BTC Spectre FET for Next-Gen Gearboxes Mk.II (No Bluetooth)

  • £99.00

User Manual

Trigger Programming Guide

3 Year Limited Warranty

A compact version of the Chimera Mk.II FET and utilizes FOUR powerful next-gen MOSFETs. Includes ALL the features the Chimera and fits completely inside the gearbox, making it ideal for AEGs with no room for an external FET. No soldering required.

The Spectre Mk.II is the most advanced FET yet with double the features of its predecessor including nearly every feature requested by the airsoft community.


Advanced Technology:
Can handle power surges up to 9000 watts and even run on car batteries.
Fully computerized with hi-speed dual ARM Cortex-M0 and PIC18F26K22 microprocessors.
Multiple internal layers of heavy copper traces for greater current capacity.
Short circuit detection and voltage spike suppression circuits to protect the controller.
Smart thermal management reduces heat buildup during sustained firing on certain settings.

MOSFET Trigger:
Eliminates damaging electrical arcing of the trigger switch contacts.
Lower resistance compared to mechanical switching, increasing motor current.
Driven by dual IRF671812PBF, a compact yet powerful next-gen MOSFET.

Dynamic Braking:
Eliminates the motor spin-down time to prevent the piston from over-traveling.
Assists in keeping the piston properly reset to reduce stress on the gearbox.
Prevents double firing on semi-fire in extremely high RoF setups.
Also driven by dual IRF671812PBF MOSFETs.

Cycle Completion:
Gearbox always completes the last cycle regardless of when the trigger is released.
Assists in keeping the piston properly reset to reduce stress on the gearbox.
The motor will always have the smoothest and most consistent startup.
Allows the anti-reversal latch to be removed.

Configurable Triple Fire Select:
All three fire select positions can be individually configured, for a total of 729 (9x9x9) possible configs.
Available options for each selector position:
Semi fire
Auto fire
Burst [non-interruptible]
Burst [interruptible]
Burst/Auto hybrid [burst non-interruptible]
Burst/Auto hybrid [burst interruptible]
Semi/Auto hybrid
Semi/Auto ramping
Non-interrupt burst completes a burst even if the trigger is released, whereas interruptable stops mid-burst.
Burst modes can be programmed to fire 2 - 10 shots per burst. Each selector can have different burst amounts.
"Burst/Auto hybrid" fires in burst and switches to full auto if the trigger remains held down.
Hybrid modes can be programmed to have no transition delay or a 0.2s - 1s delay.
"Semi/Auto ramping" fires in semi and switches to full auto if the trigger is rapidly tapped.

Hardware Semi-Only Lock:
Can only be enabled/disabled by using a soldering iron to remove/bridge a solder jumper.
Conforms to semi-only laws that forbid AEGs with readily accessible means of bypassing semi-only.

Realistic RoF Control:
Both fire select positions can be individually configured with a different RoF.
Every cycle runs at full speed and pauses between each shot to reduce the RoF.
Provides the most realistic feel and sound compared to any other forms of RoF reduction.

Adjustable Precocking:
Precocking stops the piston in a compressed state so the next shot is near-instantaneous.
The precocking is fully adjustable and thus also compatible with short-stroked pistons.
Offers improved realism and trigger response for sniper or low RoF builds.

Adjustable Firing Interval:
After a semi or burst fire, ignores trigger inputs for a certain amount of time. Programmable up to 1s.
Helps restrict rapid firing in specialized builds, such as limiting a sniper build to firing one shot per second.
Lower intervals can also help prevent accidental "bump firing" on semi when using a feather trigger.

LiPo / LiFePO4 Monitoring:
Monitors LiPo and LiFePO4 batteries to cutoff power before overdischarge occurs.
Simply set the number of cells and the controller will use the proper cutoff voltage.

Programmable Digital Fuse:
Sensor-based current monitoring negates the need for a physical fuse.
Cutoff threshold fully adjustable to help protect low-output batteries from over-current damage.

Gearbox Reliability:
Eliminates the trigger jam normally caused by the cutoff lever stopping at a certain position.
The cutoff lever mechanism is no longer needed, greatly reducing the chances of semi-fire related issues.
The anti-reversal latch can also be removed to make gearbox reassembly much easier.

Hopup Sensor Compatible:
Fully compatible with Airsoft System's hopup sensor unit to prevent firing when the mag is empty.