Saberslash
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- Joined
- Nov 6, 2021
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First of all, sorry if there is already similar topic in the forum 
My question is, today I accidentally turned on my Marshall Silver Jubilee head for approximately 2 minutes (maybe less) without speaker attached to head. As soon as I noticed I shut it off, afterwards I reconnected everything and amp plays as before.
Situation was like this: Head turned on standby, no speaker attached to head, all pots on 0, no guitar attached. Could that possibly do any damage?
I ve heard people burn their amps while speaker is not connected when they try to play guitar and they crank volume up a bit.
Also I ve read that if amp is is standby and no guitar is connected, it could be turned on like that 100 years and amp won't get damaged..
Also I found this online, is this true statement?
"Most tube amps have shorting type speaker jacks to prevent flyback voltage in case you forget to plug in a speaker. But, if you plug a cable into the amp and not plug the other end of the cable into a speaker, then you have an open circuit that can cause flyback if the amp is played loud enough to generate the flyback. But what's "loud enough" to cause flyback damage? Amps aren't created equal so it would be difficult to say. However, there's a misconception that just turning a tube amp on with no load will damage it. With no input signal, flyback can't be generated...so an amp with no load and no input signal will sit there and do nothing for 100 years if the tubes last that long. It's only when there's enough signal from the amp (or it's in self oscillation) that flyback can be generated with no load. But, again, most tube amps have shorting speaker jacks that prevent flyback from occurring even with signal into the amp and the volume turned up."
Thank you all in advance, appreciate your answers, especially if they are explained from technical and electrical perspective since I am interested to know more.

My question is, today I accidentally turned on my Marshall Silver Jubilee head for approximately 2 minutes (maybe less) without speaker attached to head. As soon as I noticed I shut it off, afterwards I reconnected everything and amp plays as before.
Situation was like this: Head turned on standby, no speaker attached to head, all pots on 0, no guitar attached. Could that possibly do any damage?
I ve heard people burn their amps while speaker is not connected when they try to play guitar and they crank volume up a bit.
Also I ve read that if amp is is standby and no guitar is connected, it could be turned on like that 100 years and amp won't get damaged..
Also I found this online, is this true statement?
"Most tube amps have shorting type speaker jacks to prevent flyback voltage in case you forget to plug in a speaker. But, if you plug a cable into the amp and not plug the other end of the cable into a speaker, then you have an open circuit that can cause flyback if the amp is played loud enough to generate the flyback. But what's "loud enough" to cause flyback damage? Amps aren't created equal so it would be difficult to say. However, there's a misconception that just turning a tube amp on with no load will damage it. With no input signal, flyback can't be generated...so an amp with no load and no input signal will sit there and do nothing for 100 years if the tubes last that long. It's only when there's enough signal from the amp (or it's in self oscillation) that flyback can be generated with no load. But, again, most tube amps have shorting speaker jacks that prevent flyback from occurring even with signal into the amp and the volume turned up."
Thank you all in advance, appreciate your answers, especially if they are explained from technical and electrical perspective since I am interested to know more.