JP II c Red sounds muffled compared to Mk IV Mid Gain in FW 21.00 - with audio and preset

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phil92

phil92

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I have played more bluesy stuff for a few FW versions and just revisited my Boogie Preset. The JP II c sounded surprisingly muffled all of a sudden. I never noticed that before. Did something change that I'm not aware of?
 
Did a little re-amping session going through FW versions. Looks like the big jump happened from FW 20 to 21.

 

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I am going to guess the changes to speaker modeling. I had to pull back down on thump a little bit and add a little more speaker drive to get it more lively. I would play around with things in there. I had to tweak my jp2c preset from 21.0 to the 21.03 as well, again.
 
jamesmarshall said:
I am going to guess the changes to speaker modeling. I had to pull back down on thump a little bit and add a little more speaker drive to get it more lively. I would play around with things in there. I had to tweak my jp2c preset from 21.0 to the 21.03 as well, again.
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possible. But I wouldn't have expected the Mark IV to move in the opposite direction then; it gets brighter while the JPIIc gets very muffled.
Also, none of these use any speaker thump or drive and I set both to the same impedance curve.
 
I used every firmware version since v2 and most betas This is the first time I'm encountering such a dramatic change and I suspect something is off
 
if you listen to the clips, compared to FW 19.08 the Mark IV loses low end while the JPIIc loses high end
 
First of all a JP IIC+ is not a Mark IV. They sound different.

The biggest difference is in the behavior of the Presence Shift. With the Presence Shift on the JP IIC+ will be very similar to the Mark IV with its Presence Shift on. With the Presence Shifts off they are very different sounding.
 
FractalAudio said:
First of all a JP IIC+ is not a Mark IV. They sound different.

The biggest difference is in the behavior of the Presence Shift. With the Presence Shift on the JP IIC+ will be very similar to the Mark IV with its Presence Shift on. With the Presence Shifts off they are very different sounding.
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they used to be much closer in FW 20 and lower, with FW 21 they moved in opposite directions; the mark IV lost low end and got brighter, while the JPIIc lost quite a bit of high end.

You are saying this new behaviour is expected and correct?

To clarify: I’m not surprised they sound different from each other; I was surprised by how much they changed, the JPIIc in particular.
 
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The JP2C Red channel is very dark, it’s always been very dark. I remember when it was first introduced I noticed the triode 1 plate freq was super super low compared to other Mark style amps, raising that takes the blanket off but then it’s also not as true to the original amp anymore.

The Mark IV channels have always been very bright too. I wanted to get into using them for some stuff I’m working on but they’ve always been so bright that I was finding the IIC+ had more bass. It sounds like they’re just continuing to go in those respective directions. I’m not surprised and I’d presume that they’re both likely a little closer to the real thing with those changes in mind (but also yeah, stick the Presence Shift on if you want more sparkly/aggressive highs, works every time)
 
Double-checked the JP IIC+ Red model and it is extremely accurate:

jp2c_red.PNG

Green trace is amp w/ Presence pulled. Blue trace is Axe-Fx w/ Presence Shift on.

Magenta trace is amp w/ Presence pushed. Yellow trace is Axe-Fx w/ Presence Shift off.
 
FractalAudio said:
Double-checked the JP IIC+ Red model and it is extremely accurate:

View attachment 116391

Green trace is amp w/ Presence pulled. Blue trace is Axe-Fx w/ Presence Shift on.

Magenta trace is amp w/ Presence pushed. Yellow trace is Axe-Fx w/ Presence Shift off.
Click to expand...
Just out of curiosity any 411 on what would be the cause of the the 3-5 unit hump in the lower third of the magenta and green traces there? Not that I think it like a "oh clearly they don't match. alert the naysayers! queue the ginned up outrage!!" discrepancy that needs nit picking (far from it)... just interested if there's any insight on what the IRL physics might be that contribute to a (visually at least) noticeable degree of variation like that at similar spots in each curve from the rest of it's own response.
 
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h.c.e. said:
Just out of curiosity any 411 on what would be the cause of the the 3-5 unit hump in the lower third of the magenta and green traces there? Not that I think it like a "oh clearly they don't match. alert the naysayers! queue the ginned up outrage!!" discrepancy that needs nit picking (far from it)... just interested if there's any insight on what the IRL physics might be that contribute to a (visually at least) noticeable degree of variation like that at similar spots in each curve from the rest of it's own response.
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60-cycle hum.
 
@FractalAudio
As none questions are stupid…have you modeled all the channels in the axe, with the 5 bands eq turned off in the real amp everytime ?

As probably no one use the real amp with the 5 bands eq off, it can explain why some would say it’s “dark” or this and that . With the eq “on”, that’s a complete different amp.
 
Because yeah some guy sometimes said that the JP2c is done to play metal only … but that’s wrong. When you disable the shred mode and the 5 band eq in this amp, turn the gain at 4/10, you can play blues and typical old mark series things . You can do many tones with this amp when you tweak it .
 
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