JP-2C speaker switch not working properly

[Pacho]

Hello everyone! I just got my JP-2C and a Engl E212VB cab (16-ohms). I’ve noticed that with the speaker switch off there’s guitar sound coming from the speakers at very low volume but still. The guitar sound is not supposed to be muted?
The amp is connected from the 16-ohms output to the cab.
Is there something wrong with my amp?
Any help would be greatly appreciated!

 

[bandit2013]

Is there anything plugged into the FX loop? It is possible something is reversed.

Also is this a new amp or a used one? you may have a bad tube like V2. It is probable the switch is at fault though or it could be the 16-ohm jack. Try using the 8-ohm jack instead (it is safe to run a higher cab load on the jack, just do not do it the other way where the cab impedance would be less than the jack rating).

Before jumping to conclusion there is an internal error with components, changing preamp tubes is usually the first thing that a tech will perform to start with and you can do that at home if you have any spare 12AX7 preamp tubes. If that does not work, you need to have a tech look at it. If it is new, report an issue with Mesa customer support or the place you bought it from.

 

[Pacho]

Is there anything plugged into the FX loop? It is possible something is reversed.

Also is this a new amp or a used one? you may have a bad tube like V2. It is probable the switch is at fault though or it could be the 16-ohm jack. Try using the 8-ohm jack instead (it is safe to run a higher cab load on the jack, just do not do it the other way where the cab impedance would be less than the jack rating).

Before jumping to conclusion there is an internal error with components, changing preamp tubes is usually the first thing that a tech will perform to start with and you can do that at home if you have any spare 12AX7 preamp tubes. If that does not work, you need to have a tech look at it. If it is new, report an issue with Mesa customer support or the place you bought it from.

Thank you for your answer.

It’s connected to an Axe Fx 3 using the 4MC so there are cables in the FX loop.

The Amp is new, bought at Thomann.

I will try your suggestion using the 8-ohm jack and disconnecting the cables from the Fx loop. I can’t change tubes because I don’t have any spare but I will try the other suggestions as soon I get home and will let you know.

Thanks again!

 

[Pacho]

Is there anything plugged into the FX loop? It is possible something is reversed.

Also is this a new amp or a used one? you may have a bad tube like V2. It is probable the switch is at fault though or it could be the 16-ohm jack. Try using the 8-ohm jack instead (it is safe to run a higher cab load on the jack, just do not do it the other way where the cab impedance would be less than the jack rating).

Before jumping to conclusion there is an internal error with components, changing preamp tubes is usually the first thing that a tech will perform to start with and you can do that at home if you have any spare 12AX7 preamp tubes. If that does not work, you need to have a tech look at it. If it is new, report an issue with Mesa customer support or the place you bought it from.

I also would like to know if I can use a different brand of 12AX7 preamp tubes along with the Mesa tubes that come with the amp.

Thank you!

 

[Pacho]

Updating the thread:
I've tried again, disconnecting all the cables and using both the 16-ohm and 8-ohm speaker outputs, but the problem persists.

I'm afraid that, although I don't know if it's the cause, there must be a damaged tube because, when increasing the master volume, with the speaker switch in the off position, a kind of metallic click is heard that sounds like hitting glass, so I suppose it must be one of the tubes.

Now I'll find out how to detect which one may be damaged and try to change it, as well as buying new ones because I don't have any spares.

I am very frustrated with this amplifier, which did not arrive in good condition. I don't know whether to return it or change the tube to see if that solves the problem.

Am I missing something else to check? Any suggestions as to the brand of tubes?

Thanks for your help!