New Kemper Profiler Rack & PowerHead

AlanRatcliffe

These have been mentioned on the forum already, but of great interest, so here they are again.

The Kemper Profiler is being released in a rack-mounted version (Profiler Rack) and with an optional 600W Class D power amp to turn the Profiler into a full-blown amp head.

More info: http://kemper-amps.com/page/render/lang/en/p/166/do/Kemper_Profiling_Amplifier___Latest_News.html

Sean

Can someone explain why "600W"? You probably know what I'm thinking :-[ and it obviously means something else ?

ezietsman

Sean wrote: Can someone explain why "600W"? You probably know what I'm thinking :-[ and it obviously means something else ?

Its a Class D amplifier and since this is a profiling/modelling whatever type thing, it needs a hi fidelity amplifier because all the tone shaping is happening inside the device and the amplifier and speaker system must not distort the signal at all, hence lots of headroom is required. Class D amps can be made very powerful yet small. Jack Flash's new Ibanez Promethean is also Class D, smaller than most people's pedalboards and gives a meaty 500W output power. I think that's how that works.

From Wikipedia

Despite the complexity involved, a properly designed class D amplifier offers the following benefits:
Reduction in size and weight of the amplifier,
Reduced power waste as heat dissipation and hence smaller (or no) heat sinks,
Reduction in cost due to smaller heat sink and compact circuitry,
Very high power conversion efficiency, usually better than 90% above one quarter of the amplifier's maximum power, and around 50% at low power levels.

Sean

Thanks EZ

Malkav

With this move they have become 100% more awesome ?

Though I still can't afford either :-[

AlanRatcliffe

More from Kemper. Seems they were keeping this one up their sleeve until NAMM:

NAMM 2013: Kemper announces Cabmaker software
IR cabinet simulations come to Profiling Amp

Kemper has unveiled Cabmaker, a new software tool that will allow users of the amp to load cabinet profiles using impulse response (IR) files.

Developed following a wave of user requests for IR integration, Cabmaker reads IR Wave files (essentially acoustic profiles of different speakers and/or rooms) and uses them to produce cab presets that can be stored on the Profiling Amp.

This will allow users to browse pre-existing IR Wave file libraries and turn them into custom settings on the amp.

Gearhead

This does mean that the user will be looking at getting some seriously good speakers to go with their amp. Firstly, you would prefer your actual speakers to be able to keep up thermally with your amp. Secondly, you want the sound quality to be Hifi. Price consequences: Don't worry about the amp price so much just yet. Or?

AlanRatcliffe

More one for the studio folk I think, many of whom will already have extensive libraries of IRs. You'll probably find the players using the amped version live will probably still prefer to use a specific guitar cab. Then again, this might be the thing to persuade them to move to a full-range system.

Gearhead

Would have been a good move for Kemper to include reverse IR operation, whereby you profile your PA and inverse the effect it has on your sound, so the end result comes out okay. Then again, all the TIM and waterfall is going to be very hard to counteract...

AlanRatcliffe

Hold on a minute... the Kemper profiles the amp including speaker - so you would need to remove the effect the speaker has on the sound before you can apply a speaker IR - and I don't know how you would do that. Otherwise you'll be adding a speaker response on top of another speakers response...

Gearhead

Eh.. no. Worse: reverse response of PA after forward response of guitar cab after simulated response of amp :-[

Tokai-SA

Not sure what you guys are discussing?

Use the Kemper "Monitor Out" with Cabinet turned OFF into a real cab/speakers...the mic'd Cab captured with the Profile is now removed.
At the same time send the Main Out with cab ON to the PA system.

We've converted a few hundred IR's to Kemper Cabs using the new software.

AlanRatcliffe

OK - I didn't know about the monitor out.

But that raises another question: If you profile an amp with its speaker, how does the Kemper remove the sound of the speaker from the profile without having separate profiles of just amp or just speaker (neither of which will respond the same without the other)? Does it have a preset model of a generic speaker that it subtracts from the signal?

Gearhead

Tokai SA wrote: At the same time send the Main Out with cab ON to the PA system.

Which will have the tonality of the cab as well as the errors of the PA/speakers - but then again there is no difference with mic'ing up a real cab.

How do they address mic placement? different presets?

Tokai-SA

Alan Ratcliffe wrote: OK - I didn't know about the monitor out.

But that raises another question: If you profile an amp with its speaker, how does the Kemper remove the sound of the speaker from the profile without having separate profiles of just amp or just speaker (neither of which will respond the same without the other)? Does it have a preset model of a generic speaker that it subtracts from the signal?

We're not sure how CK achieved this, it's part of his Profiling patent...all we know is it took him 3 years to write the algorithm.
The Kemper cabs include the mic used and a portion of the poweramp of the Profiled amp.
So, when it subtracts the cab from the Profile it leaves some of the CK 'magic' on the Profile, it doesn't remove 100% of the cab.
Let's put it this way, it has a generic everything, the tonestack is his creation, the tone controls and gain controls are all generic, they don't react like the actual amp being profiled.
All we know is that the final Profile sounds exactly like the mic'd amp, the dynamics and feel are identical as well.

Tokai-SA

Gearhead wrote:
Tokai SA wrote: At the same time send the Main Out with cab ON to the PA system.
Which will have the tonality of the cab as well as the errors of the PA/speakers - but then again there is no difference with mic'ing up a real cab.

How do they address mic placement? different presets?

When you Profile you can use different mic positions, more than one mic of course, 3 or 4 mikes if you want, send all the mics through pre-amps into a mixer, then send the mixer out into the Kemper and shoot the Profile...each Profile takes less than a minute to make, so most guys make a bunch using different mic positions and mics.
Engineers who are used to miking their amps in their studios know where the sweet spots are, so they tend to just Profile the sweet spots.
You can take a Profile of a Deluxe Reverb, change the tonestack, change the speaker/mic, adjust tube bias, sag, compression, etc, and make the Deluxe Reverb sound like some kind of weird generic tube amp...or leave it as is and it sounds exactly like the Deluxe Reverb you Profiled.

AlanRatcliffe

OK. So he's using modelling to control/change the profile. That makes sense - similar to parameter changes on a convolution reverb. Limited, but far better than nothing. It follows that small changes in tone can still be quite natural, but the bigger the change, the more unrealistic the result.

However, ascribing a certain part of the sound as being wholly due to the speaker is a major leap, so I would be surprised if any speaker IRs sounded as good with it as the full profile including speaker does.

Explorerlover

??? .... now I'm confused :-[

AlanRatcliffe

Explorerlover wrote: ??? .... now I'm confused :-[

Anything we can help with? ?

Explorerlover

Nevermind.. ?