Precision Strobe Tuner 4+

Jim Campbell

Designed for iPad

    • $9.99



A General Purpose Chromatic Musical Instrument Tuner App with special Temperament and Piano Tuning Functions.

Precision Strobe Tuner 1.91

A General Purpose Chromatic Musical Instrument Tuner App with special Temperament and Piano Tuning Functions.

The PST combines a radial Spectrum Display with a classic Strobe Tuner and Note Dial for an ultimate visualization of pitch and tone. The Strobe Display is highly sensitive with response speed that is practically instantaneous and has long been the preferred tool for piano tuners and instrument technicians.

The central Spectrum Display shows the input spectrum wrapped around the Display, with each Octave drawn in a separate color. The Note Dial is marked like a clock with the twelve notes of the Scale. All overtones of the input are shown as peaks in the Spectrum Display pointing towards their corresponding Notes. The Fundamental Indicator Tic on the Spectrum Display shows the Note of the Fundamental along the Note Dial, with the color designating the Octave. Use the Spectrum Display for coarse adjustment by tuning the Fundamental to the center of the desired Note Indicator.

As the input approaches the desired Note, a Two Group pinwheel pattern becomes visible rotating in the Strobe Display. Fine tuning is accomplished by adjusting to stop rotation. The Strobe Display responds instantaneously to changes in pitch and is extremely sensitive. The outside Strobe Display works just like a classic rotating disk strobe tuner. The Two-Group pattern rotates CCW when the input is flat, and CW when sharp. When the rotation is stopped, the note is in tune.

The previews show a general strobe display demonstration, an example of using the calibration function to measure the accuracy of a tuning fork and an example of guitar string tuning.

The first screenshot shows the display tuning a Guitar Low E string. The Fundamental appears as an Orange peak in the Spectrum Display. This string rings bright, so the overtones are also dominant in the Display.

The second screenshot shows the display for an E 440 Tuning Fork with the Calibration Dial enabled and adjusted. This Fork is 2.9 cent Flat.

The PST also includes a Programmable Temperament Function with 5 user definable banks. The third screenshot shows an example of a Temperament Bank set up to a typical Piano Stretch Curve. This can also be used for tuning alternate temperaments, pedal steel guitar setups, or special guitar intonation systems.

In addition, there are several Special Measurement Banks used for String Inharmonicity characterization and Piano Stretch Curve Estimation. Individual strings can be characterized by measuring the Fundamental and 2nd Harmonic separately. By careful selection of a few representative measurement points, a reasonable smooth fit Piano Stretch Curve can be generated. Any number of measurements can be used.

The final screenshot shows the Input Signal Scope/Spectrum Display Page.

The Detailed Operation Manual can be viewed here:

What’s New

Version 1.91

Updates for iPad and iPadOS

Ratings and Reviews

4.7 out of 5
53 Ratings

53 Ratings

Deathaya ,

Great resource for student tuners

From a student's perspective: I want something similar to "Cyber Tuner" in hand. This affordable app offers similar precision strobe display, which is valuable even just to train my hand technique. The temperament sounds quite fine; one could of course fine tune after the app.
I like that the app is being updated often.
It doesn't have presets for specific piano models, which shouldn't be a problem when a student is learning to tune by ear. I am very thankful for this app.
It does use a lot battery, my iPhone 5s wouldn't survive a whole piano tuning without external power. The phone also heats up, might cause phone to shutdown if used for too long?

Red Feather Flutes ,

Perfect tuning app

I constantly use this app to tune Native American Style flutes. A very big advantage is being able to see the harmonics of a note which shows me where slight adjustments need to be made. There are so many features available for very fine tuning. I would rate the calibration feature a “++” allowing for perfect environmental tuning. Hands down one of the best apps available for instrument making.

Much Irrated ,

Excellent and Accurate Tuner!

I use this a lot, and it’s very convenient since it’s on my iPhone. It is always with me, not in my guitar case. I love the Accuracy and simplicity!
No problem until writing this review. It is making me make up a nickname!

App Privacy

The developer, Jim Campbell, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy.

Data Not Collected

The developer does not collect any data from this app.

Privacy practices may vary, for example, based on the features you use or your age. Learn More


  • Family Sharing

    Up to six family members can use this app with Family Sharing enabled.

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