TT 12AT7 / ECC81

4 tubes, matched as quad

EL34 II has fuller low mids and low end but does not lose headroom in the high end. Stronger than regular JJ EL34 but not as aggressive as the JJ E34L.

Typical Characteristics

• Ua = 250 V
• Ug3 = 0 V
• Ug2 = 265 V
• Ug1 = -13,5 V
• Ia = 100 mA
• Ig2 = 14,9 mA
• S = 11 mA/V
• Ri = 15 kΩ
• μg2/g1 = 11

Limiting Values

• Ua0 = 2000 V
• Ua = 800 V
• Wa(max) = 25 W
• Ug20 = 800 V
• Ug2 = 450 V
• Wg2(max) = 8 W
• Ik = 150 mA
• Uk/f = 100 V
• Rk/f = 20 kΩ

Files:

• Datasheet

With a soft and detailed sound, as well as sufficient headroom, the TT 12AU7/ECC82 enhances the sound characteristics of any amplifier, whether it's for guitar, bass, or high-end. These tubes deliver a dynamic range, captivating listeners and musician with uncompromising clean sounds and rich overdrive.

Features:

• Detailed sound
• Ideal for both low and high gain amplifiers

Tip:
Often, 12AU7 and 12AT7 types are used instead of 12AX7 tubes to either reduce the overall power of the amplifier or to just reduce the overloading of the preamp. In comparison to a 12AX7, the 12AU7 brings about a very large sonic difference, typically much greater than switching from 12AX7 to 5751 or 12AT7.

When using a 12AU7 in a driver stage normally designed for 12AX7, the overall power of the power stage is usually reduced. The extent of this difference depends on the amplifier or circuit. For example, a Marshall amplifier with a 12AX7 in the PI stage set at volume 5 will then reach the same volume level with a 12AU7 at volume 6 (perceived volume, not measured).

Electrical Properties

• Heater Voltage (Uf): 6.3V or 12.6V
• Heater Current (If): 300mA at 6.3V, 150mA at 12.6V
• Anode Voltage (Ua): Maximum 300V
• Grid Voltage (Ug1): -8.5V (typical)
• Anode Current (Ia): 10.5mA (typical)
• Anode Dissipation: Maximum 2.75W per triode
• Anode Resistance (ra): 7.7kΩ
• Amplification Factor (μ): 17
• Transconductance (S): 2.2mA/V
• Input Capacitance (Cin): 1.6pF
• Output Capacitance (Cout): 1.6pF

Mechanical Properties

• Socket: B9A (Noval)
• Number of Pins: 9

Pin Configuration

• 1 Anode (Triode 1)
• 2 Grid (Triode 1)
• 3 Cathode (Triode 1)
• 4 Heater (f)
• 5 Heater (f)
• 6 Anode (Triode 2)
• 7 Grid (Triode 2)
• 8 Cathode (Triode 2)
• 9 Center Heater (f)

Application Notes

• Heater Operation: The tube can be operated at 6.3V or 12.6V, depending on the circuit design.
• Grid Resistors: It is recommended to use grid resistors of at least 1MΩ to ensure stable operation.
• Coupling Capacitors: Capacitors with low capacitance (typically 0.1µF) are recommended to minimize high-frequency interference.

Tube-Town 12AX7 / ECC83 Preamp-Tube

The TT12AX7 impresses with its fine and detailed reproduction of the highs, which is maintained even at high amplification levels. Due to a higher H3 part, the TT12AX7 sounds significantly cleaner than many other 12AX7/ECC83 tubes, which makes the bass range appear much tighter. We therefore especially recommend this tube for styles such as clean, crunch, and metal, where high amplification and clear transparency are required.

Electrical Characteristics

• Heater voltage (Uf): 6.3V or 12.6V
• Heater current (If): 300mA at 6.3V, 150mA at 12.6V
• Anode voltage (Ua): Maximum 300V
• Grid voltages (Ug1): -2V (typical)
• Grid voltages: -50V to 0V
• Anode current (Ia): 1.2mA (typical)
• Anode power dissipation: Maximum 1W per triode
• Anode resistance (ra): 62.5kΩ
• Amplification factor (μ): 100
• Transconductance (S): 1.6mA/V
• Input capacitance (Cin): 1.6pF
• Output capacitance (Cout): 1.6pF

Mechanical Characteristics

• Socket: B9A (Noval)
• Number of pins: 9

Pin Configuration

• 1 Anode (Triode 1)
• 2 Grid (Triode 1)
• 3 Cathode (Triode 1)
• 4 Heater (f)
• 5 Heater (f)
• 6 Anode (Triode 2)
• 7 Grid (Triode 2)
• 8 Cathode (Triode 2)
• 9 Center Heater (f)

Application Notes

• Heater operation: The tube can be operated with 6.3V or 12.6V, depending on the circuit design.
• Grid resistors: It is recommended to use grid resistors of at least 1MΩ to ensure stable functionality.
• Coupling capacitors: Capacitors with low capacitance (typically 0.1µF) are recommended to minimize high-frequency interference.

The Sovtek 12AX7WB has more gain and saturation than the Sovtek 12AX7WA. Its warmer, darker sound is preferred by Rivera, VHT, Demeter, and Kendrick, among other manufacturers.

Sweet and warm sounding preamp tube with high gain. We recommend this tube for guitar/bass amps.

Files:

• Datasheet

2 tubes, matched as pair

JJ EL84 / 6BQ5 Red Label

Files:

• Datasheet

TT Selection: V1 - Low Noise
This tube is selected for sensitive input stages (V1)

Sweet and warm sounding preamp tube with high gain. We recommend this tube for guitar/bass amps.

Files:

• Datasheet

2 Tubes, matched as Pair

The high-quality TTEL84/6BQ5 tube with 12 watts of power is perfect for guitar, bass, and audio amplifiers. Inspired by classic NOS EL84 models, this tube is manufactured using modern production methods to ensure consistent high quality.

It offers an ideal combination of sound and reliability and is a direct replacement for all EL84 or 6BQ5 tubes.

Specifications

Electrical Specifications

• Type: Pentode
• Base: Noval (B9A)
• Heater Voltage: 6.3 V (min 5.8 V / max 7.7 V)
• Heater Current: approx. 0.76 A
• Anode Dissipation: 12 W
• Screen Grid Dissipation: 2 W

Operating Conditions

• Anode Voltage (Va): max. 300 V
• Screen Grid Voltage (Vg2): max. 300 V
• Grid Bias Voltage (Vg1): -7.3 V (typical for Class-A operation)
• Anode Current (Ia): 48 mA (at -7.3 V grid bias)
• Screen Grid Current (Ig2): 5 mA

Characteristic Curves

• Amplification Factor (μ): approx. 20
• Internal Resistance (Ra): approx. 38 kΩ
• Transconductance (S): 11 mA/V

Mechanical Specifications

• Length: approx. 70 mm (without pins)
• Diameter: approx. 22.5 mm
• Weight: approx. 25 g

Typical Applications

• Class-A Amplifier: 5.7 W output power at 250 V Anode voltage, 48 mA Anode current
• Class-AB Amplifier: 17 W output power at 300 V Anode voltage, 48 mA Anode current per tube (Push-Pull configuration)

Pinout

1. g1 (Control Grid)
2. k, g3 (Cathode, Screen Grid)
3. h (Heater)
4. h (Heater)
5. a (Anode)
6. • (no connection)
7. • (no connection)
8. g2 (Screen Grid)
9. g3 (Screen Grid)

Usage Notes

• Operating Temperature: Should be operated in a well-ventilated enclosure to prevent overheating.
• Interchangeability: EL84 can be replaced by the Russian 6П14П or American 7189, taking into account different specifications.

TT Selection: V1 - Low Noise
This tube is selected for sensitive input stages (V1)

Warm and balanced overall sound, paired with high resolution and brilliance, which is why the TT12AT7 achieves the best results in both instrumental and audio/high-end amplifiers.

Features:

• Warm and balanced sound
• Excellent sound resolution and brilliance
• Ideal for instrumental and audio/high-end amplifiers

Hint;
Often, 12AU7 and 12AT7 types are used instead of 12AX7 tubes in order to either reduce the overall power of the amplifier or just take back the overdrive of the preamp. Especially the 12AU7 brings a very large tonal difference compared to a 12AX7, which is usually much greater than when switching from a 12AX7 to 5751 or 12AT7.

When using a 12AU7 in a driver stage that is normally designed for 12AX7, the overall power of the power amp is usually reduced. How big this difference is depends on the amplifier or circuit. For example, a Marshall with a 12AX7 in the phase inverter stage set to volume 5 will then reach the same volume with a 12AU7 set to volume 6 (perceived volume, not measured).

Electrical Characteristics

• Heater Voltage (Uf): 6.3V or 12.6V
• Heater Current (If): 300mA at 6.3V, 150mA at 12.6V
• Anode Voltage (Ua): Maximum 300V
• Grid Voltage (Ug1): -2V (typical)
• Anode Current (Ia): 10mA (typical)
• Anode Power Dissipation: Maximum 2.5W per triode
• Anode Resistance (ra): 11kΩ
• Amplification Factor (μ): 60
• Transconductance (S): 5.5mA/V
• Input Capacitance (Cin): 1.6pF
• Output Capacitance (Cout): 1.6pF

Mechanical Characteristics

• Socket: B9A (Noval)
• Number of Pins: 9

Pin Configuration

• 1 Anode (Triode 1)
• 2 Grid (Triode 1)
• 3 Cathode (Triode 1)
• 4 Heater (f)
• 5 Heater (f)
• 6 Anode (Triode 2)
• 7 Grid (Triode 2)
• 8 Cathode (Triode 2)
• 9 Center Heater (f)

Application Notes

• Heater Operation: The tube can be operated with either 6.3V or 12.6V, depending on the circuit design.
• Grid Resistors: It is recommended to use grid resistors of at least 1MΩ to ensure stable operation.
• Coupling Capacitors: Capacitors with low capacitance (typically 0.1µF) are recommended to minimize high frequency disturbances.