Hello everyone!
I have been looking into getting a new amplifier to play with. Mostly as a chance to swap my current class D amplifier in my desktop setup as well as using the building/soldering of the amplifier as some learning experience.
My current Class D amp is a TPA3116 with a 5532 Preamp.
I've been thinking about getting a LM3886 kit "on a budget", I have seen many great boards for this chip but I can't really afford them of now.
Doing some searches, Aliexpress does have some fairly interesting (looking...I know little about the 3886) kits, this is one of them:
Placa de amplificador de potencia unisian lm3886, amplificador operacional independente auido op07 ne5534 com protecao para alto falante 68w|Amplificador| - AliExpress
My question is, does anyone have any experience with those cheap kits?
Or, should I use my current budget (about 50 USD) to get another kit or components to build something?
Any recommendation or advice is much welcome, and just in case it serves the purpose, anything around 10 W or even less is good enough, as long as it can handle 8Ohms and have a fairly decent sound quality. Single rail PSUs up to 24V (I have a meanwell one) would be perfect, but I wouldn't mind needing to get a transformer, I should have a 13.5Vx2 laying around.
I have been looking into getting a new amplifier to play with. Mostly as a chance to swap my current class D amplifier in my desktop setup as well as using the building/soldering of the amplifier as some learning experience.
My current Class D amp is a TPA3116 with a 5532 Preamp.
I've been thinking about getting a LM3886 kit "on a budget", I have seen many great boards for this chip but I can't really afford them of now.
Doing some searches, Aliexpress does have some fairly interesting (looking...I know little about the 3886) kits, this is one of them:
Placa de amplificador de potencia unisian lm3886, amplificador operacional independente auido op07 ne5534 com protecao para alto falante 68w|Amplificador| - AliExpress
My question is, does anyone have any experience with those cheap kits?
Or, should I use my current budget (about 50 USD) to get another kit or components to build something?
Any recommendation or advice is much welcome, and just in case it serves the purpose, anything around 10 W or even less is good enough, as long as it can handle 8Ohms and have a fairly decent sound quality. Single rail PSUs up to 24V (I have a meanwell one) would be perfect, but I wouldn't mind needing to get a transformer, I should have a 13.5Vx2 laying around.
LM3886 is out of stock, scheduled for production maybe next year.
So you are looking at fakes.
For 10 Watts, LM1875, or TPA3116 is fine, so is 7297.
Simply buy an old amplifier cheap, and use it.
Or look at the lunch money amp on this forum.
Most will match your supplies.
So you are looking at fakes.
For 10 Watts, LM1875, or TPA3116 is fine, so is 7297.
Simply buy an old amplifier cheap, and use it.
Or look at the lunch money amp on this forum.
Most will match your supplies.
One of favourites!
Buy two for stereo 😉
Cebek E-4 | 15W RMS Mono Audio Power Amplifier Module | Quasar UK
Buy two for stereo 😉
Cebek E-4 | 15W RMS Mono Audio Power Amplifier Module | Quasar UK
Hi,
I have built this one and I can say it's allright, though probably not the amplifier you'll want to use for the rest of your life. I mean, it plays music without apparent trouble. Power supply could be better. I didn't test the protection relay circuit or anything else. My son is happy with it for making some noise in his workshop.
I replaced the amplifier chips with genuine ones from Mouser (I had ordered quite some when they were readily available) and added the Thiele and Zobel networks described in the LM3886 Application note. I had a very cheap "XY" board damaged when playing through electrostatic speakers. Not sure about the actual chips they had.
But I have always added the Zobel & Thiele networks since.
There are many threads on this forum about LM3886 coming from the Empire of the Middle being genuine. I found this one particularly instructive:
XY LM3886 Kit Review & Measurements
Not always a very encouraging reading, but illustrative of the risks.
Sucess!
I have built this one and I can say it's allright, though probably not the amplifier you'll want to use for the rest of your life. I mean, it plays music without apparent trouble. Power supply could be better. I didn't test the protection relay circuit or anything else. My son is happy with it for making some noise in his workshop.
I replaced the amplifier chips with genuine ones from Mouser (I had ordered quite some when they were readily available) and added the Thiele and Zobel networks described in the LM3886 Application note. I had a very cheap "XY" board damaged when playing through electrostatic speakers. Not sure about the actual chips they had.
But I have always added the Zobel & Thiele networks since.
There are many threads on this forum about LM3886 coming from the Empire of the Middle being genuine. I found this one particularly instructive:
XY LM3886 Kit Review & Measurements
Not always a very encouraging reading, but illustrative of the risks.
Sucess!
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Interesting to know the LM3886s are out of stock. I have a fairly reliable electronics store in here, they mostly sell cheapo stuff, but they sometimes get their hands on original parts (and they're usually original), they do have 3886s going for around 12 USD each, I think I could give it a try on getting the chips first and confirm if they're original.
This one is very interesting, although it seems like they don't ship worldwide? It also seems a bit steep for a 2003, but I might be wrong.
Thank you so much for this input, I do plan on making it my main desk amplifier, but I already have a fairly modified TPA3116 board. I was looking into something that could give me slightly better highs. My TPA is a killer in the low end, but it always feels a bit lacking in high frequency clarity (I built a simple preamp and tested with 2 different 5532 and an OPA2132).
Other than that, I also look into giving small modifications to whatever possible, if the kit doesn't sound particularly good stock (true for most TPA3116 boards from AliE, like mine).
That 3886 I linked looked interesting as it already has a set for Preamplification. Maybe some changes to capacitors would be needed, but that isn't the biggest issue (I begin those projects and slowly go over them, like the TPA).
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What is your LC filter value and your speaker impedance?
Incorrect LC filter may cause early roll off.
For 8 ohm, I do recommend 15uH and 470nF.
The cutoff frequency will be at 59.9khz and Q factor 0.708.
Also, cheap inductor can increase distortion when playing loud.
The Toko inductor that TI TPA3116 EVM uses is a good one.
Incorrect LC filter may cause early roll off.
For 8 ohm, I do recommend 15uH and 470nF.
The cutoff frequency will be at 59.9khz and Q factor 0.708.
Also, cheap inductor can increase distortion when playing loud.
The Toko inductor that TI TPA3116 EVM uses is a good one.
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That I did not know. I am still learning as a hobbyist, but the values are:
10uH Inductors from Wurth, these are possibly their highest current Inductors in that package size (they were samples, so those are not knock offs)
1uF/450v TDK Capacitors, both of these values are the recommended ones in the datasheet.
I don't know how to calculate the cutoff frequency of that filter yet. Should I revert to the 680nf Capacitors the board came with?
I was about to change the DC caps to higher values and see if that made a difference (470uF to 1000 or more).
Much appreciated!
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Here is the excel from TI to calculate your filter.
LCFILTER-CALC-TOOL Design tool | TI.com
The simulation for 10uH and 1uF seems ok. Boost of 1dB at 20kHz.
Keep the 1uF there first.
Even though it's Wurth, I won't know how good the inductor till it's measured. 😀
Any measuring equipment you have there? Multimeter?
LCFILTER-CALC-TOOL Design tool | TI.com
The simulation for 10uH and 1uF seems ok. Boost of 1dB at 20kHz.
Keep the 1uF there first.
Even though it's Wurth, I won't know how good the inductor till it's measured. 😀
Any measuring equipment you have there? Multimeter?
Chip Amps doesn't mean it is already D-class amp.
Also old signs on Op-Amp doesn't mean it is original Op-Amp.
Fake chips doesn't sound well.
I am lucky to have old chips with original signs to play with it.
Now I am playing with new original chips and I am happy with it.
What I see on attached pictures it is questionable (I mean on Op-Amp).
Also old signs on Op-Amp doesn't mean it is original Op-Amp.
Fake chips doesn't sound well.
I am lucky to have old chips with original signs to play with it.
Now I am playing with new original chips and I am happy with it.
What I see on attached pictures it is questionable (I mean on Op-Amp).
@Algray. Have you considered a TDA7293 build? I may have some spare boards from the Dibya XRK Xmas amp. Or gerbers are available for cheap PCB manufacture. You would obviously need to order all the components.
First of all, my apologies for how long this reply is...
I agree, thanks for that link! I will keep an eye at it. I do have a multimeter, it doesn't have a option to measure inductance, but it can measure capacitance. Is there a way to actually measure inductors with a multimeter?
Yes, that is true! The weird part about it all is that, I have original NE5532s and OPA2132s from TI, I got them in their website as samples. If I were to describe them in that Pre-Amp, the OPA2132 kinda sets the high frenquencies back a tad, and the NE5532 from TI is the somewhat better balanced. The only reason I kept those Philips I got from China (so yeah, most likely fakes), is that they actually have somewhat better bass while keeping the same highs as the TI NE5532s.
I gave a look at those boards, they're very interesting! I found out I actually have one of those very cheap little boards with a 7297, it's really tiny (I attached a pic). I tried removing the diode, added a bigger capactior for the input DC filtering, changed the input filter caps to 1UF as well. I did get a good sound out of it, but I don't have a good 12V PSU to run it. Although the 7293 seems a little bit overkill and would need me to get a good transformer...which is kinda expensive and also hard to find quality ones where I live...
My current 12V PSU adds a weird noise to it, I tried shorting inputs to ground and the noise remained. I actually though this PSU wasn't as bad, because I got the slightly better version of the Lunch money amp, that is this TDA7377 Board. It was just shipped and should take some weeks to arrive.
I am actually thinking about getting a small transformer (12V 5A) and build a PSU for this, but I've never worked with transformers directly yet.
There's also 2 other small amps I tried previously. One of them is a TEA2025, but this one never really powered up, I never really gave it much thought or tested what could be wrong.
I also got that "Zero Zone" 1969 clone. It worked, but one of the boards would have no bass at all. I tried changing the input caps to higher/better ones to no avail. So I just nicked the 4700uF cap it came with and put into a LM386 amp I built a while ago for fun.
Once again, thank you all for your knowledge/replies. 🙂
I agree, thanks for that link! I will keep an eye at it. I do have a multimeter, it doesn't have a option to measure inductance, but it can measure capacitance. Is there a way to actually measure inductors with a multimeter?
Yes, that is true! The weird part about it all is that, I have original NE5532s and OPA2132s from TI, I got them in their website as samples. If I were to describe them in that Pre-Amp, the OPA2132 kinda sets the high frenquencies back a tad, and the NE5532 from TI is the somewhat better balanced. The only reason I kept those Philips I got from China (so yeah, most likely fakes), is that they actually have somewhat better bass while keeping the same highs as the TI NE5532s.
I gave a look at those boards, they're very interesting! I found out I actually have one of those very cheap little boards with a 7297, it's really tiny (I attached a pic). I tried removing the diode, added a bigger capactior for the input DC filtering, changed the input filter caps to 1UF as well. I did get a good sound out of it, but I don't have a good 12V PSU to run it. Although the 7293 seems a little bit overkill and would need me to get a good transformer...which is kinda expensive and also hard to find quality ones where I live...
My current 12V PSU adds a weird noise to it, I tried shorting inputs to ground and the noise remained. I actually though this PSU wasn't as bad, because I got the slightly better version of the Lunch money amp, that is this TDA7377 Board. It was just shipped and should take some weeks to arrive.
I am actually thinking about getting a small transformer (12V 5A) and build a PSU for this, but I've never worked with transformers directly yet.
There's also 2 other small amps I tried previously. One of them is a TEA2025, but this one never really powered up, I never really gave it much thought or tested what could be wrong.
I also got that "Zero Zone" 1969 clone. It worked, but one of the boards would have no bass at all. I tried changing the input caps to higher/better ones to no avail. So I just nicked the 4700uF cap it came with and put into a LM386 amp I built a while ago for fun.
Once again, thank you all for your knowledge/replies. 🙂
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Tda7297 is a nice small amplifier, perfectly capable of 10w into 8ohm. I don't know why you want a new amp
A 12v 5amp transformer is more than enough, even 3amp is adequate. Use a 10-15amp bridge rectifier, 4700uf capacitor & your power supply is ready to rock.
A 12v 5amp transformer is more than enough, even 3amp is adequate. Use a 10-15amp bridge rectifier, 4700uf capacitor & your power supply is ready to rock.Tda7297 is a nice small amplifier, perfectly capable of 10w into 8ohm. I don't know why you want a new amp
Reason behind me wanting a new amplifier is, that 7297 was never necessarily good. I tried doing a lot of modifications and attempted using a few PSUs as well, there would always be some hiss or hum in the background I never got rid of.
Since I plan to use that as my desktop amplifier, having it be as silent as possible when idle is a must, the only amplifier I was able to achieve that feat is with my TPA3116 set to 20db gain and a pre-amplifier.
I will follow the idea of trying a transformer, although I really believe that the transformer I found here isn't of good quality (well...it's what I could find for now). I will try implementing one, but as I said, I never worked directly with mains transformers before. I've done some research on the components I will need and found quite a lot of info, ranging from people recommending voltage regulators such as the LM317/338 for an example to properly filter the ouput.
I will just try to use a 15A Bridge Rectifier and a 15.000 uF 25V cap I found in a store (should be more than enough?)
We're here to help each other. Anyway try tda7293/94, no hiss no hum, completely silent! My own experience 😎
Yes, i see no problem. You can use regulator if you wish to but ensure good heatsinking.
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I did some research on the 7293/94 and found some amplifiers for it. I think the main issue would be that, I'd need to get yet another transformer, high current one, more big capacitors, etc... I have no symmetrical PSU for now, that pre-amplifier I have is powered by a DC-DC converter I found. It works fairly well, but provides very little current (less than 100mA)
Things should arrive this week, I might only be able to test things properly next sunday, work and all.
Well, all in all, there is another reason too. It is for learning, cheap/accessible things are widely available in places like AliExpress/ebay and so on.
The problem is with actual good components, I've searched a lot, so much I ended up requesting samples from some brands and they were very helpful to provide some. Mouser and similars, for example, are nearly out of reach due to the shipping costs + taxes on those shipping methods they employ. I could be spending 50 USD on components + 100 more for shipping and taxes to my country.
Stuff from AliExpress for an example uses standard shipping methods (instead of FedEx, UPS, etc..) making it a lot cheaper and tax free, but yeah, it's hard to tell if any of those are original components, hence why I started the thread with a link to a AliE item haha
So yeah, it makes a lot harder to acquire basic components and tools to learn about, all the knowledge that comes from here is very welcome, so thanks!
How much power do you need from tda729x? A 30v CT(15-0-15) 2-3amp trnsmr is more than enough for stereo 7293 & couple of good watts into 8ohm!! No need of high capacitance, 2×4700uf 25v electrolytics are adequate for peak instantaneous power & good psu noise level.
I don't know why you're fearing about transformer, currently i'm using locally made EI core( i hate cheap toroids though) with good result. DIY always costs, but yes i understand other points you made.
I don't know why you're fearing about transformer, currently i'm using locally made EI core( i hate cheap toroids though) with good result. DIY always costs, but yes i understand other points you made.
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Yeah, I guess I get what you mean now. I have no idea why I had this weird fear about transformers. And I also really don't need much power, I recently discovered even the LM386 N-3 (around 600mW) was about enough power for my daily usage.
I received the one I bought yesterday and decided to run some tests on the 7297.
Used a 10A Bridge Rectifier, 2x 3.300uf capacitors, and it worked, really well.
There is still a tiny bit of hum, but it's much harder to notice, you need to put your ears to the speaker. I tried adding some other capacitor values to the DC input, but it didn't help much.
I am getting about 17V after retification, which seems fairly good I suppose, at least, my TDA7297 didn't explode...Actually, it kept cool, a lot better than the SMPS 12V I tried before. It would get a bit warm after a while.
The transformer did get a bit warm, but if I were to guess, it was less than 40C, nothing to be worried about.
The bigger capacitor and 15A Rectifier will arrive today, I will try to make a small board with the capacitor as I simply tried on a breadboard haha
But yeah, I gotta admit that now I am leaning towards getting more symmetrical amplifiers and some transformers, I liked the result I had here, thank you for the hints!
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