Plugging in and out damage

What are the do's and don't for plugging in and out of you amp? I got a funny look the other day when I unplugged one guitar and plugged in another while the amp was on and running. It was like «you do that, don't you know it's bad for the amp?».
I've been playing for 25years and I've never had an amp fail on me. Well most of them have been solid state, but I'm sure you'd be less likely to turn off a tube amp just to switch guitars. Is there a proper way of switching guitars while the amp is running?

Hit the standby on the amp. I will not pull a plug with the amp turned on.

Hit the standby on the amp.

That's one way, but if the amp doesn't have a standby switch, simply pull the jack-plug at the amp end half-way out so it breaks contact, change guitars, then push it in again.

Or, if you use a pedal tuner like the Boss TU-2, you can just step on it to mute the signal.

That's one way, but if the amp doesn't have a standby switch, simply pull the jack-plug at the amp end half-way out so it breaks contact, change guitars, then push it in again.


My amp doesn't have a stand by switch (Cube 60), but I still don't understand what is the potential damage in keeping the chord in the amp while switching guitars?

...what is the potential damage in keeping the chord in the amp while switching guitars?

With the Cube 60 (I have one too), only the loud "crunch" when plugging into the guitar or maybe when touching the tip of the jack plug. Theoretically this could damage the speaker. With a tube (valve) amplifier the internal circuitry might suffer too.

However, in practice, unless the amp's turned really loud, especially with a high-gain model engaged, you'll probably get away with it. It helps if you short the tip and sleeve of the jack with a finger when changing over. But it's still best to disconnect the cord at the amp end for the few seconds it takes, if only to spare the audience unnecessary noise.

With the Cube 60 (I have one too), only the loud "crunch" when plugging into the guitar or maybe when touching the tip of the jack plug. Theoretically this could damage the speaker. With a tube (valve) amplifier the internal circuitry might suffer too.

However, in practice, unless the amp's turned really loud, especially with a high-gain model engaged, you'll probably get away with it. It helps if you short the tip and sleeve of the jack with a finger when changing over. But it's still best to disconnect the cord at the amp end for the few seconds it takes, if only to spare the audience unnecessary noise.

+1. You get arcing of the signal, and with loud environments, this is bad for both ears and amps.

However, in practice, unless the amp's turned really loud, especially with a high-gain model engaged, you'll probably get away with it. It helps if you short the tip and sleeve of the jack with a finger when changing over. But it's still best to disconnect the cord at the amp end for the few seconds it takes, if only to spare the audience unnecessary noise.

How about turning the (pre)amp volume all the way down before switching. Would that help? I notice guys do that before powering down the amp.

Vladimir, turning the preamp or volume down is fine. Unplugging at the guitar is a)hard on the speaker, b0hard on the ears, and c) potentially damaging to the amp. You can take out a transformer if everything goes exactly wrong. I have never seen it happen have read the precautions.
There are grounding plugs that break the connection until the jack is fully inserted. These plugs avoid the noise and the danger....widely used these days.

Turn amp volume down, stick input into another guitar, turn volume back up, rock!

How about turning the (pre)amp volume all the way down before switching. Would that help? I notice guys do that before powering down the amp.

You certainly CAN do that, but why bother? Pull input plug out about 1cm, change guitar, push plug back in. Job done.

Turning the volume down before switching off is not a bad habit to get into but won't serve any real purpose with the Cube.

Get an A/B/Y Box and have both guitars plugged in at once and simply switch between them.....problem solved!

I'm sure amps can handle it, but I imagine that long term it is tough on the speaker. I think more than anything, though, not making that crunch/pop sound that comes with plugging in the guitar that way is irritating to any listener and just seems unprofessional more than anything... it is just like not wanting to have even a split second of feedback from a mic. As a guitar player, it can be easy to get used to that sound, but non musicians often seem to pick up on it as a bad thing just as much as other musicians might. Rather than noise, I prefer the first thing my audience hears from me be music.