Does the mythic quest for Dumble-style tones culminate in this boutique box?

The mythology that surrounds Alexander Dumble’s creations has led to an entire cottage industry of builders trying to replicate that sound, but without the five-figure price tag. Vertex Effects’ take on a Dumble Steel String Singer is billed as a “clean drive,” but I found the latter descriptor to be more apt. In addition to the volume and gain controls, there’s a filter knob that helps to focus the midrange.

I was quite surprised with how much gain the SS could churn out. In front of a clean amp, the pedal got very growly and, at times, heavy on the low end. Even with rather bright T-style pickups, I found myself fiddling with the filter control to help clear up some muddiness. The volume knob tended to really bring the best out when pushed past noon. The thick D-style feel and warm, smooth compression was there, but I think it really shined in rougher, grittier tones—with the gain knob at least at 2 o'clock. If your tastes are more Texas Flood than In Step, then the SS might be the best way to save $90,000 on your rig for the next blues jam.

Test gear: Schroeder Chopper TL, Gibson Les Paul, Fender ML212, Supro Statesman

Clips recorded with a Schroeder Chopper TL and Wooly Coats Spanky MkII.
Clip 1: All controls at noon.
Clip 2: Volume at 1 o'clock, filter at 3 o'clock, gain at 3 o'clock.


More versatile than I expected. Nice amount of gain.

Somewhat unbalanced on the low end. Filter control is surprisingly subtle.


Vertex Effects Steel String



Ease of Use:



A compact pedal format preamp designed to offer classic, natural bass tone with increased tonal control and extended headroom.

Read MoreShow less

You could WIN all five new Maestro Pedals from Gibson in this PG Perks Exclusive Giveaway! Enter before August 11, 2022.

Read MoreShow less

A warm, analog optical compression designed to offer plenty of sustain, attack, and release that can be blended in to taste.

Read MoreShow less