Acoustat TNT 200

I have an Acoustat TNT 200 that makes a click noise inside the amp while operating. I noticed this when I had the stereo at a very low volume. The sound from the speakers is perfectly fine no unusual noise ect. is this normal for this type of amp, or could there be a problem?

It's normal. The stainless steel chassis is the reason. If you leave the amp on all of the time, it will stop after a day or two. Nothing to worry about. Don
Thanks for the response. One last question if I may..I also noticed (hard not to) that it makes a whir like sound and slight hum when powering up then becomes clear. Takes about 2 seconds. Is this too normal?
Seeking scanned copy or photocopy of Owners Manual and, possibly, schematic of the Acoustat TNT 200 power amp. Will compensate for effort. Thanks.

Have been using my TNT 200 for 20 years and it has always made this noise when powering up.
Mine also..I had one for several years and did the exact same thing.Temperature variations within the stainless steel chassis is the usual big deal. Fine sounding amp with mosfet output.Although mine got a bit noisy in the right channel(hiss) but was not major. Good listening!
The thing you want to watch with a TNT200 is the DC pulse on power up. This WILL demag dynamic speakers over time.
Best to leave it powered on all the time.

This is not a guess, I had 2 TNT200's for several years.
Best sounding used SS amp under $500, IMHO. Blows the newer Hafler's (i.e. 9500) away.
Replace the coupling caps with some MIT PPFX for a real suprise!