Register Addresses 40H; Msb = 0: Detune - Yamaha YM3806 Programmer's Manual

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OPQ Programmer's Guide V 1.1

There is quite a large range of frequency numbers both under and above of the basic

octave. According to my own measurements, the highest note which can be reached by

changing only the frequency number, is the next octave's G#. At the low end the range is

bigger: more than one octave below can be reached. This is good news while

implementing pitch bend: no need to hassle with octave numbers during bend.

5.4 Register addresses 40H...5FH

operator specific. The addressing scheme is described in chapter 4.2.

These registers serve dual purpose: the most significant bit defines the interpretation of

the lower bits.

DET5...DET0

Operator's frequency will be detuned from the nominal frequency set by registers

20H...3FH. Detune can be up or down. Detune amount 32 (20H) is the mid-point:

This means that you always have to write 20H to this register if you want the operator to

be in tune!

Note

DET5

DET4

Operator's detune amount 0...63.

63 (3FH) = about 20 cents up

...

32 (20H) = no detune

...

0 (00H) = about 20 cents down

Freq number

6C6H

72DH

79AH

80EH

889H

90AH

DET3

DET2

DET1

DET0

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