You are not logged in.

  • Login

Be aware of the digital sonic artifacts (aliasing) in your KPA!

Dear visitor, you are currently not logged in. Login or Register as a new user .

miles

Trainee

  • "miles" started this thread

Posts: 131

  • Send private message

41

Friday, May 18th 2012, 4:35pm

My guess is that it comes down to the bottom line--Kemper probably had a price point that they wanted to meet, and a compromise had to occur somewhere--so perhaps there was a hardware cost-cutting measure, or they just felt like the current processor was up to the task.
When Line 6 made the POD X3--which had lots of aliasing--that unit had the SHARC ADSP-21369 at 266 MHz (KSZ-1A), 1.6 GFLOPS DSP, and when they put out the POD HD, which had no noticeable aliasing, that unit had the SHARC ADSP-21369 at 333 MHz (KSZ-2A), 2.4 GFLOPS DSP.
I imagine there was plenty of code updating, but without that faster processor, I doubt L6 could have eliminated the aliasing.

The Axe-Fx II has [2] ADSP-TS201S: 500/600 MHZ TIGERSHARC PROCESSORS with 24 MBIT On-chip EMBEDDED DRAM. Though I think the KPA is superior in most ways, the Axe-Fx II likely has more horsepower. I peaked inside the KPA and saw one main DSP with no name on it, so who knows if there is enough power there to faithfully produce the kind of resolution we would expect.

Kemper beats Fractal Audio in value, but I would have paid more to have the ultimate KPA with no compromises--that's assuming they did compromise, hell, maybe they will correct this in the next firmware update, then we can go back to making music and stop speculating.

Kemper, may we please have some specs? If you don't give it to us, we love you anyway... but throw us a bone.

Froschn

Intermediate

Posts: 216

  • Send private message

42

Friday, May 18th 2012, 4:43pm

You think line6 could do better if they just put in better hardware? I don't believe that.

MadH

Intermediate

Posts: 340

  • Send private message

43

Friday, May 18th 2012, 4:59pm

The main DSP is a Freescale DSP (formerly Motorola) running at an equivalent of 400 MHz speed.

http://www.guitar-muse.com/kemper-profiling-amp-2949-2949

I don't think the issues are due to lack of processing power although a huge amount of processing power makes programming easier since you don't need to be as efficient. I think it is just matter of time and it should not take them very long to fix it.

The Axe II uses one of the 2 processors exclusively for the amp modelling, but they were using only one for FX and amp modelling on the Axe Ultra, the sound quality on the FX is on par to the ones in the Axe FX II and the amp modelling was great just not as good as now. Don't forget that Fractal is modelling all main components inside an amp and the interaction between. They need much more processing power to get the same results than using the Kemper approach.

miles

Trainee

  • "miles" started this thread

Posts: 131

  • Send private message

44

Friday, May 18th 2012, 5:27pm

Quoted from "Froschn"

You think line6 could do better if they just put in better hardware? I don't believe that.

I didn't say that, I said: 'I imagine there was plenty of code updating, but without that faster processor, I doubt L6 could have eliminated the aliasing'. But the point is, when it comes to pro audio gear, it's always best to have the fastest processing hardware that is reasonably possible, even if it's more than is needed, to provide some headroom and to allow for future expansion. Wouldn't a dual amp option be awesome in the KPA? It's probably not possible with a single processor, so this opens the possibility of a future, more robust KPA II HD. I understand that it's business, but the technology exists now.

The global sampling rate of the KPA is 44.1 kHz, while the internal sampling rate is partially much higher, I wonder if that 44.1 k has something to do with the noise.

This post has been edited 1 times, last edit by "miles" (May 18th 2012, 5:41pm)

Radley

Professional

Posts: 617

Location: So Cal

  • Send private message

45

Friday, May 18th 2012, 6:48pm

OK - If my wording proves to be incorrect I will be happier than anyone. I have tried to be clear that I am talking about the 'containment vessel' for the Profiler, not the Profiling technology/coding itself - to me there is a substantial difference in implementation between the two...

PS: All my Strats have humfree pickups, and still sound quite 'stratty', otherwise I wouldn't take them onstage - everyone's different ^^

hoth

Intermediate

Posts: 265

  • Send private message

46

Friday, May 18th 2012, 9:28pm

Quoted from "Radley"

OK - If my wording proves to be incorrect I will be happier than anyone. I have tried to be clear that I am talking about the 'containment vessel' for the Profiler, not the Profiling technology/coding itself - to me there is a substantial difference in implementation between the two...

PS: All my Strats have humfree pickups, and still sound quite 'stratty', otherwise I wouldn't take them onstage - everyone's different ^^


Although I would take out some of the pricklies from your statements, I do generally agree that updating the "containment vessel" would be greatly appreciated and (in some places that you point out) very much needed.

Froschn

Intermediate

Posts: 216

  • Send private message

47

Friday, May 18th 2012, 10:26pm

Quoted from "Radley"

OK - If my wording proves to be incorrect I will be happier than anyone. I have tried to be clear that I am talking about the 'containment vessel' for the Profiler, not the Profiling technology/coding itself - to me there is a substantial difference in implementation between the two...

PS: All my Strats have humfree pickups, and still sound quite 'stratty', otherwise I wouldn't take them onstage - everyone's different ^^

Noiseless and stratty, you make some people jealous!

Radley

Professional

Posts: 617

Location: So Cal

  • Send private message

48

Sunday, May 20th 2012, 7:20am

Quoted from "hoth"

Although I would take out some of the pricklies from your statements, I do generally agree that updating the "containment vessel" would be greatly appreciated and (in some places that you point out) very much needed.

Please explain specifically about the 'pricklies' you refer to - don't be vague, but spell them out clearly and I will respond with a likewise serious answer...

Radley

Professional

Posts: 617

Location: So Cal

  • Send private message

49

Sunday, May 20th 2012, 7:33am

Quoted from "Froschn"

Quoted from "Radley"

PS: All my Strats have humfree pickups, and still sound quite 'stratty', otherwise I wouldn't take them onstage - everyone's different ^^

Noiseless and stratty, you make some people jealous!


No need to be jealous - it's easy! I use two hi output twin-blade Dimarzio PUs for Neck & Bridge, and one Bill Armstrong zero hum Strat PU in the middle....anytime I engage the middle PU, it's quack-city - Stratsville for days! Zero hum & noise, all the time...

hoth

Intermediate

Posts: 265

  • Send private message

50

Sunday, May 20th 2012, 7:33am

Quoted from "Radley"

Quoted from "hoth"

Although I would take out some of the pricklies from your statements, I do generally agree that updating the "containment vessel" would be greatly appreciated and (in some places that you point out) very much needed.

Please explain specifically about the 'pricklies' you refer to - don't be vague, but spell them out clearly and I will respond with a likewise serious answer...


I may not agree with adjectives such as very weak, unacceptable, unreliable, unrealistic. I have my issues with the box but I would not go so far as you.

Similar threads