YMU757B Datasheet, PDF (31/43 Pages) YAMAHA CORPORATION – MA-1C

YMU757B
A level adjustment recommendation example in all
FM volume or either of SP Volumes is a little squeezed as a default (from –3dB to -6dB).
When a user adjusts volume, it is considered controlling either FM or SP volume.
At this time, because the side which gain is raised to is secured in advance, either of FM volume or SP Volumes is a
little squeezed as a default.
It is recommended making gain of the part EQ amplifier about 3 - 4 times to secure the output level for which to be
one sound (For example, R1=22kΩ, R2=82kΩ).
When one sound is pronounced under this condition(FM volume as 0dB), EQ1 is 0.375Vp-p.
In this state, if set gain=four times in EQ amplifier, EQ3 becomes 1.5Vp-p.
When it is set up in -4dB with SPVOL, voltage between SPOUT1 and 2 becomes 3.6Vp-p, and can be get output
power 162mW with the speaker (RL=8Ω).
A level adjustment of four sound pronunciation simultaneously
When usual music is regenerated, the amplitude of DAC never almost swings to 1.5Vp-p.
Therefore, there is no hindrance by the setup of GAIN which is the same as 1 sound.
Adjust it with FM, SP Volume if you restrain GAIN of the part EQ amplifier a little when you are anxious about the
distortion of the sound.
A level adjustment of HPOUT
Adjust it outside the LSI when you raise gain on the HPOUT side.
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