200W IRS2092 Amp for $20

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#181
irribeo said:
Supportforum TI.com, optimising tpa3116 for THD, you have read it befor:
EVM is a good starting point. Select inductors that does not saturate at peak current. Any loss of inductance of more than 3% up to the peak load current can increase THD. Use at least X7R or better capacitors (MKP/MKT).
You may also use AM0, AM1, and AM2 to select higher PWM freq which can provide slightly better THD+N at the expense of higher idle current.
reg,
Paul Chen
Applications Engineer​
Click to expand...

Irribeo, I miss the point where they state that film will bring down THD.
 
#183
I can definitely see MLCC output capacitors causing increasing IMD, and film capacitors making an improvement. Suppose for a test you feed in a small 10KHz signal on top of a large 100Hz signal - the output filter capacitance will basically swing back and forth at 100Hz, dynamically changing the parameters and frequency response of the filter, effectively AM/PM modulating the 10KHz signal with the 100Hz signal and creating 100Hz + harmonics sidebands around the 10KHz signal.

Wish I still had access to AP gear or I'd be measuring this effect.
 
#186
Just fyi, and your experiences may differ, but I bought two of those Abletec power supplies and neither is able to output anywhere near their capacity. It's possibly the amp dying at this power but at about 20WRMS the power supply starts spitting audibly and then starts oscillating. One of the two is generating HF noise even on low power whereas the other is quiet. Imho not a deal.

I just tried hooking just one side up to an 80ohm load (so about 30W) and the voltage drooped to 60%.
 
#187
Speaky said:
Just fyi, and your experiences may differ, but I bought two of those Abletec power supplies and neither is able to output anywhere near their capacity. It's possibly the amp dying at this power but at about 20WRMS the power supply starts spitting audibly and then starts oscillating. One of the two is generating HF noise even on low power whereas the other is quiet. Imho not a deal.

I just tried hooking just one side up to an 80ohm load (so about 30W) and the voltage drooped to 60%.
Click to expand...


Speaky,
Were the power supplies purchased recently? or a while back? From Parts Express or Ebay?
The reason i ask is because i am wondering if there were different revisions or runs of this power supply , some being better than others as they worked out the bugs (possibly?), or are they all just as crummy?...

Apparently there are major problems with some of them (like the ones you ended up with) so that would explain the pricing on these...
 
#188
Capt Grogg said:
the company that designed it Anaview/Abeltech is/was reputable but it appears to be built incorrectly by an Asian contractor. I bought several of them a year or so ago from PE and none came anywhere close to their medium and short term power specs and only some of them came close to the long term spec. I emailed both ABELTECH and Patrick asking for information that would allow them to be made to operate as designed and got no reply. PE provided replacements which performed in the same sub par way and then allowed return and refund. They hadn't tested them and apparently had purchased them from someone who realized that they did not perform as specified and dumped them. They will work at 100w level per output and be ok on typical music duty cycles except for subwoofer with sustained signals. A good value if used within their limitations
Click to expand...

30w is even lower
 
#189
Speaky said:
Just fyi, and your experiences may differ, but I bought two of those Abletec power supplies and neither is able to output anywhere near their capacity. It's possibly the amp dying at this power but at about 20WRMS the power supply starts spitting audibly and then starts oscillating. One of the two is generating HF noise even on low power whereas the other is quiet. Imho not a deal.

I just tried hooking just one side up to an 80ohm load (so about 30W) and the voltage drooped to 60%.
Click to expand...
Yikes. I was about to order 4 of these this weekend. Thanks for the heads up
 
#191
Speaky said:
Just fyi, and your experiences may differ, but I bought two of those Abletec power supplies and neither is able to output anywhere near their capacity. It's possibly the amp dying at this power but at about 20WRMS the power supply starts spitting audibly and then starts oscillating. One of the two is generating HF noise even on low power whereas the other is quiet. Imho not a deal.

I just tried hooking just one side up to an 80ohm load (so about 30W) and the voltage drooped to 60%.
Click to expand...

try putting a load on the aux power
 
#195
Speaky said:
Just fyi, and your experiences may differ, but I bought two of those Abletec power supplies and neither is able to output anywhere near their capacity. It's possibly the amp dying at this power but at about 20WRMS the power supply starts spitting audibly and then starts oscillating. One of the two is generating HF noise even on low power whereas the other is quiet. Imho not a deal.
Click to expand...
Um, try to be more resourceful maybe???

Google is your friend:
help: having some problems with buyout Abletec swiching power supplies

and:
http://www.diyaudio.com/forums/powe...-clicking-sound-switching-power-supply-2.html

and especially:
http://www.diyaudio.com/forums/powe...und-switching-power-supply-3.html#post4075514
 
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#199
xrk971 said:
MIN REQ. CURRENT DRAW: V1 (+53v ): 100mA V2 (-53v ): 100mA V3 (+7.5v): 50mA V4 (+5.6v): 30mA
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I have had no issues with the PS after I loaded down both the lower voltage supplies to only a few tens of mA. I use a pair of these (one in each loudspeaker), each powering three class-D mono amps. I have had zero problems.

Now that I look at these numbers again, I realized that in some cases one might need to add loading to the HV rails too...

The numbers show that even the HV rails have a minimum current draw. In Watts, 0.1A @ 106V (rail to rail) is about 10W. According to the IR datasheet for the IRAUDAMP7s (the 4-om 2x250W type) the idle power consumption is only 7W with the amp "on" but no input signal. That's a stereo class-D amp. To bring the minimum current into spec, you would have to add a 1k to 2k Ohm power resistor (rated 5W or more) from each HV supply to ground to draw an extra few Watts (for instance) if you were just connecting this one amp board to the power supply!

Keep that in mind folks...
 
#200
Wow, I never would have found that. Thanks for the link. The min load on the supply I've seen before, but having the aux supplies need a load I never would have worked out. It sure would have been nice to stick a comment on the product page. and oddly only one of the two ticked at rest.
 
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