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M2 Circuits and T.M. Electronics
Universal Dual Triode PCB
Universal Dual Triode PCB The Universal Dual Triode PCB is intended to be used with the 12A*7 series of vacuum tubes, or other types with the same pinout.
The multiple configurations are achieved by the combined use of component placement and jumpers.
The PCB can be used for the most common triode configurations:- Common cathode amplifier- Cathode follower- Phase splitter
PCB Features
Jumpers
J1 is used for paralleling the filaments of a 12A*7 by shorting 1 and 2.
P# Pad Name Function
P1 B+A B+ supply for triode A
P2 B+B B+ supply for triode B
P3 GND A Circuit ground for triode A
P4 GND B Circuit ground for triode B
P5 X Filament
P6 Y Filament
P7 Z Filament, center-tap
P8 L+ Backlight LED anode
P9 L- Backlight LED cathode
P10 IN A Input to grid of triode, AC coupled, triode A
P11 FB A, P Optional feedback, output connection, triode A
P12 FB A, K Optional feedback, cathode connection, triode A
P13 OUT A, P Plate output, AC coupled, triode A
P14 OUT A, K Cathode output, AC coupled, triode A
P15 IN B Input to grid of triode, AC coupled, triode B
P16 FB B, P Optional feedback, output connection, triode B
P17 FB B, K Optional feedback, cathode connection, triode B
P18 OUT B, P Plate output, AC coupled, triode B
P19 OUT B, K Cathode output, AC coupled, triode B
1
1
2
2
3
3
4
4
D D
C C
B B
A A
Title
Number RevisionSize
LetterDate: 2018-11-02 Sheet ofFile: C:\Users\..\DualTriodeSCH.SchDoc Drawn By:
X YZR2Rg
R5Rg
R3Rk
R4Rp
R7Rp
R6Rk
2
1
3 4 59
V1A12AX7
7
6
8
V1B12AX7
B+A B+B
GND A GND B
B+A
B+B
GND A
GND B
X
Y
Z
C3
Cp
C4
Ck
C7
Cp
C8
Ck
C1
Ci
C5
Ci
P10
IN A
P15
IN B
P13
P OUT A
P18
P OUT B
P14
K OUT A
P19
K OUT B
P1
B+ AP2
B+ B
P3
GND A
P4
GND B
12
J1PAR FIL
C2Cbp
C6Cbp
P5
X
P6
Y
P7
PZ
R1
Rg
P8
L+
P9
L-
P11
FB
P12
FB
P16
FB
P17
FB
0014 C
UNIVERSAL DUAL TRIODE (12A*7) BOARDM2 CIRCUITS & T. M. ELECTRONICS
MAURIZIO MISERERE1 1
CR1LED