Question about the power switch used in KA-7100, KA-8100, KA-9100

According to the Destination Parts lists in the Service Manuals, all three of these amps used the same power switch, Kenwood part # S33-2022-05 in the U.S. and Canada (other locations had a different part number). This power switch is a double-pole, double-throw type. In the KA-7100 only one of four possible sets of contacts is being used.


In either the KA-8100 or KA-9100, did Kenwood parallel two sets of contacts on the power switch to accommodate the greater inrush current?
 
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They didn't on the 8100, but not sure about the 9100. I can't recall at the moment.

Need a switch?
 
Thanks for the reply. No, I don't need a switch. I just need to decide whether to parallel the contacts on my KA-7100's switch. I opened it up and discovered that the original contacts were a bit melted. So I turned it over to get to an unused set of contacts.

Now I am considering paralleling the two pairs of new contacts that are now on the lower half of the switch. Just for the sake of gaining maximum service life. I am completing a thorough rebuild of this amp. I increased the filter caps in my KA-7100 from 6,800uF to 10,000uF (same as in the KA-8100) so the switch will be seeing a bit more current than it did in the original state of the amp.


Is there any reason why I should NOT parallel two sets of (new) contacts on the power switch?



<these pics show the switch before the back part was rotated 180°>
 

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Ok, thank you Paul. I will get the safety cap you linked to.

The worn/damaged rocker was flipped over and the back part of the switch has been rotated so that the worn contacts are now in the upper part, out of the way. On the bottom now are two unused pairs of contacts, those are the ones that I will parallel.


It is interesting to me that Kenwood did not parallel the switch contacts on the KA-8100. Apparently they did not feel it was necessary, although it would have been easy to do.


Still curious, if anyone knows, as to whether Kenwood used just a single pair of contacts for the KA-9100??? If not, why did they use such an over-spec'd switch in all three of these units?
 
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Here is the KA-7100 power switch with two sets of new contacts jumpered and a new Murata .01uF AC safety cap (as linked above).

The solder terminal in the upper right was cut intentionally so I would remember that is the original contact. Probably won't ever in be in there again though.

The soldering work is not quite as neat as I would like, but the joints are all solid. I used 18ga bell wire from the hardware store - sanded lightly, bent, fluxed, tinned. Next time I would use 20ga because the 18ga was a lot larger than everything else in the solder joint (incoming power wires, solder terminal, and cap leads). It would also be easier to tin the wire before bending to fit.


I feel good about this mod and if I ever do another 7100 or an 8100 (9100?) will do it again.

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