200W IRS2092 Amp for $20

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This was moved over from the TDA7492 thread since it was off topic.
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A little OT, but wanted to let you guys see what just came in the mail from Aliexpress...

These things are pretty compact - a little smaller than YJ blue/black 3116.

Very nicely made, appear to be quality components and very clean soldering work - IRS2092 200w monoblocks for $19ea shipping included. I am using qnty 4 x 19v laptop smps bricks in series for +/-38v supply (4.6amp limited) as the power supply. Testes it with some PA drivers and it is loud and clean. A great deal - easy to hook up and use - just need dual rail supply is the only downside. I may have to buy a Connexelectronic dual rail SMPS for $50 to get the real juice.

Recent price drop now $16 :D

http://www.aliexpress.com/item/IRS2092-200W-Class-D-mono-amplifier-board/32257919878.html

488239d1434199057-10f-8424-rs225-8-fast-ref-monitor-irs2092-monoblocks.jpg


Update (June 19, 2015): I testes this with the $20 Abletec dual rail 53v power supply and it works very well. Clean and loud.
http://www.diyaudio.com/wiki/TPA3116D2_Boards

Test setup:
489453d1434791767-200w-irs2092-amp-20-irs2092-amp-build.png
 
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I had a modded IRS 2092 few years ago,
I can be wrong, but as far I remember,
I didn't find any big différences between 3116 and 2092.
For now, I am quite happy with 3116
Maybe I should set up a new test.

That's a good thing that you did not think there was much of a difference because the 3116 is one of the best sounding amps in the sun 40w range. If you need 150+ watts though, the IRS2092 can keep up with the demand. I have not had much time to listen but it sounds very neutral so far. A good amp should not have a sound of its own.
 
That's a good thing that you did not think there was much of a difference because the 3116 is one of the best sounding amps in the sun 40w range. If you need 150+ watts though, the IRS2092 can keep up with the demand. I have not had much time to listen but it sounds very neutral so far. A good amp should not have a sound of its own.


1/ I agree your feeling about the IRS2092. There is something more neutral, and maybe something else. It is a pure class d sound, so after 1 hour of listening , just need to turn off the music.

2/ I have only one 3116 in a big room with 2 big ditton speakers and volume is not at max level.
=> I think there are things I don't understand on amplifiers because I don't understand the run for watt.
 
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Where did you see the spec on the input impedance? I will have to check but I had no problem driving them with the 2v p-p output from miniDSP, as well as headphone outs from a CD player. It depends on the resistors used to set the gain on the input op amp, not the IRS2092 itself as that is really just a PWM switch driver.
 
Looking at the DS for the IRS2092, the suggested application shows a 3k3 input resistor in series with 10uF going into a virtual earth. So if its implemented according to this reference design (IRAUDAMP5) it will indeed be 3k3 input impedance. No mention in the DS about increasing the resistor values - that's not to say it isn't possible, but 15k does sound rather optimistic to me.
 
Application Note AN-1138 :
''Input Section The audio input stage of IRS2092(S) is configured as an inverting error amplifier. In Figure 2, the voltage gain of the amplifier GV is determined by input resistor RIN and feedback resistor RFB.
Since the feedback resistor RFB is part of an integrator time constant, which determines switching frequency, changing overall voltage gain by RIN is simpler and, therefore, recommended in most cases. Note that the input impedance of the amplifier is equal to the input resistor RIN. ''

I believe the input resistor can be raised to 6.6k which also lowers the gain.I'll try to find the paper on that with the gain settings.At least this may be workable with a tube pre.I think this is why ClassDAudio came out with their SDS series of amps.I believe they added a buffer input.
 
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On my 200w IRS2092 (YJ I believe) the input impedance is set by a 100k resistor clearly labeled next to the input pins. I also measured it and it is indeed 100k. That is is very good because it means it can be driven easily with a cell phone headphone output and is also good for PLLXO in that it won't attenuate the signal very much.
 
On my 200w IRS2092 (YJ I believe) the input impedance is set by a 100k resistor clearly labeled next to the input pins. I also measured it and it is indeed 100k. That is is very good because it means it can be driven easily with a cell phone headphone output and is also good for PLLXO in that it won't attenuate the signal very much.

Yet I can't see any opamps on that board - admittedly the heatsink's covering a large area and there could be one under it. Equally no sign of supply regulators for an opamp. Without an opamp or some kind of input buffer, the input impedance has to be that of the IRS2092 chip's application circuit.

If you measured the input impedance with a multimeter that would only show the DC resistance, but the application circuit's AC coupled.
 
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