trinityamps.com

Hi everyone, I’m having an issue with my Trinity TC-15 where the volume suddenly drops after about 15–20 minutes of playing and I start hearing crackling and slight distortion even on clean settings, and sometimes it comes back to normal if I turn the amp off and let it cool down for a while. I’ve already tried swapping cables and guitars and checked the speaker, but the problem is still there, so I’m wondering if this could be related to a failing tube, overheating, or a bad solder joint, and I’d really appreciate any advice on what to check first or if anyone has experienced something similar. Thanks in advance for your help.
Geometry Dash

Tubes are the easiest thing to check first—swap in a known-good set (especially the EL84s) and see if the problem goes away. If not, I’d open the chassis and look for any cracked or dull solder joints around resistors and tube sockets, or any components running unusually hot. Also make sure the tube sockets are gripping firmly; loose contact can cause crackling and volume loss. If you’re not comfortable poking around inside, a tech should be able to track this one down pretty quickly.
Retro Bowl 26

Here’s what I’d check first, in order:

Power tubes: These are the #1 suspect. If they’re worn out, they can cause volume drop, crackling, and distortion. Try swapping in a new matched pair if you can.
Preamp tubes: Less likely, but still worth testing by swapping one at a time.
Tube sockets: Dirty or loose sockets can cause crackling—gently reseat the tubes.
Overheating components / solder joints: If tubes don’t fix it, it could be a bad solder joint or resistor that fails when hot → this usually needs a tech.