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This is my first one of these. I bought one of the 2.1 model, AA-AB33511 at the SDC as it will work at 24VDC, and I have a switching supply with plenty of current. At the moment I am trying just to make sure it works before I get any further. I have a 4A brick plugged into it, and I can't seem to get more than 0.35VAC on all 3 channels. I then found what I thought were the LEDs are probably actually Phillips topped pots. Twisting them appears to not have a stop at the other end, trust me I was very gentle, and I can only briefly get 0.6VAC output in turning them. I am just running radio static at 0dB (very loud) for signal.
When I plug in the supply, the 2 LEDs come on and go out. When I unplug it, same thing. If I short the SD terminal to ground, which I read is how the standby function works, the LEDs stay on, but I get no voltage at the output.
I feel like I'm missing something obvious to the initiated, but I don't know what that something is.
Help?
Comments
Some of those class D amps have pots like that which set the PWM switching frequencies.
Do you have any sort of dummy load on the outputs?
Maybe a bit of shade throwing, but Sure does not have the best of reputations... The thing costs $115 but also needs power supply and has no case/chassis and has a fan.
If you want a 3-channel class-D amp this would be my suggestion:
https://www.ebay.com/itm/256177541921
Not "small" but it's good! 100/200W power level, gain controls, auto-on/off, and 3-channels that you can run balanced or unbalanced. I own several of them and use/listen to them daily. Others like it are on offer at the 'Bay. There is also a 2-channel version. Make sure not to get the 70V only version... just look for a switch on the back with one position for "4/8 Ohm".
Since I had the rest of the stuff, it thought this would be a viable track to follow.
Granted, I know their track record is not fantastic. I'm just trying to make sure I'm not doing anything wrong, as I have checked amplifiers out before in this same method and found issues. Just making sure I was doing it right and not missing something. I did not dummy load it to get those readings, as I wasn't getting hardly anything with a load connected. as i'm seeing it, this may be a bad module, but i did not expect both chips to be bad.
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IIRC, some of the Class D amps require a load....
I have purchased several of the Sure bare amps.
All have worked pretty much as specified.
Have you measured the input voltage to make sure it's not pulling it down less than the 24V? There's no mention of gain controls, are the pots you adjusting near each input? Are there three of them?
Yes, I checked the supply, 23.9VDC.
They are by the inputs, and yes, 3 of them.
I will get back to this tomorrow, likely my error at not having the load connected through all the tests.
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It doesn't look to have any "turn on" except maybe by signal present at the inputs? Should just be on when power is applied. Good luck!
That is what I was thinking too....
More to come, it's likely just the error was me.
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Have a few of the Sure boards around and other that their very optimistic power ratings, IMO, the sound quality of their tripath based stuff is above average. Although, I have no issues with the sound of their 4x100 ab33182 (tda7498), it's the 2x400 ab32313 (sta516b) I like, especially after some diy mods. Yeah, I'm a tripath fan.