The pcb's and power supplies
Project by Karl Boyle:
Monitor Gold Active crossover designed by John Ridley
Mr. Ridleys project is on this website. As Mr Ridley states the article does not constitute a full constructional project but gives you all the information necessary. I did however require some further help.I would like to thank Mr Ridley for publishing the design and for further help he gave me during construction.The design uses the highly rated AD8065 Integrated Circuit, which is a surface mount device and requires a pcb header.I designed the boards using a pcb design package.The crossover features separate dual mono power supplies.I produced frequency response curves plots using equipment shown.This was necessary in order to check that the circuit was working correctly.The above picture shows the crossover with enclosure lid fitted, ready to be inserted in the audio chain.It is always advisable to use some protection for the H.F.unit to protect from switch-on thumps (and incorrect connection).This protection could be a high quality relay or capicitor.I chose to use high value 39uF Polypropylene capicitors.My present setup uses a pair of 15" Monitor Gold Drivers in 300 LTR cabs / Pair of Quad II vave amps for the HF / Crown Amcron amp for LF. ( This is one of the advantages of the active setup, as it allows the use of different types of amplifiers ).Karl BoylePreston (UK)
