitter).  All that said (!), I will add that my primary aims in getting this unit are to use it in two particular ways:  (1) on a Moog Minitaur that I’m getting, to sync with my Minilogue; and (2) on vocals in the studio . . . and I CAN’T WAIT!!

  4. Gary

    Hi Fletcher. Great review. Are you interested in selling your PA:CE ADT rack unit?