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G8MNY > TECH 14.12.25 18:12l 154 Lines 6817 Bytes #3 (0) @ WW
BID : 47232_GB7CIP
Subj: AF Noise Generator
Path: JH4XSY<JE7YGF<LU4ECL<VK2RZ<VE3CGR<PY2BIL<HB9ON<VK7AX<GB7CIP
Sent: 251214/0900Z @:GB7CIP.#32.GBR.EURO #:47232 [Caterham Surrey GBR]
From: G8MNY@GB7CIP.#32.GBR.EURO
To : TECH@WW
By G8MNY (New Nov 07)
(8 Bit ASCII graphics use code page 437 or 850, Terminal Font)
This is a audio noise generator that can make:-
WHITE NOISE that has constant energy per Hz.
PINK NOISE that has constant energy per octave, with a series of CRs to give
a 3dB per octave filtered white noise.
RED NOISE that has reducing noise per octave, with a single CR for 6dB per
octave filtering of the white noise.
SCHEME
White ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿWhite
ﾚﾄﾄﾄｿ ﾚﾄﾄﾄﾄﾄﾄﾄｿNoiseﾚﾄﾄｴAttenuatorﾃﾄﾄo
ｳOscﾃﾄｴPseudo ﾃﾄﾄﾄﾄﾄｴ ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ
ﾀﾄﾄﾄﾙ ｳRandom ｳ ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ <ﾄﾄｴBuffer Ampﾃﾄ Output
ｳCounterｳ ﾃﾄｴPink Filtersﾃﾄo ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ
ﾀﾄﾄﾄﾄﾄﾄﾄﾙ ｳ ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ
ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ Red
ﾀﾄﾄｴCR Filterﾃﾄﾄﾄo
ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ
PSEUDO RANDOM NOISE GENERATOR
ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ____
ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ｳ +<ﾄﾄﾂﾄｴ7808ﾃﾄﾂﾄﾄ+12V
ｳ ｳ 4006 #4ｳ ｳ#8 ===ﾀﾄﾄﾂﾄﾙ===
ｳ ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ｳ ｳ 10uﾀﾄﾄﾄﾄﾅﾄﾄﾄﾙ10u
ｳ ﾀﾄｴ4 D2 D1+4 13ﾃﾄﾙ ｳ _ｳ_
Start Pulse ﾀﾄﾄﾄｴ6 D4 D2+4 11ﾃﾄﾄﾄﾙ
+>ﾄﾄｴﾃﾄﾄﾄﾂﾄﾄｴ>ﾃﾄﾄﾄﾂﾄﾄﾄﾄﾄﾄｴ1 D1 ｳ
+10u 27K 27K ﾚﾄﾄﾄｴ3 CLK D3+4 10ﾃﾄﾄﾄｿ#17
_ｳ_ ｳ ｳ ﾚﾄｴ5 D3 D4+5 9ﾃﾄｿ ｳ
ｳ ｳ ｳ ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ ｳ ｳ
ｳ ｳ ｳ 1st counter #13ｳ ｳ
ｳ ｳ ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｴ ｳ
ｳ ｳ __ ｳ ｳ
4030 Gates ｳ ｳ #34113 / 1ｳﾃﾄﾄﾙ ｳ
__ ﾀﾄﾄ)ﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄ(3 (( ｳ
__ +>ｴｳ6 \ ｳ \ 2ｳﾃﾄﾄﾄﾄ)ﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ
+>ｴｳ8 \ )) 4)ﾄﾄｴ ~~ ｳ ｳ
)) 10)ﾄﾂﾄﾄｴｳ5 / ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ #26 ｳ
ﾚﾄｴｳ9 / ｳ ~~ ｳ ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ｳ#34
ｳ ~~ ﾀｴﾃﾄﾂﾄ20Kﾄﾄｴ ｳ ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ｳ ｳ
ｳ n18 ｳ ｳ ｳ ｳ ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ｳ ｳ ｳ
ｳ __ ｳ ｳ ｳ ｳ ｳ ｳ 4006 #21ｳ ｳ ｳ ｳ
ｳ /13ｳﾃ<+ ｳ ｳ ｳ ｳ ｳ ｳ ﾚﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｿ ｳ ｳ ｳ ｳ
ﾀﾄ(11 (( ｳ ｳ ｳ ｳ ｳ ﾀﾄｴ4 D2 D1+4 13ﾃﾄﾙ ｳ ｳ ｳ
\12ｳﾃﾄ10Kﾄﾙ ｳ ｳ ｳ ﾀﾄﾄﾄｴ5 D3 D4+4 8ﾃﾄﾄﾄﾙ ｳ ｳ
~~ ｳ ｳ ﾀﾄﾄﾄﾄﾄｴ6 D4 D2+5 12ﾃﾄﾄﾄﾄﾄﾙ ｳ DIGITAL
113kHz Osc ｳ ﾀﾄﾄﾄﾄﾄﾄﾄｴ1 D1 D3+4 10ﾃﾄﾄﾄﾄﾄﾄﾄﾁﾄ>WHITE NOISE
ﾃﾄﾄﾄﾄﾄﾄﾄﾄﾄｴ3 CLK ｳ 3Hz-56kHz
83p === ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾙ
_ｳ_ 2nd Counter
After a count of #34113 the pseudo random noise code repeats.
AF FILTERS
ﾚﾄﾄﾄﾄﾄﾄﾂﾄﾄ<+12V
NOISE>ﾂﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄ56Kﾄﾄﾄﾂﾄﾄﾄﾄﾄﾄﾄｿ 220K ｳ
ｳ 2K7 ｳWhite ｳ 741 ｳ
ｳ _ｳ_ ｳ u33 ｳ ｳ\ｳ7
ｳ ﾀo<ﾄﾄｴﾃﾄﾄﾅﾄﾄﾄﾄｴ2 \ 25u
ﾃﾄ6K8ﾄﾄﾂﾄﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾄﾄﾄﾂﾄﾄﾄoPink ｳ ｳ� 6>ﾄﾄﾄﾂﾄｴﾃﾄﾂﾄ1Kﾄ(o Output
ｳ 1uｳ u27ｳ ｳ 33nｳ ﾚo ｳ ﾚﾄｴ3 / ｳ+ ｳ ｳ
ｳ === === ===2x === ｳRed 220K ｳ ｳ/ｳ4 ｳ ｳ ｳ
ｳ ｳ ｳ ｳ47n ｳ ｳ ｳ ﾃﾄﾄﾄ)ﾄﾄ10Kﾙ 100K ｳ
ｳ 3K 910 270 ｳ ｳ ｳ 2K7 ｳ ｳ ｳ
ｳ ﾃﾄﾄﾄﾄﾁﾄﾄﾄﾁﾄﾄﾄﾄﾄﾄﾙ ｳ ｳ ｳ+ ｳ ｳ ｳ
ｳ _ｳ_ ｳ ｳ === ｳ ｳ ｳ
ｳ ｳ ﾀﾄﾄﾁﾄﾄﾄﾁﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾁﾄﾄﾄﾄｴ
ﾀﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄ56Kﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄｴ 470u _ｳ_
u1 === BUFFER AMP
_ｳ_
SPECTRUMS
Level Constant Analyser Bandwidth
+0dBｴ------------------------------------------------------------------White
-3dBｴ \'ﾄ._ Noise
-6dBｴ \ 'ﾄ-..__
-9dBｴ \ ''ﾄ-...____ Pink Noise -3dB/O
-12dBｴ 'ﾄ. ''''ﾄﾄﾄﾄ-----......______
-15dBｴ Red ~ﾄ._ '''''''ﾄﾄﾄﾄﾄﾄ-----
-18dBｴ Noise ''ﾄ-..
-21dBｴ -6dB/O '''ﾄ-...
-24dBｴ '''ﾄﾄ--....___
-27dBｴ ''''ﾄﾄ---...___
-30dBｴ L I N E A R S C A L E '''ﾄﾄﾄﾄ----
ﾃﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾂﾄﾄﾄﾂ>Freq
0 200 400 600 800 1k 1k2 1k4 1k6 1k8 2k 2k2 2k4 2k6 2k8 3k 3k2 3k4 Hz
Level
+0dBｴ-------------------------------------------White
-3dBｴ \'-._ Constant Analyser Bandwidth Noise
-6dBｴ \ '-._
-9dBｴ \ '-._
-12dBｴ \ '-._Pink
-15dBｴ Red \ '-._Noise
-18dBｴ Noise \ '-._-3dB/O
-21dBｴ -6dB/O \ '-._
-24dBｴ \ '-._
-27dBｴ \ '-._
-30dBｴ \ 'ﾄ._
-33dBｴ L O G S C A L E \ '-
ﾀﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄ>Freq
16 32 64 125 250 500 1k 2k 4k 8k 16k 32k Hz
Level
+15dBｴ 'ﾄ._ _.ﾄ'
+12dBｴ Red 'ﾄ._ Constant Q Analyser _.ﾄ'
+9dBｴ Noise 'ﾄ._ Filters _.ﾄ' White
+6dBｴ 'ﾄ._ _.ﾄ' Noise
+3dBｴ 'ﾄ._ _.ﾄ'
0dBｴ-----------------------*---------------------Pink
-3dBｴ _.ﾄ' '-._ Noise
-6dBｴ White _.ﾄ' 'ﾄ._ Red
-9dBｴ Noise _.ﾄ' 'ﾄ._ Noise
-12dBｴ _.ﾄ' 'ﾄ._
-15dBｴ _.-ﾄ' L O G S C A L E 'ﾄ._
ﾀﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄ>Freq
16 32 64 125 250 500 1k 2k 4k 8k 16k 32k Hz
With constant Q filters in an AF spectrum analyser display the pink noise
gives a flat response.
Level
0dBｴ .ﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄﾄ.
-1dBｴ.�' '�.
ｳ L O G S C A L E
ﾀﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄﾄﾄﾂﾄ>Freq
16 32 64 125 250 500 1k 2k 4k 8k 16k 32k Hz
With Magnetic systems like tape, magnetic cutting heads, etc. Red noise will
produce a flat spectrum, with constant bandwidth analyser.
SOUND COLOURATION
With good hearing it is possible to judge AF response of system especially
when comparing using just these noises.
The White noise lets you predominately hear the top end, as the ear is like a
constant Q analyser. The Pink noise lets you judge the whole range, while the
Red noise lets you more easily concentrate on the bass resonances.
Used with a good graphic equaliser, mainly of the system colourations
(LS + room etc.) can be mostly ironed out.
Why Don't U send an interesting bul?
73 De John, G8MNY @ GB7CIP
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