I bought some TDA2050s off of that auction site so I could compare to the ones I bought from DigiKey. Having several, I tested, killed and dissected a couple.
real IC: large squarish shaped die (fractured a bit in removing the cover)
Fake IC: Very small die (again fractured). About 1/3rd the size of the authentic one.
Tests results. The authentic IC put out 18 watts before clipping into a 4 ohm load. The fake measured 2.6 watts less using the same supply (12.6-0-12.6v 2A transformer based dual supply).
Short circuit / thermal overload. The real IC would not blow when shorting the output lead to ground, even for several seconds. The fake did not blow either. The fake TDA2040 ICs I also tested blew instantaneously upon shorting.
With a very undersized heat sink, the authentic TDA2050 would dial back output power when it got too hot. The fake seemed like it was beginning to limit and then failed with a nice bang. Too much heat in that small die?
I did not perform a listening test.
real IC: large squarish shaped die (fractured a bit in removing the cover)
An externally hosted image should be here but it was not working when we last tested it.
Fake IC: Very small die (again fractured). About 1/3rd the size of the authentic one.
An externally hosted image should be here but it was not working when we last tested it.
Tests results. The authentic IC put out 18 watts before clipping into a 4 ohm load. The fake measured 2.6 watts less using the same supply (12.6-0-12.6v 2A transformer based dual supply).
Short circuit / thermal overload. The real IC would not blow when shorting the output lead to ground, even for several seconds. The fake did not blow either. The fake TDA2040 ICs I also tested blew instantaneously upon shorting.
With a very undersized heat sink, the authentic TDA2050 would dial back output power when it got too hot. The fake seemed like it was beginning to limit and then failed with a nice bang. Too much heat in that small die?
I did not perform a listening test.
TDA2050, "fake" or not.
Following our discussion on “fake” or genuine TDA2050s also I had to try in practice. A year ago I purchased TDA2050s at a VERY attractive price in the naive belief they were still produced by ST. With nothing to loose I could at least learn from my mistake. A video on YT claims that such TDA2050 are fake and implies not suitable for any use.
A stereo amplifier was implemented on a cheap TDA2030/LM1875 PCB. As power supply I used my variable and symmetrical linear supply with a minimum of +/-16.3V. I tested the amplifier with 16.3V, 18V, 22V and 24 V using an 8 Ohm dummy load. With a 4 Ohm dummy load I used only 16.3V and 18V supply. Listening tests were with 22V or 24V supply and 8 Ohm speakers.
The amplifier worked in first attempt. Without performing comparison with other amplifiers, no obvious sound flaws were heard. A solid and well controlled bass. No bother from hiss or hum.
Later, when trying with a very dominant and deep bass and at high sound levels that would heat the insufficiently sized heatsink, a clicking sound was heard during heavy transients.
Tests of voltage clipping points with dummy loads (both channels performed quite similar):
8 Ohm
16.3V: 11W (no reference value in the datasheet)
18V: 15W (18W typical according to datasheet)
22V: 22W (22W minimum according to datasheet)
24V: 25W (no reference value in the datasheet)
4 Ohm
16.3V: 17W (no reference value in the datasheet)
18V: 21W (24W minimum according to datasheet)
In general, the test results are on the low side of the values in the datasheet, in line with the statements in the YT video that the chip seems to be smaller than in the original ST production.
With 18V supply voltage, 4 Ohm dummy load and after heating the heatsink for a while at full output power, some spurious HF oscillations on the sine-wave would appear (on both channels). That could be the source for the “click”-sounds heard in the heavy load test. With 16.3V supply, such spurious HF oscillations were not seen.
Conclusion: Though the TDA2050, sold at very low price, may not be as performing as those produced years back by ST, the chip actually performs quite well in particular considering the price. The sound is in no way inferior to many other chip-amps. While the TDA2050 may not be the final amplifier construction in your life, it is particularly suited for DIY beginners because it is so simple in implementation and costs very little.
Following our discussion on “fake” or genuine TDA2050s also I had to try in practice. A year ago I purchased TDA2050s at a VERY attractive price in the naive belief they were still produced by ST. With nothing to loose I could at least learn from my mistake. A video on YT claims that such TDA2050 are fake and implies not suitable for any use.
A stereo amplifier was implemented on a cheap TDA2030/LM1875 PCB. As power supply I used my variable and symmetrical linear supply with a minimum of +/-16.3V. I tested the amplifier with 16.3V, 18V, 22V and 24 V using an 8 Ohm dummy load. With a 4 Ohm dummy load I used only 16.3V and 18V supply. Listening tests were with 22V or 24V supply and 8 Ohm speakers.
The amplifier worked in first attempt. Without performing comparison with other amplifiers, no obvious sound flaws were heard. A solid and well controlled bass. No bother from hiss or hum.
Later, when trying with a very dominant and deep bass and at high sound levels that would heat the insufficiently sized heatsink, a clicking sound was heard during heavy transients.
Tests of voltage clipping points with dummy loads (both channels performed quite similar):
8 Ohm
16.3V: 11W (no reference value in the datasheet)
18V: 15W (18W typical according to datasheet)
22V: 22W (22W minimum according to datasheet)
24V: 25W (no reference value in the datasheet)
4 Ohm
16.3V: 17W (no reference value in the datasheet)
18V: 21W (24W minimum according to datasheet)
In general, the test results are on the low side of the values in the datasheet, in line with the statements in the YT video that the chip seems to be smaller than in the original ST production.
With 18V supply voltage, 4 Ohm dummy load and after heating the heatsink for a while at full output power, some spurious HF oscillations on the sine-wave would appear (on both channels). That could be the source for the “click”-sounds heard in the heavy load test. With 16.3V supply, such spurious HF oscillations were not seen.
Conclusion: Though the TDA2050, sold at very low price, may not be as performing as those produced years back by ST, the chip actually performs quite well in particular considering the price. The sound is in no way inferior to many other chip-amps. While the TDA2050 may not be the final amplifier construction in your life, it is particularly suited for DIY beginners because it is so simple in implementation and costs very little.
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I wouldn't even entertain buying from a source like ebay or China.
I only buy from reputable dealers.
On the couple of occasions in the distant past when I did try them it always ended in tears.
I only buy from reputable dealers.
On the couple of occasions in the distant past when I did try them it always ended in tears.
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