DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Requested forum for discussing ARM Hardware other than the PI/PI2

Moderators: khz, MattKingUSA

Broomy
Establlshed Member
Posts: 158
Joined: Sun Apr 28, 2013 5:36 am

DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby Broomy » Wed Sep 21, 2016 7:53 am

I've always loved the idea of making a DIY effect processor.
Currently I'm making a fully analog one (which is kind of offtopic in this place..;-) ) and a digital one (now we're talking...).

I've bought a Orange Pi PC Plus (OPi) for under 20 euro's, installed Armbian on it and build Guitarix from source.
After adding myself to the audio group, tweaking the audio priorities and killing Pulseaudio, I'm able to get a <10ms latency with my usb soundcard.
Although there is some streamlining to be done, the concept works.

Final goal is to install a small touchscreen on top of the OPi and replace the bulky usb soundcard by a small diy soundcard, with the whole shebang mounted in a stombox.
I've found the following breakout board for the TLV320AIC audio codec chip . Although soldering digital IC's is new for me, I worry the most about getting the codec to talk with my PI, but we'll cross that bridge when we get there.

I would love to get some advice to further fine tune the setup (what processes can be shut down?).

Hans

p.s. for further reading: I've got some assistance so far over at the Guitarix and Armbian forum.
The Quintar Project:
- Popularizing an all fifths tuning for guitarlike instruments
- Youtube: Playing and Building
- Files: Sourceforge

User avatar
falkTX
Establlshed Member
Posts: 6586
Joined: Sat Jan 09, 2010 3:04 pm

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby falkTX » Wed Sep 21, 2016 8:30 am

That history seems exactly like the MOD one.
You know.. linux embed system, integrated display and hw knobs, running LV2 plugins etc...

I recommend using a custom build service for linux embed systems, like buildroot.
That way you only install the exact packages/software you need, and also everything is optimized for your specific CPU.
It will take a while to build from scratch, but it's worth it.

Broomy
Establlshed Member
Posts: 158
Joined: Sun Apr 28, 2013 5:36 am

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby Broomy » Wed Sep 21, 2016 8:52 am

falkTX wrote:That history seems exactly like the MOD one.
You know.. linux embed system, integrated display and hw knobs, running LV2 plugins etc...

I recommend using a custom build service for linux embed systems, like buildroot.
That way you only install the exact packages/software you need, and also everything is optimized for your specific CPU.
It will take a while to build from scratch, but it's worth it.


Yes it certainly has a some resemblance, my goal is different, though: I would love to make it polyphonic using my strings as a pickup or make a single loop pickup , Ideally the device should have a balanced microphone input (besides a regular jack).

I have to study up on making a custom build service, because at the moment it is out of the scope of my knowledge. I'll read up on Buildroot, I see that there is a good online manual.

Can you give information on what audio codec you use for the mod or is that confidential at the moment?
The Quintar Project:
- Popularizing an all fifths tuning for guitarlike instruments
- Youtube: Playing and Building
- Files: Sourceforge

User avatar
falkTX
Establlshed Member
Posts: 6586
Joined: Sat Jan 09, 2010 3:04 pm

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby falkTX » Wed Sep 21, 2016 11:01 am

The Duo codec is CS4245.
See the full details here http://wiki.moddevices.com/wiki/MOD_Duo#Technical_specs

Broomy
Establlshed Member
Posts: 158
Joined: Sun Apr 28, 2013 5:36 am

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby Broomy » Thu Sep 22, 2016 3:59 pm

Thanks, that's pretty impressive stuff.
It is great to see on what level an all open source project can operate. The Mod Duo is top notch!

I may order a few CS4245 and try me luck with them.

Hans
The Quintar Project:
- Popularizing an all fifths tuning for guitarlike instruments
- Youtube: Playing and Building
- Files: Sourceforge

User avatar
tramp
Establlshed Member
Posts: 1153
Joined: Mon Jul 01, 2013 8:13 am

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby tramp » Wed Sep 28, 2016 4:48 pm

Broomy wrote: installed Armbian on it and build Guitarix from source.


I've pushed now a striped down version of guitarix to our repository, it include just guitarix main, no ladspa/lv2 plugins.
It use vectorized floats instead doubles, to match best the ARMv7 fpu and cache. Oversampling is disabled.
Anything is pre-configured in the wscript. To build it optimized for ARMv7 just run

Code: Select all

./waf configure --prefix=/usr -j2

optimisation flags will be added by the script.
and

Code: Select all

./waf build


get it here:
https://sourceforge.net/projects/guitar ... z/download

Frank Carvalho
Establlshed Member
Posts: 356
Joined: Sat Nov 17, 2012 3:36 pm

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby Frank Carvalho » Thu Sep 29, 2016 11:31 am

Would this not be the preferred version to use on a Raspberry Pi?
Currently I use the version in the AutoStatic repo. Is AutoStatic still maintaining this repo?

/Frank
Vox, Selmer, Yamaha and Leslie amplifiers. Rickenbacker, Epiphone, Ibanez, Washburn, Segovia, Yamaha and Fender guitars. Hammond, Moog, Roland, Korg, Yamaha, Crumar, Ensoniq and Mellotron keyboards. Xubuntu+KXStudio recording setup.

User avatar
tramp
Establlshed Member
Posts: 1153
Joined: Mon Jul 01, 2013 8:13 am

Re: DIY Guitar Effect Processor using Orange Pi PC plus, Armbian and Guitarix

Postby tramp » Sat Oct 01, 2016 4:14 am

Frank Carvalho wrote:Would this not be the preferred version to use on a Raspberry Pi?

It is supposed to be "the version", but it is still work in progress. It seems that vectorisation leads to a build fail on ARMv7 so I've pushed a version without,
https://sourceforge.net/projects/guitar ... z/download


Return to “Other ARM Hardware / Software”

Who is online

Users browsing this forum: No registered users and 1 guest