Re: [sdiy] db to semitones, octaves.

[Roman]

not exactly 2 different things if we think about CV. That's voltage, one of the things measured in dB as you mentioned.
Another example is VCO using SSM2164 as core element. It's control input is specified in datasheet in decibels (about 33mV/dB) and it's used to set frequency in VCO.

Roman

---- Wiadomość Oryginalna ----
Od: John L Marshall 
Do: Roman , karl dalen 
Kopia do: synth-diy at dropmix.xs4all.nl
Data: Wed, 26 May 2004 07:07:27 -0700
Temat: Re: [sdiy] db to semitones, octaves.


Two different things:

dB is a relative unit of measure (ratio) of amplitude, acoustic pressure, voltage, current, power, and so on. A 2:1 power ratio is 3dB. A 2:1 voltage ratio is 6dB.

semitones, octaves are a relative measure of frequency in Hertz of cycles per second. One octave has a frequency ratio of 2:1 or 1:2. One semitone has a frequency ratio of 1.059463... in equal temperament or 16:15 in just intonation

If you were to observe a waveform on an oscilloscope, the amplitude would be observed on the vertical axis and the frequency would be observed on the horizontal axis.

Take care,
John
----- Original Message ----- 
From: Roman 
To: karl dalen 
Cc: synth-diy at dropmix.xs4all.nl 
Sent: Wednesday, May 26, 2004 1:03 AM
Subject: Re: [sdiy] db to semitones, octaves.


db or dB like decibels?
1 octave means times-two, what in dB equals 6.0206dB, 1 semitone is about 0.5dB
1 dB = 1.993 semitone

Roman
---- Wiadomość Oryginalna ----
Od: karl dalen 
Do: synth-diy at dropmix.xs4all.nl
Data: Wed, 26 May 2004 04:16:25 +0200 (CEST)
Temat: [sdiy] db to semitones, octaves.


Hi!

Is there any chart or table for converting db
values into span of semitones, or octaves?

Is there any formula for this?

KD.  
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