Miscellaneous Projects

This is just a brief description of my pass projects recently finished. Two monoblocks A1.2, each built in a cabinet out of 4 heat sink profiles measuring 350mm all around. All the connections, as well as the mains switch, are on the very bottom of the amp. The transformer is placed below the 4 pcs 4700microfarad capacitors. On top of that you'll find the main board where all the wiring goes to. The sinks get some 55deg centigrade. The top cover is made of some kind of grey-glass with 'Amplifier' sandblasted in. Most expensive parts were the cap's, the transformer, the glass and the sinks in this order. The preamp P-1.7 was built in one cabinet in companion with the pearl phono stage. It's got external power supply which is connected with a 12 wire cable. Only regulated DC Voltage enters the amp. The power switch in fact is a toggle type which shorts a 'flip-flop type' relay fed by a battery, both housed within the power supply, to ground. This relay turns the mains on and off. Relais, driven by irf610 controlled with standard cmos logic IC's have been incorporated for the volume control and the input select. Both are dialled with optical encoders. Output and all inputs are balanced only, but the phono input. Most expensive part of the P1.7 definitely was the front panel with the dials. It's machined out of solid alloy, anodized and 'painted'. The signal ground and the shielding is not connected at all. That works pretty well, as my sources don't have shielding connected to the wall outlets earth. Only chassis ground is connected to earth throughout all equipment. Needless to say - sound is perfect. Thanks to nelson for publishing the schematics and all the other hints. Oncoming projects: x2, Ono (with boards from Dragan), X (I'm trying to mate 2 A2's based on the original schematics) PS: Transrotor Fat Bob is already ordered - to get an excellent source ! The most complicated issue was gathering all the parts from the various suppliers. Some of the manufacturers, suppliers, distributors: Nelson Pass for the pearl PCB's and the Q-pack http://www.passdiy.com Kristijan Kljucaric for the PCB's http://web.vip.hr/pcb-design.vip Digikey for several semiconductors http://www.digikey.com Mouser for several semiconductors http://www.mouser.com Aavid-thermalloy for the heatsinks http://www.aavidthermalloy.com Distrelec for several passive parts http://www.distrelec.com Conrad for several passive parts http://www.conrad.com Neutrik for the connectors http://www.neutrik.com Sommer Cables for the wiring http://www.sommercable.com