New 13 pin version of the GR300

Started by chrish, September 27, 2017, 03:51:34 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

chrish

#25
Quote from: GuitarBuilder on February 17, 2019, 07:52:06 PM
Jim - AFAIK the "+" versions of Sonicsmith use the ACO100 chip.  The ACO160 chip is coming later this year.  Mind you, these boxes are not bad if you can get them at a good discount, just to experiment with.

The 6APPEAL is quite good at what it does; it is essentially a poly distortion unit with VCFs and VCAs.  You can buy them at Perfect Circuit:

https://www.perfectcircuit.com/spicetone-6appeal-hexaphonic-guitar-effect-pedal.html

I'm building a Eurorack analog hex guitar processor; the more I look at it, the less I want it to be a synth - unless the ACO160 really works.  I already have great synths (Gr-55, GR-99, GP-10, SY-300) and I don't think I could build anything better.  I've been at this since 1970 and keep finding the weak link to be the pitch detection (and having to use MIDI).  It just isn't all that good.  If that fails, it doesn't matter how many VCOs, VCFs, VCAs, etc. you put in the path.  I don't want to have to restrict my playing style to sound acceptable.  Using control voltages instead of MIDI opens up more possibilities (my first guitar synth was 100% CV-controlled), but the pitch detection is still critical.  We'll have to see what Sonicsmith comes up with.
agree,imo gutar pitch to MIDI systems fail in requards to touch and feel and of course tracking errors.


I just ordered a Sonicsmith converter Plus on the 10% off Valentine's Day sale at perfect circuit.

However it's going back to the store if it doesn't perform pitch to cv as claimed.

I would really like to support the development of these small companies efforts, but they do have to produce a worthy product.

It seems the first one they released was a beta test for all those who purchased it, however the company will modify it to current standards so nice to see they stand behind their products.




GuitarBuilder

I think they'll come through in the near future!
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

jim-analog



Greetings,

Thank you both for the replies! That was my concern reading about the (pre +) version; that it was essentially a customer supported Beta test program. I too really want to support the small firms that are at the forefront of tech, but don't have the funds to be a venture capitalist.

Chrish, please advise on your experience with the unit you ordered, I'm very interested.

Guitar Builder, I too have been at this a while (started with the Roland SPV-355) and also feel MIDI is not the way. Direct (Hex) Pitch to CV + Intelligent/Adaptive Gate seems to me to have the best chance to maintain the guitar play-ability/identity, while providing more extensive synthetic tones, etc..

If it's not proprietary/confidential, what front end conversion hardware do you intend to use to drive your EuroRack? That's pretty much what I've been wanting to build (though more likely in "MU"), but am stuck at the front of course.
Have you experimented with the 100/+ chip at all, and/or are you awaiting the new 160 to work with?

Thanks much everyone for keeping this conversation going. Looking forward to reviews and thoughts!

Regards, Jim

chrish

Quote from: jim-analog on February 21, 2019, 11:42:38 AM

Greetings,

Thank you both for the replies! That was my concern reading about the (pre +) version; that it was essentially a customer supported Beta test program. I too really want to support the small firms that are at the forefront of tech, but don't have the funds to be a venture capitalist.

Chrish, please advise on your experience with the unit you ordered, I'm very interested.


it might be awhile before I get my hands one one.


Quote from Perfect Circuit


"Unfortunately, we've been unable to get an accurate eta from the manufacturer as they sometimes have had supply chain issues leading to unforeseen delays and eta's being pushed back which means people, getting upset. For that reason, we don't give out eta's until we have verifiable tracking info which we don't have yet.  ON top of that we have a ton of preorders for them which will be fulfilled first so it's hard to estimate when they'll be up. "

expelec

The poll in this thread is interesting but should probably include price ranges rather than just 'Yes'.  Figuring out a realistic price point people are willing to pay is a huge determining factor in whether or not this is feasible.  I don't think just doing a GR-300 clone for 13 pin makes sense, it would have to include some new features while keeping the core GR-300 tracking and VCO methods.  In no particular order of importance:

1. Program memory.  Especially since the only controls on the 13 pin interface are patch changes.
2. Expanded VCO Waveform options
3. Filter per string and possibly more filter modes.  Separate filters would help with "multitimbral" patches.
4. A solution to LFO modulation since there's no control for it via 13 pin.  Maybe momentary footswitch with rise time.
5. Maybe some expanded options to affect envelope shape.  I think sticking with the natural guitar envelope even if modified in some ways
    helps avoid the misfires inherent when you try to determine note triggers and use synth style envelopes.
6. Auto tune routine would be nice. 

Regarding #2, #3 I've done some experiments in that field.  Videos are on YouTube if you search "Expedition Electronics".  I think the wave mod video has been posted here before.

GuitarBuilder

Quote from: jim-analog on February 21, 2019, 11:42:38 AM
Guitar Builder, I too have been at this a while (started with the Roland SPV-355) and also feel MIDI is not the way. Direct (Hex) Pitch to CV + Intelligent/Adaptive Gate seems to me to have the best chance to maintain the guitar play-ability/identity, while providing more extensive synthetic tones, etc..

If it's not proprietary/confidential, what front end conversion hardware do you intend to use to drive your EuroRack? That's pretty much what I've been wanting to build (though more likely in "MU"), but am stuck at the front of course.
Have you experimented with the 100/+ chip at all, and/or are you awaiting the new 160 to work with?

Jim - I am indeed waiting for the ACO160 to be available for my front end conversion.
"There's no-one left alive, it must be a draw"  Peter Gabriel 1973

chrish

#31
Quote from: expelec on March 01, 2019, 01:28:30 PM
The poll in this thread is interesting but should probably include price ranges rather than just 'Yes'.  Figuring out a realistic price point people are willing to pay is a huge determining factor in whether or not this is feasible.  I don't think just doing a GR-300 clone for 13 pin makes sense, it would have to include some new features while keeping the core GR-300 tracking and VCO methods.  In no particular order of importance:

1. Program memory.  Especially since the only controls on the 13 pin interface are patch changes.
2. Expanded VCO Waveform options
3. Filter per string and possibly more filter modes.  Separate filters would help with "multitimbral" patches.
4. A solution to LFO modulation since there's no control for it via 13 pin.  Maybe momentary footswitch with rise time.
5. Maybe some expanded options to affect envelope shape.  I think sticking with the natural guitar envelope even if modified in some ways
    helps avoid the misfires inherent when you try to determine note triggers and use synth style envelopes.
6. Auto tune routine would be nice. 

Regarding #2, #3 I've done some experiments in that field.  Videos are on YouTube if you search "Expedition Electronics".  I think the wave mod video has been posted here before.
welcome to the forum.

Many of us here are familiar with your work and your YouTube video interfacing with the GR300.

You make some good points. Price is definitely a consideration with any type of these gear products.

The GK switches could handle some control functions just as the knobs do on the gk1 pickup when it controls the original GR300.

Not as good as the actual G series guitar controllers themselves however.


That new gr300  would of course include other waveform types such that you've been working on.


jim-analog


Greetings,

GuitarBuilder, what are the differences you are aware of between the current ACO100 chip and the 160? Is there any data available on this?

Fellow user here Chirish just posted his initial impressions of the Converter+ in another forum section:

https://www.vguitarforums.com/smf/index.php?topic=21122.0

Perhaps he can update it here. He seems happy with it far as I could tell. SO, I'm really debating on attempting an order now, waiting on a sale or waiting for the next iteration of the chip.

The two devices I'm most interested in (this and the 6appeal) are both a bit hard to get at the moment. Figure whomever has product available first will get my biz, *unless* there are known major advantages to the 160 chip (which I'd imagine they will want to get rid of the old inventory prior to shipping the new version).

BTW, I do realize you're waiting on the new chip in part due to a larger project you have in mind (of which I have a similar ideas on). Thanks much for any info!

Regards, Jim



Quote from: GuitarBuilder on March 01, 2019, 04:05:03 PM
Jim - I am indeed waiting for the ACO160 to be available for my front end conversion.

georgef

rebuild the gr300 ??....that"s exactly what i did all in old school DIY {painful way}  and it"s not cheap .even more upgrading the roland circuit:   


I "d say that Elantic stated the obvious {as always he"s right on spot}  saying that a 200$ per string is normal. if one likes the analog mojo even more.
That"s my very first post here .
Very interesting site and people like  Elantic- Guitar Builder_Jimanalog.
I'll follow closer from now on time permitted .I might  also comment about ACO chip as I own the first version Convertor+ Interesting ic   .Kudos to all of you people  .Be well ^:}
old school DIY er Qualified by experience

georgef

Quote from: jim-analog on February 09, 2019, 06:07:58 PM
Greetings,

Chrish, kind thanks for the welcome! Seems I've found some like minded colleagues here.

Yes, I've read all of Mark Smarts infos,  probably 80% of Dr Joness and just about anything else I could get a search result for. Mark was really ahead of his time going for it in regards to a fully polyphonic version! I think that in between when he was doing that work and today, there have been pretty large advances in both analog processing and digital control, that may make some of his ideas (and others) more viable (certainly for the experimenter, perhaps for a small commercial concern).

All of this is completely off the top of my head..... So please treat errors as learning points and perhaps a bit too much enthusiasm vs too little reality! I've done a little bit of looking into some actual circuits and ideas on overall architecture, but am not close to reality on anything at this point! So, let's consider it a "thought experiment".

Where do we start and what do we already have to base our dream machine on?

What Roland really got right was the filtering and subsequent analog signal processing to allow for eventual voltage control for tracking pitch and gate signal for starting envelopes, etc.. I believe using that as a template, an improved, less complex circuit could be built today that would allow for the "standard" 1V/Oct and a "smart" gate pulse.  Once we had that front end, the synth possibilities would be essentially limitless (with size and cost being the only real issues) and the following signal path as true to 100% analog as you wanted (or didn't) it to be.

  The lack of CV standardization was IMO the biggest flaw of the 300. The I/O to support it could have stayed on the inside on a connector "for future expansion" as the device was already pretty cutting edge at that time in the marketplace. I'd have to look up the various product dates to see if they had already released the 100, 100M or 700 series modular synths and therefore would have know the importance of the standard. Or maybe the gtr product engineers didn't talk to the keyboard product engineers?

I heard a great comment in a recent documentary about the resurgence of the analog modular synth ("I Dream of Wires"). One of the new manufactures mentioned that he started his business by making a chart of all the things that Bob Moog did NOT have back in the 1960s (electronic parts that were smaller, better and cheaper; mechanical CAD programs; circuit simulation software; fast processing, cheap memory, etc.).This showed him how much of an advantage there was now (hindsight also being good to have) to building an analog modular from scratch (while of course standing on the shoulders of the previous generation).

  It would take a small team of various expertise (analog electronics, power supply distribution, synthesis techniques, digital control circuitry, memory and AD:DA, mixed mode signal integration, various levels of programming, PCB layout, mechanical/packing, etc.). It wouldn't result in a US$200 device, but perhaps could be somewhere under US$2000 (off the top of my head and depending on many dozens of things not yet considered).

  I have some ideas in sketches of a "back plane" that supported insert-able cards and also all the internal and external connections to the front panel controls, rear panel I/O, etc.. This back plain would contain all the routing and back and forth data/signal/control lines, while the cards could be either "per string" multi function or dedicated function. This could allow future upgrade or options as new voicing functions were developed, a short loaded 4 channel unit for bass, etc., whatever else may be though up. Think about a small EuroRack analog synth or perhaps an "API 500 module" standard recording gear rack. Then add a well thought out foot controller. All the knobs, switches, inputs, outputs and power supply would be at the rack. I never liked the idea of having to kneel down to make a fine adjustment to any parameter while having a guitar hanging off my neck!

In a current integrated floor unit if we look at the "6appeal" for example, (I don't have one, just going from the web page) it's pretty much a hex processing/routing unit with 6 digitally controlled analog dirt boxes, some filtering and a bunch of modulation capabilities (I'm not minimizing how clever it is or how great it may be, just simplifying for discussion). So, I think it may be really close to being a lot more. Well,  that being dependent on the internal architecture, layout, etc. and many things I have no idea on how they were implemented.

Well some stuff to think about. At some point I'm going to take apart another 300, a 33B, a 700 and a bunch of modules and see what I come up with. I got on the list for a "6appeal" (if anyone has a used unit for sale, please let me know) and I'll see what happens with that (don't want to break it the first week). I know there are hundreds of really sharp hardware, code, s/w and PCB guys and gals out there; just a matter of finding each other and having some common goals...........Best to everyone!

Regards, Jim
Very well said .Sir . excellent post
old school DIY er Qualified by experience

chrish

Welcome to the forum goergef. Curious on what filter chip you used in your project. I had heard that someone was working on reverse engineering the Roland chip but don't know if that made it into production.

I ask because I own two GR300's and spare parts of out of production chips are a concern.

Good work on your project.


georgef

Thanks for your welcome chrish.
I did NOT use the Roland IR chip in my gr300 clone filter neither reverse engineered any IC.
All i used was  matched transistor pairs and
the famous {long out of production} CA3280 RCA dual Ota ic
for the 24db  VCF which can changed to a moog type ladder filter.
Was all done on perfboard and honestly there"s many modifications
i"m still going on time permitted .
I "m very new to your forum and i will also follow your posts from now
on as i happen to own a converted+ pedal you post about sometime
which is a very interesting one Ic solution alas an expensive option
if one wants to go hexaphonic .
I'm mostly interested in DIY stuff and people
who still "care" about the "mojo" of vintage analog made synths .few left i guess

Be well ^:}
Since you own a real gr-300  i "d like to ask about a certain resistor value that never worked for me on the Roland service manual schematic.
I had to change it to make the VCOs tuning work .
If you ever have your gr300  open to access let me know .I"m sending a photo of the resistor
i am interested in ... just in case yuo could help .Be well
old school DIY er Qualified by experience

admin

#37
 Fwiw

CA3280 vca
https://www.ebay.com/itm/203657303792?chn=ps&mkevt=1&mkcid=28

There were three pcb versions of GR-300


Explained here
https://www.joness.com/gr300/GR-300.htm

QuoteThere are three versions of the Roland GR-300. These are distinguished by the letters "A", "B" or "C" appended to the part number printed on the top voice board. The only way to know which version you have is to remove the bottom panel, and look at the printing in the lower right-hand corner of the voice board. You will see either 052-539A, 52-539B, or 52-539C.

Of the three versions, "C" is the most common, and the most desirable. Electronically and functionally, these GR-300s are the same. However, version "C" is the version referred to in the well-documented Roland GR-300 service manual. Version "A" is notable for the fact that many components are found tack soldered onto the circuit board. Apparently when the circuit board was produced, some components were left off the circuit board, and so capacitors, transistors, etc. were soldered to existing components to complete the circuit. Also, there is a small network of resistors added to the power supply, not documented in the service manual, and not included in the more common version "B" and "C". The final curiosity are the two, 12 pin ribbon connectors. In all other Roland products, the two 12-pin connectors are positioned parallel, side-by-side. This configuration is in line with the way the ribbon connects to the 24-pin cable connectors. However, on the version "A" synth, the two 12-pin connectors are in series, which makes it more difficult to connect the ribbon to them. There is a companion Roland G-303 guitar, version "A" as well. Like the version "A" GR-300, the version "A" G-303/808 electronics have the ribbon connector position in line. And the circuit board layout for the version "A" guitar is similarly different from the published documentation in the service manual.

One final note: when I first found the Anderton GR-300 modifications, which inspired me to create this website, I was unable to follow Craig's directions on locating the parts on the GR-300 circuit board. It was not until many years later, when I saw my first revision "A" board, that I realized that Craig's plans were referencing the earlier, rare version "A" board, and not the version "C" board in my possession.

Foot switches: there are two versions of foot switches found on the GR-300. The most common foot switch is the larger, chunky rubber foot switch. This is the same part used on the Roland GR-100, GR-33B and US-2. Some GR-300s have a lower profile foot switch made of harder rubber. I have not been able to make a clear correlation between production date, and the use of these different foot switches, though it appears more common to find the lower profile switch in the later, revision "C" GR-300s. I will note that the actual switch mechanism used in these foot switches underneath the rubber cover is the same in both designs, and it is the same switch used in the Roland GR-700.

georgef

#38
Thank you admin for your kind response .Great site
I 'm lucky enough to still own a dozen original CA3280 tested good.
I would shy away from ebay in fear of fakes or non working vintage
Ic especially when appear 'cheap".
Had issues with fake/cheap AD633 once.
As for the link about the  versions of GR-300 i"d say the resistor i was curious about
might appear as a different reference {i.e R75} but should be in the same place on every board .
I don"t own a Gr300 so i well might be mistaken but it should be IMHO   the one on the photo
i took from Mr Joness site >
Very polite of you to comment and help
be well
old school DIY er Qualified by experience

admin

Quote from: georgef on February 05, 2022, 10:45:50 AM
Thank you admin for your kind response .Great site
I 'm lucky enough to still own a dozen original CA328 tested good.
I would shy away from ebay in fear of fakes or non working vintage
Ic especially when appear 'cheap".
Had issues with fake/cheap AD633 once.
As for the link about the  versions of GR-300 i"d say the resistor i was curious about
might appear as a different reference {i.e R75} but should be in the same place on every board .
I don"t own a Gr300 so i well might be mistaken but it should be IMHO   the one on the photo
i took from Mr Joness site >
Very polite of you to comment and help
be well

There are a few here with GR-300's -hopefully you will get the info you seek soon

chrish

Here is Roland IR3109 clone now in production.

https://syntaur.com/Items.php?Item=4243

"Analogue Renaissance AR3109 voltage-controlled filter chip, for Roland synthesizers. The original Roland IR3109 chip appears in the top photo; these chips have been long out of production, and we now have brand new clone chips just released by Analogue Renaissance (lower photo). These clones sound identical to the originals.

Installation of this part requires soldering.

This item is NEW.

This item is non-returnable.

Out of stock.
Add your email to get notified when this item is back in stock.
email address
Email address

$59.95"

chrish

#41
R74

georgef

#42
Yes yes !! green blue black brown 5K6 Ohm/1%  not 56K as stated.
I knew it was should be a typo somehow .Thank you very much chrish !!Great !!
George
old school DIY er Qualified by experience