Cabinet wiring

[Amazingmaze]

Hey,

I would like to do the following and I hope someone can help me

I have a Marshall JCM 800 and a JMP 1 Preamp with a VS 8008 poweramp (it has two in/outputs, each one has 80W).
My Cabinet is a 4x12" with 16 Ohm or 4 Ohm mono or 2x8 Ohm stereo.
I use the JCM 800 with a silencer (brand TAD, 16 Ohm but it also has a load box with a line out) and I would like to:

Use both amps only with the one cabinet I mentioned and to switch via MIDI between the two amps.

Does anyone has a good solution for my project?

Thanks,
Matthias

PS: I have also an Axess GRX4 if this would help in this case.

[Vince Neville]

Hi Amazingmaze,

Is there any specific reason you want to switch via midi? I assume it is because you have a midi controller for your jmp-1. I've never fully understood midi, even though I've owned three midi controlled pedals (never bothered to get a switcher). In this case, you are simply switching the path of your guitar signal: into the 800 OR into the jmp. You should be able to do that with any type of switcher. I have a Morley A/B/Y switch (just a simple passive one) and that is what I would use if I had a dual-amp setup like yours. It has exclusive switching (A or B), meaning that only one amp is being fed your guitar signal at a time. It also has A and B, meaning that both amps are being fed your guitar signal at the same time. There are lots of other switchers out there, but I am not really familiar with them.

If you find that your tone is affected by using the passive switcher, it is probably because of the extra cable used. A solution for that would be a buffer pedal , such as the Buffer by Wampler Pedals, which would allow you drive long cables with less loss. Gtr -->Buffer --> Switcher --> Amp1/Amp2. I've never done this myself, so I can't verify that it is a definite solution, but it is something to consider if you go that route.

Hope I've been of some help. If you still want to switch via midi, I'm sure someone on this forum knows how midi works. Sorry I can't help with that topic.

All the best.
Vince

[908ssp]

Check out the Lehle line of switchers I think they are midi capable. You should keep a load on the output of both power amps at all times even if you're not feeding in just to be safe.

[Amazingmaze]

Hey,

First, thanks for your information.

Regarding Midi:
I need to switch it via Midi because I would like to use different presets on my JMP1.
Without Midi I'm not able to change the presets and the position of the switcher/other FX.

Can I use any switcher after the loadbox or has it to be a special one?
I would have an Axess GRX4 which is a Midi switcher (like the Voodoo Lab GCX switcher, only smaller) but I thought I could only use it in the effects loop.
Could I put it after the loadbox?

But if I use a loadbox I have to buy a good poweramp.
Can you recommend one which only needs one rackspace (sorry, don't know the english word )?
Would you use the Marshall VS8008 for this purpose?

[908ssp]

Let's see. You have one pre-amp and one full amp with load with a line level out. The output of the amp and load using the line level output and the preamp are both line level signals so all you need is a line level switcher controlled by midi. 2 into 1 line level switcher the output of that goes into one mono amp feeding one speaker cab.