spraying the guts of my amp...

[9am53]

Hello all, this will likely be a dumb question, but here goes...from what I understand when building point to point amplifiers the quality of your soldering and connections directly effects how noisy your amp is...ie. if there is lots of exposed wire you may hear unwanted hum. What I have been thinking about is if I get my current amp to where I want it to be, and wont be doing any mods on it anymore, can I spray the underside with some sort of insulating material to shield all exposed leads? a spray paint or something...?

[tiroth]

Air is actually a better dielectric than anything you could coat it with. You won't get any shielding no matter what you coat it with--generally, it isn't necessary to do so inside a shielded chassis anyway.

You might be afraid of corrosion of exposed copper though, in which case it might make some sense to protect them. There are commercial spray urethane coatings available that are designed for this -- any large distributor will carry them. The advantage is that the urethane is reworkable if you need to make changes or repairs.

[anatech]

Hi 9am53,
It's not the exposed wire at all. The isulation only protects from shorts. The problem is where the wire is run (ie. lead dress). Component placement is also important.

So don't spray anything in your amp. Keep heater wires near the metal chassis and away from low level stuff. Cross leads and wire at 90° for minimum coupling. AC leads ought to run along one side away from everything near the power transformer.

Lot's of other stuff you can do but those are the basics.

-Chris