Posts by DunnyDaw

Thank you both for the comments, help and clarifications.

Quote from slateboy

I've certainly never needed to do any midi-maths, other than calculate a sysex-checksum (not for Kemper) or bit-shift operations so your stuff seems overly complicated, but again, maybe i dont fully understand your mission

slateboy "your stuff seems overly complicated" - maybe, but all I have done is quote what Kemper says in its page 13 of the MIDI Parameter Documentation 8.6. If you re-read that page 13, you will see what I mean.

Yes, I think you have mis-understood what I am trying to do. All I want to do is to use one of my commercially available, already-existing MIDI controllers, programme it with the proper commands and values, and then get it to change settings in my Kemper Player, also an already-existing, commercially available hardware product - I'm not designing or coding anything. I made the mistake of reading the Kemper documents, and struggling to understand them.

In the end, I have read many times what Torsten (@ToH2002) wrote here, and also the comments from 0K1900 above, and then decided to ditch a fair bit of what Kemper does in its example.

So, if my task is:-

• Change the Amplifier Gain setting in the current rig to 81%

Then my process is

• Use NRPN cc numbers to do this (therefore, use decimal numbers)
• From the Kemper document page 17 - Amplifier module is Address Page 10 {this is then the MSB}
• From the Kemper document page 17 - Gain is parameter number 4 {this is the LSB}
• The adjustable range is 0 - 16483
• 16483 x 0.81 = 13,351 decimal (give or take 1)
• Convert 13351 to binary = 11010000100111 {I used this online converter}
• MSB = left-most 7 bits = 1101000 = 104 decimal
• LSB = right-most 7 bits = 00100111 = 39 decimal

So, using Torsten's info, my MIDI command becomes:-

cc 99 value 10

cc98 value 4 (or 04)

cc 06 value 104

cc38 value 39

Et voila - it works!! Amp Gain becomes 8.1

A bit of a torturous path, and maybe not strictly correct from a programming/computing point of view, but I got there.

Now, for my own edification, I've just got to work out how to do it all using SysEx.

I don't know the thread you are talking about, but the Luminite Graviton M1 is a small and wireless controller, and it has a very small "joystick" which can be mounted on your guitar.

LuminiteFX Graviton M1

Quote from 0K1900

You're AND'ing the value to mask out 127.
The simplest way I can explain this is as follows: With an arbitrary value (say, 243).
If I mask with 127 (7 bits) I'm asking:
Out of 243, how many of these bottom 7 bits are on?

C++

#include <bitset>
#include <iostream>

using std::cout;
using std::bitset;

int main()
{
    // 7F = 0b1111111 (7-bit max)
    char value = 243;
    char mask = 0x7F;
    cout << "  "   << bitset<8>(value) << " [value]"
         << "\n& " << bitset<8>(mask) << " [mask]"
         << "\n= " << bitset<8>(value & mask);
    return 0;
}

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Output:

11110011 [value]

& 01111111 [mask]

= 01110011

...1110011 is the "status" of the last 7 bits.

Yes it will. Depending on how your serial connection is made through midi you might be sending additional bits that the receiver end might not be expecting.
It's not going to fry anything but I imagine the receiving end is just going to think of it as garbage. You could try it out though.

In serial you're essentially creating a hose of bits and firing off groups of bits and if one number you're trying to send is larger than the group of bits I imagine that you'd be sending a lot of data that receiver probably won't respond to correctly.

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Thanks so much for this response, it has clarified a lot for me.

There is a further complication for me though.

In Kemper's "MIDI Parameter Documentation 8.6" document, page 13, they seem to be splitting a 14-bit number into two sections of 7 bits:-

The "SHR 7" (Shift Right by 7 bits?) seems to me to be selecting the first 7 bits, if so, do they then need to do an "AND $7f" action on what is now a 7-bit number? In your discussion, the number was more than 7-bits, so I can see the purpose. It seems to me that, by Kemper splitting it into the 7-bits, the "AND $7f" action becomes superfluous.

Quote from slateboy

What are you using to do all this midi communication? ie, an arduino, rapsberry pi, PC, mac.

What is the end device going to be? a bit of hardware or just software?

I believe it is Wheresthedug has the droll comment in his sig "Way more gear than talent". That applies massively to me. I will be using a MIDI foot controller for sending the MIDI messages, an XSonic Airstep or maybe a PaintAudio MIDI Captain. I have a couple of other old devices I have accumulated over time that I might dust off also. The Airstep can send PC, CC, and SysEx, I believe the MIDI Captain will be soon able to send SysEx also. The end device is hardware, a Kemper Player or maybe a Stage. I am slowly piecing together all the info I have found on MIDI as related to Kemper, and can do basic stuff likely changing rigs, etc. But I want to understand the Kemper doc fully, so I can start going the next step of changing Kemper effects to intermediate levels, etc.

Quote from 0K1900

Okay, I'll take a shot:

C++

#include <stdio.h>
#include <iostream>
#include <bitset>

using std::cout;

int main()
{
  // value max is 8192 = 0x2000
  const auto nrpn = 6169;
  const auto value = 8192;
  cout << std::bitset<7>(nrpn / 100) << '\n';
  cout << std::bitset<7>(nrpn % 100) << '\n';
  cout << std::bitset<7>((value >> 7) & 0x7F) << '\n';
  cout << std::bitset<7>(value & 0x7F) << '\n';
  cout << 0b10000000000000 << '\n';
}

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Output from code:

0111101

1000101

1000000

0000000

8192

As you can see above, sending 8192 by two pairs of seven bits means sending 1 value of 0b1000000and a second value of 0b0000000.
Join them together and it makes 0b10000000000000 (8192)

Does that help? Maybe I misread something, there is a lot of text here.

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Thanks for this response, and the comments. I don't know C or its derivatives at all, but I think I can work out what the code is doing/saying.

Yes, there is a lot of text in my post, sorry for that.

But I was trying to explain my reasoning and deductions in working through the MIDI doc and the example on page 13, and the conversions of dec --> hex --> binary, etc. If I am wrong in my reasoning, hopefully someone can correct me, and I'll be the better for it.

I was able to work out how to convert 8192 into 7-bit binary, but thanks for your comments.

My real question is why the example includes the "AND $7F" operation, and what it means if this is not done. {Edit: It seems to me if you "AND" any 7-bit number with $7F, you will get the original number as the answer, so why do it?}

If I'm looking for parameters and values for some other operation controlled by MIDI (changing delay settings or gain settings, etc), and I don't apply an "AND $7F" to whatever parameters and values I read from the Kemper MIDI doc, will that matter?

I'll do some googling on "AND" and "$7F" and binary and MIDI, and see if I can work it out.

I’m a MIDI and NRPN noob, and trying to educate myself in this area. I’ve read heaps of threads and posts on the subject, some of which have been very helpful. This post by Torsten ToH2002 was awesome, as have been many posts by Burkhard , and clarified a lot. But I’m still struggling with page 13 (and associated pages 11 and12) of MIDI Parameter Documentation 8.6.

The example on page 13 references ““Reverb Mix” in module REV is at NRPN #6169”. I can see from page 23 of the MIDI document, the Effect Module REV is at Address Page 61, so I presume 61 becomes the MSB. And from a Decimal to Hex converter, 61 Dec = 3D Hex (written$3D?). And then on page 20, I can see that “Mix 3 (delay and reverb effects)” is 69, which equals Hex 45. So I can see where the first couple of numbers in the example are from.

But I can’t understand the next paragraph, starting with “So, why $40 and $00?”. I can see the conversion of 8192 into Hex 2000. $2000 when converted to binary becomes 10000000000000. The SHR 7 is (I think) a Shift Right by 7 bits (= 1000000) to get the MSB. Converting Binary 1000000 to Hex = $40. The remaining binary bits are 0000000. And unsurprisingly, Binary 0000000 = Hex $00. So I can see where those two numbers come from.

So why is the “AND $7F” function used?

Trying to remember back to my university days, which preceded the existence of desktop PC’s, phones, internet, you name it, the AND function compares the same bits from two numbers, and returns a 1 where the two bits are both 1, and returns a 0 otherwise.

Hex $7F = Dec 127 = Binary 1111111.

So if the MSB is 1000000, and you AND 1000000 with 1111111, the answer will be 1000000. Which per the above converts to Hex $40, so all good.

But why do you do that?

Similarly, if the LSB is 0000000, and you AND 0000000 with 1111111, the answer will be 0000000. Which per the above converts to Hex $00, again all good.

But again, why do you do the AND function/calculation?

And why use the number $7F, (or127), apart from the fact this gives you seven bits of one’s?

Or asking these questions the other way round, what happens (or what is the risk/issue) if I just used the numbers I got from the MIDI parameter lists, and didn’t do the “AND” calculation?

And lastly, assuming I can get on-board with all the maths and numbers above, I’m guessing that, if I was sending a SysEx command, I would be using the Hex numbers, and if I was using NRPN, the numbers would all be decimal?

Thanks for anyone who has read this far, and even more thanks for anyone who responds!!

Quote from hkkt1987

For the software update, i did it as instruction. Hold Fx1 and Fx2 and connect Cable. Fx1 and Fx2 were blinking and look like software update in progress. but it was like 20mins now and how to know software update is completed ??

From memory, there is an error in the instructions which come with the Player software download. The downloaded instructions say "press and hold the two knobs for FX1 and FX2" - for me, this didn't work (but the startup cycle went through in a few seconds, not 20 minutes). The Player manual (also in the software download pack) page 134 says "hold the FX1 button together with the FX2 button (not the knobs!)...". For me, this process worked.

I wrote to Kemper Support, told them about this error and suggested they update their instructions. They agreed they would, but I don't think they have yet.

I had this issue, and I found a post or a thread on this forum, where it was answered by a Kemper employee. Sorry I can't find the post right now.

From memory, it was something like hold two buttons or knobs down, until some light changed to yellow, then release the knobs, and the start-up or install would progress. If you held the knobs or buttons down too long, then the Player dropped into this error mode. The employee agreed their documentation wasn't clear, and they intended to update it, but maybe hasn't happened yet.

Sorry this is not clear or specific, if I get time later today I will look again for the post or thread, but maybe someone else can chime in and clarify.

Quote from ToH2002

The address for the current rig name is 00 01 - as shown above and also in the MIDI parameter documentation. There is no access to previous or next rig via MIDI as far as I know - that's not something typically accessible via MIDI. Typically, you can access what is currently loaded (performance or rig)

If you want to display previous and next rig, your best option is to grab all rig names first - step through all rigs and request the current rig name, then store them in your program. Now that you have all rig names, you can simply react to the current rig selected.

No idea if the Player has the same MIDI implementation as the Toaster, Rack or the Stage - best to try requesting the current rig name via sysex and see if there's a useful reply from the Player...

Thanks for this. All the threads I had seen related to slot names in performance mode, but I didn't see anything related to browser mode. I'll start playing with this using the controller I have.

ToH2002 ; sumsar ; slateboy ;

Do any of you have the codes or "request string parameter" addresses for Current Rig Name: Next Rig Name; Previous Rig Name, when in Browser mode, or with respect to the new Profiler Player? And for the Player, also Current Rig Bank and Number: Next Rig Bank and Number; Previous Rig Bank and Number?

I am interested in trying to be able to display those three names and numbers when using the Player.

Thanks for the suggestions - I'll look into those a bit further.

Just tried with a different power supply than the Kemper supplied unit - seems to be a lot lesser buzz than using the Kemper-supplied PS, but still much more than the nearly-silent Stage.

Disconnected the Ipad from the WiFi connection to the Player - didn't seem to make much difference.

I've been comparing the Player to my Stage, using preset 1971 Mars Golub Crch.

At the same settings, I'm getting a loud buzz from the Player, while the Stage is very quiet. Same guitar on the same pickup, output/monitor volume is about -11.9dB, all other settings are factory on both presets, and are the same. I'm listening via headphones, only a guitar input, a USB connection to Stage for Rig Manager, and using Rig Manager on Ipad for Player.

Is the Player considered noisy, or is there something else to look at?

So how could I connect this with another MFX pedal - say a Fractal FM3 or a Boss GT1000Core (or a Helix of some sort if I owned one) etc? Use the Kemper Player as the amp in the signal chain.

I've had a brief scan of the manual and am not sure. My current thinking is something like:-

First half of a signal chain in FM3 (drive, distortion etc) --> Send in FM3 --> Instrument In on Kemper Player -->Pre-Stack Effects Blocks A and B are empty --> guitar rig in Kemper --> Monitor Out in Kemper is set to Stack --> Out of Kemper to Return of FM3 --> Rest of signal chain in FM3 (wet effects etc).

Is that how it would be done?

You've probably got all you need already, but here are a few suggestions from Tone Junkie.

(If you've come from Helix on The Gear Page forum, Tone Junkie gets baked unmercifully there, but I have still found a lot of his earlier (3 or 4 years ago) Kemper Tips and Tricks YouTube videos very helpful from a beginner's perspective).

Building up a Performance, by copying and pasting rigs to slots, then changing effects presets in each slot (using Rig Manager):-

I'm not saying this is the sound you're going for, but the process is well demonstrated.

{Added bonus - at the end, there is 2 minutes of the best guitar faces ever recorded on video or celluloid}

Building a Performance (on the Kemper Profiler):-

Beginner Tips in using profiles and changing effects:-

These are a bit of a time commitment (because he can waffle a bit), but it was worth it for me.

Thanks, Whippinpost and others.

And thanks for the explanations above, I didn't realise that was how the presets worked in Kemper. All clear now.

Hello,

Just starting down the Kemper journey, and trying to understand various rig constructions.

I've got a Stage, and using Rig Manager I want to analyse a rig (any rig) to see how it was constructed. Want to understand the effects. So I click on (say) Dual Delay in the signal chain, then click on Dual Delay in the Effects window. Up comes a selector box of effects types, with Delay ticked. So I then go to the second selector box, which has Dual Delay ticked. From there up comes third selector, with all the Delay types available (Main Station, Ping Pong, Smear, Tape, etc). But I can't see how to determine from here which actual effect type had been seected in the rig being played or previewed. Is it possible to see this somehow?