Post on 04-Sep-2015
description
1 2 3 4 5 6 7 8
A
B
C
D
87654321
D
C
B
A
+V +V+V +V
-10V -10V
-10V
-10V
-10V-V
-V
Eref
KBD1/SEQ CV
KBD2 VCF CVMIXER
FROM
Eref
FilterKBD Track
CV
EXPONENTIAL AMP 1.2V/OCTVCF Cutoff
VCF ModeLPF
BPF
HPFVCF OUT
TO VCA
LPF Out
BPF OutHPF Out
Res (Q)VCF Input
FROMVCF Mix
REF Voltage -10V
1
910
+V
-V
+15V
-15V
GND
-V
8
6
5
uA 726
+V
4K7
50K
10K
10K
470R
1K5
BC550BC550
1K5
2K2
6K8
4K7
50K
1K
10K2K49
10K
10K
10K
2K49
470R
37K4
100R1N4148
uA 7265K6
267R
1K5
22K
8K2
5K
15K
1K5
1N4148
22K1
10K
10K 470R
15K
3K6 3K6
3K6 3K6
10R 10R
1K
10R10R
1K
100K
100K15K
1K
50K
100K
100K
3K63K6 3K63K6
1M51M5
221K
100n
3p3
C
6n
C
6n
C
6n
C
6n
1n
100n
ZENER 8V2
VCF OUT MIXER
CURRENT DRIVERS
INTEGRATORS
TRANSISTOR PAIR 1 PAIR 2
TRANSISTOR
3
26
U1
TL071
3
26
U2
TL071
3
26
U3
TL071
3
26
U4
TL071
3
26
U5
TL071
3
26
U6
TL071
3
26
U7
TL071
3
26
U8
TL071
3
26
U10
TL071
3
26
U9
TL071
Cutoff
50K
50K 50K
ORIGINAL ICs :U1,3,4,5,6,10 = uA741 U2 = 1456U7,8,9 = uA748U11 = uA726TR. PAIR 1,2 = TD101
Use TL071 for all ICs, for Tr. pair use matched NPNs (~1mV) or tr. pairs likeMAT02 or 2SC1583, or you can use CA3046 or CA3086 instead, with pinsshowed in brackets, and use it for expo tranny also, but you lose uA726heated stability so you must consider using separate CA with heating andsensing transitor shceme (like shared with VCO expos). You can put discrete NPN in place of 726 and lose some temp. tracking, but it's not crucial in VCF.Q1,2 are labeled "14", use some NPNs.Capacitors C can be changed with some higher values for different effect.
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(1)
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(3)
(4)
(5)(6)
(9)
(8)(11)
(7) (10)
EML-101 Multimode VCF1998. Drawn by Marjan Urekar