Amseco BZ-50P, got any information on it?


I’m sort of in a pickle there, let me explain:

So I’ve spotted a Amseco BZ-50P on eBay recently, (it was very cheap by the way, well that’s moot because, since I live overseas, well, do I need to explain? Shipping costs…) and subsequently smashed that “Buy it now” button, b’cause well, the BZ-50P was a horn that was on my bucket list of “devices to find absolutely” (I can’t help but love to pieces the design of the grille on this thing).

Now, I’m asking for a few things:

  1. How does it fares (in terms of sound output in dB) compared to say, a Simplex 4050 or 4051? (not sure about 4040s and 4041s* but we can exclude the 4030 already :mrgreen:)

  2. are those considered rare or just uncommon (there is very little information about these, and the only video about these is… Well quite old, so once I get mine (coming from Tucson, AZ) I’ll be sure to make a video), on a scale of 1-10, how rare would you consider it to be?

  3. Since mine came without a backbox, how can I mount this thing? (is there is any other way, or could I find a compatible backbox?)

  4. is there is any harm that I power it from [filtered] 12V instead of 24V (my only 24V PSU burned out, and looking at the pictures, the BZ-50P I bought takes 24V)?


    Alexis, future owner of a BZ-50P.

Here are the seller’s pictures (EDIT: Restored missing pictures as of 02/24/2021):



Welp, it came home just today, straight outta Tucson, AZ, it’s in pristine condition, almost as if it was never used.

Two things I noticed:

  • it’s quite heavy (nearly 1kG on a scale) I surely didn’t expect it to be this large or heavy
  • there is no screw to change the pitch of the horn (well that’s not a problem for me, I wouldn’t risk touching such a screw, better not screw (no pun intended) something up already)

Pictures and a video will follow…

Regarding 3) and 4), you can mount it to any 4 square electrical box, I wouldn’t recommend running it on 12V since it likely won’t work, or if it does it’s going to sound horrible.

Thank you for your answer and well, about running it on 12V, I just did that, it didn’t sound that terrible… Just weaker (half than it would sound off) than it should be, hopefully I’ll be able to track down a 24V transformer.


Nonetheless, I’m stoked at how loud it is @ 12V

I certainly don’t think it sounds that bad. Almost like a 9806.

Indeed, I didn’t expect to sound like that however :smiley: and what’s more is that when I unplugged the transformer, it kept blaring for a few seconds :mrgreen:

Still it was very loud in person, even at half the voltage (my 24V transformer bit the dust âgés ago) it still packed a punch, that’s for sure!

Not sure if this information is something anyone would need, but the Amseco BZ-50P also seems to be just a rebranded Cerberus Pyrotronics HDC-24C. Though seeing it as that brand seems to be rare since the only other video on YouTube of this horn is also one that is an Amseco BZ-50P.

Oh that one?

<LINK_TEXT text=“The Schumin Web » Fire Alarms … m-hdc-24c/”>The Schumin Web » Pyr-A-Larm HDC-24C</LINK_TEXT> that’s… Very odd.

Very nice find! That horn is also at the very top of my list of wanted alarms. I’d love to get my hands on a Pyrotronics-branded version, but they seem to be incredibly hard to find.

I believe Amseco was the original manufacturer of these horns. In Canada, Pyrotronics also rebranded other Amseco devices, including the BZ-51 horn (which appears to be the successor to the BZ-50) and, later, the BZ-54 “motor horn” (which I have in my collection).

These horns appear to be quite rare in actual installations. In fact, I don’t think I’ve ever seen a photo or a video of a BZ-50 in the wild. I only know of one building that features these devices in my area; the horns (which are flush-mounted, as pictured below) are paired with Pyr-A-Larm MS-51 pull stations and are original to the building (1981).

Based on my experiences, I would likely consider this device to be an 8 or a 9 on your scale (with respect to the likelihood of seeing one in an active installation). However, they appear to be a bit more common on eBay; a quick search shows that there are currently two listings for BZ-50s, although the horns in both cases are 6VDC versions.

I have to say that the way the trim plate is around the horn there looks very weird.

The 6V version would’ve made sense for older security systems that ran on 6V, but that’s just a wild and raw guess.

Also I don’t know if that’s relevant but my Amseco BZ-50P isn’t exactly a BZ-50P… It’s a BZ-50BP!