i could not replicate the problem.
Used the same di track and reamped it 8 times. No phase shifting in any way.
[Blocked Image: http://dl.dropbox.com/u/5902643/reamping_phase.jpg]
I used SPDIF in/out. Not sure if this would make any difference. Are you sure your problems dont originate from your audio interface? Perhaps the buffer size set too low?
You used just one Kemper preset, right?
Yes, with the same Kemper setting phases are correct most of the time. I had it out of phase once, should have made a screenshot....
anyway, I set my audio interface´s latency to 25ms, which is higher than what I ever had to use.
I recorded 6 tracks with different Kemper Amps, 4 in phase, 2 out of phase.
You used just one Kemper preset, right?
Yes, with the same Kemper setting phases are correct most of the time. I had it out of phase once, should have made a screenshot....
anyway, I set my audio interface´s latency to 25ms, which is higher than what I ever had to use.
I recorded 6 tracks with different Kemper Amps, 4 in phase, 2 out of phase.
I have reamped over 150 tracks each with full song length and also different amps within the last weeks. I never had any phase issue here. Could you go a little more into detail about your audio routing?
sure:
DI-Track playing back in Cubase 6.5 into->
Steinberg MR816 Firewire Interface mono out ->
Radial active Reamp box into->
KPA Input ->
KPA Master out left into->
Chandler Germanium preamp into ->
Universal Audio 4-710s direct input ->
Universal Audio ADAT out into ->
Steinberg MR816 Firewire Interface ADAT in ->
back into Cubase for recording
digital devices are securely clocked with wordclock
nothing special here, this is my trusty setup for years, except the KAP instead of a real amp with miced cab
I doubt that the randomly changing phases are caused by any of those devices except the KPA.
Just to make sure we´re talking about the same scenario:
I record a DI-Track via reamper into KPA several times with different amp presets. The results are tracks that randomly change phase to each other.
Very strange indeed. And really a pity since you a quite nice signal chain there. Just to make sure it´s really the KPA that cause these problems i would suggest that you bypass the analog devices for a test and hook up the KPA with SPDIF and try to reamp over this. Just to make sure.
I can vouch in here and say that this is a real life issue. As you can see on my video, i tried combining two profiles at the very end of different passes on the same DI dry guitar signal, and with no matter how much phase shifting you do, there wont be a right spot, everything will constantly have phase shifting issues.
http://www.youtube.com/watch?v…mRqzclw59NayE_jbGCBC9M%3D
I also mentioned this in another thread just yesterday. I deal with reamping all dsay long at my studio. I wish it was something simple that ive overlooked, but its something to do within the kemper.
As i was reamping anyway i testet again. Same DI Track, reamped 8 times, each with a different profile. Though i slightly had to move the offset a little bit for a perfect match there was no dynamic change in there.
Perhaps the SPDIF method makes the difference, in the way that the KPA analog input section can cause this?
Beau_Mckee, which method do you use? Analog or SPDIF?
Thanks for chiming in Beau!
The phasing issues are a bit hard to hear in your video because of the hard left/right panning. But I´m sure a mono version will clearly show the same results I had.
tylerhb:
I will do a test with a signal chain simplified as much as possible, just to be completely sure!
hello Tills (Tylerhb)
Dumb question:
For comparison, Can you describe your DAW recording setup you use with the KPA?
This might help us all understand your lack of phase error during repeated re-amping .
Thanks!
Display Morehello Tills (Tylerhb)
Dumb question:
For comparison, Can you describe your DAW recording setup you use with the KPA?
This might help us all understand your lack of phase error during repeated re-amping .
Thanks!
Just Cubase 5 and a RME HDSP9632 mainly.
Cubase DI Track -> RME ADAT out -> Yamaha 01v96 ADAT in -> Yamaha 01v96 SPDIF out -> KPA SPDIF in -> KPA SPDIF out -> RME SPDIF in -> Cubase -> RME SPDIF out -> Monitoring
The Yamaha is just inbetween to make the routing a little more flexible and comfortable. It would also work to just connect the KPA´s SPDIF I/O with the RME SPDIF I/O.
Perfect - thanks!
FWIW - I suspect the excellent interface between your RME HDSP9632 , the RME ASIO Drivers, and Cubase are important aspects for all to consider.
Many other DAW combos may yield phase errors, if the the hardware latency is not compensated somewhere. In your case I suspect its the combo of RME HDSP9632 Audio Driver and Cubase = excellent handling of managing everything.
Are you running a Win7 box or a OSX Mac?
Display MorePerfect - thanks!
FWIW - I suspect the excellent interface between your RME HDSP9632 , the RME ASIO Drivers, and Cubase are important aspects for all to consider.
Many other DAW combos may yield phase errors, if the the hardware latency is not compensated somewhere. In your case I suspect its the combo of RME HDSP9632 Audio Driver and Cubase = excellent handling of managing everything.
Are you running a Win7 box or a OSX Mac?
RME interfaces are awesome, i have been using them at home and at work since 10 years and cannot praise them enough. Perfect performance, rock stable drivers, super flexible routing. Never had any problem ever.
On the other hand, i cannot imagine that other well kwown interface brands like m-audio, focusrite or Motu will lead to such strange behaviour. Somehow it looks as if some kind of buffer is "swallowing" some data.
I have been using Cubase on PC since the mid 90s.
here´s a Cubase 6.5 test project, analog recording with just my Steinberg MR816 an the radial reamper in use.
http://www.frogstar-battle-machine.de/KPA-Test_analog.zip
If you don´t own Cubase, you can grab the audio files in the audio folder and use your DAW of choice.
you´ll will see one DI track and 5 recorded tracks with different sounds. All start at the same position
always compare two of them, don´t pan them, listen in mono!
some are in phase, some are not, for example listen to the Diezel and the Soldano tracks and watch how the sound changes in the middle!
I wanted to do a digital test, but the SPDIF input isn´t working. SPDIF input is checked!
digital out is working....strange.... 
Just as a crazy thought, did you try to 1. delete your rigs, 2. do a system reset, and 3. load back your rigs? It seems that has helped with other issues going on in the box. Perhaps settings or rigs are getting randomly corrupted and the changes are causing dynamic latency issues?
well, one of the first things I did with the fresh unpacked KPA was reamping. the described problems were alredy there. Since then two new firmwares came and lots of new profiles and tweaking was done. The phasing issue is still there like in the begining.
But for the sake of trying anything possible, I´ll give a system reboot a shot.
Beau_Mckee, which method do you use? Analog or SPDIF?
Hey Tyler
Im using SPDIF at this point in time for reamping. I'll happily test out the analogue reamping early next week so see if i can gain some better results
Hey Tyler
Im using SPDIF at this point in time for reamping. I'll happily test out the analogue reamping early next week so see if i can gain some better results
I only thought that SPDIF might give you better result, since R U Serious uses analog and i use SPDIF. But since you got the problem too it doesnt seem to isolate the problem 
