TC Electronic Polytune Review

Stompbox tuners aren''t typically fodder for EM reviews, but because of the groundbreaking polyphonic detection technology in TC Electronic''s PolyTune ($99), we thought it deserved coverage.
Image placeholder title
Image placeholder title

PolyTune''s Polyphonic mode lets you see the in-tune status of your strings all at once.

Stompbox tuners aren''t typically fodder for EM reviews, but because of the groundbreaking polyphonic detection technology in TC Electronic''s PolyTune ($99), we thought it deserved coverage.

The size of a standard stompbox, the shiny white unit features spiffy-looking blue-and-black lettering, and has a single footswitch in the middle that toggles from active tuning status (with the output muted) to True Bypass. The latter is an important feature because it means the unit won''t adversely affect your tone when plugged into your signal chain.

PolyTune''s I/O comprises mono ¼-inch jacks, with the input on the right side and the output on the left. (Typical of a floor tuner, it has no built-in mic.) The display is an LED, but it''s not one of those cheesy ones where you only see part of a letter—it looks really good. It''s easy to read indoors and on a dark stage. In direct sunlight, the readability drops significantly, but you can still see enough to tune.

What makes PolyTune different is its polyphonic detection of string pitches, which means you can strum your guitar when it''s set to Guitar mode or your bass when it''s in Bass mode (which can accommodate 4-, 5-, and 6-string basses), and you''ll get a reading of all the strings at a glance, showing which are sharp, which are flat, and which are in tune. In Polyphonic mode, the strings are represented in a semicircular pattern of green-light pairs, each of which indicates an individual string.

If you see red lights below the green pair for a particular string, it indicates flatness; above indicates sharpness. (If a string is more than a half-step sharp or flat, the green lights will either blink or not even show up, but red ones will indicate sharpness or flatness.) When you begin to tune, the unit switches automatically into Chromatic mode—for which you can choose either a Needle display or a Stream display (similar to a strobe tuner)—for the string you''re tuning.

I asked the product manager at TC for more details on the technology used for the polyphonic detection, and he was understandably reticent, explaining that the company needs to keep its methods secret for competitive reasons. He said that what made that feature particularly challenging to engineer was the amount of harmonics created when a string is plucked. To give you the near instantaneous all-strings-at-a-glance display, PolyTune''s software has to be able to quickly separate the fundamentals from the harmonics.

In Polyphonic mode, you strum an open chord (assuming you''re in standard guitar or bass tuning), and you instantly see your tuning status and know which strings need to be tuned and in which direction. I''ve been using the tuner, both in my pedal board and in my studio, and I''ve found it to be extremely accurate and stable. PolyTune also has a very handy feature called Tuning Magnet, which slows down the Needle or Stream display in Chromatic mode as it gets closer to the target pitch, making it easier not to overshoot.

However, PolyTune is not for everyone. If you play in open tunings and want to use the Polyphonic tuning mode, you''re out of luck. That mode can only recognize standard guitar tuning, although it allows you to drop the entire tuning down as far as a fifth below standard. Other instruments, like violins or mandolins, are not recognized in Polyphonic mode either. That said, the Chromatic mode is awesome and will smoothly detect any note on any instrument, which is the best you can say about any other tuner.

When I tried PolyTune with my Taylor 510 acoustic, which has a built-in piezo pickup and with a piezo-equipped resonator guitar, the display wouldn''t stay in Polyphonic mode for more than a couple of seconds before snapping back to Chromatic mode. Not a deal-breaker by any stretch, but curious. One other minor drawback is that the tuning indicator doesn''t read out in cents, so if you want to use a tempered tuning, it will be difficult to gauge what the correct pitches are.

Overall, PolyTune is an excellent product that gives you accurate tuning and the unique all-strings view of Polyphonic mode. If you''re an iPhone user, you can get the PolyTune app, which offers essentially the same functionality (albeit with the iPhone mic substituting for ¼-inch jack) for $9.99. It wouldn''t be as useful onstage, but in a quiet studio environment, it provides a very inexpensive way to tap into TC''s impressive new technology.

Overall rating (1 through 5): 4