This pedal mirrors the Dumble amplifiers in many ways. The Holygrail Overdrive is a simple, somewhat homely looking pedal, and its knobs and jacks appear to have been labeled with a garden variety label-maker. The controls are Drive, Accent, Tone, and Volume, and features a Comp/Open voicing switch, just like the Dumble Overdrive Special Jazz/ Rock switch.

Absolutely next level when it comes to sweet, touch-sensitive overdrive and impeccably clean, transparent boost. The Dumble-like tones that come out of these little stompboxes is unreal! The controls are extremely responsive and allow for a massive spectrum of tonal options, all of which are completely usable.

GTOWN amps

Review by The Gear Page

Review by Stompbox Steals

Demo by Mike Hermans

Demo by John-F. Klaver

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Holygrail OD 1

This pedal mirrors the Dumble amplifiers in many ways. The Holygrail Overdrive is a simple, 
somewhat homely looking pedal, and its knobs and jacks appear to have been labeled 
with a garden variety label-maker. The controls are Drive, Accent, Tone, and Volume, 
and features a Round/Open/Sharp voicing switch. HiCut switch for using the pedal 
in front of bright sounding amps.

Absolutely next level when it comes to sweet, touch-sensitive overdrive and impeccably 
clean, transparent boost. The Dumble-like tones that come out of these little stompboxes 
is unreal! The controls are extremely responsive and allow for a massive spectrum of 
tonal options, all of which are completely usable.

Demo by SRGuitar

Demo by  魔法の箱研究所 - Stompbox Review Channel -

Review by guitar pedal X

Review by delicious audio

Holygrail OD v2

his is Dr335’s little brother. Where the Dr335 is a two channel drive, this is a single channel.

Built along the lines of the classic Dumble amps. The goal was to achieve the sound of Mr335, so it’s a very Larry Carlton/Robben Ford sounding pedal.

The sound can be described as transparent, natural and woody going from a clean boost to mid gain. Three clipping mod switch Hard/Open/Soft which gives a nice versatility of sound options depending on the amp/guitar-combination being used and your playing style.

Demo by  John-F. Klaver

Demo by Sam Vilo

Built along the lines of the classic Dumble amps.
The goal was to achieve the sound of Mr335, so it’s a very Larry Carlton/Robben Ford sounding pedal.
The sound can be descriped as transparent, natural and woody going from a clean boost to mid gain.

Four controls are available on each channel: Drive/Tone/Edge/Volume. Each channel is equipped with a three clipping mod switch Hard/Open/Soft which gives a nice versatility of sound options depending on the amp/guitar-combination being used and your playing style.

DR335

Dumble style sounding double channel overdrive. Covers as many as from clean booster till roaring high gain.

Holygrail DualDrive channel 1 is our Holygrail Overdrive. Channel 2 is our 335 overdrive. Channels connected series as follow:
Input->CH2 -> CH1->Output.

Each channel have a three way clipping switch allows to choose three different clipping modes. Each channel have a different voicing which in conjunction with clipping mod options provides a lot of sounding combinations.