Akashic Guitar effects circuit lookup
VOLINPUTGAINLEVELVOICETONE

1590BB2 · 6 knobs

GuitarPCB

NostalgiTone DumbleTone Deluxe Dual Combo

Category
Other
Controls
Vol · Input · Gain · Level · Voice · Tone
Price
see vendorout of stock

From the vendor

Now Available in (3) Purchase Options:

PCB + Matching Plate Bundle — $15.95PCB Only — $13.95Matching Plate Only — $7.95

Plate Fits 1590BB2 size enclosure w/ 5mm LEDs

Description

The DumbleTone Deluxe combines two carefully selected circuits inspired by the original reverse engineered John Mayer Dumble units: the smooth, expressive overdrive character of a Dumble drive section and the dynamic enhancement of the preamp clean channel. With NostalgiTone order switching, each circuit can be placed before or after the other, revealing two unique signal paths with their own feel, response, and tonal character.

The JFET preamp clean channel captures the dynamic response of a classic amplifier front end, providing natural harmonic enhancement, improved touch response, and a more expressive feel under the fingers. While the original design utilized a J309 JFET, the readily available J113 has proven to be an excellent choice for this application, offering similar performance characteristics and excellent reliability. The onboard bias adjustment makes setup simple and precise.

The Input control is not a gain control. Instead, it adjusts how the preamp stage responds to the guitar signal. Increasing the control allows players to explore changes in compression, fullness, and harmonic response. Full CCW provides a thinner, precise character, and full CW delivers a fuller, rounder tone.

Designed for a 1590BB2 enclosure, featuring the same dimensions as a 1590BB but with 125B clearance.

DumbleTone Deluxe Build Document

1590BB2 size (Drilled for dual wiring board mounted LEDs) – Drilled Enclosure Link

Schematic

The schematic is in the vendor's build document, page 2. Open the build document. No KiCad fragment has been drawn for this circuit yet.

Parts list 16 rows

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Variant
RefValueNormalizedTypeNotes
Resistors 4
R11M51.5M
R21M1M
R35k65.6k
R4100R100
Capacitors 5
C1100n100n
C2100p100p
C34u74.7u
C4100u100u
C5100n100n
Diodes 2
D11N58171N5817
D2StatusSTATUS
Transistors 1
Q1J309J309
Potentiometers 2
INPUTB2MB2MPotentiometer
LEVELB10KB10kPotentiometer
Jacks & sockets 2
J113C6C6
J309package.PACKAGE.