Posts by Job Posthuma

I run a stereo setup, KPP running preamp profiles into the returns of 2 combos.

Atm the only way to set levels between the amps is via Pan per rig, a way to do that “global” would be nice.

I have run analog preamps together with digital on a board for a while. Works great, sounds great, I like the direct interaction with amp controls and different way of switching.

But…also the observation that when I captured those preamps, I couldn’t tell real from capture. So what I liked about them was not about the digital/analog differences, more so the difference between “full amp” and “preamp only”.( In my rig I use tube power and a cab, capture of a full amp is doubling up on the powersection.)

If you use a cab and tube poweramp with your rig, imo it’s defenitly worth trying preamps or captures of preamps…I run my Kemper player with preamp captures exclusively when I can use the return of a combo.

The global EQ is probably the only reason I startup rigmanager at a gig. Doing so on a phone is a lot more fiddly then on the device.

Maybe with some press and hold of (a) button(s), the tonestack can toggle to the global EQ?

Maybe different button(s) for monitor/mains?

Kemper support investigated and the conclusion is (fortunately), that the audiopath remains integer when switching the ampblock off. My hypothesis that a clean path was added was incorrect.

The observation of a difference in the testsetup was correct, however the rootcause was the fact that also a profile of a patchcable includes a gain stage, and cause in my test setup the volume of the drive was set at 5, that stage clipped, which explains the different lvl of cleans in the observation, but is “as designed” and not an issue for use in 4cm and or in front of an amp.

Repeating the test without clipping the gainstage resulted in equal results, which confirms the integrity of the audiopath.

Quote from Wheresthedug

I hear differences but whether that is the clean path that you hypothesis, I'm not sure.

There are a lot of things going on. First kill all delay and reverb and just listen to the Drive. any discrepancy could be caused in other parts of the signal chain.

Did you set Amp Volume Compensation to 0?

There is way more noise in the K Drive strums 3 and 4 than in 1 and 2 so, again, something else is happening which may or may not be attributable to "clean signal". What are the input settings? Noise Gate? Clean Sense? Distortion Sense?

Is there anything else on in the Kemper signal Chain? What Block is the K Drive In?

I don't seem to get the same results as you are experiencing so something is different but I don't know what.

I tried my own test again and recorded a quick example.

Clean = KPA Direct Out into front input of THD BiValve. Line Out of THD BiValve into MOTU ULMK5. Recorded in Logic with TwoNotes Genome as an IR Loader only.

I made my own cable profile with Volume Compensation at O and Amp Volume at +12db. Even in this scenario the cable is still slightly quieter than with Amp bypassed but the difference is minimal.

First take KPA Amp Block Bypassed. Second take KPA Amp Block Active. Thereafter I switched the Amp Block on/off at random. There is a very slight difference which I attribute to the slight level difference.

Overdriven = As Above but with Full OC loaded at Default settings. Full OC used as this effect type does not have an analog clean signal in the real world so is a better comparison of the amp section hypothesis. Using a TS style pedal which deliberately models a clean signal clouds the comparison as any clean signal anomalies could come from Pedal Model OR Amp Section.

Again, first take is Amp bypassed. Second has Amp active. Subsequent clips are randomly toggling Amp ON/OFF

As with clean clips there is a slight volume discrepancy due to the cable profile but I don't hear anything else significant.

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Thnx for your effort, appreciated! Support is taking the time to look into it now…I’ll hold my breath a bit on the subject for now to not further stir the pot…untill the smoke clears.

Quote from Jarick

That's clever actually, I'm going to run my Kemper into my tube amp set clean and see how it sounds for gain and effects! Sure is cheaper than buying some new pedals!

Isn’t it? Both 4cm and/or Kemper player in front of an amp when you play in tight places and/or need to travel super light!

Quote from Wheresthedug

Where did the analog drive come into play?

I used that for comparison of the effect of switching the amp block off between the 2. I did this to exclude the option that switching the ampblock on/off has an effect that is mistakenly contributed to the Kemperdrive. Now you can compare effect on A to effect on B, which should be similar, but are not. That means something else is happening under the radar.

Quote from Wheresthedug

What was the signal path in both scenarios?

Equal between the 2, albeit the analog drive going into the input of the Kemper. The only variable is the ampblock between 1&2, and also between 3&4.

Quote from Wheresthedug

How does this make the clean path hypothesis more plausible?

Switching the amp off using the analog drive causes a lower output.

Using the K drive causes a higher output. I did all this cause I hear a clean path is added, adding something is consistent with a level increase.

All test methods aside, do you also hear more clean signal in the 4th strum in the audio clip in post 42?
I also hear in the 4th strum, that the level of the driven sound is reduced compared to 3…exactly like between 1 and 2.

Quote from dango123

the drive effects sounded essentially the same whether the amp was in or out of the signal chain. I'm guessing the earlier cable patch profile we were using (LMTTRAY - A-Stick) had some profiled qualities that reacted in unexpected ways when the drives were engaged.

Edit: see post 49 with the conclusion that this hypothesis is incorrect

I’ve been going back and forth between trusting / not trusting my ears on this matter for a while,
but this test result sets in stone to me that there is something going on:
Drive test2.wav

1st/2nd chord is the difference as a result of switching the amp off using an analog drive: level reduction only

3rd/4th chord is switching the same variable (amp on /off), but now using the K drive: level increase, and clearly a very different sound. (>clean path to my ears)

That’s a clear test result: unmistakably a significant difference switching the same variable, with the levels going the opposite direction, which makes the hypothesis that a clean path is introduced/raised even more plausible then just the observation by ear.
This makes it incomprehensible why support does not further investigate this…unless they don’t see 4cm as a usecase for the unit.

Besides that, I want to be able to trust the integrity of the signal path, and concerns with it properly adressed and or explained…but none of it atm.

*I made a profile of a patchcable for the test (and selected a cab from an earlier one), but that profile is actually irrelevant cause it remains switching 1 variable giving different impact on the end result.

Edit: see post 49 with the conclusion that this hypothesis is incorrect

Quote from ckemper

Hi!

As some have mentioned here, all overdrive pedals - including our Green Scream and the Kemper Drive - have the clean signal added to the overdriven signal. That is the nature of overdrive pedals.

The output level of the profiler is not necessarily equal to the output level of an overdrive or distortion pedal.

Have you tried to change the output level to achieve the desired sound?

CK

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Edit: see post 49 with the conclusion that this hypothesis is incorrect

Hi,

Do you share the observation that if the amp block is turned off, the level of clean signal of the Kemper drive changes significantly? (Post #16)

Heres a test:

https://drive.google.com/file/d/1bs24MgMMQLz5-McPZrHyq6Nel54dQxtV/view?usp=sharing

Sample A: "null profile" active, analog drive in front

Sample B: "null profile" NOT active, analog drive in front
A/B should establish that switching the ampblock on/off, does not have major impact when an analog drive is used.

Sample C: "null profile" active, Kemper drive in front

Sample D: "null profile" NOT active, Kemper drive in frontC/D should establish that switching the ampblock on/off, does have major impact when Kemper drive is used, to my ears clean signal is much louder.

Edit: I did another attempt cause the levels where off and did an interesting observation:

In A/B (analog drive), the level decreases when switching amp block off.
Between C/D, the level increases when switching the amp block off. (Which matches the observation the observation that clean signal is added)

Drive test2.wav

Quote from Wheresthedug

The Green Scream and Kemper Drive both have a clean signal mixed in with the overdrive in the same was as analog Tube Screamer style pedals. Christoph has spoken on the forum about this in some detail on the past.

Edit: see post 49 with the conclusion that this hypothesis is incorrect

I don’t hear it in the Kemper drive with the mix at 100% tbh.

Regardless, with the amp block switched off, the amount of clean mixed in changes drastically…to me a bug.

Quote from dango123

I had a few moments to try this suggestion out - while it is having an effect, for me it doesn't solve the problem - here's my test case

1) Load the LMTTRAY - A-Stick profile (as is from Rig Exchange)
2) Disable all effects
3) Set monitor output to Master Mono (note that it was already there on my player)
4) Toggle the amp model on to off, and back on again
5) Load a Bit Shaper (8Bit Solo) model in front of the amp

For me, the bit shaper sounds like it is lingering softly in the background (like 5-10% active), while the clean/uneffected sound dominates - the parallel path mixed sound still seems to be happening. To a lesser extent I still heard this effect in some of the drive models (like Green Scream) as well. Some Drives are definitely moving in the right direction, but still have a softish kind of feel to them (at least some that I tried out).

Wheresthedug and Job Posthuma Can you please see if you can duplicate what I'm hearing (or possibly tell me that I'm crazy...) - I know you had few additional suggested tweaks to the output section, but what I'm hearing is not a slight eq difference, there is still something definitely not right (on my machine at least) in the upfront signal chain. Appreciate your help with this, thanks again!

Edit: see post 49 with the conclusion that this hypothesis is incorrect

Afaic…we both do the observation a clean path is unexpectedly introduced. I submitted a support ticket with reference to this thread.

Btw..the greenscream probably has a clean path by design.

Quote from BayouTexan

I would not expect good results using a digital distortion into a tube amp. The big question arises "Why?" I do get great results using an analog distortion and effect pedals into the Kemper.

Multi fx in front of amps, or in 4cm…a very common usecase for digital devices, been doing that (on and off) for years.
And imo digital drives sound the same into digital amps as into analog.

KPP in front of an amp as a mini pedalboard, or in the loop for time efx only and a few pedals in front…not to silly right?

Edit: see post 49 with the conclusion that this hypothesis is incorrect

Tested it, made a profile of a patch cable, compensated in the amp parameters for volume differences between amp off/on, did the observation that there were no appearant differences between amp block on or off.

Then engaged a kemperdrive, full gain for the most obvious difference.

With the amp block turned off there is a very distinct clean sound mixed in, with the amp block on that disappears, (and the drive sounds like expected)

It’s a workaround, but I hope this is considered a bug by Kemper HQ, and can be fixed, for use in 4cm, but also for use of a KPP as a mini board into an amp.

Quote from Wheresthedug

This isn't something I have ever felt the need to do but you got me curious so I had a play with it.

I hear what you mean and it certainly isn't the behaviour I would expect. However, I think I might have a solution.

Try the following and let me know what you think.

1 Set DIRECT OUT to MASTER MONO and connect from DIRECT OUT to INPUT of valve amp.

2 Load a dummy rig into the stack section. This would be a profile or a cable only. The one I used was on Rig Exchange LMTTRAY-A-Stick by Tom Wendt

3 Go into amp settings and set Volume Compensation to 0

4 LEAVE THE AMP SECTION ON - it is literally just an extra patch cable.

5 In the Output Menu flick between DI Analog and Master Mono to compare volume. Adust Volume of Direct Out to achieve unity gain between DI Analog and Master Mono.

Now load whatever FX you need and play as normal.

I don't know why bypassing the Stack section creates the parallel path thing but this seems to fix it (at least to my ears).

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Edit: see post 49 with the conclusion that this hypothesis is incorrect

Thnx for trying and confirming the observation!

So basically, create a profile of a cable…in my words a “null profile”…and put that in to mitigate the effect of no amp active on the drives.

I’m gonna try that and expect it to work..but tbh..does make me a bit concerned about signal integrity for “not standard” usecases.
I build a board where I aim to use the player only for time efx and a clean boost…so also no amp active…if that also has parallel paths going on, I need to triple check for phase issues.

The thread I made about it couple months back.

Thread

Switching stack&cab off causes a parallel path to overdrives pre stack?

I was fiddling with a toaster in 4cm with an amp, and noticed some odd behaviour from the Kemper drive: I heard both an overdriven signal, as well as a clean one.

My conclusion is that when you switch amp&cab off on the KPA, there is a clean path going to the main out, alongside the overdriven signal. Doesn’t seem to be there when the amp section is on. Mix is at 100% on the drive. I cant think of any other setting causing this.


Can anyone confirm what I’m hearing? Is this a bug / as designed?
Is…

Job Posthuma

January 28, 2025 at 6:51 PM

Burkhard, 2 cases on an uncommon usecase..reason to investigate a bit further?

I dial my presets on speakers I consider a good reference with the global EQ flat…and use the global EQ for situations where speakers/sound/room are suboptimal.

So flat by default, dialed to fix problems on a certain day.

Quote from paults

What Output settings do you both use?

Edit: see post 49 with the conclusion that this hypothesis is incorrect

All unity, but imo irrelevant cause the observation is that you get a combo of drive & dry sound (with the mix parameter full up)…that’s just not right, and not an output settings thingy.

Iirc, also when i tapped into the signal from a loop (send) just after the drive block.

Quote from dango123

I get thin/weak results which sound nothing like plugging a distortion box into the front of an amp. It's almost as if the guitar signal is going partially thru the drive box, and partially in parallel for a half dirty/half clean kind of sound.

Edit: see post 49 with the conclusion that this hypothesis is incorrect

I have exactly the same experience, in the same usecase, support said they couldnt reproduce it…so I ran into a dead end there. Seems to me it occurs as soon as the amp block is switched off.

I’d rather see a remote with a (touch) screen, functionality to edit all parameters, wireless connection, battery powere, and possibly some added I/Os (if that’s possible via USB without latency.)