The Keeley Verb O Trem is a collaboration between Robert Keeley and session guitarist Eddie Heinzelman — designed around the observation that reverb and tremolo are two of the most universally useful effects in any guitarist’s setup, and that most boards benefit from having both at the end of the chain.
The concept is straightforward: one pedal, two effects, independent footswitches, and the sounds that most players reach for — spring or plate reverb on one side, and a choice of three tremolo types on the other. Compact enough for a fly rig, versatile enough for a main board.
Keeley’s spring reverb has a reputation in its own right — good enough to be installed in Keeley’s own amplifier. The plate reverb is a smooth, high-fidelity alternative. One important note: the Spring/Plate switch is internal, accessed by opening the pedal. Set it once for your preferred reverb type.
The Tremolo Modes
R+T (tube bias tremolo): An organic, amplitude-based tremolo that simulates the bias fluctuation of a tube power amplifier — the classic vintage tremolo sound of a Fender tweed or blackface amp. Personal, slightly haunting, with a natural swell rather than an abrupt chop.
Mack (pitch vibrato): Uses phase manipulation to create a smooth pitch-based movement rather than conventional amplitude tremolo — silky and continuous, useful for adding flowing motion to clean tones without the volume pulsing of a standard trem. MagnaAmp style.
HAR (harmonic tremolo): Splits the signal into two frequency bands and modulates them out of phase with each other, creating a complex notch-filter tremolo with more tonal character than a simple amplitude chop.
Controls
- Rate: Controls the speed of tremolo / vibrato
- Depth: Controls the intensity of the tremolo / vibrato
- Reverb: Sets both reverb decay and volume
- Volume: Sets overall output level
- Mode switch: Selects between R+T, Mack, and HAR modes.
- Internal Switches:
- Spring/Plate Selects between spring and plate reverb.
- Vintage / Modern: Select Vintage to cut treble
Key Features
- Spring and plate reverb — selected via internal switch
- Three tremolo modes — R+T tube bias, Mack pitch vibrato, HAR harmonic
- Independent footswitches for reverb and tremolo
- Collaboration with session guitarist Eddie Heinzelman
- Compact enclosure — ideal end-of-board solution
- 9V DC centre-negative, 65mA
- Made in the USA
Important Note on Reverb Selection
The switch between Spring and Plate reverb is inside the pedal, not on the face. You need to open the enclosure to change it. For most players this is a one-time decision — pick your preferred reverb character and leave it.
Watch The Keeley Verb o Trem In Action
Yes — independent footswitches for each. Use reverb only, tremolo only, both together, or neither. Switch either on or off mid-performance without affecting the other.
The Spring/Plate switch is internal — you need to open the pedal to change it. For most players this is a one-time decision: open it, set your preferred reverb character, close it, and leave it. The spring reverb is splashy and vintage-characterful. The plate reverb is smoother and more studio-like.
R+T simulates the bias fluctuation of a tube power amp for a classic organic volume swell — the kind associated with vintage Fender amplifiers. Mack uses phase manipulation to create a smooth pitch-based movement rather than amplitude modulation. HAR splits the signal into two frequency bands and modulates them out of phase, producing a complex notch-filter tremolo with more tonal character than a standard chop.
At the end of the chain, after compression, drive, and modulation pedals. Reverb and tremolo generally work best as the final effect before the amplifier.
Yes — true bypass on both footswitches. Your dry signal is unaffected when both effects are off.
9V DC centre-negative at 65mA.
Alan P (verified owner) –
I’m very impressed with the Verb o Trem. Robert Keeley has a good reputation anyway, but I’m really happy with it. The trems are all very good indeed, especially the harmonic trem. The vibe setting can also get very close to a fast Leslie sound (Let it Loose from Exile…comes to mind).
Not sure if I like the dip switch inside the pedal, to change from spring to plate reverb – having tried both out, I’ve decided to “set and forget” on the plate setting, which is really very good – probably more authentic than the spring sound. It’s a shame the switch couldn’t have been put on the outside, even if it stayed as a dip switch – on the side, maybe.
I can see that some players would rather go for the Hydra, to get independent switching for the trem and reverb – can’t say I’m bothered, I think it works well, I prefer a simple set-up.
Onno (verified owner) –
Best tremolo pedal I’ve ever owned. It even beats the Mr. Black Deluxe (which is already very good). Super versatile, and all sounds are very useable. At low settings, it can bring your tone to life, without even realizing that it’s a trem you’re listening to. Notes suddenly become three dimensional and start to “dance around the room”. As a consequence, I’m using this pedal far more often than I thought I would. Some people are bothered by the fact that it does not have a separate footswitch for the trem and the reverb, but it does not bother me in the least; don’t use its reverb as a separate effect anyway, but rather as an extension of the trem. Highly recommended.