Hopefully this post will not upset too many Power Head fans, but I would like to post my observations about the Power Head with the Icepower 1000A amplifier (and the Power Rack as well I assume, since they use the same power amplifier) .
I purchased my first KPA, a Power Head toaster model (as an Xmas present to myself) back in Dec 2013. My intention was to use it as a standalone amplifier to drive a cab and eliminate my pedalboard and boat-anchor tube amp. Since I bought it, I have had many comments from fellow bandmates (in the bands I have been in or am in) regarding how dark the sound was from the cab, no high end. Going through the main out direct to the PA sounded nice and sparkly all the time, but the cab sound was dark no matter what I did. I was using a Weber Vintage speaker at the time in an old Lopoline 1X12 convertible cab, as well as some Carvin 2X12 cabs.
I figured the issue was the speaker. I went to a Beyma 12GA50 in my little ol' Lopoline 1X12 cab, no difference. Then I bought a Mission Engineering Gemini 1-P passive FRFR cab, but still no substantive difference. Weird. Then, for grins and chuckles, I tried running the toaster monitor out into my Quilter Tone Block 200 into the Gemini 1-P, and it really opened it up. I went back and looked at the Icepower 1000A -3dB upper bandwidth spec, it's only 3 kHz (albeit at 4 ohms, likely a little higher at 8 ohms). The Quilter Tone Block 200 has an upper -3dB BW limit of 10 kHz (I know, I emailed Quilter Labs about it, Pat Quilter answered me personally and told me the bandwidth). That explained the more sparkly and open sound, it was getting close to the direct-through-PA tone I was experiencing.
I then went and purchased a Matrix GT800FX, which has an upper -3dB BW of 24 kHz, and I now enjoy even more high-end goodness out of my rig. It sounds darned near just like the PA tone. My bandmates have stopped complaining about the blanket-over-the-amp tone from my cab, another benefit of higher bandwidth. [Blocked Image: http://www.kemper-amps.com/forum/wcf/images/smilies/biggrin.png]
I have purchased a KPA unpowered rack unit and intend to use that with the GT800FX for live use, and I'll use the toaster with the Quilter for rehearsals and recording. So all's well that ends well.
If I had known then what I know now, I would not have purchased the Powerhead, I would have just bought the unpowered version and used an external power amp with wider BW for driving a cab, as well as just biting the bullet and buying a good FRFR cab. I know, I know - if I didn't like the tone, why didn't I just skip the cab altogether and go with the PA and some monitors maybe some DXR10s? Well, I LIKE having a cab behind (or sometimes in front of) me interacting with the guitar, and I like the traditional cab look. Just my druthers. Anyway, I thought I should share the results of my experience with you all, it may help someone else shorten their path to tonal Nirvana with their Kemper. [Blocked Image: http://www.kemper-amps.com/forum/wcf/images/smilies/thumbsup.png].