Mic preamp?

sambrox, you are correct in the range the Kemper captures and as for electric guitar amps, most speakers don't have much information above 5k.

Sorry if I went off topic. I do believe that people pay for profiles not only for the amps, but for quality mics and mic amps used to create them.

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Very interesting thread.

@schreckmusic Rather than integrating the preamp while profiling, why not use it as an insert after you've recorded the guitar track to warm it up? That Steven Slate everything bundle for $14.99 a month seems pretty good. I think there's a trial and their preamp emulations are supposed to be nice. I am definitely thinking of getting one, but only after I can get that Sonarworks bundle that you clued me into. Room is so bad that all the gear in the world won't help.

Quote from Dean_R

I read that all the time, event though I don't know the science behind it, I believe if you cut or boost frequencies above that range, even 10k and above, the character of the guitar tone changes, it's not like nothing happens if you lightly boost at 7k or 15k for that matter from my experience, it's likely that a boost at 15K somehow ends up effecting frequencies under 5k somehow and possibly freqencies that we can't even hear that are way up there might affect, frequencies that we hear, otherwise what's the point of 192KHZ sampling rate.

192 kHz sampling rate is, in fact, redundant, unless you're using the very best in cutting-edge converters ie ridiculously expensive ones! It's been proven that with current tech, 192 kHz places such a strain on the physical limits of the components, that more often than not, it actually degrades the audio. If you want to include the parts of the frequency spectrum that is inaudible to humans, I'd stick to 96 kHz, until engineering and physics catch up. You'd be then capturing everything up to about 48 kHz, more than twice the audible spectrum of humans, though dogs might appreciate it.

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Quote from Dean_R

@sambrox I agree, 192k is too much. The advocates of using sample rates up to 96KZ say that the reason to include frequencies that we can't hear is because they affect frequencies and natural harmonics that human can or have an effect on the overall mix that we hear, so not including those frequencies that can't be heard can rob your tracks from desirable harmonics that can be heard in how they affect the overall sound.

I totally get what you're saying. It could be a pretty interesting blind test, to play two mixes back to back, one at 96 kHz and one truncated at 44.1 kHz, and see if anyone can pick out which is which, or even hear a difference. Think I might just do this, actually. I've never seen any scientific test that confirms that ultra high frequencies have any effect on those we can hear, though a fair few industry people claim that they do.

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There's an interesting article on this here:
https://people.xiph.org/~xiphmont/demo/neil-young.html

(spoiler alert: it argues against using higher sample rates - based on insufficiencies of playback systems, which introduce intermodulation distortion)

Quote from Dean_R

I know the internal sample rate inside the Kemper is 700 kHz, I read a while back that Sony was working on something that has ridiculously high sample rate approaching thousands (can't recall the exact number).
Sorry for the diversion to the OP, but it's possible when that in a digital age all of these mic Pre-amps analog information end up reduced to 44 or even 96, it could be narrowing the differences that exist between the different Pre-amps. However I'm not an expert, but on the other hand , there must be some value for what some are willing to pay significantly more for a mic Pre.

Also I hear real differences between profiles made with different pre-amps, for instance Guido who uses Neve add a character that I really like. I actually think in the profiling, I expect the mic Pre amp to make a huge difference since the sounds of the profile of amps that we heard on commercial records include the various mic pre amp used and not just simply the amp.

The Kemper works at 700-ish kHz after A/D conversion, so my point is still valid with regards to extended bandwidth of mic pres.

It's true that the digital age has changed the sound of records, but it isn't true that the days of tape had a higher bandwidth; it's the exact opposite. Even the most well-built and maintained multitrack tape machines introduced compression, distortion, noise and hiss in to the audio and the bandwidth and dynamic range of tape doesn't come anywhere near digital audio. However, that compression, distortion and yes, even the noise and hiss was very musical and contributed to the warm-sounding analogue mixes and masters. There was a video with Fabrice Gabriel of Slate Digital/Eosis from when he designed the Virtual Console Collection where he stated that for ages he couldn't get the same 'glue' that the real consoles seemed to add. Then he realised it was because of the slight operating hiss of the old analogue consoles was missing. Once he'd put that back in, hey presto!

Quote from Dean_R

I know the internal sample rate inside the Kemper is 700 kHz

I don't think it's the sample rate - I think it's the clock frequency of the internal processor. Like my computer has a 4.2 GHz processer, but I still record at 44.1 kHz

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Yeah, it's effectively internal oversampling to reduce processing error, much in the same way that DAWs employ 32bit float for buss summing.

Quote from Dean_R

According to CK the Algorithm for tube simulation is acually more than 700k
" The algorithm for the tube simulation runs on more than 700 kHz sampling rate "

this is a link tot he interview with CK

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

Well, I stand corrected, I guess

Using a microphone preamp will change the profiling results, but in addition to the changes caused by the preamp, there may also be an impedance effect...