Xover Module

Single module LTspice simulations:

Low-Pass phase comparison between Linkwitz-Riley and Butterworth configurations.

High-Pass phase comparison between Linkwitz-Riley and Butterworth configurations.

2nd order mode filter module response.

4th order mode filter module response.

The Xover Filter Module

3 X matched 2nd order precision State Variable Filters (SVF), configurable like a 4th order (SVF).


PCB Dimensions:

Double sided 220mm Length x 130mm Width x 1.6mm thickness, 1Oz. copper for square feet.


Digital controller:

I2C controller: MCP23017 with selectable address

Relays drivers: ULN2804A or ULN2803A depending from running voltages

2 X 10-LED-Bar for debug


Operational-Amplifiers:

OP-Amps: Dual OP-Amps like TL072, NE5532, OPA2134 or any unity-gain stable pin compatible (and voltage compatible off-course) dual op-amp.

There are many discrete OP-Amp choices with the same pin out, even discrete ones.

Input Impedance: around 100 KOhm depending from OP-Amp choice.


Controls from MCU:

  • Bit-1 = 12db/oct - 24db/oct selection
  • Bit-2 and Bit-3 = Geometry (Butterworth, Bessel1, Bessel2, Linkwitz-Riley)
  • Bit-4 to Bit-8 = Crossover Frequency


Dual latched micro relay types:

20 X AGN2104H or AGN2104HJ


Grounding:

  • Separated Analog and Digital Ground planes
  • Built-in RC Loop Breaker for Analog Grounding
  • Built-in Electromagnetic Interference (EMI) filter and Radio Frequency (RFI) filter for Digital Grounding


Connections:

Golden plated Molex KK (2.54mm pitch) series connectors:

  • Digital I2C = 5-pin Molex KK
  • Audio input = 2-pin Molex KK
  • Audio output = 4-pin Molex KK
  • Analog Power supply = 3-pin Molex KK

Cable-less Board-to-Board connections:

  • I2C = 5-pin header (20mm long metal pin)
  • Audio output to next board audio input = 2-pin header (20mm long metal pin)
  • Analog Power Supply = 3-pin header (20mm long metal pin)