K4003 Heatsink Assembly

I have a couple of questions about attaching the heatsink on the K4003. I am quite the beginner at building thisgs like this, so forgive me if the answers are obvious.

The manual says: The inulation (covered on both sides with some optional heat-conductive paste[…]) mica must be inserted between the IC and the heatsink. My questions about this are:

  1. The supplied mica in my kit seems not to fit in the intended area - it seems too big. Here’s a picture of what was in my kit - I am holding the mica to the heatsink. As you can see, the screw holes are too narrow to fit the mica between. How is it intended to be oriented?

  1. How optional is the paste? What are the advantages/disadvantages of using it in normal use? I am intending the amp to be in operation for hours at a time.


position the mica between the two holes. It is possible that it slightly covers the holes. Make sure the metal side of the IC does not touch the heatsink. Push the two bolts in place. We’d recommend to use the compound if you intend to use the amp for hours in a row at reasonable output.