A curious anomoly?

  • Good evening all,

    New user here, I've been making direct profiles of some of my amps as an experiment to then run through a Marshall 20/20 poweramp and into a 212 with cream backs.

    So far I've had some amazing results - really, the profiles through the valve power amp sound almost indistinguishable from the real amps.

    However...

    On creating some profiles tonight of my JTM45 ri I discovered the following :

    Profile A -

    Amp settings Bass 6, Mid 4, Treble 6, presence 6, high treble volume 6, normal volume 4. Inputs jumped and guitar into high treble 1.

    This profile through the Kemper into the 20/20 power amp and the cab sounds great - just like the real amp through the cab.


    Profile B -

    Exactly the same settings as above but with the normal volume on zero.

    It should sound just like profile A above but with a little less gain and less bass/ bottom end - and on the real amp, it does.

    BUT, on the profiler profile B sounds like it's a jcm800 on full gain and volume and with a tubescreamer boosting the front end, ie. Absolutely nothing like a real jtm45.

    Completely different and wholly innacurate.


    I've checked all the connections and settings on the Kemper and redone the same profile 10 times and each time it's the same result.


    So the curious anomoly is, in a nutshell, the profile that should be cleaner and have less bottom end (as the real amp does when keeping the exact same settings on the amp but just turning down the "normal" volume) has the opposite effect of making it sound like a completely different amp with a boost pedal in front of it on the profiler.


    Anybody have any ideas why this may be?


    Thanks in advance! :)

    Edited once, last by Slate68 ().

  • Hey,

    So Kemper did reply but were of no help whatsoever - they just asked if I had "no cabinet" checked and a few other innocuous questions regarding settings, but they made no suggestions or request for any further info from me regarding the matter.

    Which is rather poor I think.

    Anyhow, I persevered and made profile B again (the 11th attempt with these amp settings) and strangely this time the Kemper nailed it.

    I can't think for the life of me how it got the profile this time after getting it so wrong 10 times before - the connections and settings on all 11 profiles were identical.

    I was considering selling the Kemper after its spectacular failure to profile a simple "loud and clean" direct amp profile but have decided to keep it a while and test it further.

    I took delivery of a fryette power station today so we'll see later how that sounds through a cab, and later this week I'll be making some studio profiles for recording and a/b-ing against the real amps through a suhr reactive load into some celestion IRs.

    Merry Xmas to all ?

  • I'm curious, was the 11th profile made after rebooting the Kemper?


    I had a similar problem once, there was more distortion in the profile then what should have been and I tried it several times, I even tried making a clean profile and it came out distorted. I tried several things to fix the problem including changing cables, using the 1/4 inch return instead of the XLR and I rebooted the KPA. Unfortunately I did all three things at the same time so I'm not sure what fixed the problem but it was working correctly after that.


    Oh, and welcome to the forum!

  • Hey Tim,

    The successful profile was made after rebooting. However, I made the initial 10 profiles over several days so it had been rebooted at least three times during which it made the same distorted profile over and over.

    I'm at a loss, not so much as to why this time it has nailed it because that is what is claimed that it does, but as to why it made 10 profiles that were absolutely nothing like the amp being profiled.

    I must add at this point that I've brought a couple of commercial JTM45 profile packs and have noticed that on the higher amp volume setting profiles they also sound nothing like any JTM45 that I've ever heard or played through. Far, far too much gain - much more than is available from this amp even with both volumes dimed.

    I'm now wondering if the Kemper is able to consistently, accurately and reliably profile NMV amps set at high volumes? :/

    Thanks for your reply and merry Xmas :)