VGuitar Forums

Please login or register.

Login with username, password and session length
Advanced search  
Pages: [1]   Go Down

Author Topic: Non-GK PCM triggering has arrived !!!  (Read 4244 times)

0 Members and 1 Guest are viewing this topic.

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Non-GK PCM triggering has arrived !!!
« on: July 22, 2011, 07:53:26 AM »

Totally related to these threads of adding a normal pickup external effects loop:

http://www.vguitarforums.com/smf/index.php?topic=3386.msg22471#msg22471
http://www.vguitarforums.com/smf/index.php?topic=3793.msg25649#msg25649
http://www.vguitarforums.com/smf/index.php?topic=3994.0

After wiring a switched FX SEND/RETURN I then simply jumpered the FX RETURN signal to PIN1 on the 13PIN GK board to feed the normal pickup signal to STRING L and VIOLA! Mono PCM triggering has arrived!!! WOOT!

In this quick MP3 demo I literally just plugged in my Lakland Duck Dunn 4 string P bass and started playing, no adjustments to GK settings or the PCM patch at this time. Due to this SENS seems a little low and I have to play harder than normal. And the tracking was only working from the 9th fret up for whatever reason, even though I was running in BASS MODE with a normal 4 string bass which should theoretically track down the entire range.

Of course you totally lose all polyphonic capabilities which would likely be unusable for guitarists. And that also means no string split functionality which is pretty powerful stuff. But for bassists who are used to monosynth effects where you typically have to play clean mono lines and high on the neck this could very well prove out to be totally usable.

For my setup specifically since I play 4 strings I could theoretically continue to feed the FX RETURN to PIN1 or maybe PIN6 since my GK bass is only feeding 4 strings using PIN2-5. Thus normally I'm not using PIN1/6 in my PCM patches anyway. That's just me doing some early morning brainstorming.

I'll need to try tweaking the GK settings to see if I can improve performance at all. And see if I can find a solid octave-up pedal effect that can push a normal bass into guitar territory so I can run the GR-55 in guitar mode which based on my personal experience thus far has far superior tracking speed and performance. I've been running a piccolo strung bass with the GR-55 in guitar mode for the past couple months and it feels much more natural VS bass mode which I always feel like I'm fighting against for PCM speed and tracking.
Logged

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #1 on: July 22, 2011, 08:24:14 AM »

Couple other comments:

* Running my non-GK into the BOSS OC-2 then into the FX RETURN does have a slight volume drop as seen on the GK SENS screen. Even with SENS = MAX it's not as sensitive as running the non-GK into the GK CONTROLLER 1/4" jack where I can run SENS = 70-80.
* Running the non-GK into the GR-55 seems to improve glitches, probably since it's now forced into mono-tracking, thus string brushes, etc. on other strings aren't triggering "glitches", and some "glitches" are actually where the PCM voices are overlapping notes, most often the decay of one note causes a dissonance with the next note which sounds like a "glitch". That's gone now due to mono triggering.
* At first test it seems I can run GK LOW CUT at 0 and have no immediate degradation in performance. I'm assuming this is due to it being forced into mono-tracking.
* Octave jumps are more difficult to trigger, again likely due to mono-tracking. You need some more careful playing when doing octave jumps for it to trigger them successfully.

One huge issue I haven't figured out yet, but likely some more experienced GK electronics person can comment on, is that the mono PCM triggering via FX RETURN does NOT work if there's no GK instrument connected to the 13 pin input. I had my GK instrument still connected to the 13 pin while my non-GK was connected via FX RETURN during my initial testing. I have to run to work so hopefully when I get back someone more experienced with GK electronics can tell me what I need to do to work around this as it would defeat the purpose of non-GK PCM triggering if you still need some GK controller plugged in to the GR-55. :)
Logged

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #2 on: July 22, 2011, 09:41:41 AM »

One huge issue I haven't figured out yet, but likely some more experienced GK electronics person can comment on, is that the mono PCM triggering via FX RETURN does NOT work if there's no GK instrument connected to the 13 pin input. I had my GK instrument still connected to the 13 pin while my non-GK was connected via FX RETURN during my initial testing. I have to run to work so hopefully when I get back someone more experienced with GK electronics can tell me what I need to do to work around this as it would defeat the purpose of non-GK PCM triggering if you still need some GK controller plugged in to the GR-55. :)

Further thought, this is likely due to the GK controller's volume and 3 position switch being disconnected when I unplug the 13 pin cable. Need to investigate further to flesh that out. But that's my guess at this time.
Logged

Elantric

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 238
  • Offline Offline
  • Posts: 13493
    • Elantric's Tips and Blog
Re: Non-GK PCM triggering has arrived !!!
« Reply #3 on: July 22, 2011, 10:53:47 AM »

Quote
Further thought, this is likely due to the GK controller's volume and 3 position switch being disconnected

Correct!

With nothing plugged into the 13pin GK INPUT, the GK- VOL control voltage is not present, and thus this has set the Volume to Zero.

On patches you wish to use your new 1/4" FX Return input for normal guitar, Reassign the "GK VOL" parameter to something else.
« Last Edit: July 22, 2011, 10:59:14 AM by Elantric »
Logged

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #4 on: July 22, 2011, 11:17:34 AM »

Correct!

With nothing plugged into the 13pin GK INPUT, the GK- VOL control voltage is not present, and thus this has set the Volume to Zero.

On patches you wish to use your new 1/4" FX Return input for normal guitar, Reassign the "GK VOL" parameter to something else.

Actually if you set GK VOL = OFF, or anything really, you still get no PCM triggering.  Unless I'm missing something with the GK VOL I think it's actually the 3 way toggle being disconnected which likely sets it to BASS (normal pickup only) as opposed to MIX or GK, thus defeating the PCM totally. And there's no system or patch setting that I could quickly find to control what the 3 way toggle does.
Logged

Elantric

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 238
  • Offline Offline
  • Posts: 13493
    • Elantric's Tips and Blog
Re: Non-GK PCM triggering has arrived !!!
« Reply #5 on: July 22, 2011, 11:50:09 AM »

If you build this DIN 13 "dongle" with the two resistors, that should allow your signal to pass.

Basically what this is does is set the "GK-VOL" setting to Max, anytime the dongle is inserted into the GK Input on any Roland 13 pin gear.(VG-99, VB-99, GR-55, GR-20, Axon, etc, )

Buy a Male 13 pin DIN plug

Use two resistors

One 120 ohm (indicated on Schematic as "121 ohm")   

One 240 ohm (indicated on Schematic as "243 ohm")   

These resistors create a voltage divider that feeds a fixed voltage to the "GK-VOL" Pin#8, which fools the GR-55 to believe a phantom  GK-Volume knob is set to "Maximum volume".


Wire as described below:




Insert this plug in the GR-55's 13 pin input, and this should let you use the "FX Loop return" as a normal guitar input.

Although I do not feel this "DIN13 Dongle" plug is absolutely necessary, it might be handy, as it avoids the need to reprogram all your GR-55 patches.

Review the GK-2 schematics here:

http://www.vguitarforums.com/smf/index.php?topic=73.0
« Last Edit: July 22, 2011, 12:02:38 PM by Elantric »
Logged

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #6 on: July 22, 2011, 01:09:52 PM »

I'll have to give further modifications some detailed thought. If someone was going to go full monty towards a mono-trigger with a non-GK instrument they would likely want to gain full GK control with S1, S2, GK toggle, and GK volume since you wouldn't have a physical GK controller on your instrument. Plenty of users want those features external already even WITH a GK instrument, heh.  In that case it would be more robust to build an external box similar to what you've discussed in other threads, and wouldn't require permenant modification of your GR-55 chassis since you'd pass everything back into the stock 13 pin input from the external box.

I'd think you could build it all into a medium/large sized stomp box chassis. 

* 13 pin input, 13 pin output, 1/4" send, 1/4" return
* (2) momentary footswitches for S1/S2
* (1) 3 way latching footswitch for the GK toggle
* (1) latching footswitch or manual toggle for switching between GK or 1/4" PCM triggering
* (1) external expression jack for connecting external expression to work as GK Vol

Then you can easily jam whatever circuits are necessary inside. Probably harness 7V for LED indicators for everything.  Only $99 including short 13 pin patch cable! Heh.
Logged

Elantric

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 238
  • Offline Offline
  • Posts: 13493
    • Elantric's Tips and Blog
Re: Non-GK PCM triggering has arrived !!!
« Reply #7 on: July 22, 2011, 02:52:14 PM »

Quote
* (1) 3 way latching footswitch for the GK toggle


Would be nice if you could Find one! ;)


Obviously some other circuitry would be required to implement a foot operated duplicate of the GK-3 "3-way" GTR/MIX/SYNTH switch .

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #8 on: July 22, 2011, 04:35:55 PM »

We all keep hoping you'll make one. :)
Logged

Elantric

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 238
  • Offline Offline
  • Posts: 13493
    • Elantric's Tips and Blog
Re: Non-GK PCM triggering has arrived !!!
« Reply #9 on: July 22, 2011, 04:41:34 PM »

Quote
We all keep hoping you'll make one. :)

Your ideas and desired features for this type product  are being heard load and clear!

stay tuned.

Spider

  • Senior Member
  • ****
  • Karma: 20
  • Offline Offline
  • Posts: 451
Re: Non-GK PCM triggering has arrived !!!
« Reply #10 on: July 26, 2011, 07:46:35 AM »

I try do the same:) I will try use one of hex PU buffer (from GK-2 schematics) before normal (non-GK) instrument input. 

I'll have to give further modifications some detailed thought. If someone was going to go full monty towards a mono-trigger with a non-GK instrument they would likely want to gain full GK control with S1, S2, GK toggle, and GK volume since you wouldn't have a physical GK controller on your instrument. Plenty of users want those features external already even WITH a GK instrument, heh.  In that case it would be more robust to build an external box similar to what you've discussed in other threads, and wouldn't require permenant modification of your GR-55 chassis since you'd pass everything back into the stock 13 pin input from the external box.

I'd think you could build it all into a medium/large sized stomp box chassis. 

* 13 pin input, 13 pin output, 1/4" send, 1/4" return
* (2) momentary footswitches for S1/S2
* (1) 3 way latching footswitch for the GK toggle
* (1) latching footswitch or manual toggle for switching between GK or 1/4" PCM triggering
* (1) external expression jack for connecting external expression to work as GK Vol

Then you can easily jam whatever circuits are necessary inside. Probably harness 7V for LED indicators for everything.  Only $99 including short 13 pin patch cable! Heh.
Logged

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #11 on: July 30, 2011, 09:05:26 PM »

Experimented a bit more with this tonight. I severed the PIN1 wire and hard wired my FX RETURN signal to PIN1 so I wouldn't have to have the chassis open and alligator wires jumper it. Here's my observations:

* Opted for a BOSS LS-2 with the level slightly boosted to make up for the slightly dropped signal I've observed running a passive bass through a BOSS buffer instead of directly through the 1/4" on the GK controller
* In GUITAR MODE even though I've wired it to PIN1 which should be STRING1 (high E) neither a piccolo bass, nor a regular strung bass triggers PCM well. Barely at all, actually. Even though SENS is reading levels well, normal pickup is coming through clearly, PCM simply is unusable.
* Simply swapping the GK SETTING > PU DIRECTION = REVERSE assigns my PIN1 signal to STRING 6 and magically everything is triggering great. I get the almost the full range of a 4 string piccolo bass triggering PCM (open low E through A# 14th fret G string), and a slightly reduced range of a regular strung bass from C (3rd fret A string) to A (13th fret G string). Note this is still GUITAR MODE. I'm not exactly sure what conclusions you can draw from this, but apparently that there's different processing on each of the strings and a somewhat fixed range of note tracking as opposed to identical pitch/PCM triggering algorithms on each of the 6 strings. At least that's what I'm getting from this exercise thus far. This took me a while to figure out, the problem is that my regular strung bass has the pickup physically reverse and a matching GK setting, but my piccolo is setup with normal orientation, with it's own GK setting. Confusing seeing the SENS levels high but absolutely nothing on VELOCITY. Serious head scratcher. :)
* MODELLING > WAVE SYNTH has the same effective range.
* MODELLING sounds general poor or unusable with either instrument, but with the regular strung bass in particular since the bass/bass synth modelling is octave shifted and sounds terrible shifted back up +1 octave. I tried briefly adjusting the GK settings with no immediate success. Run the same instrument through the GK controller and instant modelling greatness. Always fun to run the piccolo bass with guitar/sitar/banjo modelling, though the bass models sound really bad IMO, at least with the piccolo bass, which is very ironic.
* Of course NORMAL PICKUP works great regardless.
* Portamento is crazy since you're pushing every note through the same string so it thinks you're doing seriously wild same-string note jumps and portamento gets applied all of the time.

I currently only use PCM only 90% of the time and NORMAL PICKUP 10% of the time. So I wouldn't miss the modelling. And I wouldn't likely miss the polyphonic aspect with the exception of PCM string splits. But I think running non-GK into the unit holds a lot of promise for me, personally. Forces the unit to work as a "normal" bass synth pedal, plus a regular multi-effects.

I've acquired the resistors that will theoretically force a simulated fully open GK controller volume, but haven't had time to experiment with it yet.  I'm ever so slightly nervous feeding 7V to the wrong pin and frying something as I've utterly voided my warranty at this point. :)

Sorry, no new sound clips yet.
Logged

Bill Ruppert

  • Senior Member
  • ****
  • Karma: 53
  • Offline Offline
  • Posts: 592
Re: Non-GK PCM triggering has arrived !!!
« Reply #12 on: September 30, 2011, 09:18:13 PM »

So if I feed a mag pickup to to pin 7 and ground it should work with with just the amp modeling and effects.
What is the input impedance of pin 7???
Will be happy with a humbucker pickup or does it look for a buffered low impedance signal?
Thanks Bill
Logged

gumtown

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 154
  • Offline Offline
  • Posts: 2708
Re: Non-GK PCM triggering has arrived !!!
« Reply #13 on: September 30, 2011, 10:20:29 PM »

So if I feed a mag pickup to to pin 7 and ground it should work with with just the amp modeling and effects.
What is the input impedance of pin 7???
Will be happy with a humbucker pickup or does it look for a buffered low impedance signal?
Thanks Bill
You will need to buffer the signal if running the guitar direct to pin 7, OK if using a stompbox in between, but the low impedance of the pin 7 input would suck the life out of your guitar tone with only the passive guitar pickups connected.
Logged
Free "GR-55 FloorBoard" editor software from http://sourceforge.net/projects/grfloorboard/

Skyze

  • Contributing Member
  • ***
  • Karma: 0
  • Offline Offline
  • Posts: 25
Re: Non-GK PCM triggering has arrived !!!
« Reply #14 on: October 01, 2011, 05:52:25 AM »

sorry for being a newb.. but I take it this is somewhat similar to the Sonuus guitar MIDI thing then?? In that it can work as a monophonic device..

My other question which is somewhat off-topic; can the Sonuus device be used to connect a non-GK guitar to the GR55?? Can it also allow the non-GK guitar to at least use the guitar modelling along with monophonic synths??
Logged

Bill Ruppert

  • Senior Member
  • ****
  • Karma: 53
  • Offline Offline
  • Posts: 592
Re: Non-GK PCM triggering has arrived !!!
« Reply #15 on: October 01, 2011, 07:53:53 AM »

Thanks thats what I thought.
Could be an easy build in a mini bud box.


You will need to buffer the signal if running the guitar direct to pin 7, OK if using a stompbox in between, but the low impedance of the pin 7 input would suck the life out of your guitar tone with only the passive guitar pickups connected.
Logged

Elantric

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 238
  • Offline Offline
  • Posts: 13493
    • Elantric's Tips and Blog
Re: Non-GK PCM triggering has arrived !!!
« Reply #16 on: October 01, 2011, 08:16:13 AM »

Or simply insert any Boss pedal ( or any other Non True bypass pedal) between guitar and hombrew 1/4" Phone plug to DIN 13 plug cable.

leave the Boss Pedal in bypass and voila - instant buffer amp for your Hi-Z guitar.

Gastric

  • Senior Member
  • ****
  • Karma: 1
  • Offline Offline
  • Posts: 231
    • Effects sound samples and patches
Re: Non-GK PCM triggering has arrived !!!
« Reply #17 on: October 01, 2011, 09:39:14 AM »

It's also been reported by someone else that an active preamp in the instrument will work as a buffer as well.
Logged

Bill Ruppert

  • Senior Member
  • ****
  • Karma: 53
  • Offline Offline
  • Posts: 592
Re: Non-GK PCM triggering has arrived !!!
« Reply #18 on: October 01, 2011, 09:47:04 AM »

All good ideas!
I have a 13 pin connector here I will try it.
Logged

Elantric

  • Global Moderator
  • Senior Member
  • *****
  • Karma: 238
  • Offline Offline
  • Posts: 13493
    • Elantric's Tips and Blog
Re: Non-GK PCM triggering has arrived !!!
« Reply #19 on: October 01, 2011, 09:58:54 AM »

Correct

Same applies to guitars with EMG Actice pickups or MusicMan Basses.
No additional buffer necessary.

Bill Ruppert

  • Senior Member
  • ****
  • Karma: 53
  • Offline Offline
  • Posts: 592
Re: Non-GK PCM triggering has arrived !!!
« Reply #20 on: October 01, 2011, 06:44:58 PM »

Steve this is great info!!


If you build this DIN 13 "dongle" with the two resistors, that should allow your signal to pass.

Basically what this is does is set the "GK-VOL" setting to Max, anytime the dongle is inserted into the GK Input on any Roland 13 pin gear.(VG-99, VB-99, GR-55, GR-20, Axon, etc, )

Buy a Male 13 pin DIN plug

Use two resistors

One 120 ohm (indicated on Schematic as "121 ohm")   

One 240 ohm (indicated on Schematic as "243 ohm")   

These resistors create a voltage divider that feeds a fixed voltage to the "GK-VOL" Pin#8, which fools the GR-55 to believe a phantom  GK-Volume knob is set to "Maximum volume".


Wire as described below:

(Image removed from quote.)


Insert this plug in the GR-55's 13 pin input, and this should let you use the "FX Loop return" as a normal guitar input.

Although I do not feel this "DIN13 Dongle" plug is absolutely necessary, it might be handy, as it avoids the need to reprogram all your GR-55 patches.

Review the GK-2 schematics here:

http://www.vguitarforums.com/smf/index.php?topic=73.0
Logged
Pages: [1]   Go Up
 

Blog