• Eliminates need for constant re-adjustment of Bias to compensate for mains variations and valve aging
• Regulation of cathode current of tubes from around 1mA to 250mA with10R cathode resistor current match between halves depends on cathode resistor tolerance ± 1% due to circuit (typical mismatch << 0.1mA). Perfect current balance produces better bass
• Current regulation is not influenced by music signal
• Current set by standard 1/4W leaded resistor (exchangeable)
• Current can be adjusted from 0mA to 90mA per tube if a 10K Pot is connected instead of the resistor
• reduces noise on bias supply by at least 40db (100 times) so even the most basic bias supplies sound good.
• Lower noise improves resolution and imaging
• Turn on Delay of 45 Seconds
• Slow ramp up of current over a further 45 Second
• Fault Indication via LED’s (Red) on PCB; they can be re-mounted on the Amplifier chassis
• Fault Indication via TTL compatible open collector output (can be used for additional protection circuitry or for our upcoming electronic choke PSU PCB)
• multiple mounting holes for easy mounting
• Can be fitted to any existing fixed bias equipped Amplifier without changing the original circuit and with absolutely minimal modifications, except bias potentiometers (and possibly cathode resistor changes)
• Small size due to use of existing supplies already present in your amplifier
• No high voltage connections are required to be made

Electrical Parameters

• Maximum Tube current up to 250mA with 10R Cathode resistors
• Output voltage up to -150V (depending upon the original bias supply in the amplifier)
• Outputs can sink at least 2mA current or much more
• Requires a single, ground referenced 6.3V to 12.6V AC supply (ie power tube filament supply draws 60-100ma) for the actual module and the original negative bias supply of the Amplifier

Mounting And Installation

• Designed for easy installation: one module can control two power tubes.
• The only connecting voltage is needed are the existing DC 70 — 130 V bias voltage,a 6.3 — 12V AC connection (taken from the filament supply of the power tube {note: must not be a center tapped winding unless the winding is disconnected and if one side of AC winding is grounded then THAT side must connect to pin 4 of the ABS module} current draw 60ma/100ma—6.3v/12.6v)), and then a single connection to the grid and cathode of each tube to be controlled.
• Designed to fit right into the current Ella chassis with no special mounting hardware or fixtures needed.