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Power adapter/supply for Mirage LFX-3 crossover

I need to replace the power adapter for my Mirage LFX-3 crossover. The crossover is connected to dual Mirage BPSS-210 subwoofers.
The supplied wall wart adapter puts out 18 volts AC. However, the back of the crossover where the output of the adapter goes indicated that it takes 16 volts AC. See photo.
So, looking for a replacement power supply, should I look for a 18 volt AC output or a 16 volt AC output. Aside from 2 volts, what is the difference between using 18 volt or 16 volt supply? Is there a downside or an upside to using 18 volts if 16 volts is specified by design. Why? I assume that Mirage thought that 18 volts was OK (probably what was available off the shelf). But, I would prefer to do what is best rather than what is potentially just OK. I would ask Mirage, but they don’t really exist.
Thanks for the help!

lotusm50
lotusm50 OP
31 posts
 

So, I asked Klipsch product support (they bought and eventually killed the Mirage brand) and they gave me an answer that didn't make much sense to me (I'm not an electrical engineer, but do have a science/engineering background). They said, "You want to replace the adapter with an 18 volt to keep in aligned with the speaker."
Does that make sense? The only connection between the crossover and the 2 subwoofers (BPSS-210's) is the line level output from the crossover (1-2 volts?). The BPSS-210 subwoofers run on 120 Volts AC house current (although I assume there is a transformer in the sub). I have the schematics for the subwoofers if that of interest.
Thanks!

p.s. I have schematics for Mirage M-3si speakers, the Mirage BPSS-210 subwoofers and the Mirage LFX-3 and LFX-2 crossovers, is anyone needs them.

willcycle
49 posts
 

I think the reason for the 2V discrepancy is once the transformer is loaded down the secondary voltage drops to near 16.  If you decide to go with a higher rated transformer it should be closer to 16V.

imhififan's avatar
imhififan
2,205 posts
 

I will opt for a 16VAC 1A rated Walmart. if you look at the schematic, the 4700uF filter cap is rated 25V which is a bit too low for 18VAC after rectified (18VAC X 1.414 - 1.4 = 24VDC), and the 7815 regulator only required 17V input voltage, anything higher will be dissipate as heat.

lotusm50 OP
31 posts
 

Thanks.  I think that is how I am going to go with this.

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