I've already read quite a bunch of all these threads before I asked here because I could not find an explanation how a static magnetic field created by the magnet in a relay influences AC signals running through the switches of said delay.
Hello
LTig,
I read your inquiry as "
I've already read quite a bunch of all these threads before I asked here because I could not find an explanation how a static magnetic field created by the magnet in a relay influences AC signals running through the switches of said relay."
Please understand that the followings are just my speculations as I am not an expert in these physics and theories ...
The
static magnetic field given by rather
strong permanent magnet or
strong electromagnet (with coils) existing very near to the audio signal wires would be not fully
static against the audio signal because of AC "electromagnetic induction" interaction, and may give audible negative effect,
i.e. blurriness and/or uncleanliness, to the audio signals.
It would be also possible that in these relays with
strong permanent magnet or
strong electromagnet consist of magnetizable metals (contact plates, screws, housing,
etc.), and such magnetic metals, together with the environmental strong static magnetic field may give audible negative effects to the audio signals.
About two years ago, I tentatively tested this type of (X-Y X-Z 4-terminal) snap (toggle) switch in my speaker level signal handling;
I could purchase
two different brand ones (
switch-A and
switch-B) of exactly same functionality,
i.e. X-Y X-Z 4-terminal, for AC/DC toggle switching, up to "15A 250V AC/0.5A 250V DC/0.9A 125V DC/15A 30V DC", consists of magnetizable metal plates and magnetizable screws (which I can catch with magnetized screwdriver). Both of the
switch-A and
switch-B gave considerable negative effect to the audio signal which not only myself but also my wife could hear the sound deteriorations, blurriness and uncleanliness, and we found such negative effect was apparently more obvious with
switch-A compared to
switch-B.
In any way, I abandoned to use this type of toggle switches with magnetizable metals in my audio project in handling of speaker level signals, and I went back to use all non-magnet metal terminal strips (barrier strips) and non-magnet screws as shared in
my specific post.
Then I contacted with the both manufacturers for the details of the specification and design of the switches, especially the use of tiny strong permanent magnet in it or not, and I fould very interestingly that
switch-A (expensive one) contains small strong Neodymium magnet in it (for the purpose of maximum escape of the possible electric arc discharge in case of high voltage operations), on the other hand,
switch-B (cheaper one) has no such magnet in it.
Furthermore, even for
the simple screw terminal strips (screw barrier strips), the cheap magnetizable ones always give audible negative effect to the audio signal, while non-magnet audio grade strips (comparably rather expensive though) with non-magnet plate and non-magnet screws give no negative effect at all.
Please understand that the above findings are my empirical experiences, and I have no capabilities in giving physical and/or theoretical explanations or evidences for that.
