GR-55 - Tracking Solved - No bad notes

Started by Moja, April 25, 2017, 09:40:19 AM

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gumtown

I don't think there is much cable cross-talk, since the GK output impedance is only at around 100 ohms.

Magnetic hex pickup crosstalk can only be avoided if you were to magnetically shield between adjacent strings and pickup poles.
As one pickup pole will receive a small amount of 'flux' from adjacent strings.

Hex Piezo crosstalk is from physical string/body vibration, mostly at low frequencies (sub-harmonics?), where a high pass filter will greatly help this.
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

admin

#26
QuoteMagnetic hex pickup crosstalk can only be avoided if you were to magnetically shield between adjacent strings and pickup poles.
As one pickup pole will receive a small amount of 'flux' from adjacent strings.

Like adding Mu Metal surrounds for each Coil inside the Gk-3 PU
https://en.wikipedia.org/wiki/Mu-metal





http://www.skguitar.com/SKGS/sk/Images/pickups/Pickup%20stuff/Magnetics.htm


vtgearhead

The second photo reminds me of the ARP Avatar pickup. 

nix808

how about subtracting the string next to the string signal you want?
... say the interference reads .0005 digitally,
then subtract from the signal you want, the adjacent string multiplied by .0005
hehe- maybe stringport used to do this. I have actually tried, but I don't have bleeding problems with GK-
it was Rubenstein ones where I attempted it a couple of years ago.
Rock and Rock my boat, as long as you don't rock and rock my boat!hehe

Moja

I so wish it was that easy.
Sadly it is not a matter of simple arithmetic . +, -, ..

It's defiantly a totaly different tenth order Polynomial for each setup guitar/PU,....

nix808

#30
Nice for you to solve it.
The subtracting of the adjacent signal would be a conditional 'and',
not a polynomial I guess- but the square in RMS would be first order, if that was used,
although amplitude or peak possibly both apply too

Enjoy your creation!

edited-some misthinking
Rock and Rock my boat, as long as you don't rock and rock my boat!hehe

mmmmgtr

#31
I thought of another question.

Does this solution support both PCM sounds as well as COSM sounds? If there is any sort of frequency based filtering or adjustments going on that would really be undesirable for the COSM sounds. It could also potentially limit the usefulness of some of the PCM sounds, but the COSM sounds really need to have the guitars harmonic content to faithfully reproduce what they are trying to emulate.

After thinking about it a bit more, I agree with smhirsch in that I'd be willing to spend up to $150...

Moja

Lol, exctly . You've read my mind . Thanks

Smash

So it's really for synth tracking and not COSM as there would be an effect on the harmonic content of the actual note - is that right?

tbeltrans

#34
So what we have here is the OP has developed a device that addresses the problems with tracking on the GR-55, but he can't tell us anything without jeopardizing his work.

I would think there would be interest in this on the part of many GR-55 owners.  Pricing and availability, as well as how well it really works in each person's situation, will determine how this development translates into sales.

Unfortunately, there is a Catch-22 situation here.  The developer can't tell us anything.  Not knowing anything, we as potential customers, have nothing to go on so there isn't really any constructive discussion leading to any conclusive action on the part of either the producer or the consumer, and all we have to populate this thread are these sorts of "20 questions" guesses as to what the product might be.

There is really nothing I can do beyond adopt a "wait and see" stance and probably nothing I can really contribute to this thread other than posting the message to join the ranks of those watching for further development regarding this potential product.

Tony


HecticArt

I'd be interested if the cost was reasonable.

Personally, I think that you need an endorsement/peer review.
I'm sure one of the guys here like gumtown, codesmart, admsustainiac, or elantric would be willing to test one out for you and provide a review. They all seem like the kind of gentlemen that wouldn't divulge your trade secrets, but would be trusted by our community to give an honest review.

Worth consideration.

gumtown

Maybe a new lotion you rub into your guitar, made from an oily extract from snakes. ??  :P
Free "GR-55 FloorBoard" editor software from https://sourceforge.net/projects/grfloorboard/

Moja

Quote from: Smash on April 26, 2017, 02:00:16 AM
So it's really for synth tracking and not COSM as there would be an effect on the harmonic content of the actual note - is that right?

No, it complies with both requirements .

Moja

#38
Here is a crude factory patch Grand Piano Demo on YouTube.
I tried posting this video on this forum several times last night . But I did not realize our site has a Max size issue.



A new type of solution to the age old poor tracking , poor latency , bad/wrong notes, weird notes , when used with standard GR-55 & GK-3. The GR-55 is set to standard factory Grand Piano Patch.

Moja

#39
QuoteAnd Piezo pickups often are the source,  Graphtech Ghost pickups are the  top offender.

Totaly agree.  I had one of these because it looked so neat and clean, nothing visible. But results were extremely poor.

QuoteThus the importance of following and adhering to the correct GK-3 installation and setup procedure.

No amount of " set up " truly solved the problem ..!

QuoteIMHO - Only 20% of GK-3's are setup up correctly with the host GK processor's (VG-99, GR-55, GP-10) "GK settings" set correctly too.


This 20% may be true but it still performs very poorly IMHO.

Elantric

#40
Quote
This 20% may be true but it still performs very poorly IMHO.

The player's technique is a big role too.

https://www.vguitarforums.com/smf/index.php?topic=8208.msg58356#msg58356


And there exist sub filters to aid tracking

shawnb

I have a theory on the root cause of the GR-55's poor tracking, ghost notes & "mousie death squeals"...

Ever notice that when you are setting the string sensitivity, you can hear the string signal being used? 

Ever notice how unusual it sounds?  It is not the input signal. 

To me, it sounds like a significant amount of gain (& possibly some natural compression) have been applied.  I think that early in the signal flow, for some reason, they jacked up the gain...  Thus, even little incidental pick noises are transformed into "mousie death squeals".  Also, we see hypersensitivity due to compression, where a minor input signal produces the same/duplicate result as a note played. 

I've wondered if there were a way to counteract this upon input... 
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

Elantric

#42
Quote from: shawnb on April 26, 2017, 08:24:59 AM
I have a theory on the root cause of the GR-55's poor tracking, ghost notes & "mousie death squeals"...

Ever notice that when you are setting the string sensitivity, you can hear the string signal being used? 

Ever notice how unusual it sounds?  It is not the input signal. 

To me, it sounds like a significant amount of gain (& possibly some natural compression) have been applied.  I think that early in the signal flow, for some reason, they jacked up the gain...  Thus, even little incidental pick noises are transformed into "mousie death squeals".  Also, we see hypersensitivity due to compression, where a minor input signal produces the same/duplicate result as a note played. 

I've wondered if there were a way to counteract this upon input...

Sure -




use a 6 channel High pass filter before the GR-55 Gk Input stage.

( - several folks have been selling them for years. )

find them here
https://www.vguitarforums.com/smf/index.php?board=13.0

Elantric

#43
Quote from:  sec6
Moja,

I don't use the GR55 and the piano patch.  I use a GP-10 to control vsts and have no glitchy tracking issues.  So I wouldn't be buying.  It does seem that you are boosting the output of the GK pickup (as evidenced by your before and after pictures) and this results in better piano patch tracking. So a hotter output = better GR55 piano patch tracking.  That would explain the great results I get using a really hot Casio hexaphonic pickup that I use with an internal GK kit.  I've gotten over the curiosity of turning my guitar into saxaphones and pianos long ago. So once again I am one that won't be interested in the double-secret-GK-improved-GR-55-piano patch-fixer gadget.

Study an opamp data sheet, and Alter the gain of your GK-3 preamp if you want to try on the cheap .

Just a few resistor swaps

https://www.vguitarforums.com/smf/index.php?topic=4729.msg149534#msg149534


http://www.learningaboutelectronics.com/Articles/Op-amp-gain-calculator.php#answer1

the GK-3 has a gain of "x 12.2  "

If you want more power and sub frequency input filtering

try one of these
http://www.primovasound.com/gkfx_1.html


shawnb

#44
Quote from: Elantric on April 26, 2017, 08:45:15 AM
use a 6 channel High pass filter before the GR-55 Gk Input stage.

Actually, my concern is at the other end - the loud, brittle high-end & overall gain. 

The high-pass was intended to deal with rumble & body noise issues. 

My suggestion is more along the lines of attenuating the input level - and/or - adding a low pass (transforming the high-pass into a band-pass). 

It's the loud, brittle high-end heard when setting string sensitivity that makes me think it's a problem. 
Address the process rather than the outcome.  Then, the outcome becomes more likely.   - Fripp

Elantric

Quote from: shawnb on April 26, 2017, 09:11:12 AM
Actually, my concern is at the other end - the loud, brittle high-end & overall gain. 

The high-pass was intended to deal with rumble & body noise issues. 

My suggestion is more along the lines of attenuating the input level - and/or - adding a low pass (transforming the high-pass into a band-pass). 

It's the loud, brittle high-end heard when setting string sensitivity that makes me think it's a problem.

perhaps inserting a 6 channel EQ  between GK-3 and GR-55

https://reverb.com/item/3332455-akai-peq6-6-channel-digital-programmable-equalizer





carlb

Quote from:  sec6
<...> It does seem that you are boosting the output of the GK pickup (as evidenced by your before and after pictures) and this results in better piano patch tracking. So a hotter output = better GR55 piano patch tracking.  That would explain the great results I get using a really hot Casio hexaphonic pickup that I use with an internal GK kit.  I've gotten over the curiosity of turning my guitar into saxaphones and pianos long ago.

Chances are your Casio pickup has less crosstalk to begin with than the Roland and certainly the piezo pickups. Hotter signal alone will often make the problem worse, as the crosstalk contributions from the other strings begin to confuse the processing algorithm for any given string.

What's impressive about Moja's approach is that he is getting higher desired string output while at the same time lowering the unwanted crosstalk into the other string's outputs. You can see that: when he plucked the third string with his circuit activated, the third string output volume was higher while all the other strings (which he hasn't plucked) are near silent. So nearly no crosstalk.

That might not be as important for your setup, but for users of Roland/Boss 13-pin gear, it would be a welcomed game changer. The "warbles" we experience on the output of frequency shifted strings when they tail-off should go way down.
ES Les Paul, internal Roland GK
Boss SY-1000, Valeton Coral Amp pedal
Morningstar MC8 & MC6
QSC CP8 powered speaker

carlb

Quote from: Moja on April 26, 2017, 07:55:29 AM
Here is a crude factory patch Grand Piano Demo on YouTube.
I tried posting this video on this forum several times last night . But I did not realize our site has a Max size issue.

Could you also post a patch of an acoustic modeled output that is shifted down a whole step (for instance). Let a 'G' chord and then an 'A' chord ring? Do that with and without your circuit, to see its effect on the dreaded "warbles" when strings are left to ring.

That would be great, thanks!
ES Les Paul, internal Roland GK
Boss SY-1000, Valeton Coral Amp pedal
Morningstar MC8 & MC6
QSC CP8 powered speaker

Beirne

Same here. If it was an on-board guitar add/on or would it reside in the GR55 floor unit?
Either way I would buy at minimum 2 @ 150 to 300$ US.
www.intangiblesny.com
www.facebook.com/intangiblesband

Moja

Quote from: carlb on April 26, 2017, 10:41:19 AM
Could you also post a patch of an acoustic modeled output that is shifted down a whole step (for instance). Let a 'G' chord and then an 'A' chord ring? Do that with and without your circuit, to see its effect on the dreaded "warbles" when strings are left to ring.

That would be great, thanks!

Yes sure in few days sorry. Tax season here .
Thank you for your kind interest and input, suggestions .
Regards
Bob