ECC82JJ 12AU7 JJ tube V1+low mic+lownoise Röhren Set

JJ ECC82 / 12AU7 Red Label – low-noise V1 set of two

This set contains two current-production JJ ECC82 valves. Each valve is an indirectly heated medium-mu dual triode with two electrically separate systems, relatively low plate resistance and a nine-pin B9A Noval base.

BTB selects both valves for sensitive V1, line, buffer and driver positions with attention to low noise, low hum and low microphony. An optional matched / balanced grade additionally groups the valves so that all four triode systems have closely corresponding electrical measurements.

Suitable applications

• Hi-fi and studio line stages using ECC82 or 12AU7 valves
• Cathode followers and relatively low-impedance buffer stages
• Driver stages for compatible valve power amplifiers
• Phase-inverter, differential and long-tail-pair circuits
• SRPP stages with a correctly calculated operating point
• Stereo amplifiers using one ECC82 per channel
• Compatible guitar amplifiers and effects equipment using 12AU7 valves

BTB selection and product configuration

Package contents

Two JJ ECC82 / 12AU7 valves

Standard selection

Checked for low microphony, low noise and low hum in sensitive V1 and audio positions

Matched option

The two valves are grouped for closely corresponding electrical measurements

Balanced option

The two triode systems within each valve are selected for closely corresponding values

Complete selection with the option enabled

All four triode systems in the two valves are considered together

Red Label version

Product or printing version of the offered JJ ECC82 rather than a separate electrical type

Production type

Current production, not historical NOS stock

Manufacturer

JJ Electronic, Slovakia

Technical data

Valve type

Indirectly heated medium-mu audio dual triode

Type designations

ECC82 and 12AU7

System construction

Two electrically separate triode systems with individual plates, control grids and cathodes

Base

Nine-pin B9A Noval

Parallel heater voltage

6.3 V

Heater current at 6.3 V

300 mA per valve

Series heater voltage

12.6 V

Heater current at 12.6 V

150 mA per valve

Typical operating point per system

250 V plate voltage, -8.5 V control-grid voltage and 10.5 mA plate current

Amplification factor

Approximately 17

Transconductance

Approximately 2.2 mA/V

Plate resistance

Approximately 7.7 kΩ

Maximum plate voltage

300 V per triode system

Maximum plate dissipation

2.75 W per triode system

Maximum cathode current

20 mA per triode system

Maximum negative grid voltage

-50 V

Maximum grid-circuit resistance

1 MΩ according to the JJ limiting-value table

Maximum heater-to-cathode voltage

180 V

Manufacturer phase-inverter example

JJ documents 15 or 24 V RMS output at 250 or 350 V supply respectively, with 1% total distortion under the specified test conditions

Dimensions

Maximum approximately Ø22.2 × 56.3 mm including the base pins

Pinout and heater wiring

Triode system on pins 1 to 3

Pin 1 plate, pin 2 control grid and pin 3 cathode

Triode system on pins 6 to 8

Pin 6 plate, pin 7 control grid and pin 8 cathode

Heater connections

Pins 4 and 5 with pin 9 as the centre connection of the split heater

6.3 V heater connection

Join pins 4 and 5 and apply 6.3 V between this connection and pin 9

12.6 V heater connection

Apply 12.6 V between pins 4 and 5; pin 9 is not used for the heater supply

Pin-numbering view

Pin numbering follows the conventional underside view of the base

Comparison with related dual triodes

ECC82 and 12AU7

European and American designations of the same basic valve family

6189

Related industrial or quality version whose exact ratings and equipment approval should be checked before substitution

ECC802S

Related long-plate version with different mechanical construction and potentially different microphony behaviour

ECC81 or 12AT7

Uses a greater amplification factor and higher transconductance; not an identical direct substitute

ECC83 or 12AX7

Uses substantially greater voltage gain and much higher plate resistance; not an unchecked replacement

Sound positioning

JJ subjectively describes the ECC82 as smooth and well defined for audio and guitar amplifiers. BTB subjectively positions the Red Label version as slightly warm and detailed. The audible result also depends on the operating point, plate load, cathode circuit, coupling capacitors, power supply, feedback and complete audio system.

Selection and application notes

V1 selection primarily describes acoustic behaviour. The additional matched / balanced grade can be useful in stereo, differential, SRPP and phase-inverter stages because it considers the electrical characteristics of all four systems.

A 20 mA maximum cathode-current rating does not mean that every ECC82 stage should operate at this current. The plate resistor, cathode circuit, dissipation, supply voltage and required voltage swing must be calculated together.

The ECC82 can provide greater current and drive lower impedances than a typical ECC83 but offers substantially less voltage gain. Substitution must therefore not be based on the common socket alone.

Hazardous plate voltages and stored charge may remain inside the equipment. Disconnect the mains supply, discharge the circuit properly and allow the valves to cool before replacement.

Questions about selection and use

Is the JJ ECC82 V1 set suitable for line, buffer, cathode-follower and driver stages?

Yes, the JJ ECC82 V1 set is suitable for compatible line, buffer, cathode-follower, driver and phase-inverter stages specifying an ECC82 or 12AU7. The heater wiring, operating point, load and heater-to-cathode voltage must suit the circuit.

Can the JJ set replace two existing ECC82, 12AU7 or compatible 6189 valves?

Yes, the JJ set can replace two ECC82 or 12AU7 valves and compatible 6189 applications when the base, heater wiring, operating point and ratings match. The ECC81, ECC83 and 12BH7 are not identical substitutes despite related applications.

Is the matched / balanced option useful for stereo, SRPP or phase-inverter stages?

Yes, the matched / balanced option is useful in such stages because it supports closely corresponding values between the two valves and across all four triode systems. The standard V1 selection primarily focuses on noise, hum and microphony.