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Tube circuits contain dangerous high voltages. Care must be taken when designing and building tube equipment. We assume no responsibility for any injury attained while using our product.

M2 Circuits and T.M. Electronics

Universal Noval Output PCB

Universal Noval Output PCB

The Universal Noval Output PCB is intended to be used with the EL84 vacuum tube, 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 power tube configurations:

- Class A- Class AB (when using two PCBs linked together)- Triode Mode- Tetrode Mode- Super Linear Mode

PCB Features

The following pads are provided for connecting the module to an external circuit, and to other modules.

Jumpers

J1 is used to select the bias source for the control grid. Shorting 1 and 2 will ground the bias resistor R1. Shorting 1 and 3 will connect R1 to the BIAS pad for use with an external bias.

J2 is used for selecting the screen grid source. Leaving the jumper out will allow for an external connection from the SCRN pad to an output transformer screen tap or B+ via R3. Shorting 1 and 2 will connect the screen to the plate of the tube via R3.

Class AB

Class AB can be achieved by linking the K pads of two PCBs and populating one of the boards with cathode resistor R2.

P# Pad Name Function

P1 BIAS Pad for feeding bias to the ctrl grid via R1, selected using J1

P2 X Filament

P3 Y Filament

P4 GND Supply ground

P5 IN Input to the ctrl grid, AC coupled

P6 GND Ground point for incoming signal, connected to supply ground

P7 OUT Plate connection for the output transformer

P8 SCRN Connection to the screen grid via R3, source selected by J2

P9 K Connection between cathode and cathode resistor

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\..\NovalOutputSCH.SchDoc Drawn By:

R3

RscC1

CinR1Rb

231

J1BIAS

GND

X Y

BIAS

P8

SCREENP5

IN

12

J2SCREEN

P7OUT

C2Ck

P4

GND

P2

XP3

Y

GND

X

Y

P1

BIASBIAS

P6

GND

R2Rk

P9

K

2

7

3 5 4

9

V1EL84

MAURIZIO MISERERE

UNIVERSAL NOVAL OUTPUT ASSYM2 CIRCUITS & T.M. ELECTRONICS

C0016