Description:	Two-channel (stereo) Linkwitz-Riley 2-way active crossover filter with single sub-woofer output (pack of five PCBs).
Manufacturer:	KMTech Design (UK).
Configuration:	Pack of five circuit boards only, no components, buyer must assemble, instructions included.
Noise-Cancelling  Method:	n/a
Crossover  Frequencies:	User-definable by changing resistor values.
Filter Gradient:	24dB/octave.
Operation  Amplifiers:	6 x OPA2134 ultra-low noise dual audio-grade op-amps (not included).
Power Supply  Filtering:	Ceramic/electrolytic noise bypass capacitors.
Power Supply Type:	Dual 5V-0V-5V DC to 12V-0V-12V DC (see our shop  for suitable PSU). Optional single 12V supply.
Transformer Type:	Recommended 6VA dual-voltage toroidal.
Filtering caps:	33nF polyester.
Port configuration:	Two inputs, three outputs.
Power Connector:	3 Way 5mm terminal block for dual supply. 2 way 5mm terminal block for single-ended supply
Input Signal  Connector:	2 x RCA phono connector.
Output Signal  Connector:	3 x RCA phono connector.
Physical  Dimensions:	100mm x 100mm x 1.6mm.
PCB Mounting:	4mm mounting hole each corner.
	A pack of five high performance active crossover filter circuit boards (saving you £12.50)  by  KMTech Design. This crossover filter is designed to run from a dual DC supply OR a single 12V supply. Please note for single supply use you will need to fit extra components for the rail splitter sub-circuit. One of these components is a BUF634  op-amp. WE DO NOT SUPPLY THIS COMPONENT, YOU WILL NEED TO SOURCE IT ELSEWHERE. How it works. The two inputs are both filtered into low and high frequency channels. The high channels output via two RCA connectors. The two low channels are mixed, and exit via a third RCA connector for the sub-woofer.   CIRCUIT BOARDS ONLY, SOLDERING SKILLS REQUIRED!
	Let us know what crossover frequencies you need  and we will get as close as possible by suggesting resistor values. The default crossover frequency is 125 Hz, using 27k resistors.
	For your information, the formula for  calculating the filtering resistor values is: R = 1 / (8.89 x C x f) Where R = resistor value in Ohms f = Desired crossover frequency in Hertz C = 0.00000033 ***You don't need to worry about the maths! We will do all the  calculations for you! Happy to help!
	Please note there is no enclosure included with  this product, it is as shown in the first listing photo. Components needed to complete each filter: 6 x OPA2134 ultra-low noise dual audio grade op-amps or compatible. 6 x 8-way IC sockets. 5 x PCB mount RCA sockets. 1 x 3 way 5mm terminal block. 2 x 100k resistor (all resistors 1/4 Watt, metal film 1%). 2 x 1k resistor. 3 x 20k resistors 20 x 27k resistor (for filtering, can supply different values depending on required crossover frequency). 3 x 100 ohm resistor. 6 x 100nF ceramic capacitor. 2 x 47uF electrolytic capacitors 20 x 33nF polyester capacitor. Extra components needed for the rail-splitter sub-circuit: 1 x 2-way 5mm terminal block 1 x 220uF 16V electrolytic capacitor. 1 x BUF634 op-amp 2 x 220k resistors.