TDA2050 vs LM1875 on the QA403 audio analyzer

[@jaymz168]

"Why didn't I buy this a long time ago?" I just got one last week and asked myself the same question haha. I've been using a MOTU M4 with REW for the last few years and it's been fine but the QA403 is actually calibrated for absolute readings, USB isolated, and can deal with larger voltages. Plus I'm getting a -143.7dBFS noise floor with the input terminated, it's insane.

[@JohnAudioTech]

It is a good bit of kit for the money. Part of the reason for not getting one sooner is because of availability problems (chip shortages and such).

[@ItsAllGoneHorriblyPearShaped]

Yep, I love my Q403...its one of the most useful peices of equipment I have...there's lots more that it can do when you enter the programming aspects of the device...

[@electromagix]

Thank you Jhon, that's well detailed one for the pentawatt chip.

[@barrychiarello8493]

Thank you John,

[@migalito1955]

Hmmm, A year or more ago you measured & reviewed a bag of mixed chip amps and had the TDA2050 on the top of your list. At the time I bought one, likely a knock off. Skip ahead: In my retirement I am aiming to build each style of receiver up to superheterodyne from scratch. The most recent receiver is a type of regenerative receiver. My audio out comes from two 2n3904 transistors & is rather weak. I was going to use the standard lm386 to boost the audio & remembered I had the TDA2050 chip amp. I added this and it was a really nice improvement that brought the signal that had been just enough to input into line level on a commercial audio amp to easily provides line level requirements. My ears tell me it's a nicer chip amp compared to the lm386. It's very clean sounding.

[@montynorth3009]

Good. Similar tests on newer chips, higher wattage if possible, would be much appreciated.

[@robertkovar8710]

The resistor (magneticall -most) inside the coil increases the distortion

[@phillipmorris9847]

thank you

[@IliyaOsnovikov]

John, what about TDA2050L by UTC that seems to be currently in production? Have you ever used those amps?

[@AnnaVannieuwenhuyse]

Unlikely to be significantly different. :)

[@jameswarren1831]

If you have time I would greatly appreciate the setup on the QA403 for the test scenarios, as a rookie the level of options can be overwhelming.

[@chronicfatigue5416]

Looking forward to watching this later when I get a chance. I bought the 1875 because of your video on it. I salvaged a heat sink out of a 2004 Dell desktop. I want to try guitar preamp circuits into it, ones I'll build on a breadboard.

[@charlesdorval394]

Those a great source of heatsink, I know exactly the one! :)

[@xverteX1]

Amazing 2050 definitely fav. I made a bridged tda2052 and it also sounds awesome. Not sure what's really the difference between both except 10 extra watts and pins for mute and standby if im not wrong.

[@SimonB6706]

I’ve been using the QA401 for about four years and wouldn’t be without it. Now when I see KZbinrs repair an amp, hook up some speakers, then listen to it and say “sounds great, fixed” after a repair and without any measurements makes me cringe.

[@1pcfred]

In the end how an audio amplifier sounds is all that really matters. Most humans cannot hear less than 3% distortion. We're just not that sensitive. So the values these test instruments come up with are largely academic. What we humans do tend to notice and enjoy are louder sounds. So if it is loud enough and sounds OK it's all good.

[@arkadiuszweiss]

These systems originate from the TDA2010 and TDA2020 systems from the late seventies, where the best scientists in the world wanted to make the best low-frequency integrated circuit in the world and give it to society. At that time, these were all the possibilities of science of the richest country in the world. The systems are cheap because they are produced by a machine, but it is very valuable equipment, unavailable without technology for many billions of dollars. The idea was to give the quality of equipment for billions to almost every person. Unfortunately, the first TDA2020 systems exploded due to thermal overload from the use of an inappropriate housing, but this was an unknown technology. Immediately after that came the TDA2030, TDA2030A, TDA2040 and TDA2050 and TDA2051, all based on the same system, produced by many countries, including poor communist ones. The TDA2040 was quickly discontinued due to its low maximum voltage, as was the TDA2051 due to the lack of any visible/needed improvements over the TDA2050. It didn't make sense to incur the costs associated with producing so many similar devices.

[@andymouse]

Great tutorial !

[@1pcfred]

Plasma rifle in the 40 Watt range.

[@opalescenthermit800]

After watching your original comparison video from a couple years ago I bought a couple LM1875 boards from Aliexpress and found the sound excellent from a pair of speakers I made at the 10 watts and below range. Given this current updated video, to a normal lay person listening at the lower power levels, averaging below 10 watts, would there be a discernible audio difference between the two chips based on the 0.001% and the 0.01% distortion levels? To me the lm1875 sounds fine, but would anyone literally be able to say after listening to it, oh my god why aren't you using a tda2050 chip you numpty your missing out on the 0.001% audiophile quality music!! And storm off in disgust at my choice of chips 😅

[@1pcfred]

The reality is most people can't hear less than 3% distortion. No one can hear the difference between 0.01% and 0.001%. That is far beyond our perception. I don't care who they are or what they think. Most people are absolute idiots. I'm sorry but that's just the world we live in.

[@McTroyd]

Live audio engineer here. For most people, if it sounds fine, it is fine. Any harmonics created by the distortion will be so far down in the noise, the environment you're in will probably make them inaudible. In fact, for most of the applications I might use either of these chips for, I might prefer the LM1875 myself. It has low enough noise floor for "CD quality" applications (defining as > 85 dB in dynamic range, from unity to noise floor). Plus, the consistent THD across audible frequency means it won't be increasing harmonics as the frequency goes up. It's a small advantage in this test, but if one doesn't need the lower noise floor, it means better representation across the audible range. Of course, any modern IC will blow both of these out of the water. My current favorite small amplifier IC is the Texas Instruments TPA3116D2. I have one in a Dayton-branded amp which I use for garage speakers. If you can feed it enough voltage, it's got lots of power, but it's otherwise unremarkable -- exactly what one wants, when one wants uncolored sound reproduction. More than adequate for oil changes. 😁

[@1pcfred]

@@McTroyd that's the long and short of it. If it sounds good it is good. It can always be better. But once you reach a certain point that should do it. If I wanted it to sound better I should have used hearing protection more. I have so much buzzing in my ears now I'm lucky I can hear at all.

[@JohnAudioTech]

I consider distortion levels of .1% or less to be fine. Even at 1%, I'm hard pressed to tell the difference with low order harmonic content.

[@keithblume5159]

On the video you are calling it TDA2050. I'm assuming it's TDA2030 as the name suggests. Love this amp thanks for the video!

[@JohnAudioTech]

No, it is the TDA2050. There was also the TDA2040.

[@1pcfred]

@@JohnAudioTech have you ever thought about reviewing something that isn't obsolete? Asking for a friend. Or failing that maybe reviewing the counterfeit parts that are available today. Because that's what anyone is going to get now. Maybe the fakes aren't so bad today?

[@planet_oith]

​@@1pcfred I have a fake tda7297 and a factory original but I really like the fakey for its valve like warmth compared to analytical sound of the real deal. Now I'm interested in the 2050 and how it will compare with the 7297's.

[@GeoBass-89]

@@planet_oith keep TDA7297 is good ic for 8ohm load and wide voltage range. only if you want bigger power for 4 ohm speaker is better choice tda2050 even fake ic. if you want to use single supply with better amplifier and 4 ohm load use tda7379 bridge configuration and you will thank me after

[@1pcfred]

@@planet_oith I can totally see what you're saying. People like tubes. It's not because tubes are cleaner. But the tube sound is perceived as being warmer than solid state. Not all distortion is the same. A flat perfect response can be pretty bland.

[@colombowala]

What type of 10 Ohms resistor is recommended - wirewound, MFR or CFR

[@JohnAudioTech]

Not really critical. Any inductance in the resistor will add to the total of the network and that would be relatively small.

[@mosfet500]

Thank you. Distortion is overrated in audio amps, neither of the those amps, run in spec, would be a problem.

[@lossfound]

Where do you like to source your LM1875 boards?

[@JohnAudioTech]

I bought the kits off of ebay many years ago. The boards are of good quality. I can't say if they are the same today.

[@MBr-l9o]

Did you mean 700uH?

[@JohnAudioTech]

No, that would be too much inductance.