Boss TU-3 Chromatic Tuner Pedal

The Boss of tuner pedals! With accurate tuning over a wide range and a super-bright LED meter, it's no wonder the Boss TU-3 tuner is on so many pedalboards.

The world's top-selling stage tuner, the BOSS TU-2, evolves and improves with the debut of the TU-3. Housed in a tank-tough BOSS stompbox body, the TU-3 features a smooth 21-segment LED meter with a High-Brightness mode that cuts through the harshest outdoor glare. Choose between Chromatic or Guitar/Bass tuning modes, and enjoy visual pinpoint tuning verification with the Accu-Pitch Sign function. The TU-3 incorporates a convenient Note Name Indicator that can display notes of 7-string guitars and 6-string basses, while the Flat-Tuning mode can support up to six half-steps. It's the standard tuner that no guitarist or bass player should be without.

Check out our overview of the Boss TU-3 Chromatic Tuner Pedal:


- 21-segment LED meter with brightness control
- High-Brightness mode enhances meter visibility outdoors
- Accu-Pitch Sign function provides visual verification when tuning is complete
- Chromatic and Guitar/Bass mode (tune by string number, with support for 7-string guitars and 6-string basses)
- Flat tuning is supported with Guitar Flat mode, which allows for "drop" tunings up to six semitones below standard pitch
- Signal is automatically muted when the tuner is on
- Supplies power for up to 7 BOSS compact effect pedals when used with Boss PSA-120S Power Supply (not included) and Boss PCS-20A Parallel DC Cords for Effects Pedals (not included)

- Tuning Range: C0 (16.35Hz)-C8 (4186Hz)
- Reference Pitch: A4=436-445 Hz (1Hz step)
- Tuning Accuracy: +/-1 cent
- Power Supply: DC 9 V: Dry battery 6F22 (9 V) type (carbon), Dry battery 6LR61 (9 V) type (alkaline), AC Adaptor (PSA series: optional)
- Current Draw: 30 mA (DC 9 V), 85 mA (DC 9 V, when High Brightness mode is on)
- Accessories Included: Owner's Manual, Leaflet ("USING THE UNIT SAFELY," "IMPORTANT NOTES," and "Information"), Dry battery/9 V type (6F22)
- Options NOT included: Boss PSA-120S Power Supply for this pedal
Dimensions and Weight in Packaging
Base Item
Shipping Weight: 1.25 lbs
Shipping Dimensions: 6 x 4 x 3 in
Manufacturer Part Number (MPN): TU-3

For support or warranty questions, please contact the manufacturer:
Phone: 323-890-3700

Reviewers gave this product an overall rating of 5 out of 5 stars. (26 ratings)
Submitted July 28, 2023 by a customer from

"The "industry standard" for a reason"

Overall: 5 out of 5 stars
(see rating details)
Verified Customer zZounds has verified that this reviewer made a purchase from us.
This review has been selected by our experts as particularly helpful.
OK so, yea, a tuner isn't exactly the sexiest bit of gear available - it doesn't affect the sound at all (except for muting, which is useful but not fun), and even the case is about as utilitarian as you can get. But you know what's NOT sexy? Being out of tune.So, at some point, you should get a tuner. Yes, YOU. It doesn't have to be this one, but there are several reasons why it should, and only a few reasons to choose anything else. I'll mention those first:1. If you're a professional setup tech or luthier who's setting intonation on guitars all the time, then you should spring for the ultra-expensive rackmount strobe tuner. Not the "digital strobe" version, the real one. Nothing else can come close to the accuracy of a true strobe tuner, and if people are paying you to intonate their guitars, you do need it.2. If you're a touring player with a rack, then a rackmount tuner makes more sense. Again, more expensive, but if you're rocking a rack then you're already in for at least several grand, so the tuner won't be a huge bite in comparison.3. If you're an acoustic-only guitarist who doesn't have a 1/4" output on your guitar, then some kind of "contact" tuner is a better choice. Most of these clip to your headstock and sense the vibration of the guitar that way, so you don't need to plug in. BUT - If none of these describes you, then you need a proper stage tuner, and the TU-3 is the unit that all others are judged against. It has a bunch of tuning modes, +/- one cent accuracy, read more 21-LED meter, dual outputs (more on that in a second), DC power pass-through so you can daisy-chain other pedals off of it, and that legendary Boss enclosure which is I assume is literally bulletproof. And, the price is about as "reasonable" as you could possibly ask for.

While a tuner doesn't really do much to the sound of your instrument, that's OK - it's totally not supposed to! It mutes the (main, but NOT bypass) output when it's actively tuning. It does also buffer the signal, which is great for me and most others who run long cables but might be a consideration if you prefer true-bypass.

The tuning is quick, clean, and plenty accurate (although again, this is not a strobe tuner, so intonation is probably not going to be the best). But another thing I love (and actually the main reason I bought it) is the dual outputs. The "Main" out will mute when you activate the tuner function, and the "Bypass" out does not - it's active all the time. This lets you send the "Main" out to your amp, while running the "Bypass" output to a DI or recorder, so you can monitor through your live rig while recording a clean DI signal that you can re-amp later. Your recording engineer WILL thank you for having a DI signal, and this is a cheap and easy way to get it. Finally, it also allows you to daisy-chain power to other pedals if you have an AC adapter and the daisy-chain cables, which is handy if you don't have a separate power supply and cables for each (or if you just want to save space on your power strip).

Ease of Use
For a pedal with so many tuning modes, it's super-easy to use. Just plug it in, push the buttons on the top to select your tuning mode and (if desired) offset, step on the switch, and tune your instrument.

Three words: It's the Boss. If you've played guitar and/or bass for more than a few weeks, you probably already know what's up, but I'll recount the story of the day I got it anyway: I opened the box, examined it for any issues (I bought this one used), and finding none, proceeded to plug in and test it. From there I picked it up to bring it into the office with the rest of my rig, and promptly tripped over the coffee table, sending the pedal crashing into the wall. My fiancee looked HORRIFIED with the fear that I might have just damaged a pedal I'd just bought, so I couldn't help laughing as I assured her that I was totally confident that the drywall had taken the worst of the collision. And I was right. ;)

Very, very worth the money. There are other pedal tuners out there, and this is the yardstick that all the others are measured against.

Manufacturer Support
Has anyone ever had to contact Boss for problems with one of their pedals? I sure haven't, and I don't know anyone who ever has. I'm not SURE they would survive a direct nuclear strike, but I'm also not sure they wouldn't.

The Wow Factor
I lived without a pedal tuner for years and years, and since getting this one, I feel like a total chode for not doing it years ago. Just buy the thing - your bandmates, housemates, audience, and production crew will all be grateful, even if they don't say it.

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