Friday, May 06, 2011

Fixing Quad 303 boards in the chassis


We often get the question if we can supply the plastic clips for mounting the Quad 303 driver-boards and power-supply boards in the chassis, as they can break off while removing one of the boards.




In fact a simple and cheap alternative solution is using 4 mm plastic cable-ties, like in the pictures.



They are sold in most hardware-stores or in the Velleman cable-ties set we sell in our Webshop.



The 303 in the pictures belongs to Ad from the Netherlands and has been fitted with Dada High-end boards, new MJ15003 and MJ802 transistors and better internal cabling.



(Click on the pictures to enlarge.)





Stefaan

Thursday, May 05, 2011

BHC Aerovox ALC10C instead of ALP22A in Quad 606-Mk2, 707 and 909


BHC recommends using the ALC10C capacitors instead of the older ALP22A in new developments. It is less expensive, smaller and it has better specifications. The ALP22A is still produced for replacements in older circuits (but is out of stock for the moment, new stock is announced for July 2011).


In the Quad 606-Mk2, 707 and 909 the ALC10C 15000µF 63V can be used but the pins won't fit the printed circuit board. This can be solved by cutting the two unconnected pins and drilling an extra hole 1,5mm) in the PC-board (see the picture).


Make sure to double-check the polarity, when the polarity is wrong the capacitors will be damaged. The - pin is beside the gold line on the side and it has a "-" sign on it. The + pin is the middle one of the 3 pins on the other side. The two pins beside it have to be cut.


Dada is developing an new Printed-circuit board with a 500 Watt Amplimo transformer and 4x BHC ALC10C 15000µF for replacing the transformer and the capacitors in a 606 Mk1, making it an Mk2.


The 15000µF 63V ALC10C can be bought in the Webshop here.


The (general) BHC Aerovox datasheet can be downloaded from our Website.



Stefaan