How to clean inside Amps and PreAmps

No Matter how clean I keep my room with air purifier running 24/7 except when I am listening, I still see some micro dust inside my Amplifier and Preamplifiers. How do I clean it ? I have also removed my top covers recently and keeping the equipment without covers. This might put more dust going forward.

Appreciate any suggestions that will keep my equipment clean.
First, I would put the covers back on. I doubt that you are increasing performance by having them off but you are increasing potential damage to your unit and possibly creating a fire hazard.

After you return the lid to its proper place the only entry for dust would be air vents. When not using your pre or amp you can drop a cloth over them to minimize dust settling in. If you do this you will not have an issue with dust.

To remove the dust that is currently there I found that a loose, natural hair painters brush works best.
Thanks for you suggestion. That's what I have been doing. I just removed the cover 2 days back and found dust inside. I always covered them with cloth after usage. thanks for Painters Brush suggestion.
BTW, stay away from compressed air as it can create moisture and freeze components.
I would put the covers back on as well. Then cover as you have been. Why did you remove the covers? If they are SS you are not doing yourself any favors. Sometimes the lids are integral to the heat sink operation and need to be present. Be careful and what is microdust? Can you see it with the naked eye?
I have ARC Ref 5SE preamp and REF 250 AMPs and read many posts they sound good without covers . Also removing covers was dissipating heat faster than built in fans.
I remove the cover on my SS amp, and keep it off.
We all have to breathe (especially when pets and small children
are not present.) I concur to a draped cloth when not in use.

Occasionally I apply some anti-static spray
(3M, for example) to the end of a small
acid-free brush (electronic or art supply store).
Apply spray to brush when you are away from amp.
When the brush is moist but not dripping wet, dust
treated areas slowly with a light stroke. A small brush can get
into crevices neatly. Reapply spray as needed.

You will see and hear a substantial difference!
Re-treat as needed. Anti-static spray has other useful
applications... try wiping a sprayed microfiber cloth
on the outside of components, cables, shelves, and racks.
If you are going to clean the inside of your equipment, please unplug the items first. This is obvious, but needed to be said. Dust will collect, so occasional cleaning is really necessary, but do so safely. Non conductive brushes (still unplugged mind you), is a good idea.

The best way to clean solid state equipment is to throw it into a lake and let it lay on the bottom for a couple of years. In the meantime, replace all of the equipment that now sits on the bottom of the lake with good quality vacuum tube equipment. All other responses above apply. :>)
+1 Oregonpapa
Does dust harm the gear? If not, why bother dusting it out. I see the potential for damage or worse.

Like the old adage goes, "if it ain't broke, don't fix it."

Dust across PCB tracks and component legs, can become conductive in hi humidity and cause trouble.

Just in the last few days in Sydney we had the worst storms ever recorded damp everywhere in the house.

I had I thought my computer motherboard had bit the "dust" as it would not turn on even with a blade shorting out the turn on pins. Checked everything even changed the powersupply.
I saw a layer of dust across some of the tracks and swept it clean, then she turned on while I was sweeping it off, and it been fine ever since.

Cheers George
If this is a problem for you, consider my solution. I use Jeff Rowland Design Group S2 integrated amp but the following information applies to most, if not all, of his equipment manufactured in the last 20 years.
Rowland gear is sealed - no vents for dirt or dust to invade. The entire chassis serves as a heat sink. When you open any of this gear, the interior looks just like it did the day it was closed at the factory. I imagine this is why JRDG components have such high resale.
I know of a guy who cleans old tube amps by removing the tubes, placing them in a dishwasher and running them through a cycle! He then lets them air dry, puts the tubes back in and applies power.

I'm not making this up, nor am I recommending it for your new gear, just thought it might interest folks.
George, I take your point, but such is not the case where I live.

If Gary (Hifigeek1) catches this thread, I hope he weighs in. Gary is an ARC authorized service tech and knows his business well.
Nothing wrong with compressed air in a can. Just keep it upright and it won't freeze anything. That's why it comes with a long tube. It's actually the best if your starting with a pristine surface. Once you get the heavy gunk off, it's still the best.
Thanks for that info, Macrojack .
Never knew that about Rowland stuff.
Actually the Bosch came up with the laundry machine especially made for washing the Amps/Preamps.
They still working on a dryer