Firing up an old tube amp

[Doug]

I have what's probably a silly question but I need to ask. I have an '85 or '86 Marshall 15 watt (tube) combo amp and I literally have not turned the thing on for probably 20 years. I had it stored in my attic, garage, etc over the years, so it hasn't been exposed to a lot of bumping around or anything, and living here in California has kept it within pretty good temperature ranges.

So back to my silly question. Is there any electrical risk in just plugging in and turning it on? I guess I'll do a quick inspection of the power cord and connections but that's all I need to do, right? Any other precautions?

 

[PacoCasanovasOld]

turn it on.....if it smells funny or start humming very loud, turn it off and visit a technician! What ever comes - keep it don't give it away. This is a pretty unique combo (Studio 15)!!!

 

[s0c9]

I would take a look at the tubes/pcb inside... at least remove any dust that has collected after 20 yrs.. if it smells like PacoCasanovas says after you power it up.. take his advice.

 

[axel]

I would unlpug/plug the tubes in several times to scuff the tube pins and tube socket contacts. These can corrode over time and lose connection. This can cause problems like crackling/popping and possibly blowing a tube. The only other thing that might have gone bad by just sitting would be the capacitors (mainly electrolytic caps). Short of taking it to a tech to have all the caps checked, you can just turn it on and see what happens. Like mentioned, loud hum is usually a sign of a cap gone South, the worst that will probably happen is you'll blow a fuse. If you're lucky, everything will be fine.