Can u tell me what year my peavey amp is?its a bandit 65 serial # 2a-01223413 thanks

I have to assume you're really meaning a tear in the speaker cone. If so, yes you can repair it if it's small and yes, it will affect the sound. Peavey Bandit amps have come with a few different speakers over the life of the name, but all will still be available either online or directly from Peavey's parts department. Here's the link-
http://www.peavey.com/support/contactinfo

There are a lot of possible problem areas it could be. I would first check that the speaker is working correctly. If so, I'd clean all jacks and pots. If that doesn't do it, it'll be time to take it to the shop.

If the amp is only doing this when the pedal is plugged in, there is either a problem with the pedal (try it with a different amp) or possibly you have plugged it in using a speaker cable (unshielded) rather than a guitar cable (shielded).

yes, if you know what is the amp module check.

have you tried using a foot pedal? Are you sure it is switching (green light turns red, etc?). On the lead channel are you turning up the gain all the way and the volume down?

Overdrive is the key to the crunchy metal sound. The only effect on that amp is reverb.
You may want to consider getting an overdrive pedal to get the sound you want.

No the 'send' socket is to plug in an external effects unit (it may also be used to feed a slave amp) but it will not disconnect the loudspeaker

The intergrated circuit is most likely gone out. Not much you can do, cost in repair is more than the amp. Check out the peavey vypyr, it's a great modeling amp for about $100.

TRY GIOVANIA FOR HELP.