Monday, 10 March 2014

Looks a Bit Like a Mixer

It's funny how sometimes you end up doing some things twice. Recently I wired up the PSU to the sub-rack and fitted them both into the 19 inch Rakz box. For the heater wiring I used heavy gauge mains cable. Nice and thick, low voltage drop but not exactly flexible. Thing is, you do need some flexibility in the power wiring so you can move things about for wiring up and testing other parts of the mixer. So you make the power cables somewhat longer than they need to be to provide this flexibility which is just what I did. The trouble is they do not sit very neatly in the bottom of the mixer because the heater wiring is so stiff. What you really need is some high current but flexible wire for the heaters.

This evening I was starting to wire up the XLRs at the back of the mixer and I was looking for the cable to do this. In this search I came a cross some Van Damme loud speaker cable that I had forgotten I had purchased. Examining it showed it had really thick cores, ideal for heater wiring, but the cable as a whole was really flexible. It seems that in a moment of lucidity some time ago I had ordered a few metres of this cable for just this purpose. So that is how I ended up re-wiring the heaters this evening. Here is a picture showing the sub-rack removed from the main chassis and laid on its back on top of the VU meter bridge:

The black and red twisted pair is the HT supply, the blue and white is the phantom power and the thick blue cable is the new heater cable. Next I replaced the sub-rack into the chassis in order to check that the cable curled up neatly and it did.

Lastly I connected to the mains to make sure the supply worked and lastly I fitted all the finished modules and ran a burn in test to make sure the power supply does not get too hot. In fact it just gets luke warm. At last it is beginning to look like a real mixer.

No comments:

Post a Comment