Doc Bob

Get yourself tuned into the delightful tones of the Vox UL730 preamp. "What's that?" came the cry. It's the secret sauce in the guitar tones right across Revolver and Sgt Peppers. If the Beatles don't float it for you, try Joy Division's "Unknown Pleasures" for good measure.

We've taken some artistic license with our interpretation of the original pedal. It's a mighty big and cumbersome pedal for four knobs and two footswitches, the second of which gives you an alternative final boost stage with more saturation. We've dispensed with that to keep it in a vertical format 1590B. You always have the option to build it with the saturated boost in place of the normal cleaner circuit. To make up for the lack of this second mode we've moved the internal Bass and Treble trimmers outside the box. Frankly it's a bit weird that they're internal, but that's just our opinion.

We've designed the PCB to take through-hole or SMT FETs, as through-hole are getting more scarce. SMT parts aren't exactly simple to work with, so you need to be confident in your abilities before tackling them if you want to save a couple of quid.

Kit comes with 3mm resistors by default, but you can opt for 6mm if you find those hard to work with. These will need to mount vertically on the board.

The kit is supplied with vertical-mount pots which have round shafts, so you'll need set-screw fitting knobs.

If you want the PCB without parts there's a link for that at the bottom of the page.

Partial kit: PCB, all board-mounted components, pots.

Full kit: As above, plus footswitch and appropriate daughterboard/components for your selected bypass type (see Downloads section for details of those), jack sockets, DC socket, battery snap, hook-up wire, LED.

Enclosure (pre-drilled) is available as an option with full kits, and will not take a battery. Knobs are not included.

Builds are only available with full kits including enclosures and vertical-mount pots. Please choose appropriate knobs.

Inspired by: Dr. Robert

Difficulty: Medium

PCB size: 50 x 50mm

Knobs required: 5

Enclosure: 1590B

Direct-Connect compatible (4-way)

Download the INSTRUCTION PDF