'Boost' randomly activates!

Please help! I have the GMD40 in conjunction with the FSM 432 MKIII and on at least 8 occasions in 6 hours of play the boost function randomly turns on! Since I am new to this rig I just thought I was hitting it by accident, or, I don't know, doing something wrong, but while I was sitting there guitar in hand staring at the amp wondering about all the ways I could be the problem and not the amp, it happened. Just sitting there staring at the face of the am in the clean channel - 1 watt saturation - in sb mode on the foot switch - the amp decided it was time to 'boost' without my permission.

Does anyone know how I can correct this problem without having to return the equipment? I'm super happy with it otherwise.

Thanks for reading. I'll be standing by with fingers crossed.

So you are controlling it via a FSM432. Check to see whether you have this problem when you run the amp manually without the FSM432 attached. Play it for a while with just the switches controlling your changes. (I know it's a pain, I have had to do this myself.) It is very possible that the problem isn't in the amp but is in the foot controller unit. In Stompbox mode as you said you use you have a switch dedicated to the Boost function. If that switch is dodgy or if its control line has some other issue it may be triggering the Boost to switch when you aren't kicking it about.

I would also perform a factory reset too as this could possibly be a software fault. You MUST backup any preset patches you have created as these will be lost when the presets are reset to the factory default set along with the rest of the amp software. Remember, the patches are stored in the amp not in the footswitch unit. All the FSM432 does is to tell the amp when and what function or which patch to switch to. The amp then takes care of the change in settings from its own stored data. If you don't have a midi interface and the free control app it might be worth considering whether to get one. Just don't get anything too cheap, the Chinese generic interfaces which do not support Sysex midi data transfer will not work! It is surprising how many little niggles can be corrected with a factory reset but no one thinks to do it as a matter of regular maintenance.

Try those two approaches and get back to us with what you find.

Thank you for getting back to me quickly! I had already tried the factory reset on the amp before the issue was occurring, but the issue remained. However, The past five or six hours of amp use have been without the FSM432 and I have yet to encounter an issue. Is there a factory preset for the controller by chance?

At this point, I am going to exchange the controller and see what happens. I am pretty sure it is the controller. I will respond once this experiment is concluded for other future users that may have the same issue. Thanks for your assistance! Standby for conclusion.

Unfortunately, as far as I know, there is no factory reset procedure for the FSM432.  It only acts as a source of responses to your stomps on its switches.  It knows what mode it is in from the switch on the back and it simply gives out dumb commands in response to the switches which are pushed.  It does not tell the amp how to set up every control for a patch for example.  It only sends a single command which tells the amp "switch to the patch you have stored in your slot for Bank 3: voice 2".  The amp then looks up that patch in its own memory and applies the full set of settings it finds there.  After it has sent the "change to patch X" command the FSM goes back to sleep in its armchair.

There is one other thing you can try before you give up on it.  There are two external control sockets in which you can plug standard type footswitches and programme them to control any of the settings.  Control socket 2 is already preprogrammed for Control Number 64 which is the Boost.  I wonder if that could somehow be interfering with things.  Plug either a standard type footswitch or just a plain jack plug into that socket on the back of the FSM432 and see if the Boost responds as it should.  If you short out the jack plug connections or unshort them it has the same effect as stomping the switch.

If everything works as it should that way I would then reprogramme Control 2 to any other setting, just not Boost, and see if that changes things.  Changing the control number attached to the switches is covered in the FSM432 manual in section 2.6.  If it isn't clear, (it isn't very), get back to us.  You will always be able to reprogramme it back if you want to afterwards and it won't affect the normal action of the switches.