good luck, it is actually much harder than it looks.
the cutoff frequency doesn't seem change that much, but the roll of (dB per octave) does.
turned all the way down, you even get a resonance.
so far, I never heard a convincing tone knob simulation from an EQ.
this would also only work in a reamping scenario, since the tonal change is of course pre gain
I agree. For all the reasons I mentioned above (and likely a few more that I missed), it isn't just a simple LPF.
Display MoreThe description above stating that the pickup is a tone generator and
As mentioned, this is an oversimplification. All of the above is relatively incorrrect depending on how accurately you want to understand how the pickups, control, cables, etc.. work as a system.
I attached a file that I found on the web several years ago. It will either help you understand fully, confuse you, or make you decide that you would rather not know. GuitarFreak_6_60_051219_xlsm.pdf Due to allowed extensions I had to rename it as .pdf. Download it and rename to GuitarFreak_6_60_051219.xlsm.
Have fun
BTW, the answer to your original question is that it kinda acts like a low pass filter in a first approximation. The devil is in the details and in the end there are quite a few factors that can contribute to errors of that approximation.
Yes. It was an oversimplification. In my first response I wasn't sure of the OP's background so I kept things as simple as possible.
The actual circuit is more complex because the pickups are big inductors that are being driven by metal strings that interact with those inductors making the entire circuit a serious PITA to analyze as it is seriously more complex than just an simple LRC circuit.
I felt my explanation was enough to understand basically what is going on with the tone knob without attempting to teach the entire board how to setup a pSPICE simulation that accurately models all the things going on with an electric guitar ;).
.... and I agree. It is "kinda like" a low pass filter.
Thanks for chiming in! I was hoping you would. I was even going to drop your name in my first post.
Engineer here also. But I spent my whole career doing programming and system integration. So I do not have a ton of day to day use of my degree. Just enough to be dangerous and sometimes lead people astray
When I first started going to school I had dreams of making a pedal switcher and modding some amps etc. Once I bought a computer, I started programming and never looked back. Now I am not good at either engineering or programming. Trained in the one I dont use, self taught in the other.
I Have done a good amount of both hardware and code, but I too am self taught in code. I have been in management for over 15 years, but still sneak off and write code or do some hardware design once in a while when no one is looking 😀. Now days I pretty much make presentations and go to conferences.
I did make a custom back panel for my Kemper rack and replaced the RJ45 with an Ethercon ony Kemper remote cable.
When my daughter asked what I do as an engineer, I told her I mange people who manage engineers 😁.
It's great when I get to brush off my old skills though. I was once a damned fine engineer!
Maybe when I retire I will do a board or so now and then for travel money in retirement
Oh, BTW, your thought on how the pot works is ACTUALLY how a WAH pedal works (or at least a simple one) The actual circuit used in a WAH pedal is called a band pass circuit. The variable resistor in a WHA is used to change the center frequency of the bandpass.
A bandpass filter squelches the HF beyond a point AND the LF beyond a point allowing only a band (Q width) of frequency through.
The biggest failure mode with the WHA pedal is the resistor wears out from the repeated sweeping contact over the resistor coil.
If you are interested in the brain crushing details of an active band pass circuit, you can see it here: http://www.geofex.com/article_folders/wahpedl/wahped.htm
This is more complex since, unlike your guitar tone knob, there are powered circuit elements that have behaviors that are much more difficult to describe. Analog amplification circuits were long ago replaced with operational amplifiers that keep a host of analog circuitry goodness concealed from we engineers so we can simply rely on the Op Amp to just amplify the signal like we want it to without having to do a metric ton of math to figure it out (engineers are lazy) :).
I don't know about smart, but an electrical engineer at least :).
From here: https://miro.medium.com/max/14…LzFj-r0rv_JmGntXulf1g.png
Imagine your pickup is basically a sine wave generator (it isn't of course), and some resistance. Your tone pot has a resistor and a capacitor. The capacitor can't change (without you getting a soldering iron out), and the tone pot is a variable resistor that can go from nothing (a hard piece of wire like it isn't there at all) to either 250K Ohms or 500K Ohms (these are the most common).
Capacitors present a dead short at very high frequencies and present a complete open circuit for DC signals (ones that don't move up and down at all). This is important you can see as the more of the signal you allow to go through the cap (ie, you lower the resistance on the tone pot toward zero), the less high frequencies will make it through and onto the volume pot.
Note, that even when you have your pot turned all the way up, there is still SOME high frequencies going through the capacitor. The higher the resistor value, the less this is true.
Also, just a note, there are several different ways to wire up your tone knob and volume control to your pickups. I have shown only the most simple one for the purpose of explanation.
This guy goes through this simple setup in a video here:
Note: In this video the internal resistance of the pickup is ignored.
I think that most of us tend to play first and then (maybe) ask questions later.
My first run through the KPA presets in 2013 was .... uninspiring for the most part. I found 2 or 3 of each type of sound I was looking for that sounded "good" to me, and I went from there.
Then there was the rig manager and the thousands of rigs all of you have made. No person can possibly audition them all, but with some hints from threads here, and picking up a commercial pack or two, I got a bit better.
I suspect it took me a full 2 years to get around to reading much in the manual (although I did see several youtube vids when new features were released). Even then, I admit, I have mostly tried to address any issues I have found in a specific tone I was looking to achieve. Example, U2 Streets Have No Name delay setup and new delays by Kemper.
Sometimes I read a post that is particularly interesting on a feature that has been in the KPA for some time and I will play around with it. Sometimes it makes it into my gigging patches, sometimes not.
I absolutely agree that it would have been best to RTFM right out of the gate. I think I have read or watched vid on most everything the KPA can do now (9 years now, so it isn't like I was a quick learner). Now I give training to others on the KPA setup based on what they are complaining about in their Kemper tone. I also have converted several tube amp purists over to Kemper and helped them get started.
The truth of the KPA is that (for most people) if you take the time ..... really take the time to learn the gear, you can have a gig rig that is absolutely top tear in the industry and is right down super easy to deploy in a live setting.
CR250 and Suz PE175 guy here.
Can't believe I didn't break any bones... or worse!
No broken bones (that I had diagnosed anyway), but got knocked out a couple of times .... and once a guy out in the Idaho dunes thought I was dead.
Gigging with a Kemper is WAY less dangerous ... but nearly as much fun :).
Oh, yes the Suzuki RM125.....I loved that bike with its crazy powerband.....that analogy made me smile!!!!
Me too. I was generally a CR250 kind of guy though since I did way more scrambles riding than motorcross. That 125 light-switch powerband sucks on hills :). My wife says I have to live with my pictures of doing crazy things on a motorcycle. No more new bikes for me :(.
To the OP, it seems strange that the amp sensitivity would have been as jerky as an RM125 ;).
Glad you like your setup now.
I received a Powerstage 700 Friday evening I had ordered, I took my Sweetwater sales rep's advice and stayed with the Eminence EM12 and stopped pursuing frfr solutions that I was struggling with. Switching from the TC Electronic Bam200 to the Powerstage 700 made a huge difference, not only in the sound of my rig but the touch responsiveness when playing. I wasn't expecting that much of a change, it was a purchase to allow me to move towards a stereo setup, but I'll take it nonetheless.
I did load one of my Kones in the 112 cabinet and it sounded better than it had before but still had a fizz that seems to be present over the whole eq spectrum of the speaker. But that was my experience with all the other frfr speakers I tried, so it's just me and not the frfr speakers.
To be honest I was getting close to selling the profiler and going back to a tube amp but today I'm very happy I kept trying different options. I've been auditioning profiles and with the eq on the Powerstage and monitor output dialed in each one is a very good representation of the amp profiled, different in tone and characteristics.
I've never had an amp sound this good by itself, let alone with the benefit of of being a chameleon of multiple great sounding amps in one unit with more stomp boxes and effects available than I'll ever use. I imagine that I represent a very, very small category of users, I no longer do multitrack recording nor do I intend on playing live where I need to be mic'd up, so I'm not really using the Kemper as intended but as a combo amp. But as of this weekend it has become the greatest combo amp I've ever encountered and has surpassed all my expectations, it just took some work on my part to find the component combination that best suited me, and that combination is killer!
From here: https://www.parts-express.com/…egend-em12-spec-sheet.pdf
That speaker has a pretty big bump in the eq from 2k to 4k and then a super steep cut of anything beyond that. This is what is taking the "fizz" out and is changing your perception of the sound IMO.
Additionally, the "impact" you are hearing is because the new amplifier is WAY more powerful than the old one. In fact, it is marginally too powerful for that speaker (the speaker is rated at 200W while the amp is rated for 350W into 8 Ohm ... which is what your speaker is). Guitar speakers seem to be able to take a bit more abuse than FRFR though and the speaker impedance is only as low as 8 Ohm between 200 - 400 Hz. Everywhere else, it is quite a bit higher so it is very likely that the amp is well matched to this speaker's impedance curve.
Glad that sorted it for you!
I’ve been contemplating the in ear route for years. I used a sennheusee system years ago but hated it. In reflection it was obviously down to the earbuds themselves. Anyway, I normally use a pair of earplugs on stage. Not so much down to the backline volume more to reduce the nightmare of cymbals in small venues. My question is, would the in ears have the same effect as earplugs but with the additional bonus of mixing in a ‘low volume’ ox on top of the attenuation caused by earplugs or would it be a completely different experience.
Good IEM's (say Shure e215's or better) isolate the noise from the stage about as good as ear plugs; however, I never feel like I am wearing ear plugs as the sound in my head is very open.
Even without micing drums, I assure you, you will hear them in your IEM's from the mic blead alone.
For all venues, I mic the kick and at least one tom mic to capture the toms and snare. If I am using my gear and PA, I will always individually mic all the toms and kick. If it is a small to medium venue, I don't mic the cymbals or snare. If it is a larger one, I do.
Less expensive IEM setups are mono which does take something away IMO. If possible, it is really nice to get a stereo image from at least the vocals as the reverb efx really add space to the vocals making the room image feel more real in the monitors. I get this in my system by starting the IEM mix with the main L/R out. The individual mixes then get "more me" for their vocal mic and their instrument. The band members can then use a phone app to adjust their mix to their liking from the stereo mix. This is easy to do with the X32 setup. Depending on your mixer, you may need to dumb down your IEM mix to what the hardware can do.
A lot of good points made so far. For me, IEMs are never going to sound as good as natural hearing and suffer from unaviodable issues. Plugging your ears leads to less that optimum results, always. My ears physcally fatigue just from being plugged for long periods of time. Bone conduction is a real problem. No matter how the IEMs are fitted, ear canal changes have an impact on the sound and feel. This is true especially for singers. The disconnected feeling is also real. The hassle of a separate mix is just that. I use IEMs when volume issues dictate that I 'save' my hearing. IMO, the best situation is to get everyone to play at at proper level. This allows the freedom to not use IEMs and experience natural hearing. This is absolutely the best situation for me. IEMs are a fallback when I am on a stage where the volume levels are out of control. Otherwise, I don't want them.
Just because 'everyone' uses them, doesn't mean they are the optimum solution. Natural hearing is always best and it is worth taking steps to avoid any other compromised 'solution'. There are pros who refuse to compromise, i.e Derek Trucks, one of the most talented guitarists on the planet, won't use them.
There will always be those that IEM's and a silent stage don't work for. It seem to be more prevalent in older guitar players than any other group IME. In fact, there are those musicians that simply can't stand playing with IEM's and will flat out refuse to use them. Mostly, these musicians will have to settle for less adept bands as most touring bands use IEM's (as do most wedding bands and better bar bands).
Just to be clear, there are really only 2 monitoring choices here. One is IEM's, and the other is floor wedges.
I do take issue with your assertion that using IEM's "... leads to less than optimum results, always." The "results" must be considered 2 fold. First, what does the audience hear and second, what does each musician hear.
With regard to the result #1 "What the Audience Hears", bands with low (or no) stage volume that use IEM's have a drastically better chance of sounding better to the audience. Getting good instrument separation when the stage is quiet is way easier while with a noisy stage, it is impossible (not just unlikely, but impossible).
With regard to the result #2 "What each musician hears", it is more nuanced. Each musician can absolutely hear the rest of the band better with IEM's. I would argue that this is the over-riding reason for musicians to like IEM's. Can the musician hear what the stage ACTUALLY sounds like? Nope. The guitar player CAN'T tell exactly what his amp sounds like on stage.
Using EITHER IEM's OR wedges for monitoring, NONE of the musicians on stage can tell what the audience hears. Using IEM's and having an option to hear the main mix out would be the closest to hearing what it sounds like out front, but ONLY if using eDrums and all DI with NO other amps on stage (and no wedges either). This is rarely the case, so even IEM's can not provide the musician with what the audience hears with any accuracy.
I also take issue with the assertion that IEM's are only popular because "everyone uses them". They are popular because it is a superior monitoring solution (superior because it achieves better results in every possible way EXCEPT the musician hearing what his stage amplification sounds like (if he/she is using a stage amp).
Where I completely agree with you is that it is ALWAYS best if every musician keeps his/her stage volume under control. This is true with wedges and IEM's. The one time I believe that just playing at a decent volume and "mixing from stage by adjusting your individual volume" works is for very small blues band venues.
Fundamentally, I think that many musicians believe they need to hear what things sound like on stage to make sure the audience is getting a good sound out front. Sadly, those "many musicians" are fundamentally flawed in their thinking since what you hear on stage is a million miles away from what it actually sounds like in the audience.
Once you give up on this fundamentally wrong thinking, I believe it gets much easier to love IEM's. I don't know about everyone here, but I sure don't miss lugging around all those floor wedges and the amplifiers to push them! I also don't miss running speaker cable (which weighs a ton too in the "speaker cable" bag) all over the stage and trying in vain to find room for the wedges .... somewhere.
Finally, I don't miss constantly hearing band members complain "I can't hear myself" or "I can't hear __________ ". With the wonder of IEM's and individual mixes, these issues are nothing but a bad memory :).
Of course, I must admit, it is possible for a band to use floor wedges and sound great. It is less likely IMO.
Nice post! All points valid!
Thanks!
I think many of us have lived through this problem.
I remember auditioning for a new lead player years back. One guy came over with 2 JCM900's with 2 4x12 marshal slant top cabs because he needed a stereo image on stage for himself.
Sent him home before we even got through the first song. It was an ear splitting experience.
Ironically, he felt we had no clue how a rock band was supposed to sound 
Check out the description. Tom's a trip.
"Sure its a little hungover and sloppy, but this is a pretty good illustration of why Uncle Larry doesn’t use Kempers and Fractals and all that modeling horseshit. He likes it loud and raunchy, that land where the speakers and the pickups are united in total solidarity."
Yuck!
Not even close to a good mix. Seriously, who would want to hear that AM radio quality voice and ear piercing guitar all night?
If you want to be asked back, play to the crowd and the venue owners, not to get "your tone" on-stage.
Don't get me wrong, I like to fiddle in my basement with the guitar really loud. It is inspiring! It just isn't something that makes the band sound good and it is WAY more important to me that the band sounds good that a few guitar heads in the crowd come and give me complements on break about my guitar tone.
Having a guitar monitor pointed AT THE GUITAR player does help quite a bit. First, it makes it so that the sound is going to his / her deaf head instead of past the pant legs, out into the crowd, bouncing off the back wall, then finally reaching the guitar players ears. Second, it helps keep the guitar amp OUT OF THE VOCAL MICS.
Still not as good as a KPA straight in, but way better than a full stack pointed at one side of the audience.
I have been using IEM's since the late 90's (as you can see in my picture 
). I have been gigging in bands since the early 80's.
Bands with low stage volume have a fundamental advantage over bands with loud stages. All that noise causes several problems:
1) All the open mics pickup the noise from the stage and reamplify it through the FOH resulting in a mushy mix out front
2) If the volume of the stage at the vocal mic is louder than the vocalist, it becomes impossible to get the vocals above the mix
3) Guitar amps are directional in the extreme. Part of the audience will be blasted by guitar while part will barely be able to hear the guitar.
4) None of the band members can hear each other well. Turning the floor wedges up just makes the problem worse (or causes feedback)
I play guitar like all of you so of COURSE I like to hear my rig dimed. The strings come alive and feeling a palm mute thump your chest is amazing...... but it isn't a good way to play in a band. In fact, it is a sure way to kill the sound of the band out front.
I believe that lead guitar players (I play rhythm and only a few leads since I am also the lead singer) do need a live monitor on stage, but one pointed at them, not at the audience. This is to get the string action for a good lead. I still think that even the lead player should use IEM's as it is by far the best way to hear the rest of the band.
I don't care how good you are, if you can't hear the rest of the band, you won't be able to sound as good as you could hearing them.
No, IEM's DON'T sound like an amp in the room. In many respects they sound better, but for pure guitar tone, they just don't IMO. That's OK. I actually like hearing a good mix in my IEM's.
As an aside, you are much more likely to be able to hear what the audience hears with IEM's than you are with floor wedges IME.
My opinion, if you turn up to the same volume you’d use with an amplifier, you’ll get what you’re looking for.
This!!! Yep.
Now ..... the philosophical question here is if having an amp on stage that loud is a good idea for a band in the first place :).
I remember the first time I worked in a band with a lead guitar player that had his 4x12 quite low, but mic'ed with the mains doing the heavy work ..... it felt "wrong" to me since I had always been in bands where the guitar amps were loud on stage.
The overall sound with lower stage volume makes for a much superior mix at FOH for the audience. I think that this is a lesson most guitar players never learn because they want that "amp in the room" feeling on-stage which really just means they want their amp up loud IMO.
A little off topic, but you should really consider upgrading your mixer. The MG mixers are .... really bad. It is a crying shame to have all the incredible goodness of the KPA being doused by a Yamaha MG mixer.
Think about going with something like the XR18 which would give you 16 XLR inputs (vs your current 10) an a metric ton of features too much to list in this post that the MG doesn't have. Further, the sound quality of your band will definitely improve.
Back on topic, I agree with all of the above. Use the XLR output (Monitor) or the main XLR outputs for stereo. Do you use a stage monitor for your Kemper?
I have never broken a string on a floating FR before from bending because it's nearly impossible to do anyway. I have had the high E and B string pop out of the saddle one time each from me not tightening down enough. And that happened on a 2 whole step pull.
I don't think I have ever broke a string on a bend. It is always on a strum (usually a pretty hard one).
My drop D one was always a non tremolo model, that way if I broke a string, I could use the backup for either! I really should have got a D tuna I think that's the way to go.
LOL. Yea, if you are playing (any scale) on a tremolo model and the trem ISN'T hard pinned down, a broken string puts all the other strings so far out of wack you can't even begin to finish the song with it like that!
I don't generally wack at my strings hard enough to break them these days (when I was young...... different story). It also helps to keep good strings on your guitar. Personally, I don't like changing strings before a gig (because they stretch). My perfect timing is 1 week before the gig :). It also helps to wipe them down after every practice/gig to keep your finger sweat off them.
On the original topic, I do like using the transpose for practicing along with youtube with bands (you all know who they are) that are famous for tuning down some amount. Generally, I always try to just have the A440 guitar play those songs too and force the singer (that would be me) to handle singing a little higher
I would use it as part of the efx chain to get feedback in specific places in songs. This isn't any different then how we do it with a speaker. You face the speaker and move the orientation of your guitar around to get it to resonate, but only in the place in the song where you want it.
Of course, if you have the stage volume way up, the guitar will be constantly begging to ring (and I have to admit, that is a really cool feeling .... but generally that much stage volume isn't contusive to a good FOH mix (actually, it is NEVER contusive to a good FOH mix) :).
Personally, I have never warmed up to the transpose (either on the rig level or in a slot).
1) I feel the latency and it drives me crazy (short drive admittedly)
2) It feels like it makes the sound a bit .... not natural.
It isn't just the KPA though. I feel this way about every pedal and efx processor that has this feature. I have simply given up on using it and bring 2 guitars to the gig (A440 and Drop D). This solution has worked well for over 30 years
