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I just bought a car-audio active crossover to use iton my main system. The thing was discounted from 220$ to 36$ on all website I saw it; I figured maybe they were closing the line or the brand or something like that, and for what I wanna do with it, it'd be good enough (I'm just planning to use the low-pass section)
Being car-audio, the thing feeds on 12v; there's a 1A fuse next to the PSU input so i figured (but maybe i'm wrong?) that it feeds on 12v and max consumption would be less than 1A... so I'm using this wall PSU I got with some small DIY DAC, I just desoldered the original terminated cable and soldered a simple generic wire on the pSU board, the V+ going straight in the crossover's V+ input, the V- in the -, and there's a small piece of wire going from V+ to "remote" ("remote" triggers the device ON)
My preamp's main 1 output goes straight to the little amplifier feeding the passive crossovers for the midrange and treble (the lows are filtered passive, and there's a 6 ohms resistor connected where the woofer used to be)
the preamp's main 2 output goes to the active crossover, and the low-pass output of the active crossover feeds the amp for the 15inch drivers.
The active crossover LED indicates it's on, and the clipping leds turn red on each channel when I turn things up too much, yet there's absolutely NO SOUND coming out of the crossover, just hum. I tried all outputs (low pass, band pass, high pass, mono sub), there's no sound coming from any of the crossovers output.
I have no idea if the PSU I "made" is wrong (not enough current? but it's just opamps and resistors in there) or if the crossover has a problem.
I don't really know where to start to try again: borrow a car battery? get a regulated pSU with more output current?
I'm most likely going to buy a CABRE AS45 crossover but it would be nice to make sure this thing is functional, so I can put it on the bay or use it on a cheap project...
Follow Ups:
I suggest that you don't bother testing it with a battery; test it with any other 12V wall-wart to find out if it is PSU related. I use a Nakamichi EC-200 mobile electronic crossover for a home audio low-pass crossover application, and its current demand is only 0.53 watts 40mA, with 10.8V to 15.6V allowable. BTW, it's very worthwhile to upgrade the wall-wart with an audiophile-quality regulated linear power supply, if you get your crossover up & running. Best of luck.
Like Coner mentioned, make sure your PS is DC, and not AC. If it is AC, you may have destroyed the opamps. It should require very little current, so I would think any wall wart would have enough.
Damn. For whatever stupid reason, I was kinda sure all 12v supplies were DC... turns out they're not, BUT on the one I used nothing is written at all! JUst 12V - 1A. Could be AC, could be DC, no way to know just by reading what's written on it.
How big are the chances that I destroyed the opamps?
I'll get a 12V DC wall wart and try again. Fingers crossed.
Do you have a multimeter? If so, measure the voltage on the output plug, using the VDC setting on the meter. If it is a DC PS, you will measure 12V or so. If it is AC, you will read very low or nothing. That should tell you.
If you are serious about this hobby, you need a fairly decent multimeter, and a scope would be your best friend. A good used analog scope can be found for very reasonable prices these days.
I'd try a 12 battery. Also, verify the your wall wart is putting out
DC, not AC. Hum would come from AC. 1A should be plenty to run the unit.Putting a large capacitor on the wall wart (DC) output will reduce residual
AC hum (called "ripple") quite a bit.
Edits: 08/24/16 08/24/16
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