Is Standby OK for Switching Cabinets?

[OSAR]

I have a Dual Rectifier and like to change from one cabinet to another quite often. Is it safe to just switch the Standby switch off or do I need to kill the main power also before disconnecting the cable?

 

[mikeymike]

I have a Dual Rectifier and like to change from one cabinet to another quite often. Is it safe to just switch the Standby switch off or do I need to kill the main power also before disconnecting the cable?

I believe standby is sufficient. Others may chime in though.

 

[mikey383]

Standby will work. It just keeps the tube heaters running, and there's no input or output giong through the amp.

 

[dmcguitar]

i do it all them time.. actuallly i tend to turn my amp on before hooking up any cables when setting up for a gig. So by the time i ahve my 4 cables plugged in i know that there was a little warming up. (yes i always make sure that its on standby first... but since there is no guitar connected and there for no signal go through that shouldn't cause any issues).

 

[brh34]

I do not know the answer to this question, but I would like to throw this out for pondering all the same.

I would think that it is not good to have the power amp on without a load connected to it. Maybe having the amp in the standby position nullifies this thought?

I can't remember where I read / heard this, but I was somehow informed that the amp should be hooked up to a load prior to powering it up.

Perhaps someone could elaborate on this and correct my misconception, if it is incorrect.

 

[dmcguitar]

well having the power amp on with no speaker connected is bad, if there is a load going to it.. so if you play the guitar and forgot to connect the speakers the power has no where to go... bad.... but if you mistakenly put it on and had no guitar connected to send signal through it , then i dont think the power amp would be getting any harmful signal, i wouldnt leave it like that though.. (i could be wrong)

also when the amp is on standby, that turns of the power amp. so no signal goes to it.. so no harm should come of disconnecting the speaker cable to change cabs.

 

[mikey383]

As long as there's no signal going to the amp, it should be okay to have no load connected to it, even if removed from standby. Some amps have a shorting jack in the input so that it connects the input to ground when not in use, removing the input jack from the signal.

 

[mikeymike]

As long as there's no signal going to the amp, it should be okay to have no load connected to it, even if removed from standby. Some amps have a shorting jack in the input so that it connects the input to ground when not in use, removing the input jack from the signal.

Now THAT is a useful piece of information I did not know about. I figured even if there is no input most times you still need to have a load because of the way tubes work they're always making signal. Do you know if Mesa's have this shorting jack? specifically the 2:100 and 50/50 ?

 

[mikey383]

As long as there's no signal going to the amp, it should be okay to have no load connected to it, even if removed from standby. Some amps have a shorting jack in the input so that it connects the input to ground when not in use, removing the input jack from the signal.

Now THAT is a useful piece of information I did not know about. I figured even if there is no input most times you still need to have a load because of the way tubes work they're always making signal. Do you know if Mesa's have this shorting jack? specifically the 2:100 and 50/50 ?

I'm not sure, but you could find out by taking the chassis apart and looking at the jack. If it's a shunted jack, there will be two metal tabs on it that touch together when there's nothing in the jack. If it's not, there will just be one metal tab.

Even so, if there's nothing in the input, you have no signal. There's nothing there to amplify, so the output stage is dormant.