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: