Apologies if this is a long dead and undoable topic but I gotta ask...

Has anyone ever attempted or is there a DIY project out there with the goal of modifying/reverse engineering the GR-55 so that custom PCM samples could be loaded and available to the patches banks.
One old disappointment I had when I initially was introduced to the GR-55 box was that aside from the huge number of possible combinations of mixing 2 PCM sources, running them through effect chains, amp sims and mixing with normal PU outputs etc. that Roland (in their dedicated device Marketing mindset I guess) locked out access to the PCM banks by burning everything into their custom ROMs.
I came originally from the keyboard synth world where as you all know I'm sure, most high-end key-synths can be loaded with your choice of samples from the wide world of sample libraries as well as ones you create yourself.

Now granted it's cool and amazing to pump guitar based midi out and trigger something like a Korg Kronos or Ableton with Plugin Packs but I want to open up my GR-55 to more customization within itself!

Jazzy Cheers,
-Mike

Quote from: mapperboy on February 04, 2014, 12:59:28 PM
One disappointment I had was that Roland locked out access to the PCM banks by burning everything into their custom ROMs.

The answer is in your question.

Quote from: mapperboy on February 04, 2014, 12:59:28 PM
Has anyone ever attempted or is there a DIY project out there with the goal of modifying/reverse engineering the GR-55 so that custom PCM samples could be loaded and available to the patches banks.

Quote from: mapperboy on February 04, 2014, 12:59:28 PM
I want to open up my GR-55 to more customization within itself!

To reverse engineer the GR-55 firmware would envolve a few dead/bricked GR-55's along the way.
An alternative might be to insert a small midi sampler or an iPod with patch based sampler software and camera-kit & midi adapter, internally connected to the GR-55 midi out port and L/R outputs.
There is a lot of room inside the GR-55 case to place something in there.

In the studio I feed GR55 MIDI Out to a 2008 Roland Juno-G which I upgraded to 8gb Ram for sampling.

To be blunt, the MIDI tracking/output of the GR-55 is its weakest link.  And the only thing you'd keep if you found a way to trigger a different set of samples... 

If you don't like the '55s PCM tones, I'd find a different way to approach this entirely, using a GR-30's midi output or an FTP. 

I actually like the '55s PCM tones.  I just didn't realize how much I liked them until I built an FTP rig... 

Shawn

Shawnb, in my use (and I know it greatly depends on the style of playing/plucking/picking one uses) I actually haven't found the tracking bad, close attention to separate fine tuning GK/Piezo PU setup screen for each guitar I plugin make a big difference.  You're right, I too like and even love a lot of the PCM samples, my quest is to expand out into uncharted territory sonically (is there such a thing here in 2014 after 50+ years of synthesis evolution ?). 
Specifically to your comment about an FTP, do you mean you haven't found sample sources you can triggering with the FTP which are as compelling/useful as those in the GR or ??

Gumtown, I know you're absolutely right about the probability of bricking a few GRs in attempting to develop an on-boards alternative PROM or RAM based PCM sample holder to substitute for the Roland ROMs.

I was trying to dream outside the MIDI conversion Output space because I believe the HRM (Harmonic Restructure Remodelling) chain uses or mixes into the PCM samples, does it not?

Quote from: mapperboy on February 05, 2014, 09:26:28 AM
my quest is to expand out into uncharted territory sonically (is there such a thing here in 2014 after 50+ years of synthesis evolution ?)

Yep, same here.  And yes, you do tend to see the same things over & over again in synthesis.  Some of the NI stuff, such as Reaktor, feels new. 

Quote from: mapperboy on February 05, 2014, 09:26:28 AM
Specifically to your comment about an FTP, do you mean you haven't found sample sources you can triggering with the FTP which are as compelling/useful as those in the GR or ??

I purchased a package & library (don't want to trash the vendor) and most voices are OK, but I do miss some of the tones & configurability of the '55.  In particular, I like the timbre of the pianos & saxophones; they're not as sterile as some of the other ROMplers out there.  I wish I could trigger the '55 PCM tones with my FTP! 

QuoteI wish I could trigger the '55 PCM tones with my FTP!

http://www.rolandus.com/products/mobile_studio_canvas/





If you like the GR55 PCM sounds , all are available in the Roland SD50 here, which could be triggered by FTP using a Kenton or IconnectMIDI USB  Host to 5pin  MIDI converter.or simply attach both FTP and SD50 to the same PC/Mac.

www.roland.com/products/en/SD-50/

You know, I've seriously considered the SD-50.   And the voices do seem to line up with the GR-55's...  Somewhat...   Tempting...   

But the SD-50 manual shows ZERO PCM configurability (only mute/solo, volume & pan!), unlike the GR-55's overabundance of PCM configurability.  How much of it would be actually reproducible?   

The SD-90 seems much closer to the GR-55 in terms of PCM and FX configurability.  It's like the SD-50 is a SD-90 with a stripped-down UI, while the SD-90 has about 90% of the GR-55's PCM options (missing, for example, nuance & LFOs).   

A lot of the liveliness of the '55, I think, is created by subtle usage of the LFOs/filters to add 'breathiness' to piano & sax.  It doesn't appear that either the SD-50 or SD-90 really offers that. 

To the OP. 

Making your own PCM samples really sucks.  It sounds cool to add your own on paper but sampling something and making it playable and musical at every register is a huge pain.  You will probably want to get a dedicated sampler or use a plugin that serves the same function.  The GR55, even if you could hack it somehow, doesn't have the tools necessary to edit PCM waves.  Even more it probably would only understand Roland's proprietery, ultra compressed encoding, so any third party eprom that you somehow crammed in there would probably be misread or garbled.  You'd get similar results by performing a VC hack on a child's Speak and Spell.

i have to admit, I'd love to see a way to do this too.  Given that it's probably not possible though, here's some food for thought.

Grab any basic subtractive VST/AU synth program that has 2 oscillators with 3 or 4 waveform choices each (saw, sin, sqr, perhaps white noise), a filter, amp and filter ADSR envelopes, an LFO, and maybe a delay/chorus effect.  Go through the presets and observe just how many different sounds and the massive tonal variety that can be created from just these basic building blocks.

The GR-55 has all of these basic building blocks, a comprehensive FX section, an additional LFO per PCM voice, a mod matrix of sorts (via assigns), and it's two oscillators have 900+ more base waveforms to pick from.  Plus an additional synth voice via COSM.

Even with all of the factory presets and the large library of patches that have been shared here, I guess what I'm saying is that I don't even think the surface has been scratched on the tonal possibilities built into the unit. 

Since you come from a keyboard background I'm not telling you anything you don't know, but it's easy to overlook possibilities that are there in front of you on a unit like this.  Even though I've done a fair amount of synth programming, I do get stuck in a certain mindset of "pick a PCM sound and that's what you get" with this unit.  I'd love to see more threads exploring what the GR-55 can do in terms of synthesis.

QuoteI'd love to see more threads exploring what the GR-55 can do in terms of synthesis.

Precisely the reason I posted these threads in the Tutorial section

"Analog Synthesis Primer"
https://www.vguitarforums.com/smf/index.php?topic=6418.0
* Making Sounds with Analog Electronics_MRuss.pdf
https://www.vguitarforums.com/smf/index.php?action=dlattach;topic=6418.0;attach=5507


http://www.soundonsound.com/sos/allsynthsecrets.htm

http://www.timespace.com/product/SOSS-100/3/9999916/rob_papen_the_secrets_of_subtractive_synthesis_(book_&_dvds).html


http://www.matrixsynth.com/2012/01/intro-to-synthesis-part-1-building.html



And midway down the GR-55 FAQ Thread is :

https://www.vguitarforums.com/smf/index.php?topic=4006.msg30460#msg30460

If you are clueless about all these GR-55 PCM Synth parameters and settings and how they inter-operate

Roland Glossary of Terms
http://www.rolandus.com/support/glossary_of_terms/

Looks like the Roland SD-90 Studio Canvas Owners Manual is a Must Read for GR-55 Owners interested in mastering the PCM Synth Engine.
http://lib.roland.co.jp/support/en/manuals/res/1811325/SD-90_e3.pdf


see this post and download the Analog Synthesis Primer by Martin Russ
https://www.vguitarforums.com/smf/index.php?topic=6418.msg44034#msg44034

and

Gordon Reid's SOS Synth Secrets series
http://www.soundonsound.com/sos/allsynthsecrets.htm

Gumtown's GR-55 Editor has a mode to reveal the sysex commands which control bulk of GR-55 parameters

My grateful thanks fly out to all who have responded with valuable comments, advice and pointers.

My first job will be going back to deep dive into the root of the GR and start again with a blank init patch slot.
I may be trying to stretch too much out of the GR alone with regards to long-tone time based ambient style variations.

Been recently hooked on the Soma Space Station channel...hadn't realized the extent of what's been happening since early 2000's especially in the Euro Electro-Hypno-Dance groove scene, so you can maybe see why I'm asking all this.  Definitely not your average cover band material quest...

Jazzy Cheers,
-mike