Pickup comparison on a 12 string via audio injector. .

I’ve just revisited zynthian-alm ( an audio injector in a raised Aluminium case with 4 i/o connected encoders.

I’ve also been knocking holes in my 12 string and added a humbucker coil, so I now get the choice, Humbucker or piezo + pre-amp, and with a suitable stereo lead these can go straight into the synth. All very compact.

So I have two quite different inputs rather than provide an amplifier could a stereo input ‘pan’ solve this rather nicely in one control main control and a separate overall gain ?

Channel one (L) (Peizo + preamp from guitar) High level
Channel two ® passive humbucker Low(ish) level . . .

It’s a WAV cos it’s more measurement than pleasure …

image

Here’s the ogg . . . for comparison. . .

Here’s the mp3 for comparison again, . . .

Goodness I make you suffer ! but this looks interesting… :smiley:

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So lets pick up the bits and pieces . . .

A Putty connection to the relevant machine . . .

For those, that words like git have little meaning, Wikipedia says
Git is a distributed version-control system for tracking changes in source code during software development. . .

It accesses where teams & oneself keep stuff when developing code. It’s also where one can easily grab the project at various points in it’s history, which is very helpful. I’ve known people who keep audio collections under git. It does its job very well but it has a certain surrounding mythology for the infrequent user.

One needs a suite of programmes loaded on your machine to access the git repository and these are run by either the command line using the word git . . with a command and parameters, or a GUI, perhaps for instance, built into an Interactive Development Environment (An iDE).

so
the line described in the page pointed to by the weblink in the definition of the lv2 plugin . . . .

so
git clone git://github.com/x42/xfade.lv2.git

will copy the recognised structure defined at this site . . .
which is:- I’ve opened the clone dialog to show how this can be picked up from the site itiself… at github which surprise, surprise is a place for git repositories to hang out.

We can now use the cd command to move into the directory that the git clone command has magically created for us.

and we can see that the files structure from the repo has been ‘cloned’ to our directory in root.

So onwards . . . .

the next instruction on the readme page is . . .

make

so what’s going on here. . . ?

Wikipedia :- Make is a build automation tool that automatically builds executable programs and libraries from source code by reading files called Makefiles which specify how to derive the target program.

so what is this doing? Well the cloned repo contains a description of the code . . .

xfade.c

Which actually does the work . . .

But this programme needs to be connected or linked to the machine it will run on and this is where make comes in. it makes sure that the details are all up to date and choose the versions of code libraries on the machine that will be used.

there is a file with various possible names Makefile in this case: https://github.com/x42/xfade.lv2/blob/master/Makefile for those that like the gore . . .

so after make . . . .

we can see some response and notice it’s now built a directory called build

which contains two text files and an .so file

image

the so file :face_with_monocle:
An .so file is a compiled library file. It stands for “Shared Object” and is analogous to a Windows DLL.

So we have descriptions of the lv2 setup and a programming plug & socket ( .so file) to allow the programme to connect to the bits and pieces it needs. . .

sudo make install PREFIX=/usr

well sudo is the magic invocation that allows you to take on poweruser status to modify files in the structure that would normally be blocked from you. Now in the zynthian we run with root power all the time, so we can do this anyway but the sudo does no harm . . .
so we are running the next command as superuser, and the next command is

sudo make install PREFIX=/usr

so we are running make again but with the install command which is actually defined in the Makefile, and a specific setting of a parameter called prefix with a specific value

image . . .

and just checking we can see the file that the make install has created.

image

notice these are owned by root, which is why the sudo would have been needed.

so from the

we get @Baggypants

  • ssh on to the zynth,
  • git clone the repo.
  • install any dependencies
  • Run make, to compile the LV2,
  • copy the <somename>.lv2 directory into /zynthian/zynthian-my-plugins/lv2/ .
  • reboot
  • enable the plugin in the webconf

and checking it seems to be there . . . :smiley: ( I’m not sure how but hey …!)
image

and there it is in the lv2 menu in webconf . . .

So we choose a new effect . . .

and there we have our new effect Stereo DJ X-Fade . . .

with the parameters . . .

sadly the encoder for A A+B B only selects those values not a gradual fade… . . .
But this is probably because I now realise it’s a stereo input device so has 4 inputs that ar being mapped to 2 so that might well explain it…

:smiley:

Thank you for this excelent tutorial. I’ve always struggled with the build process and this has shed light on areas I didn’t quite understand. :smiley:

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