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Technical Information

Direct Coupled Bridge
The patented Yairi Direct Coupled Bridge is both visually unique and ultimately functional. This significant improvement in guitar design better utilizes the energy of the vibrating string by “coupling” the string to the top – a more efficient transfer of energy. This energy is applied directly to the top, increasing volume and projection. With traditional bridge designs, string tension forces the bridge toward the neck. This causes lifting of the bridge at the rear and a dip in the top behind the soundhole. The Yairi Direct Coupled Bridge redirects the string tension downward on the bridge, eliminating the problems of lifting and top distortion, and allowing lighter bracing of the top for maximum tone.

Alvarez Yairi Neck Extension
Many years ago, Kazuo Yairi realized that traditional neck joint designs did not allow for broad adjustment of the fingerboard. Most guitars would develop a hump at the neck/body joint. Yairi developed his unique neck extension, which allows truss rod adjustment over a wider range of the fingerboard, eliminating neck/body fingerboard irregularities.

Hand-Scalloped Top Bracing
Each Alvarez Yairi guitar is individually “voiced” to unlock its complete sonic potential. Yairi luthiers hand-carve each top brace depending on the thickness and flexibility of the top, allowing for the perfect balance of tone, volume and structural integrity. This gives each Yairi its own distinctive sound.

System 600T MK II

1. BAT Battery Indicator: When a guitar cable is connected to the output jack, the BAT LED will light, and the System 600T MK II preamp/Eq functions are activated. (Please note that the digital tuner function can be activated without connecting a cable to the output jack). To prevent excessive battery consumption, unplug your cable from the output jack when the System 600T MK II is not in use. When the battery is wearing out, the LED will become dim, and the signal will become distorted. If the LED does not light, remove the chassis and replace the battery. 2. PIEZO: This control adjusts the level of the under-saddle bridge piezo pickup. 3. AUX: This control adjusts the level of the auxiliary input, either an Alvarez ASP50 MK II sound hole pickup or an Alvarez ACM50 condenser microphone.
4. LEVEL: This switch adjusts the input level of the AUX input. When using a magnetic sound hole pickup or condenser mic, this switch should be set in the -20dB position. When a dynamic microphone is used, this switch should be set in the 0dB position.
5. PHASE: This switch reverses the polarity of the PIEZO input relative to the AUX input. If the polarities of the different inputs are “out of phase”, a noticeable loss of low frequencies (bass) will occur. If there is a loss of fullness, or low end when two input signals are mixed, reverse the position of this switch (In/Out) to correct the polarity.
Note: If only one input is used, this switch will have no effect.
6. TREBLE: This slider provides +/- 15 dB of boost/cut at 10kHz. In its center position, there will be no effect.
7. BASS: This slider provides +/- 15dB of boost/ cut at 100Hz. In its center position, there will be no effect.
8. MID: This slider works in conjunction with the MID FREQ control. It provides +/- 15 dB of boost/ cut at the center frequency determined by the MID FREQ control.
9. MID FREQ: This control adjusts the center frequency of the MID slider, variable from 600Hz to 1.2kHz. If the MID slider is set to its center position, no effect will be heard. Maximum effect of this control can be heard as the MID slider is set for boost or cut. Note: The main Eq system (TREBLE/ MID/ MID FREQ/ BASS) controls will only affect the piezo input signal. These controls have no effect on the AUX input signal.
10. MASTER: This control is the Master Volume, which adjusts the overall output of the System 600T MKII, including both the PIEZO and AUX inputs.
11. NOTCH: This switch engages a notch filter, which is used to control feedback in live performance applications. When the switch is in its IN (down) position a deep, narrow band of frequencies is cut from the signal, depending on the position of the FREQ control. This notch filter is located “post Eq” in the circuit and will affect the combined PIEZO and AUX input signals.
12. FREQ: This control adjusts the center frequency of the “anti-feedback notch”. With the NOTCH switch engaged, turn the MASTER control up until feedback is heard. Adjust the FREQ control until the feedback disappears.

For more information, down load the Alvarez System 600T MKII manual.

When was my Yairi made?

By reading the number stamped on the heel block of your Yairi, you can tell in which year it was made. The first two numbers correspond to the year of the Emperor of Japan at that time. (See chart below.) The second two numbers refer to the month of production.