Path: news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Chris Ahlstrom <OFeem1987@teleworm.us>
Newsgroups: comp.os.linux.advocacy,comp.os.linux.misc
Subject: USB MIDI device plug-in changes sound volume
Followup-To: comp.os.linux.misc
Date: Thu, 27 Mar 2025 09:21:20 -0400
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Been happening lately on my Debian Sid mini-PC. It has a USB-to-headphone
adapter [1] plugged in the back (USB 2), a USB 3 hub plugged into the front
via a USB-C to USB-B adapter, and another USB 3 hub plugged into that hub.
There are various USB-MIDI controller plugged in, plus a (currently unused)
USB audio codec from Behringer.

So I take one device (Korg nanoKey2) and plug it in. The volume drops.
I turn it up via alsamixer. But it would be nice to figure out what is
happening.

[1] This adapter is a Philips product bought at Target. In alsamixer,
it is called "iStore Audio". In pavucontrol, it's called "AB13X Headset Adapter
Analog Stereo". Via lsusb it's called "Walmart AB13X Headset Adapter".

-- 
It is now quite lawful for a Catholic woman to avoid pregnancy by a resort to
mathematics, though she is still forbidden to resort to physics and chemistry.
		-- H. L. Mencken