Axe III via Studio Monitor v.s. Tube Combo at the Same Volume

[Mark Al]

Today, I spent some quality time with a 68 Custom Vibrolux Reverb on an amp stand side by side with my Axe III through a pair of Genelec 8330 (GLM calibrated) on my desk.

The 68 CVR is really a nice amp with custom Schumacher transformer, it sounds, feels and responds great at low or high volume, it reminds me all the reasons we love tube amps. However, under direct comparison, Axe III plus studio monitor sounds OK but feel quite a bit meh... Both setups were played side by side at around 95DB, so not quiet but not super loud. Such difference is all the more obvious for clean (high dynamic) playing. Here is the difference:
1. The tube combo reacts more immediately at the beginning of the picking, hence it feels more immediately connected with the fingers.
2. However, after the immediate response, tube combo ramp up the dynamic more smoothly, slowly and musically, which allows me to explore the dynamic range of the response more easily.

On the other hand, Axe III plus monitors seem to do exactly the opposite:
1. It seems to have some (very subtle) delay in the very initial reaction, e.g. there is an ever tiny delay, making the amp feel less connected with the finger. I have tried things to minimize the delay all this time, including upgrading my studio monitors, using AES digital directly from Axe III to monitor, saving some A/D/A conversion etc, but it remains very much tangible to me.
2. Once the initial delay is over, the amp responds much more eagerly, e.g. it then jumps from quiet to loud too quickly as I vary the picking strength.

By the way, so far no modeler or any SS amp is able to nail either one above for me, they all exhibit such tiny delay and SS like dynamic more or less.

Interestingly, when wearing my IEM, I am less bothered by these two factors, and somehow they seems quite lessoned, which I suspect has something to do with the (good) quality of headphone amp used in Axe III....

I know, we musicians sometimes could be a nuanced anal bunch about such subtle details, but they often make a world of difference for our playing experience....

Thoughts?

 

[Andrew Male]

I think Cliff has said the total system latency is around 1ms which is imperceptible, so I can only assume your devices are introducing some more post-AxeFX.

Just found this about those Genelecs.

"There is approximately 3ms delay due to internal DSP processing."

This may take the total latency into the realms of being noticeable, even still, 4ms is only 1.3 metres.

If there's a way of turning off the Genelec processing, I'd try that.

 

[Postretro]

I also notice these small but important differences in digital modeling. I don't think it is latency. I agree that the latency is too small to really notice or be bothered by it. My speculation involves onset transients -- pick noise -- scissor-cutting type transients. I wonder if the onset transients are just too much fine, fast, detail to catch digitally. Also, like you, I can make adjustments that put these things in the background so I can enjoy the FM3 for all the great things it does.
This is the state of my current speculations: I sometimes wonder if tube amps don't add some fine ringing and transient distortion to onset transients -- pick noise -- that are now part of our expectations in the pick attack. That is to say that, tube amps exaggerate the onset transients in a very inaccurate (Matti Otala) TID (Transient Intermodulation Distortion) kind-of-way. The old 1967 model Marshall Majors added TID in a big way by putting the tone circuit inside the NFB loop. In fact, I have toyed with the idea of using a Williamson Tube Amp as an FRFR amp to try to add this onset TID back in. I think it might be the element in the pick attack that I miss. I had an old Marshall Major back in the day. And, I loved the pick attack. I thought the pick noise was almost magical. It was actually the TID that killed the OT's in those old Marshall Majors and even in the old Williamson amps. A fast rising signal wave could produce a huge fast voltage spike -- 2KV sounds extreme but that is not even an exaggeration. The NFB just lagged the signal by enough to make squarish-waves really dangerous for those amps.

 

[Mark Al]

I think Cliff has said the total system latency is around 1ms which is imperceptible, so I can only assume your devices are introducing some more post-AxeFX.

Just found this about those Genelecs.

"There is approximately 3ms delay due to internal DSP processing."

This may take the total latency into the realms of being noticeable, even still, 4ms is only 1.3 metres.

If there's a way of turning off the Genelec processing, I'd try that.

In term of latency, That’s pretty much the best one can do using studio monitor, eg using AES is already minimizing that, compared to analog XLR.

 

[mr_fender]

Mic the combo in another room and then compare them both through the Genelec's. That would be a more even comparison. The Axe III provides a mic'd sound, it's not meant to replicate the experience of the open back combo in the room. Studio monitors are not guitar cabs. Expecting them to react and sound exactly the same in a given listening environment is only going to lead to disappointment.

 

[Mark Al]

Mic the combo in another room and then compare them both through the Genelec's. That would be a more even comparison. The Axe III provides a mic'd sound, it's not meant to replicate the experience of the open back combo in the room. Studio monitors are not guitar cabs. Expecting them to react and sound exactly the same in a given listening environment is only going to lead to disappointment.

That's fair. To be honest, I am not exactly expecting them to sound or feel the same...

I think I am just disappointed that I much prefer the playing experience with the combo amp, while I wish my preference would be otherwise....

By the way, forgot to mention earlier, I had exactly the same experience comparing Axe III with PowerCab 212 v.s. tube combo. In this comparison, both set ups are AITR, and PC212 is THE best output system I have tried with modelers, after going through multiple FRFRs, etc... However, the tube combos always exhibit that immediacy of response and smooth dynamic afterwards (as I mentioned in OP), which is lacking (the opposite) from the digital setup....

It's definitely not a EQ or tonal thing as the response plays out in time, I wish we could really pin-point and quantity that, and hopefully someday nailed it.

 

[cardinal]

I just use real cabs with a neutral power amp. It's very tricky to get the Fractal master volume set "correctly," but once it's there, the Fractal/power amp set up is very hard if not impossible to tell is not the "real" amp.

I've stayed away from these flat response/IR set ups because they are just not the same playing experience. YMMV.

 

[Mark Al]

I just use real cabs with a neutral power amp. It's very tricky to get the Fractal master volume set "correctly," but once it's there, the Fractal/power amp set up is very hard if not impossible to tell is not the "real" amp.

I've stayed away from these flat response/IR set ups because they are just not the same playing experience. YMMV.

Axe III with PowerCab 212 makes a big difference/improvement compared to other FRFRs for me, however, the aspects I described above remains very much true and tangible.

Personally, I don't believe it's the cab's fault, e.g. PowerCab 212 is like a traditional guitar cab, with built in SS power amp. I believe it's the SS power amp's fault, which is physically located outside of Axe III, whose response/performance is not exactly under Fractal's control.

Curiously, for me, IEM (with a good/quality pair) playing experience is much less affected, in comparison, it's still not exactly the same, but it's far less obvious than using speakers.

 

[∞Fractals]

I just use real cabs with a neutral power amp. It's very tricky to get the Fractal master volume set "correctly," but once it's there, the Fractal/power amp set up is very hard if not impossible to tell is not the "real" amp.

I've stayed away from these flat response/IR set ups because they are just not the same playing experience. YMMV.

I run traditional cabs too, but also run an out to FRFR ... fills that “need”. (I also haven’t spent the money it probably takes to get really good thumping FRFR)

Different strokes for different folks

 

[sprint]

Surprising how many joyously state after new firmware that their FR rigs sound just like AITR, while many others say there is something missing and they much prefer Axfx models into tube heads/combos/poweramps + real cabs. At any given moment, both opinions are popular. I feel like this topic will never ever be resolved quantitatively - seems purely a matter of personal taste.

Personally, I tend to be a bit uneasy about the "Axefx FR sounds just like AITR!!" statements since it's not supposed to, and if it does sound like AITR a lot with PA/cab modelling on, then isn't something wrong?

 

[Mark Al]

Surprising how many state after new firmware that their FR rigs sound just like AITR, while many others say there is something missing and they much prefer Axfx models into tube heads/combos/poweramps + real cabs. At any given moment, both opinions are popular. I feel like this topic will never ever be resolved quantitatively - seems purely a matter of
personal taste.

Personally, I tend to be a bit uneasy about the "Axefx FR sounds just like AITR!!" statement since it's not supposed to, and if it does sound like AITR a lot with PA/cab modelling on, then isn't something wrong?

Axe III into the heads/combo's tube power amp section, yeah, I don't feel much is missing there (despite being a Frankstein). That's a completely different story than SS power sections of FRFR, studio monitor, etc.

 

[cardinal]

Axe III with PowerCab 212 makes a big difference/improvement compared to other FRFRs for me, however, the aspects I described above remains very much true and tangible.

Personally, I don't believe it's the cab's fault, e.g. PowerCab 212 is like a traditional guitar cab, with built in SS power amp. I believe it's the SS power amp's fault, which is physically located outside of Axe III, whose response/performance is not exactly under Fractal's control.

Curiously, for me, IEM (with a good/quality pair) playing experience is much less affected, in comparison, it's still not exactly the same, but it's far less obvious than using speakers.

Not all SS power amps are the same, that's definitely true. A lot of folks will say that the newer class D power amps just don't sound the same as older "lead sled" PA amps that weigh 40 to 50 pounds. It's not the wattage, but things like the power supply and capacity that are different.

 

[sprint]

I wonder how many turn up their FrFr's volume (or output volume on Axefx) expecting PA magic to increase similarly to when tube amp MV is increased - instead of turning up MV on Axefx to increase FrFr volume along with associated increase in PA magic modelling.

 

[Mark Al]

Fundamentally, in some sense, all modelers currently are still sort of trying to model power amp characteristics in "preamp circuit", e.g. the actual/physical power amplification happens out side of Fractal's codes, and it depends on what the Axe III is actually plugged into....

Maybe there is something in the headphone amp that makes such difference less noticeable than in the case of loud speaker SS amps, maybe it's because headphone amps doesn't need to "stretch/amplify" the signal nearly as much as a loud speaker SS amp does....

 

[Andrew Male]

In term of latency, That’s pretty much the best one can do using studio monitor, eg using AES is already minimizing that, compared to analog XLR.

I mean your monitors's DSP processing literally adds 3x latency of the axe. So blaming the axe seems a bit weird. Also the axe is replicating a mic'd amp/cabinet, not amp in the room, I thought we'd established this in about 2010,

 

[Mark Al]

I mean your monitors's DSP processing literally adds 3x latency of the axe. So blaming the axe seems a bit weird. Also the axe is replicating a mic'd amp/cabinet, not amp in the room, I thought we'd established this in about 2010,

No one is blaming anything. I say no need to feel defensive either. And your hand-wavy 3x number is likely far from being correct.

Each A/D/A conversion adds 2ms or more, so if one connects Axe III's XLR out to loud speakers, it'd theoretically incur more latency than AES directly to speaker's DSP... DSPs in all loud speakers incur some latency (Genelec is transparent about it), unless your speaker is purely analog, like the old generation Genelec 8040, which I had before...

That being said, it may well be latency is not exactly the issue/cause here.

And see my posts above regard AITM..

 

[Budda]

You say the axe iii doesnt sound like a tube amp and then get surprised when people respond, on the axe fx iii forum?

 

[sprint]

It's total latency that starts to cause issues, not necessarily any one component's latency (which is why I've stayed away from DSP based monitors which add to the total). Go out/in thru Axe3 fx loops to a couple of digital pedals, then out to an audio interface, then out to dsp based studio monitors and, in total, your up around 12ms which is where one can start feeling it (for me that means everything starts feeling lifeless).

 

[jamongrande]

As a small thing to check, I sometimes find certain input gate settings to soften up the attack too much, particularly if using lower output pickups and cleaner tones. (But this goes for any rig with an input gate). I often find myself using extremely light gating settings (low threshold, log gain reduction) and just live with noise.

 

[angelworm]

Today, I spent some quality time with a 68 Custom Vibrolux Reverb on an amp stand side by side with my Axe III through a pair of Genelec 8330 (GLM calibrated) on my desk.

The 68 CVR is really a nice amp with custom Schumacher transformer, it sounds, feels and responds great at low or high volume, it reminds me all the reasons we love tube amps. However, under direct comparison, Axe III plus studio monitor sounds OK but feel quite a bit meh... Both setups were played side by side at around 95DB, so not quiet but not super loud. Such difference is all the more obvious for clean (high dynamic) playing. Here is the difference:
1. The tube combo reacts more immediately at the beginning of the picking, hence it feels more immediately connected with the fingers.
2. However, after the immediate response, tube combo ramp up the dynamic more smoothly, slowly and musically, which allows me to explore the dynamic range of the response more easily.

On the other hand, Axe III plus monitors seem to do exactly the opposite:
1. It seems to have some (very subtle) delay in the very initial reaction, e.g. there is an ever tiny delay, making the amp feel less connected with the finger. I have tried things to minimize the delay all this time, including upgrading my studio monitors, using AES digital directly from Axe III to monitor, saving some A/D/A conversion etc, but it remains very much tangible to me.
2. Once the initial delay is over, the amp responds much more eagerly, e.g. it then jumps from quiet to loud too quickly as I vary the picking strength.

By the way, so far no modeler or any SS amp is able to nail either one above for me, they all exhibit such tiny delay and SS like dynamic more or less.

Interestingly, when wearing my IEM, I am less bothered by these two factors, and somehow they seems quite lessoned, which I suspect has something to do with the (good) quality of headphone amp used in Axe III....

I know, we musicians sometimes could be a nuanced anal bunch about such subtle details, but they often make a world of difference for our playing experience....

Thoughts?

My thoughts:

1) tube amp + guitar speaker Vs Axe + FRFR monitor is not a rigorous test, for so many reasons, some of them already explained by others

2) I tend to value the quality of the sounds as i would do in a recording session, where the cab is in another room and I’m hearing the mic’ed sound. I don’t really care of other factors, including the “feel” of the speaker moving air. That’s mostly impractical in real life (and on most modern stages)

3) latency is very annoying, but I’ve never experienced it with Axe 3, with my setup. On a stage, just standing a few feet away from the amp would introduce a more pronounced delay.