Old valve bass amp crackling

[Kimblea]

Hi all

Does excessive crackling in an old valve bass amp indicate faulty valves?
The crackling noise is constant and does not really change when the volume control is moved.

If so, then would anyone know where I could find new valves in South Africa?

[Lisandro_P]

Either that or something's loose inside the enclosure (it's a combo, right?)... bass amps are subject to much more mechanical vibrations than regular ones, and this makes things go loose.

[HDTVman]

Try cleaning the tube sockets and tube pins. This is often a source of noise in older tube equipment caused by oxidation on the metal contacts. Use a good electronic contact cleaner and gently brush the socket contacts with a pipe cleaner or similar tool and clean the tube pins with a cotton swab.

If that doesn't do it you could have some coupling caps getting leaky but I'd bet on dirty sockets.

[fragman56]

Just a quick question since I have a similar problem with an old Calrad sa30b amp. I do have another thread going on my issue under "...distortion..."

How do you clean the tube socket with a pipe cleaner? My sockets are tiny! Are there pipe cleaners or similar tools that can get in there?

Thanks from an aspiring diyer,
Rick

[HDTVman]

Fragman56

Try looking for pipe cleaners at a hobby/craft store. Sometimes they have several different sizes for craft projects.

Later Bruce