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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