Posts by yeky83

Quote from alligatorlizard

btw, ckemper can I ask a specific question about Liquid Profiling:

In cases where an amps tonestack is located between pre and power amp stages, how does a liquid tonestack simulate this?

e.g. say the treble control on such an amp is set very low - this doesn't just lower the volume of the high freq's (as a post-amp EQ would), but it also alters the way the high freq's are subsequently driven by the power amp - so less distortion on them, or at least a different character. So, with a liquid tonestack modelled on such an amp, when you e.g. lower treble, does it also alter the distortion character of these high freq's?

I'd like to hear ckemper address this too, but practically speaking...

Most amps have distortion driven primarily by either the preamp or power amp.

In case an amp's tonestack is located between pre and power amp stages and it's a preamp distortion amp, you'd set the tonestack to Post.

In case an amp's tonestack is located between pre and power amp stages and it's a power amp distortion amp, you'd set the tonestack to Pre.

And... just checked the manual and it says the same:

✓The position of the tone stack in the signal flow is influenced by the selected Amp Model. For Amp Models of vintage amp designs, which have no master volume control and only power amp distortion, the tone stack is positioned before the distortion stage. For Amp Models of more modern designs that feature a distorting pre-amp stage and a master volume, the tone stack position has been set by the creator of this Liquid Profile. Usually this is the “Post” position. If the PROFILE has been captured with predominantly power amp distortion, the tone stack is positioned “Pre” – that is, before the PROFILER’s distortion stage

Quote from ckemper

I have considered it for a second or two.

But as long as I don't see the community of (digital) guitar amps using parametric equalizers - or even for a better start, graphic equalizers - placed before the amp (!) to sculpture the guitar sound going into the distortion in a very easy way, I have no hope.

Using graphical EQs for that purpose is known since the 80ies, I guess.

Now with digital amps, it is a no-brainer in terms of cabling and noise issues.

But it hasn't made its way in 15 years. Has anyone ever tried it?

I have been waiting for long, that this existing 80ies technology, still present and evolved 'till today, will find a place in the guitar community.

For sure it is possible to further parameterize the tonestack technique from the 1940ies, by using advanced computer technique from the 2000's and todays.

As a player of a digital amp, do you need the technical echoes from the past, but combined with todays technique to improve it, to find your tone? I don't want to sell snake oil to you guys.

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ckemper What prompted the Liquid Profile development? It was a long-requested feature, and I recall years ago that you seemingly decided not to pursue individualized EQ stacks after exploring it at the time. Was there a paradigm shift? Or is it just the "no hope" as described above and giving into what guitarists want?

Quote from GCNC8068

I wonder if someone can answer this question: what does the gain knob do differently on a regular profile and a LP? I read this thread, watch both the Tone Junkie and HW/Michael Britt videos, and I think I understand the tone knobs.

The LP gain knob behaves as if there's a bright cap.

Manual:

The authenticity of the [LP] Amp Models is also true for the amp’s Gain control, which will mirror the exact range of the original gain potentiometer, as well as the tonal changes of the attached “Bright Cap”.

Quote from GCNC8068

In my understanding, the current (non-LP) tone controls are similar to changing the tone on the mixer channel the amp is mic’d into - you’re not changing the amp’s tone controls, you’re changing the tone of the amp’s mic’d (or recorded) sound.

No. The non-LP tone controls still function as an amp's tone controls, just a generic one. LP tone controls are not generic, that's the difference.

Quote from GCNC8068

I can’t get my head around the gain in this scenario, however - and haven’t really thought about it before liquid profiles. Turning up the mixer’s “gain” on a recorded or mic’d amp doesn’t increase it overdrive or distortion. So what is the Kemper doing with generic gain above that which the amp could actually generate?

Have you tried putting a volume boost pedal in front of an overdrive pedal? Depending on how much volume boost you give, the overdrive pedal gets more distorted. And if you give it a ton of volume boost, then the overdrive pedal gets distorted beyond just the distortion it can provide by itself, right? That's basically what's going on. When you turn up the gain into a nonlinear system, you get more distortion.

Quote from OneEng1

What I said was:

"Your contention that the power amp distortion and speaker distortion are a minor part of the overall distortion when the gain on most amps is turned up is really only true for high gain amps IMO."

To be clear, what you said was:

Right, I never said what you said I said. Glad we cleared that up.

Just to clarify, in general most amps distort either at the power amp or at the preamp. Traditional old school amps like Fenders, Vox, Plexi, etc. get most of the distortion from the power amp. More modern amps keep the power amp clean and get most of the characteristic distortion from the preamp.

This is why the Kemper's gain knob, along with the ability to move the tone stack to pre or post the gain stage, just works. And it'll just work for most amps with Liquid Profiles too.

Quote from OneEng1

Your contention that the power amp distortion and speaker distortion are a minor part of the overall distortion when the gain on most amps is turned up is really only true for high gain amps IMO.

Oh and I never said this.

Quote from OneEng1

I understand the Kemper gain staging. My point was that there can be differences in a real amp that are volume dependent vs gain dependent with regard to the amount of distortion the amp creates.

LQP as documented says to profile the amp with all the eq flat and the amp gain at max. It doesn't specify the volume at which to perform the profile at.

Your contention that the power amp distortion and speaker distortion are a minor part of the overall distortion when the gain on most amps is turned up is really only true for high gain amps IMO.

As a result, even a LQP would need to be profiled at multiple VOLUME levels in order to account for the volume related distortion.

LQP has no other mechanism of handling this volume induced distortion that I can see. It must be profiled at the volume the amp displays the characteristic distortion you wish to recreate on the KPA.

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What is this "volume" you're talking about? On guitar amps, we're talking about the master volume knob, yes? Then of course, you need to turn up the master volume if the "master volume turned up" amp tone is what you want to capture in a Kemper profile. This goes without saying, so I dunno what the point is and calling it "the real question" and whatnot when it's been standard practice for a decade.

Quote from Kemper Support #1

the amp volume parameter in the Profiler has nothing to do with the power amp volume of the amp that was profiled. It is just a digital gain stage to give you control over the level that hits the effect section.

Oh. OneEng1 did you mean the Volume parameter within the Amp module of the Kemper? Well then there you go, it's just a volume knob. I thought this was common knowledge, so I misunderstood you and thought you meant the master volume of the amp being profiled.

Quote from OneEng1

Not sure this is relevant. Yes, at higher volumes, some amps produce "power amp" distortion vs "preamp distortion"; however, it isn't like the KPA knows that the distortion is from the amp or the speaker cone .... and my point was that this distortion is output volume dependent.

If you want to capture some distortion that is volume dependent, then of course it goes without saying you need to turn up the volume to present and capture it.

Quote from OneEng1

FWIW, I know that cabs (some of them anyway) distort because I have driven them with powerful PA amps that don't distort and still got distortion at high volume even with a clean guitar signal. Most speakers will distort if you push them hard enough. Of course, some speakers do this without hitting the coil xmax while with others, you are about to blow your drivers in your cab when you hear it.

My contention was not that cabs do not distort, rather that they do not distort audibly enough to contribute to an overall guitar amp tone.

Quote from OneEng1

Ok, so let me rephrase the question here:

Pre-LQP, it was necessary to capture an amp at many gain levels, with many cabs and many mics/mic positions.

Post LQP it is STILL necessary to capture an amp with many cabs and mics correct?

Now, the real question is, since the LQP is based on the max gain of the amplifier, and cabs distort at different volume levels, does that mean that to properly capture an amp/cab profile you should dime the volume as well as the gain to achieve the "most distorted" version of the combination?

It is well known that some artists (like AC/DC) relied heavily on cab distortion for a relatively "clean" sounding distortion.

So ... in that particular case, the REAL amp/cab combo will absolutely change tone based on the main volume

Yeah, I know ..... there's always one in the bunch

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Cabs do not distort significantly enough to be audible, especially above the amp distortion which is orders of magnitude greater. What's often thought of as "cab distortion" is simply the amp's power amp being pushed harder and distorting.

This is in fact proven with the Kemper. The fact that Merged Profiles work at all is because cabs do not distort audibly to cause issues with the Kemper's linear Cab block.

With that said, even with LQP it'll still be necessary to capture an amp with many cabs & mics cus different cabs, mics, and mic placements sound different.

I wonder how profile sellers will adjust to selling Liquid Profiles.

They’ve been selling amp packs with dozens of profiles for tens of dollars. Surely they can’t charge the same for a couple Liquid Profiles now, but they wouldn’t want to charge just a couple dollars either…

Maybe profile packs will become more effects centric? For instance, if it’s a DRRI pack, maybe there’ll be bunch of rigs built around famous songs using the DRRI? Interested to see how they respond.

Quote from benifin

For "legacy" profiles, making them "Liquid Profiles" will only really work OK *if* you know (a) the exact Amp values the real amp was set up with for the profile you are trying to "reverse liquify" ..... and (b) the Amp you made your older legacy profile is in the current list of the 40 or so current Kemper Amp Channels.

Depends on what you mean by "work OK." You are free to choose any Amp Model that does not match the reference amp, and the Liquid Profile will work just fine.

Quote from benifin

And .... even allowing for this, it wont - from my reading of the addendum - sound like a new ground-up new Liquid Profile of that Amp as the Gain was not set to full and the EQ controls [probably] not set to 12:00 noon when it was "legacy" profiled.

This is recommended, not required.

Quote from V8guitar

Not sure I see the difference in creating a profile and "adding" the Kemper tonestacks ( Liquid profiles) so not sure what that constitutes creating liquid profiles......BUT I don't profile these days and I'm probably confusing myself as well as other people so I might just shut up

What constitutes creating Liquid Profiles is putting in the original gain and tonestack values. You can put in the original gain and tonestack info to either existing or new profiles, and in both cases you get Liquid Profiles.

Quote from loddie

I'm definitely hearing changes when applying liquid stacks to older non-liquid profiles (for the better in my case), but the manual addendum seems to imply that it should sound the same as long as the EQ knobs stay at neutral positions. Am I misunderstanding that?

"Changing an Amp Model will not affect the sound of your PROFILE, as long as the controls remain at their original positions."

So you shouldn't hear changes when you just flip through amp models...

I mean, the Kemper already allows the user to do this if you want. Just load up a bunch of cab IRs with mics in different positions and go through them within the Cab module.

Quote from Michael_dk

I'd guess this is some kind of proprietary technique. I don't thin Kemper would do component-level modeling, that's just not how they have done things so far (supposedly). Although I'm sure they have looked at the schematics in the process.

Quote from Wheresthedug

nobody is saying they aren’t coded merely that they aren’t component level modelled. It is easy to see the output from any tonestack based on component values using software that does component level modelling (check out the Duncan Amps tone stack model software for an example). All Kemper need to do is code the output results they don’t need to get those results by actually modelling the circuit which proced them. Basically all profiles are currently models it’s just that they are only models of the output without the need for processing power capable of doing the heavy lifting of all the component level calculations that produced that outcome.

Here’s some basics.

What is a bright cap? A resistor and capacitor which functions as a filter.

What is a tone stack? Resistors and capacitors that make up a set of filters.
How are these analog filters going to get modeled in digital signal processing? With digital filters.
Is digitally modeling the behavior of resistor-capacitor filters component modeling? Yes, by definition.

Liquid Profiling is very clever and will work great. But there’s no mystery at this point, no need to make up some “secret sauce” or some “modeling of components that’s not component modeling” oxymoron.

If none of this makes sense to you, just go watch CKemper’s interview. He literally says Liquid Profiling is a marriage of profiling and modeling.

Quote from Jarick

Does liquid profiling model specific amplifier gain structures?

For example, could I take a clean Fender Deluxe profile and crank it up in a realistic manner?

Or same thing with a Marshall JCM 800, can I take a slightly crunchy amp and turn it all the way up to sound like the same amp on 10?

No. The fact that the sound does not change when you apply Liquid Profiling to existing old profiles should make it clear that there is no new modeling of gain structures.

The Liquid Profile gain knob now replicates the effect of the bright cap on real amps. Yes, this will help a Fender Deluxe or Marshall JCM Liquid Profile to crank up in a more realistic manner.

This is all explained quite thoroughly in the interview CKemper did with ToneJunkie.

Quote from Serjinio

Profiler Stage. After installing 8.7.18 beta, sometimes, when the power is turned on, the sound disappears, and the Input LED is constantly lit. Turning off the PA and turning it back on solves the problem. I returned to OS 8.7.17 release and so far there is no such problem.

If power cycling the PA solves the problem, it's a problem with the PA, not the Kemper...

The QC is very nice, with its great touch screen, form factor, plenty of DSP power, etc...

But a full year after they were supposed to release the product, they still haven't caught up to their initially advertised features… a bunch of amps and effects that were promised are still missing. And it still has less than advertised very rudimentary footswitching capabilities, which will be a deal breaker for some.

In light of that, the big extra features they've advertised as coming soon - plugin porting, looper, better cloud, vendor marketplace, desktop editor, etc. - will probably also trickle out in the coming years... which is all fine I guess, but blech their hype marketing sucks.

More than that, my current main issue with it is...

- There's a known noise issue, and they've been saying "if you have the issue, email us and we'll ship you a noise-fixing new power supply in a couple weeks" for the past half-year.

Quote from VegasG

I am with a small, mostly not as vocal group of persons awaiting the release of a couple videos that simply walk through all the amp models that are to be included in the initial QC release. Capture technology is cool, but not ground breaking as Kemper as "been there done that," and Neural is giving their take on the established process. But the amp models included are very interesting to me.

Are these "models" or undisclosed captures, or possibly a capture run through a derivative modeling process for improvement or enhancement?? The Neural software amps previously released, claim neither to be models or captures of vintage or current amps, but we all have suspicions that they were software recreations of some "real" amps. Or not?

Please bring on the flood of QC preset walk-through videos while we wait on release. Give us something more than capture comparisons, which have demonstrated quality, but nothing breakthrough and World shattering. Please?

Their amp models are models. Neural's said they use some AI to create the amp models, they probably use it to solve nodal state-space/ODE equations like other modeling companies do. It's still component modeling.

Neural DSP's amp plugins don't outright claim to be models of specific amps, but if you ask the artists whose names are on the plugins they'll tell you what actual amp models they are based on.