Any Marshall JMP-1 with AxeFX 4CM users here?

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Fractal Fanatic
How have you set it up?

Are you using AxeFX the fx loop in the JMP-1 or sending the JMP-1 main outs direct to the AxeFX?

Any issues with gain staging or tone suck?

Any way to utilise an isolated stereo cab IR into a FOH feed? (It's not possible I know without another device added - but what tapped off stereo/2 channel DI Cab emulation device exists to do this that can go between power amp and speaker .... I'd prefer to be able to use third party IRs .... but if it's silly money then I'll just use real Mics)

The reasons and thoughts are below if you want to read more
For some of our small gigs (cramped stages, iffy PAs, strange shaped rooms etc) I'm having too much hassle with FRFR so want to use a conventional tube power amp and guitar cabs. I'm therefore ressurrecting my old Marshall JMP-1 /G Major 2/Mesa fifty/fifty rig ..... and was thinking of going 4CM with the AxeFX. The G Major 2 is a bit disappointing IMO - especially in the loop of the JMP-1.

The thing is the fx loop in the JMP-1 is a little strange - it has a per preset setting range of 0-12 - 0 being off and then varying degees of 'parallel' up until 6 (so at 6 it's sending an equal amount of dry to it's main outs as it's sending to the FX device in the loop) and then from 7 to 12 it's varying degrees of 'serial' (so at 12 it's sending all it's dry signal to the FX unit).

There's some sort of phase inverting going on in the JMP-1 loop and at full serial setting it seems to thin out the sound (I just have a patch cable going from send to return L to test that)

I'd rather just have the loop 'proper' serial - there's apparently a mod (remove 2 resistors - R167 and R169 in the loop circuit) to acheive this and let the AxeFX handle any parallel FX routing set up before feeding back into the JMP-1 loop returns - but I'm not sure if that cures the phase inversion issue.

I want to use the fx loop in the JMP-1 if possible because once set it's unaffected by any adjustment made to the main 'level' knob on the front of the JMP-1. If I were to take the direct outs on the JMP-1 straight to the AxeFx loop returns and then from there to the power amp then if I was to turn up my stage volume using the JMP-1 level knob it would affect the input levels on the AxeFX.

However ..... if I do have to do it that way then I guess the output level on the AxeFX is where I'd need to go to when wanting to send more level to the power amp.

With the AxeFX in there I think I've options to also set up presets to use it direct to the power amp (power amp simulation off) for backup

Options I see are:

1. Guitar > AxeFx in > (add mono front of amp fx stomps) > AxeFX fx send L > JMP-1 In > JMP-1 fx send > AxeFX L Fx return > (add stereo mod/time based FX) >AxeFX Output 1 L/R > Power Amp

2. Guitar > AxeFX Instrument in <front of amp FX stomps followed by FXL block> AxeFX FXL send L > JMP-1 Instrument in > JMP-1 main outs > AxeFX FX returns > AxeFX Output 1 L/R to Power amp/cabs
 
I find it amusingly ironic that your solution to smaller gigs is to bring an even bigger rig along. ;):D
 
Well yes I suppose it's 1U different. A 5U rack compared to a 4U if the AxeFX is used ....... but it fits with the situation.

Maybe one day I'll be able to get a Fryette LXII and go back to 4U :) ...... but added bonus is I only need bring a small MIDI floor controller and a Wah and can leave the heavy MFC loaded floorboard at home. I'm going to use e609 mics and just hang them over the cabs for this rig.

With both the real JMP-1 and the AxeFX sharing the same rack I'll be able to easily A/B real against model and then maybe drop the JMP-1 out if I can get the AxeFX dialled in.

Or .... I'll just use a 1U FX unit to remain at 4U and keep the AxeFX /Matrix/ FRFR cabs rig as is and use whenever the venue merits it.

The weak link for me is not the AxeFX but the SS amp and speaker reaction ...... conventional cabs sound way better with the tube amp and even with the volume lower than my FRFR cabs were running at everyone on stage can hear them better at the little gigs. FRFR cabs work fine with the SS amp .... but if I can't hear them in a live situation then it's not good.
 
I do basically the same thing with my Mesa Triaxis and Mesa fifty/fifty power amp using the 4CM. The small bars we play at don't always have good PA's. Actually they almost always have a terrible PA. So I like using my preamp, power amp, and cab. It sounds amazing, why change it? Now on to your question...

I don't own a JMP so I can't help with the weird fx loop that it has, but I will tell you my experience using a triaxis. I've always used "option 1".

1. Guitar > AxeFx in > (add mono front of amp fx stomps) > AxeFX fx send L > JMP-1 In > JMP-1 fx send > AxeFX L Fx return > (add stereo mod/time based FX) >AxeFX Output 1 L/R > Power Amp

I've had no problem with clipping the input of the axe fx like this. The output of the Triaxis is so hot that I usually leave it on 1 and raise it up to 2 for loud gigging volume levels. The fifty/fifty power amp is usually set to about 5. Maybe it would clip the Axe fx if I turned up the triaxis even more, but I never have since it is already earth shattering loud for the size of venues I play. I actually never even thought about this until this thread. There is an fx loop on the triaxis but I was always confused why you would need that. Now I guess it makes sense.
 
The output of the Triaxis is so hot that I usually leave it on 1 and raise it up to 2 for loud gigging volume levels. The fifty/fifty power amp is usually set to about 5.
Well 5 on the 50/50 is certainly loud - probably as loud as it gets. Anything more will just be adding tube distortion rather than volume :) I used to chicken out at around 3 with the JMP-1 sitting at 12 o'clock (half volume).

My 50/50 has just recently had a bias pot added and the tubes properly biased to a medium setting rather than the really cold set bias that Mesa had - haven't actually tried it out yet .... but as well as a bit more warmth I'm expecting even more volume from the 50/50 now!
 
This thread helped me realize the error in my ways of not using the triaxis effects loop. So thanks for making this thread. Hopefully your JMP effects loop is working OK now. The bias mod for the 50/50 sounds interesting.
 
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