On output modes and EQing in the MG-30...

Started by eUphonic, February 12, 2022, 12:19:13 AM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.


Quote from: admin on March 06, 2022, 04:35:13 AM
Change the CAB TYPE  to your preference- can also load a third party CAB IR, will have a large impact on achieving desired tone.

Yes, that's why I've wrote above that "2)third part IR's can change drastically any of the amp models in this unit as in other modelers". :-)


Quote from: aptfx on March 06, 2022, 05:23:57 AM
The output transformer is only modeled in the VIVO model. The SLO is an older one. My theory is that there is something wrong with the bias parameters in the SLO model. As soon if I max out the Bias it sounds much closer to neuralDSP. The rest of the difference is that misses MIDDLE a lot.. I cranked it and now the result sounds quite similar to NeuralDSP. The rest is maybe finetuning Gain, treble and presence.

My idea was that some high gain models tend to share the same bassrange in the MG30, suggesting that the seeds of OT modeling were already present in older models - and once again, real amps can behave like that. That's what I was saying to myself yesterday while we were on stage with tube amps (and with the sound engineer struggling to mike them just because he has refused to amplify directly my direct outputs with IR's)...  :D

Regarding the bias setting: thx for sharing, I've not yet tried to tweak this parameter with high gain models.

Regarding frequencies: I share below the frequency response obtained when a polyphonic signal is injected in the MG30.
White line = 1987. Green line = SLO. Pink line = Friedman. Blue line = Recto.
According to this test, the SLO has actually the most mids among these models... BUT the Friedman and Recto generate a narrow deep dip @ 80hz (not far from the frequency of a low E string unfretted).
My thought when I read your testimonial is that cranking the mids with the SLO might give the same kind of relative difference between bass and mids than flat settings with the Friedman or Recto sim with their selective dips in the bass.

Therefore, it might be interesting to tweak the bassrange with a preEQ between guitar and  SLO model (which would involve once again the para EQ)... I'll try this solution and report my findings later.


Small addition here. According to NUX they started investigating the SLO and VIVO models as there seems to be some data error. It will take some time, but it will be interesting what they come to.


Did the V3.2.2 firmware update yesterday at night. Then played a bit with the MG30, then did a frequency analysis of the amp models...

SLO and VIVO are certainly more playable now. And their bias control doesn't react no more as a third volume control, like it did in my unit after V3.1.9 update...

The Princeton is nice but it has something in common with the SLO: a big bass boost, reminding the impedance peak measured between output and loudspeaker(s) of some tube amps. Other amp models don't do this in the MG30, or not so much, and it requires some "bass cut" with some IR's.

Nux didn't fix the EQ: "500hz" sliders still affect the 800hz range, for example.

And the flattest output option is still not flat when all FX's are disabled: I still need my correcting para EQ to flatten the response in a realistic way (albeit it adds a wee bit more mids since the V3.1.9 firmware update).

While I'm at it: the patch with my flattening EQ,  shared in the post 17, was designed to give unity gain when the (physical) volume knob of the unit is full up. So the patch level is set extremely low. It's intentionnal: it allows to avoid any inconsistency due to the position of the physical volume knob on the MG30 (more accessible to clumsy feet on stage than a "lateral" / perpendicular pot would be).



For the record, I share below the response of the SLO (all controls at noon) as it is now emulated by the MG30 (in blue), VS the curves of other digital MG30 models: the JCM800 (in white), 1987X (in green) and Friedman (in pink).

To compare for instance to the curves in the second picture, obtained from an "analog modeler": my Mesa TA15 tube head, tested through its voxy channel (in white) then through the three modes of its red channel: Tweed (Fender emulation, in green), H1 (Marshall emulation, in blue) and H2 (Boogie emulation, in pink)... As usual, these curves were captured by a direct box inserted between power amp output and cab.

My flattening EQ would have made these pics closer to each other. This EQ was not enabled below (the pic about the MG30 shows the "crude" raw response of its amp models, with the +6dB high shelf generated by its Studio output mode, and not the "corrected version" with preparaEQed input that I systematically use now).


Did firmware update 3.2.3 a while back.

There's still bugs that I won't list here because it would be off topic.

My flattening EQ shared in the post 17 is still necessary with this last firmware update: I need it to make the MG30 sonically closer to my various analog PB's.

I find the drive pedals a bit hit or miss... The NUX TS clone hasn't the subtlety of my real Tube Screamers (TS 808 or TS9). But the Crunch Box clone, for instance, is really satisfying to my ears. YMMV.


IMO the studio direct mode is fine as-is, for recording I actually want less bass and more impact in the highs. Otherwise I'd need to cut the bass and boost the highs when mixing. A matter of preference I guess.

Very happy with the device, using it for high gain mostly - the amps have lots of "body" in the mids and pinch harmonics will work fine with most amp/IR combinations. Also the perceived latency is basically zero, which makes it feel much more organic than many competitors. No flabby artificial deep bass, no hissy unnatural treble, sounds very tight and pleasant to the ear. It already replaced the Ampero, which was my former favorite for home use.

Seems like they hit the jackpot with the input circuit, regarding attack/sustain/decay it feels very nice, close to a real preamp.


Quote from: SK on June 15, 2022, 05:14:17 AMIMO the studio direct mode is fine as-is, for recording I actually want less bass and more impact in the highs. Otherwise I'd need to cut the bass and boost the highs when mixing. A matter of preference I guess.

Yes, the MG30 seems pre-EQed for recording (or for garden variety PA's / sound systems, often too bassy with modelers)...

...but that's what makes it sound harsh as a simple FX pedalboard and the reason why I've a flattening preEQ in all my patches. Less bass and more high can always been obtaining from the amps and/or cabs models, anyway.

Nux could have offered a really neutral output mode, with a normally flat response once all FX's disabled: they can do it, since that's what happens when one plugs in the FX return jack. But its lower input impedance makes this input a bit dull for guitars, so it's not really an alternative to the main guitar input... and the global EQ is too selective to cure the EQing due to studio/direct mode.

Regarding other specs, I agree: the amp models are gorgeous.

A thing that I do is sending NUX FX's to a real tube amp through the "send" jack plug, while the same FX's are sent simultaneously to a digital amp model in the MG30, itself plugged direct to the board. As I use impulse responses reproducing my own cabs, I can obtain really similar tones from the real amps in the room and from the MG30 throught the board...
I've still to try this on stage but it seems a credible substitute to amp miking - Now, I couldn't do the same without my flattening EQ, since it would send a brigthened guitar signal to the real amp and would sound artificial (been there, done that. The result was not pleasing to me). YMMV.


Got you. I'm using it only directly for recording or with phones on the sofa, so no such issues here. I just need a believable, juicy amp tone and proper dynamics and that's just what it delivers. I edit the patches in the same mode, so the EQ (from the amp or post IR) gets adjusted accordingly.

Live use will be a bit limited, not enough switches for most people I guess.


Euphonic, I made an account to say cheers for this - the issue has been driving me crazy all week!

Do you think it would be possible to introduce a physical EQ pedal into the loop after the S/R for further tone shaping, given the parametric EQ is right at the front of the chain?


Quote from: Grantymc on May 03, 2023, 02:29:05 PMEuphonic, I made an account to say cheers for this - the issue has been driving me crazy all week!

Do you think it would be possible to introduce a physical EQ pedal into the loop after the S/R for further tone shaping, given the parametric EQ is right at the front of the chain?

Glad if it helps. :-)

Yes, an EQ in the loop would work, albeit it might add a bit of noise... and I wouldn't necessarily ditch the post EQ for post amp sim tone shaping, even if it's not really flexible.


While I'm there: as already mentioned in post 32, I now use the "send" plug of the FX loop as a "normal" output for FX's.

IOW, in a few patches, I've put all the FX's or most of them as following:

FX's>volume pedal>FX loop>amp simulation.

So I can use the "send" plug to feed a normal guitar amp while the same chain still feeds the inner amp sim + its IR. And as I've captured the response of my cabs as IR's stored in the "user" or "collection" folders, I can feed the board directly instead of miking my amps.

Done something similar with the Valeton GP100, whose left and right outputs can be differentiated as enabling an IR or not.

Pretty useful on stage and in the case of the MG30, the sound doesn't seem fake or tiny compared to a real amp played in the same time... It just sounds like a miked amp to me. YMMV.