Touring with a Ramone JCM 900 100W no speaker cable

[Oscar Fernando Perez]

Hi. We were on tour with one of the Ramones as opening act and backliners. During soundcheck in NJ somebody stole my speaker cable. My 100W Marshall JCM900 was ON for around 30 mins without an speaker cable (nobody played it during that time thou).

I thought my amp was fried. I turned it off, plug a new speaker cable, turn it on again, and it sounded right. I played a full gig at full blast and everything went ok. The main act also played their gig and everything went ok.

The next day at the next gig the amp dropped volume here and there. I decided to remove the two outter tubes thinking they would be the ones that fried (accounted for new impedance) and the amp continued for another 10 dates at full blast sounding awesome.

I didn't take it to a tech because we were in between towns at one gig a day and then I got busy and never ended up taking it for any check up.

This was over 6 months ago. I've been using the amp at home and it sounds great...but I'm still paranoid!!!!

I want to go back to the 4 tubes.

I don't understand why the amp wasn't destroyed!!! Why would everything be ok? Shouldn't the output transformer be destroyed?

Can anybody explain what happened? I want to know technically.

What's your advise? Should I take it to a tech before putting 4 new tubes?

Sorry for the click bait, true story thougg.

Thank you!

 

[V-man]

Clickbait Jackpot w Ramones in title BTW (Jamming behind Robbie Krieger isn’t exactly the Doors).


Regardless, I am assuming one of the two things below occurred.

1. The powered amplifier was on Standby (Most likely). Tube amps do not need need a speaker load on standby. However, it is not smart to operate that way outside of necessity with one careless negligent moment can end badly.

2. The powered amplifier was on very low volume before the problem was discovered. Volume is the exacerbator of all catastrophic failures. Dime an old amp, accelerated chance of component failure. Crank an amp w impedence mismatch, Fuse, tube, or worse blows. Crank an amp without a load, fuse tube or worse is likely to fail. However, the same occurrences with minimal volume drastically decrease the potential of catastrophic failure over short periods.

Why do you think outer tubes (any tubes) “fried”? Is there visible evidence of one blown?

 

[Dogs of Doom]

amp's probably ok, since you didn't run anything through it. Even so, if it works, you're probably ok...

Chances are, one of those tubes just went out & you need to replace them all, bias it up & you'll be good to go.

 

[Ufoscorpion]

Not generally a problem if you’re not playing.

 

[marshalled]

One time in live stage (2 hour)I played my split channel 2210 moderate volume at 16 ohm on 1936 8 ohm... Nothing problem.. Valve is OK output transformer work fine.

If you don't have problem in that time when the Amp was on and played at different ohm or not cable ... Is all OK