The NUX NTU-3 Flow Tune MKII is a compact pedal tuner built for guitarists and bassists. It offers four tuning modes: Chromatic, Guitar-Standard, Guitar Compensated, and Bass1. The Guitar STD (Standard) and Guitar CPS (Compensated) modes are, in NUX's words, "Enhanced for guitarists, the NTU-3 includes Guitar STD(Standard) and Guitar CPS(Compensated)."1 The compensated mode is "Inspired by the tuning style of James Taylor, aka Compensated Tuning"1, a tuning approach that adjusts individual strings to suit how the instrument plays rather than tuning every string to one flat reference.
Tuning and display modes
The MKII covers the full range of both guitar and bass, from A0 (27.5Hz) at the bottom to C8 (4186Hz) at the top, with a stated tuning accuracy of ±0.1 Cent1. A4 calibration is adjustable from 430Hz to 450Hz, so you can match orchestral pitch or detune slightly to suit a recording1.
The display offers three modes: Strobo Mode, Arrow Mode 1, and Arrow Mode 21. NUX describes the screen as a "bright and high-definition LCD display" that "works well on any stage in both of sunlight and darkness"1, and says it is readable at a distance1.
Bypass and buffer options
One of the more flexible features of the NTU-3 Flow Tune MKII is its three bypass modes. You can switch between TB (True Bypass), BF (Buffer), and BFM (Buffer Monitor), which NUX says lets you choose "according to your tastes and environment"1.
- True Bypass (TB): the pedal is out of the signal path entirely when off.
- Buffer (BF): NUX explains that "A buffer boosts the signal over long cables to avoid loss of tone, keeping it clean and clear, even when your pedal is off"1.
- Buffer Monitor (BFM): with this mode engaged, "you can even monitor all the notes you play in real time"1, so the tuner keeps working as a pitch reference while you play.
The 10MΩ input impedance and 1KΩ output impedance are the figures NUX gives for the pedal's signal path1.
On the board
The enclosure is compact: 97.4mm long, 43.5mm wide, and 41.6mm high, weighing 197.4g1. NUX describes it as having a "Compact size and steady weight, easy to fit the pedalboard with Velcro"1. The footswitch is described by NUX as "specially-designed" and offering "comfortable pressing feedback"1.
Current draw is listed as less than 100mA1, which most standard pedalboard power supplies can handle on a single output.
The Flow Tune MKII sits alongside the original NUX Flow Tune and the smaller NUX PT-6 Pedal Tuner in NUX's tuner range. If you are comparing compact pedal tuners, it is worth looking at how each handles bypass and display, since those are the features that differ most between models.
Documentation
NUX publishes the Flow Tune MKII User Manual in three languages on the product page1:
- NUX Flow Tune MKII User Manual English
- NUX Flow Tune MKII User Manual Japanese
- NUX Flow Tune MKII User Manual Italian
Where it sits among pedal tuners
The NTU-3 Flow Tune MKII is one of many options in the pedal tuner category. If you want to compare it against other compact tuners with buffers and strobe-style displays, the Tuner Pedals page lists the wider field, including models like the Peterson StroboStomp HD and the BOSS TU-3s Tuner.
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Questions
What is compensated tuning on the NUX Flow Tune MKII?
Compensated tuning is a tuning style associated with guitarist James Taylor, and NUX says the Guitar CPS (Compensated) mode on the Flow Tune MKII is inspired by it. Alongside the standard chromatic and Guitar STD (Standard) modes, it gives guitarists a way to tune that accounts for how a guitar actually plays, rather than tuning every string to a single flat reference. The pedal offers Chromatic, Guitar-Standard, Guitar Compensated, and Bass tuning modes in total.
Does the Flow Tune MKII have a bass mode?
Yes. The NUX NTU-3 Flow Tune MKII offers four tuning modes: Chromatic, Guitar-Standard, Guitar Compensated, and Bass. The tuning range runs from A0 (27.5Hz) to C8 (4186Hz), which covers the low end a bass reaches as well as the full range of a standard guitar. A4 calibration is adjustable from 430Hz to 450Hz.
How much current does the NUX Flow Tune MKII draw?
NUX lists the current draw of the NTU-3 Flow Tune MKII as less than 100mA. That figure comes from the maker's product page, so plan your pedalboard power supply accordingly: it is well within what most standard isolated supplies deliver per output.
Does the Flow Tune MKII come with a manual?
Yes. NUX publishes the Flow Tune MKII User Manual in English, Japanese, and Italian on the product page, so you can read the full operating instructions before buying or download the version in your language.
Sources (1)
- Flow Tune MKII, NUX Audio, 2025-10-29
