gxAmplifier GUI

I downloaded ardour-4.2 from ardour.org and I installed on my Debian testing. Unfortunatelly it seems that some guitarx plugin interface does not work (ex. gxAmplifier-x) and I cannot see the classical GUI of this plugin but just a minimal interface with some buttons “add, delete, bypass” but no controls.

Does anybody know how can I solve the problem?

Thanks in advance!

I am not certain, but I think you have to open Guitarix as a stand alone app and patch it into Ardour via Jack to see the entire, classic GUI. If used as a plugin, I think only the amp head section appears in plugin window. There should be more controls than what you are describing, though, like Gain, Bass, Mid, etc. Are you not seeing the GUI for the amp head?

When you say you installed it, do you mean you downloaded the precompiled binary, or that you built it yourself from source?



This sounds like the dreaded fallout of gcc-5 to me… Debian Testing has been turned upside down with it in the last few weeks…

Ahh yes, lots of commits I have seen happening recently as a result of GCC5 in the codebase, but I couldn’t begin to tell you what the end effect is for an end user.


thanks for your help!
Yes, I downloaded the precompiled binary from ardour.org. All started when I upgraded my Debian testing and Ardour4 disappear, then I downloaded the binary. So, the workaround could be recompile Ardour from source?
Thanks again!

I had the same problem and I solved it by installing kxstudio. You could have some issues with duplication of packets, but once you fix them (I had to reconfigure jackd through limits.d), everything goes perfectly. There are repositories for Debian, so you do not need to install a new operating system, just adding repositories.


There are gcc5 versions of Ardour available from http://nightly.ardour.org/list.php

But note that this only matters for cases where the plugin uses C++11 (or depends on libs that use C++11) with a host that is compiled with gcc4 (or uses libs that are gcc4/c++11). Vice versa also applies (gcc5 host, gcc4 plugins).

In the case of Ardour, the conflict arrises with glibmm (used by gtkmm et al) and affected plugins are: abgate, ams-lv2, amsynth, beatslash, deteriorate, eq10q, ingen, midimsg, newtonator, triceratops, vocproc.

While standalone Guitarix uses gtkmm, the guitarix LV2 plugins do not. Guitarix GUI not showing up is not a gcc ABI issue. It must be something else. Is there anything in the log window? or stdout/stderr output in the console?

The vast majority of plugins are plain C (no C++) and even if they use C++ they depend only on libstd++ (which is dual ABI on most systems) and hence things are not as bad as it seems. Latest count (by falktx, KXStudio): less than a dozen plugins are affected (see prev message).

Ups, guitarix LV2 plugins use gtkmm as well.
They hand over a pointer to a GTK widget to the host, indeed, but internal they all use gtkmm widgets (libgxwmm).
And all of them are written in C++, many of them use glib directly, at least the gxamplifier does.
I guess it’s a gtk-version mismatch here (a known issue with binary’s provided outside a distribution), in case of the GxAmplifier-X plugs, as if it will be a GCC5 issue, a crash is expected, isn’t it?

GTK and gtkmm have been ABI stable for a significant period of time. This is unlikely to be an issue. The gcc5 ABI issue does not necessarily lead to a crash and is more likely to just lead to a failure to load the GUI object associated with a plugin. Note that glib (not glibmm) is also unaffected by the gcc5 ABI issue.

@Brummer: is this a recent change? We (falktx and I) did check with ldd ${LV2PATH}/*/*.so | grep gtkmm and guitarix didn’t come up.

@Max-B (or anyone who can reproduce this): Could you check Ardour’s Window > Log there should be a message “cannot load gx_amp_gui.so” (or similar) and in the terminal there’ll be should be something like

Unable to open UI library /usr/lib/lv2/…_gui.so (undefined symbol: _ZN4Glib7ustringC1ERKNSt7__cxx11…)

@x42 No, the guitarix LV2 GUI’s use gtkmm from the beginning on, have a look at the widget.h file in any gxLv2plug.
GxAmplifier-X use glibmm in the plugin, not glib.