The Sushi Box FX Dr. Wattson X is a tube preamp pedal built around two 12AX7 tubes. Sushi Box FX describes it as designed for classic British high-headroom tube tone, with the circuit modified from the original design to make it more suitable for pedal and preamp use while staying true to that design1. Bass Musician Magazine referred to the Dr. Wattson as the maker's "super popular big brother" in a 2023 review of other Sushi Box pedals2.
Power and what it means for your board
The tube complement is what separates this pedal from solid-state preamps, and it also dictates its power needs. Sushi Box FX lists the voltage range as 9 to 12V DC with center-negative polarity, like most guitar pedals1. The current draw is another matter: 900mA at 9V DC during warmup, settling to 480mA at 9V DC after warmup1.
With a warmup draw of 900mA at 9V DC, the Dr. Wattson X needs a dedicated high-current power output. A daisy chain or a low-current output will not run it.
Controls
| Control | Function |
|---|---|
| Gain | Drive amount into the tubes |
| Bass | Low EQ |
| Mids | Midrange EQ |
| Treble | High EQ |
| Master | Output level |
A single footswitch handles bypass1.
Availability and price
Sushi Box FX's listing marks the Dr. Wattson X as Archived, with a listed price of $205.00 USD3. The maker's page also notes the design change from the original: "It has been modified to make it more suitable for pedal/preamp use while staying true to the original design"1.
Questions
How many tubes does the Sushi Box FX Dr. Wattson X use?
The Dr. Wattson X uses two 12AX7 tubes, according to Sushi Box FX's product page. That dual-tube design is what lets the pedal deliver genuine tube preamp tone in a pedal format, and it is also why the pedal draws considerably more current than a typical solid-state pedal.
How much current does the Dr. Wattson X draw?
Sushi Box FX lists the draw as 900mA at 9V DC during warmup, dropping to 480mA at 9V DC after warmup. That is far beyond what most pedal power supplies or a daisy chain can supply, so the pedal needs its own dedicated high-current output.
Is the Dr. Wattson X still available?
No. Sushi Box FX's own product listing marks the Dr. Wattson X as Archived, meaning it is no longer in current production. It was listed at $205.00 USD.
What was changed from the original design to make it a pedal?
Sushi Box FX says the circuit was modified to make it more suitable for pedal and preamp use while staying true to the original design. The pedal is designed for classic British high-headroom tube tone.
Sources (3)
- Dr. Wattson X, Sushi Box FX
- Review: Sushi Box Elementary and More Pedals, Bass Musician Magazine, 2023-11-13
- Underground Accelerator, Sushi Box FX