GuitarPCB Zenith Mini Technical manual

Zenith Mini
Based on the Zen Drive™ this circuit is a dynamic, touch-sensitive overdrive pedal. Inspired by a legendary Dumble
amplifier & guitarist, the Zenith Mini will allow you to dial in amazing blues, rock, country and jazz tones. Are you
looking for a pedal circuit to produce Dumble style tones? This is the one!
Also note the new TimZee style mod on page 4 of this build document. (Mods are not included with kits)
New v4 2020 Version Previous Mini Version
Board Dimensions (W x H) 1.59” x 1.25” (W x H) 1.36” x 1.36”
Bill of Materials is identical for either Mini Version
Part
Value
Part
Value
R1
2M2
IC1
TL072
R2
470K
Q1
2N7000
R3
1K
Q2
2N7000
R4
1K
C1
470n
R5
10K
C2
100n
R6
1K
C3
100p
R7
10K
C4
3n3
R8
10K
C5
470n
R9
3K3
C6
100u
D1
1n4148
C7
47u
D2
LED or jumper
Volume
A100K
D3
1n4148
Gain
B500K
D4
1n4001
Tone
B50K
D5
Bi-Color LED
Comm. Anode
Voice
B10K

Build Notes:
●We like using the LED for D2 in this build, but if you like a more stock-sounding pedal, put in the Jumper instead.
●To experiment we advise the use of sockets. Also note the TimZee Mod below for further experimentation.
●While the board is small enough for a 1590A enclosure because it uses four potentiometers we only suggest this if you are
experienced at working small enclosures.
Wiring Diagram
Be sure your In/Out Jack wiring is correct. A Stereo Jack (for battery use only) has a
RING lug which is used to connect to the battery ground. If you do not intend to use a
battery there is no need for a Stereo Jack. If using Stereo then only use the Tip and
Sleeve lugs. S4, S5 & S6 is only needed when the LED is wired to the Main Board.

If using our convenient 3PDT Wiring Boards (below) here is an LED wiring guide. You may use Common Anode Bi-Color
or Standard On/Off. The wiring boards use the same symmetrical layout as if wiring straight to the switch.
Use the Board Silkscreen for hand wiring potentiometers &
switches. (1) in the silkscreen means Potentiometer Lug 1.
Note: If wiring the LED to our 3PDT board no need to connect S4, S5 & S6 or populate D5 or R9 (CLR) on the
main board since you are wiring your LED directly to our board.
Direct Online Link: 3PDT Wiring Board Build Document
Mod: Thanks to Tubenit try his TimZee Mod - This is a unique mash-up mod based on two
popular circuits. This mod is not to be misrepresented however it is a fun way to try a
“Transparent Version” of this circuit. The mod has been verified.
This Mod can be done on the v4 2020 version as well. All component numbers are the same.
Before beginning any build or if you have questions please see our Guides Page on our site.
The Guides Page is located in the Main Menu Bar of most pages. Also we have a dedicated
forum for questions about your build.
Soldering Tutorial on Youtube
Need a kit? Check out our authorized worldwide distributors:
USA – Check out PedalPartsAndKits for all your GuitarPCB kit needs in the USA.
Europe – Das Musikding Order either boards or kits direct from Europe.
PedalPartsAustralia - Order either boards or kits direct from Australia
This document, PCB Artwork and Schematic Artwork © GuitarPCB.com. Schematic, PCB and this document by Bruce
R. and Barry. All copyrights, trademarks, and artworks remain the property of their owners. Distribution of this
document is prohibited without written consent from GuitarPCB.com. GuitarPCB.com claims no rights or affiliation to
those names or owners.