TT 12AT7 / ECC81 - Balanced

Kit of a bias probe for indirect measurement of the quiescent bias current of a tube. The adapter is placed between the tube and the socket and is connected to a standard voltmeter (not included). Pay attention to the quality of the meter and to sufficiently charged batteries!

The quiescent current is measured indirectly via a precision resistor built into the adapter. The advantages of this measuring method are harmless voltages in the mV range at the measuring plugs as well as short ways for the current, since it does not have to be led through the measuring device (common practice with many measuring adapters of Far Eastern production). As a result, there is no risk of oscillation of the amplifier, which could damage the tubes or the amplifier itself.

Note: This adapter cannot be used when additional tube brackets are installed. These must be removed before using the measurement adapter and reattached after the measurement is complete.

Measurement procedure
Determine the resistance of the adapter, including the test leads. Connect the adapter to the meter, but do not connect it between the tubes and the amplifier. Select the ohms range on the meter and note the reading, e.g. 1.1 ohms.
For the final measurement, insert the adapter between the tube and the de-energized amplifier, connect it to the meter, select the mV range and switch on the amplifier. When the amplifier has reached a stable operating condition, read the value in mV from the meter and calculate the quiescent current using Ohm's law.

Example
Measured voltage = 47 mV, adapter resistance = 1.1 ohms.
Formula (I = V / R) or in this case
Bias Current (in A) = Measured Value (Voltage in V) / Measured Value (Resistance in Ohm)
0.047V / 1.1 Ohm = 0.042A or 42mA

For the calculation of the correct bias current as well as further information on bias measurement please refer to further documents or the bias setting instructions in the info section as well as the manual of the amplifier itself.
This adapter is suitable for all EL34, 6L6, 6550, KT88, 6V6, 6CA7 and other tubes with the same pinout.

Attention HIGH VOLTAGE ! Measurements and work on tube amplifiers should only be done by qualified personnel.

Files:

• Datasheet

• Contacts: gold-plated
• Connection type: solder contacts
• Color: black
• Cable diameter: 7 mm
• Housing: steel

• Type: Slide Switch
• Version: DPDT, ON-ON
• Dimensions: 23 x 17 x 7,5 mm
• Hole spacing: 19,5 mm
• Rating: 0,5 A / 50V DC
• Termination Style: solder-lugs

The TRICONE® MKII is a flexible cable for guitar, keyboard, the live musician, studio keyboarder, and the home recorder. Based on the sound wire diameter of 0.22 mm² and the fine individual strands of 0.10 mm, it is protected against cable breaks and convinces with high bending cycles. It is very robust, easy to wind, and very reasonably priced.

When working with it care should be taken when removing the concutive shielding (black PVC-hose) from the insulation, so that it does not touch the inner conductor.

TRICONE® is a protected and registered trademark of SOMMER CABLE GmbH.

THE ADVANTAGES:

• Very robust due to the large conductor diameter and fine individual stranding
• Good electrical values due to the insulation made of skin PE
• 100 % Protected due to double shielding (copper spiral + conductive carbon shielding)
• High number of bending cycles

• Dependable cable for live application (guitar and keyboard)
• Reasonable line or patch cable for the home recorder

• Construction LI2Y(LS)DY1x0.22mm²
• Jacket, diameter PVC 5,9 mm
• AWG 24
• No. of inner conductors 1 x 0,22 mm²
• Copper strand per conductor 28 x 0,10 mm
• Conductor insulation skin PE 1,8 mm
• Shielding copper spiral shielding + semiconductor
• Shielding factor 100 %
• Temperature range min. -20 °C
• Temperature range max. 70 °C
• Fire load per m 0,26 kWh
• Color: red
• Weight per 1 m 42 g

• Capac. cond./shield. per 1 m < 85 pF
• Cond. resistance per 1 km < 90 Ohm
• Insulation resist. per 1 km > 1 GOhm

Protective contact plug (Type F, CEE 7/7) > Loose cable ends

The power cable with open ends and crimped wire end sleeves for confectioning. This power cable comes with a plug (angled) for connecting to electrical devices. The power cable can be creatively and versatilely used.

• Connection Type: Protective contact plug (Type F, CEE 7/7)
• Connection 2 Type: Loose cable ends
• Maximum Current Rating: 10 A
• Operating Voltage: 250 V (AC)
• Cable Length: 2m
• Conductor Cross-section: 0.75 mm²
• Cable Type: H05-VV-F3G
• Color: Black
• Markings: CE

2 tubes, matched as pair

TT 6L6 NG - Selected and tested by hand, suitable as a direct replacement type for all 6L6GC and 5881 tubes.

• Triode
  • Ua = 450 V
  • Ug2 = 450 V
  • Wa = 30 W
• Pentode
  • Ua = 500 V
  • Ug2 = 500 V
  • Wa = 30 W
• Grid No 1 Circuit Resistance
  • Fixed Bias 0,1 MΩ
  • Self Bias 0,5 MΩ

• Springs: 2
• Delay Type: long
• Size: long
• Replacement: Fender, Marshall, Ampeg "F"
• corresponds to Fender part number 006-4063-049
• Accutronics by Accu-Bell, Made in Korea