Back to Top
LCD Display - Basic Operation
The LCD displays information such as the note being tuned, the temperament, open tuning mode etc. The diagram below shows the general layout of the information on the LCD for normal operation.
The ST-122 has many special features, and the LCD configurations for these special features are shown in a later section.
The examples below show the display when using the equal temperament. In this case, the temperament name is not displayed.

Back to Top
Using The Special Features
Open Tuning Modes
The tuner operates in either chromatic mode, or one of up to 17 different open tuning modes. The open tuning modes are useful for any stringed instrument. The tuner comes programmed with a number of commonly used open tunings for guitar, bass and bowed instruments. The user may program any desired open tuning for any stringed instrument no matter how many strings it has. See the appendix for a complete list of the pre-programmed tunings.
In an open tuning mode, the tuner only selects notes that are defined for the particular tuning. For example, standard guitar tuning has six notes, E4, B3, G3, D3, A2 and E2. Open tunings are very handy when an instrument is way out of tune, such as when putting on new strings or changing from one alternate tuning to another.
To select an open tuning, press the Mode button. The name of the currently selected tuning along with the string number is shown on the bottom line of the LCD as shown below.

Each time the mode key is pressed the tuner advances to the next open tuning. Holding the Alt key and pressing Mode will backup through the list of available tunings.
Back to Top
Flat Tuning
Flat tuning lowers the pitch of all notes below the regular tuning from one to six semitones. Hold the Alt key and press the Note- key once for each flat desired. The LCD display will show the number of flats selected. In the example below, four flats have been selected.

To reduce the number of flats, use the Alt-Note+ key combination, or clear them with the Alt-Clear key combination.
Sharp Tuning
This is the inverse of flat tuning and operates in the same manner.
Back to Top
Changing the Reference Pitch
The default reference pitch is A4=440 Hz. This can be changed in .1Hz increments to any value from 220.0 Hz to 880.0 Hz.
To change the reference pitch, press the Alt-A440 Change key combination. The display will then look as shown below:

Use the Note keys to change the frequency in 1 Hz increments, and the Cents keys to change it in .1 Hz increments.
Pressing Note+ and Note- simultaneously will set the frequency back to 440.
When finished, press the Alt key by itself to save the new value and return to normal operation.
When the A4 value is anything other than 440Hz, its frequency is shown in the upper right of the LCD display as demonstrated below (A4 is set to 445.3Hz).
To set the pitch back to 440Hz, you can use the Alt-Clear key combination, or Alt-A440 Change then press Note+ and Note- together.
Back to Top
The Cents Keys
The cents keys adjust the selected note by up to ±50 cents in increments of 1 or .1 cents. This allows you to precisely measure a note, or create a custom tuning for special purposes.
To see how far a note is out of tune, sound a note and use the cents keys to adjust the tuner until the strobe display is stationary. By default the increment is 1 cent. To change to .1 cent, press both keys at the same time.
The cents offset is displayed to the right of the tuning note on the LCD as shown below.

The Cents keys have an auto repeat feature where if you hold the key down for one second the value will automatically increment or decrement.
Pressing and holding both keys for 1 second resets the cents offset back to zero.
Back to Top
LCD Backlight
The LCD backlight mode is set using the Alt-BAKLITE key combination. Hold the Alt key down and repeatedly press the BaKLITE key to scroll through the four different backlight options:
-
Off - the backlight is never used.
-
On - the backlight is on all the time. Note that this will cut the battery life in half.
-
On Key - the backlight will illuminate any time a key is pressed, and will remain on for about 5 seconds.
-
On Sound - the backlight will illuminate when a note is played.
The Clear Key
Pressing the Alt-Clear key combination is a quick way to reset any special functions and offsets that have been set. The following happens when Alt-Clear is pressed:
-
Cents offset is reset to zero.
-
The A4 reference frequency is set to 440Hz.
-
Any sharps or flats are cleared.
-
The temperament is set to equal temperament.
-
The display frequency feature is turned off.
-
Auto mode is selected.
- Chromatic mode is selected.
Back to Top
The Setup Menu
Pressing the Alt-Setup key combination enters the setup menu. The menu is set up so that pressing the "Auto" key advances to the next menu item without making any changes, and the "Note+" key performs the indicated action.
The Setup Menu is used to perform the following functions. These are covered in detail in later sections:
-
Auto Power Off - when on, unit will shut off after about 5 minutes of inactivity.
-
Show Note Frequency - when selected, the tuning note's frequency in Hertz is shown on the LCD.
-
Power on Settings - by default the tuner powers up in exactly the same state as when it was shut off. There are several other options, explained in the next section.
-
Enter New Tuning - allows the user to program custom open tunings.
-
Delete Tuning - user may delete the currently selected tuning.
- Edit Tuning - user may edit the notes in any existing tuning except "Guitar".
-
Change Temperament - the user can select any available temperament.
-
Delete Temperament - self explanatory
-
Edit Temperament - new temperaments may be defined, and existing ones may be edited.
-
Restore Defaults - this will restore all the factory defaults including the tunings and temperaments. Any user defined tunings and temperaments will be erased.
Back to Top
Power On Settings
There are three different options for the tuner's settings when it is powered on. As shipped from the factory, it powers on with the exact same settings as the last time it was shut off.
The three options are:
Factory Defaults - The tuner will always be set as follows when first turned on:
Current Settings - When this is selected from the Setup Menu, the current settings are saved and the tuner will start with these settings each time it is powered up.
From Power Off - The tuner powers up with the exact same settings as when it was last turned off. This is the default as shipped from the factory.
Back to Top
Defining a New Open Tuning
To define a new open tuning, first enter the Setup Menu via the Alt-Setup key combination, then advance through the options using the Auto button until you come to a selection called "Enter New Tuning". Press the Note+ key to get started.
Enter the Name for the New Tuning
The first step is to enter a name for the tuning. The name may be any combination of letters and numbers. There can be a maximum of 7 characters in the name. The name is entered as follows:
-
Note+/- scrolls through the alphabet
-
Cents+ toggles between upper and lower case
-
Chrom advances to the next character position
-
Cents- backspaces over the previous character
-
Auto accepts the name and advances to the next step, entering the notes for each string.
Entering the String Tunings
This starts with the highest string, which is always string 1. The strings must be entered starting with the highest note and going to the lowest.
-
The display will show the currently selected note on the first line, and the second line will read "Set str 1 enter"
-
Use the NOTE+/- and CENTS+/- keys to select the note. The unit is in manual mode. You can set the note by plucking the desired string and adjusting the note and cents to match it.
-
Press the AUTO button (under the word "enter" on the display) to enter the note into memory and proceed to the next string.
-
It will then ask if there are any more strings. Pressing yes will repeat the procedure for entering a new string. No will enter the tuning into memory and return to normal operation.
Canceling a Tuning
If you wish to cancel entering a tuning, simply shut the power off. The tuning is not saved until you tell it there are no more strings.
Back to Top
Editing A Tuning
You may edit the notes of any tuning except Guitar. the note values of the tuning may be changed, but the number of notes and the name of the tuning cannot be changed.
To edit a tuning, first use the MODE key to select the tuning you wish to edit. Then enter the Setup Menu via the Alt-Setup key combination, and advance through the options using the Auto button until you come to a selection called "Edit Tuning?". Press the NOTE+ key to get started. The display will then show the following message, reminding you that the MODE key is used to exit edit mode.

Press the AUTO key (under the word "Start" on the display) to enter the edit mode. The display will then look similar to this:

The AUTO/ALT keys are used to scroll through the different notes in the tuning. The bottom line shows the "string number" and the upper line shows the note for that string. Simply use the NOTE+/- and CENTS+/- keys to adjust the notes you want to change.
When you are finished, press MODE and the tuner reverts to normal operation.
Back to Top
Deleting A Tuning
Any tuning except Guitar and Chromatic may deleted.
-
First, use the MODE key to select the tuning you wish to delete.
- Enter the Setup Menu and advance to the option "Delete Tuning?". The second line will have the name of the tuning. Pressing NOTE+ for yes will delete the tuning from memory. Pressing AUTO will return to normal operating mode without erasing the tuning.
Once erased, a user defined tuning can only be restored by entering it again.
The tuner comes from the factory with a number of open tunings build in. These may be erased, and can be restored by selecting the "Restore Defaults" option from the Setup Menu. However, doing so will erase any user defined tunings and temperaments.
Back to Top
Temperaments
Selecting a Temperament
Enter the Setup Menu (Alt-Setup keys) and advance to the option "Change Temermnt". Select the "Yes" option by pressing the NOTE+ key. The display will then look something like this:
The top line shows the currently selected temperament, in this case the equal temperament. Use the NOTE+/- keys to scroll through the list of available temperaments. NOTE+ scrolls forward and NOTE- scrolls backward. Press the AUTO key to use the temperament shown on the first line.
When the temperament is anything other than the equal temperament, the name will appear in the upper right of the display as shown below, where the Pythagorean temperament has been selected. Temperament names are limited to 7 characters.
Editing a Temperament
Temperaments are defined as offsets from the notes of the equal temperament. These offsets may be edited for any temperament except the equal temperament. Temperament names cannot be changed, however.
To edit a temperament, enter the Setup menu (Alt-Setup keys) and advance to the option "Edit Temperament". Select the "Yes" option by pressing the NOTE+ key. Here's how the display will look if the tuner was in the Pythagorean temperament:
The top line shows the temperament to be edited. If the tuner was in the equal temperament, the display will look like this:
This is used to create a new temperament, and is covered in the next section.
Use the NOTE+ and NOTE- keys to scroll through the list, and press the AUTO key to edit the temperament. The display will then show the note, the offset in cents and the name of the temperament being edited as shown below.

Use the NOTE keys to scroll through all 12 notes of the scale, the CENTS keys change the offset for the note in increments of .1 cents. Holding one of the CENTS keys down for one second will cause it to auto-repeat. Press the AUTO key when done.
Creating a New Temperament
To create a new temperament, follow the same steps as for editing a temperament, using "New Temperament" as the name of the temperament to edit. You will then be prompted to enter the name for the new temperament. This is done in exactly same manner as entering the name for a new open tuning:
-
Note+/- scrolls through the alphabet
-
Cents+ toggles between upper and lower case
-
Chrom advances to the next character position
-
Cents- backspaces over the previous character
-
Auto accepts the name and advances to the next step, entering the offsets for each of the 12 notes.
The offsets for each note in the new temperament are set to 0.0, and are changed just as for editing a tuning.
Back to Top
LCD Display - Advanced Features
The LCD displays information such as the note being tuned, the temperament, Auto/Manual mode, tuning mode (Chromatic or Open Tuning), A4 reference and the frequency of the note. Many of these are options and only displayed if selected.
The diagrams below show the most common display configurations.
The note being tuned is always shown in the upper left of the display. The bottom line always shows the tuning mode, and Auto/Manual.
Below is the display when the Guitar mode is selected.

This tells the user the tuner is in the Guitar mode and currently is tuning the 3rd string which is G3.
The note can consist of as many as 4 elements: The note letter, the octave, any cents offset, and any sharps or flats. The example below shows the note offset by 1.5 cents and two flats:

The important thing to remember is the note is always displayed at the start of the first line.
The upper right of the display shows special features. If in a temperament other than equal, it shows the temperament name. Here the Pythagorean temperament has been selected.

The upper right is also used to show the reference pitch if it has been changed from 440 Hz. Here it's been set to 438.7Hz.

So what happens if there is a conflict and there are two values that by themselves would be in the upper right? The ST122 will configure the display so that all of the information is shown. Certain fields will be abbreviated. The example below shows how the display would look in the Pythagorean temperament with A4 set to 438.7Hz.

Back to Top
Specifications
Dimensions |
4.75" (12cm) x 2.7" (6.9cm) x 1.4" (3.6cm) HxWxD |
Weight |
175 g / 6.2 oz (including battery) |
Temperaments |
Equal plus 14 user defined (Just and Pythagorean are pre-programmed into user defined temperament memory) |
Tuning Range |
C0 (16.35 Hz) to C8 (4,186.0 Hz) |
Accuracy |
+/- .02 Cents (calibrated crystal oscillator) |
Reference Pitch |
A4 = 220.0 Hz to 880.0 Hz in .1 Hz increments. |
Jacks |
Input, Output (1/4") and external 9 VDC |
Power Supply |
9 Volt Alkaline Battery(included), or external 9 Volt DC adapter (optional). |
Power Consumption |
23 mA typ., 50mA with backlight on |
|