Infineon MA12070 Class D

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#1,885
I was interested if the caps could stand the input voltage
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#1,887
So that card seems to be okay for unbalanced use. No extreme degradation by the tone controls or caps even at 40 Hz.
20dbV out so about 0 dBV on in0A
(You need pretty special sub drivers to have 0.2 percent distortion at 20dBV and 40 Hz)
 
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#1,889
Found a 2 ohm load. Only 19Volt PVDD
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20 Volt peak to peak. So 10 Ampere through the load. Smell off solder in the air.
Chip got really warm and shut down with higher utput voltages.
So heat are a real limiter of this chip at low impedances.
But I am really impressed.
3,3 Volt pp was really fine
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#1,891
What is the use of this torture test? As can be read the chip can die when making a mistake and now they are out production you might regret blowing it.

With an unrealistic 2 Ohm one would normally choose a real power house with external MOSFETs on a heatsink isn't it?

mamocel said:
The MA chip in single can be a little light on speakers that are difficult to drive... And 2 is better... (we are made that way). 😂
On speakers with low efficiency or chaotic impedance curve, and it would seem that we gain a few Watts before the 10% distortion. To be confirmed, I have not made any measurements... And yes often in normal listening 5 good Watts is enough
To choose between a car of 70 HP AND 140.... I prefer to take a safety margin.
Click to expand...
Hi I thought about this but with only 1 chip the risk of defects is halved. So the safety margin is likely not improving with 2 chips. Never heard any difference playing at normal levels (tested 2 x MA12070 devices too) between 1 or 2 chips. Using a linear PSU on a single chip amplifier makes more of a difference. I use Elac BS244.3 that are 3.6 Ohm. My class AB amplifier is 2 x 3W when it has wind in the back on a sunny day.

Firm believer of less = more here 🙂
 
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#1,892
Looks like it is really well protected. Shut down several times and got up again with no issues.
Also a test of this spesific card with dual chips.
As it can stand this test, it is in its safe area at least above 3 ohm and up to 20volt peak to peak (20dBV)
Impressive for a 30euro card
 
#1,893
But why do they sometimes just blow up? Heard it, read it and had it myself once. In some devices it occurs more often. I recall an amplifier where they blew when plugging in the DC connector after the AC connector (when this one was already energized).
 
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#1,895
Should have been prevented by protection. Anyway not wanting to bring the chip down but one must be careful with power on/off and connections. Anyone that had Tripath equipped amplifiers is used to some catastrophic results now and then 🙂 I recall a friend that was vacuuming and pulled one of the speaker wires banana plugs accidentally followed by a loud BOOM.
 
#1,897
Many in this thread know, we have used it from the time it came out about 4 years ago. BRZHiFi, Topping A20a and A10a, PA3S, Aiyima A8, SMSL A100 etc.

Big question is what Infineon will do with now all multilevel class D chips discontinued. Hopefully a new multilevel class D IC without the need of an army of X5R 10 µF ceramic caps.
 
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#1,899
Eh listening is believing. Never got around making a DIY version as I think it is simply too cheap to bother making way higher costs. Also the DIY attempt of a member where various chips died was not promising.

The example of a lone quality IC coming of series/mass production meant for series/mass produced ultra cheap stuff and delivering more than one would expect. Should happen more often.
 
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