Px8 plus and amp switching

Q & A for building and interfacing your rack gear with Ground Control Pro and GCX-based systems.
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Troybuilt1979
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Joined: Mon Apr 23, 2018 11:59 am

Px8 plus and amp switching

Post by Troybuilt1979 » Mon Apr 23, 2018 12:06 pm

Hey guys, first post. So I recently acquired and amplifier that has midi channel and function switching(the new Marshall dsl line). I was wondering if it’s possible to get the px8 plus to switch the channels and functions if it’s the only midi object I’m controlling. I have no pedals that use midi. Thanks for all your help in advance.

JohnClark
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Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: Px8 plus and amp switching

Post by JohnClark » Tue Apr 24, 2018 12:52 pm

After looking at the Marshall manual, it should work right out of the box, however this is an untested setup.

These amps appear to have their Program Changes hard coded so likely it will be that PX-8 Plus Buttons A, B, C, and D on each Bank will recall Clean, Crunch, OD1, and OD2 respectively.

I hope that helps!

Troybuilt1979
Posts: 4
Joined: Mon Apr 23, 2018 11:59 am

Re: Px8 plus and amp switching

Post by Troybuilt1979 » Tue Apr 24, 2018 1:06 pm

Well that’s pretty great news. I guess what you’re saying though is I wouldn’t be able to access all 6 functions of the amp though? What I’m trying to avoid is paying 200 dollars for the upcoming 6 button footswitches. I like your switchers and I’m wanting to upgrade my board to a bigger board. But if I can’t access the lead boost of the dual master volumes, then I’ve come to another crossroads

Troybuilt1979
Posts: 4
Joined: Mon Apr 23, 2018 11:59 am

Re: Px8 plus and amp switching

Post by Troybuilt1979 » Tue Apr 24, 2018 3:18 pm

Here’s some info I found on the midi. It’s a little bit to read but it looks as though I would need to be able to send both pc and cc programs to the dsl to fully utilize the functions. Please excuse me too because I’ve never done anything with midi. But I want so bad to be able to use the px8 plus and dingbat with my dsl.





On the DSL each of the 4 channels clean, crunch, OD1, OD2 are assigned in a loop to every four MIDI program change messages and can’t be changed e.g.



PC 00 = CLEAN

PC 01 = CRUNCH

PC 02 = OD1

PC 03 = OD2



PC 04 = CLEAN

PC 05 = CRUNCH

PC 06 = OD1

PC 07 = OD2



PC 08 = CLEAN etc.









Connect the MIDI controller to the DSL – MIDI Out to MIDI In. Multiple equipment can be connected using MIDI thrus where available. Always ensure each piece of connected equipment is set to a different MIDI channel.



Set the receive MIDI channel on the DSL, this only needs to be done once.…



Press and hold the Loop On/Off switch (Front Panel Function #23) while powering up the amplifier to activate MIDI waiting mode.



The LED will flash until a valid MIDI command is received.



Send a MIDI PC command on the required MIDI channel from the connected controller to the DSL.



The MIDI receive channel on the DSL will now be set.



If the user just wants to recall one variation of each channel, they can select each channel in turn from the front panel and set the state of the FX loop and Master (the switch settings are remembered per channel). They then only need to set their MIDI controller to send the appropriate program change message to recall that channel on the DSL.



If the user wishes to have multiple variations of each channel recalled e.g. Clean with FX Loop on and Master 1 and then clean with FX Loop Off and Master 2. They will need to set their controller to send a program change message to select the DSL’s channel and then MIDI CC messages to set the state of the FX Loop and Master.



e.g.



Clean with FX Loop On and Master 1



Send…



PC=00 [DSL Clean Channel]

CC=13 Value = 1 [DSL FX Loop On]

CC=14 Value = 0 [DSL Master 1]



Clean with FX Loop Off and Master 2



Send…



PC=00 [DSL Clean Channel]

CC=13 Value = 0 [DSL FX Loop Off]

CC=14 Value = 1 [DSL Master 2]



One final thing to note. When the 2-way footswitch is connected the amplifier will not respond to any MIDI messages and the channels won’t recall the saved state of the FX Loop (the 2-way overrides it), but the 6-way can be used without

JohnClark
Posts: 7086
Joined: Tue May 05, 2009 2:33 pm
Location: The Lab

Re: Px8 plus and amp switching

Post by JohnClark » Wed Apr 25, 2018 10:00 am

Sorry I wasn't completely clear in my first reply... yes the PX-8 Plus would only directly control the Channels. It appears the amp doesn't learn any functions beyond having the Loop or Master 1 or 2 hard set with a specific Channel... so if you will always have Channel 1 with the FX Loop OFF and Master 2 Enabled, you will be fine, but if you want to have all combinations possible or live switch the FX Loop or Master 1 and 2 while on a specific Channel then it will not work for you.

I hope that helps!

Troybuilt1979
Posts: 4
Joined: Mon Apr 23, 2018 11:59 am

Re: Px8 plus and amp switching

Post by Troybuilt1979 » Wed Apr 25, 2018 10:14 am

Yes sir thank you for helping me out.

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