Svetlana 12AX7 / ECC83 Reissue

R.F. DOUBLE TRIODE

ECC99 is a 9-pin double triode usually used as a driver for directly heated power triodes (i.e. 300B and 2A3), but in some applications can be used as power tube (headphones amps, small power amps...).

Files:

• Datasheet

for Fender Pilot-Light

• BA9s
• #47
• 6,3 V

Medium-Mu twin triode driver tube. 3.5 watts dissipation per plate.

This is a kit of the famous Dumbleator, can be used as standalone device or for installation in an existing amplifier.

When build as a stand-alone device, the kit can be powered with the TT-VPump, in an amplifier the kit must be supplied via the existing power supply of the amp.

The Dumbleator offers numerous configuration options which are shown in the appended schematics.

Input Levels:
InA: 10-15 Vpp
InB: guitar level - 5 Vpp

The kit includes all the parts needed to build the "standard version" incl. a 12AX7, potentiometers and leads.
It does not include components that are required for the building the extended versions,  as well as a power supply or casing.

The Dumbleator utilize POTENTIALLY FATAL HIGH VOLTAGES.
Seek help from a competent technician if you are in any way unfamiliar with high voltage circuits.
Use at your own risk.

Files:

• Schematics

The Sovtek 12AX7WC has a little bit more gain than the Sovtek 12AX7WB and  the 12AX7WA. The noise floor is still pretty low compared with other 12AX7 tubes and the dependabiliyt very high.

• Type: Electrolytic can capacitor
• Capacitance: 10 µF
• Voltage Rating: 63 V
• Tolerance: - 20 % / +20 %
• Operating Temperature Range: - 40°C / + 105 °C
• Dimensions: Ø 5 mm x 11 mm
• Termination Style: radial
• Grid: 2

Images are for reference only. See Product Specifications

Electro-Harmonix has released a low noise, low microphonic version of the 12AX7 that meets all specifications required for the tube to be designated 7025. The original 7025 tube was a 12AX7 that was tested and selected for the lowest noise and microphonics for use in the critical first preamp stages of amplifiers where noise and microphonics could be an issue. In order to ensure that the 7025 specification is consistently met, Electro-Harmonix has redesigned the structure of the 12AX7 and has implemented construction techniques to ensure the absolute lowest noise and microphonics possible. In all samples tested, noise and microphonics could not be detected.

The Electro-Harmonix 7025EH has a mid-range that gives clarity and definition to the sound and a smooth top end for warmth and balance. With these characteristics, along with the exceptionally low noise and low microphonics, the Electro-Harmonix 7025EH will work equally well in vintage and modern high-gain guitar amplifiers, as well as sensitive phono preamps.

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

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 12AX7WA is a defacto standard in 12AX7 tubes for many years yet because of its high dependability and its low noise floor.

EH 12AX7 / ECC83

• The 12AX7EH provides high gain with ultra low noise and detailed, musical tone that rivals the most desirable NOS types.

Files:

• Datasheet

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

• The 12AX7EH provides high gain with ultra low noise and detailed, musical tone that rivals the most desirable NOS types.

Files:

• Datasheet