Hi And thanks for reading this thread.
I am trying to find out the sound quality of a lm3886 ic, most say it sounds good, but would you say it is audiophile / hi-fi. Do you have an opinion on this.
These are a few boards i am looking at: ebay 283257875566 162854460968 262584747995
Are they cheap and nasty, or do you think the price is low because of the low number of components. Asking a lot i guess, but would the sound from these boards be hi-fi, or just decent say sounding similar to a £300 manufactured amp
I am trying to find out the sound quality of a lm3886 ic, most say it sounds good, but would you say it is audiophile / hi-fi. Do you have an opinion on this.
These are a few boards i am looking at: ebay 283257875566 162854460968 262584747995
Are they cheap and nasty, or do you think the price is low because of the low number of components. Asking a lot i guess, but would the sound from these boards be hi-fi, or just decent say sounding similar to a £300 manufactured amp
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I played with LM3886 a few times. I'd say it can get into 'audiophile' territory but only if you either improve the power supply considerably or pair it up with an opamp to give a composite (like the 'MyRef'). In its stock implementation its sound is relatively mid-fi in that the high frequencies sound rather harsh and the bass is soggy.
I would shy away from the eBay boards. I measured one of the better eBay boards here: XY LM3886 Kit Review & Measurements. I found the performance to be mediocre at best. I bet many eBay implementations don't even get the data sheet performance out of the LM3886. This goes for the board I measured as well.
As you have observed, the boards are cheap and nasty. I can't even ship the board across Canada for that price!
A good implementation of the LM3886 can sound very nice. As Abrax points out above, the highs can be a bit harsh and the bass could be tighter. But overall, it's not bad. And you can improve the sound quite a bit by adding a regulated power supply or SMPS.
In my Modulus-86, I use a precision opamp to perform error correction on the LM3886. The result is truly state of the art - as you can tell from the measurements: Modulus-86 R2.4: Composite amp. 70W (4Ω) @ 0.0001% THD
However, as you will also note, I do charge more than the eBay vendors. 🙂
Should you wish to optimize for cost, you can always get my LM3886DR: LM3886 Done Right
I get performance that's slightly better than what National Semiconductor (now TI) published in the data sheet.
So, yeah. You can get state of the art performance from the LM3886. It just takes a little work and clever circuit design.
Tom
As you have observed, the boards are cheap and nasty. I can't even ship the board across Canada for that price!
A good implementation of the LM3886 can sound very nice. As Abrax points out above, the highs can be a bit harsh and the bass could be tighter. But overall, it's not bad. And you can improve the sound quite a bit by adding a regulated power supply or SMPS.
In my Modulus-86, I use a precision opamp to perform error correction on the LM3886. The result is truly state of the art - as you can tell from the measurements: Modulus-86 R2.4: Composite amp. 70W (4Ω) @ 0.0001% THD
However, as you will also note, I do charge more than the eBay vendors. 🙂
Should you wish to optimize for cost, you can always get my LM3886DR: LM3886 Done Right
I get performance that's slightly better than what National Semiconductor (now TI) published in the data sheet.
So, yeah. You can get state of the art performance from the LM3886. It just takes a little work and clever circuit design.
Tom
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Lots of blanket statements here 😀
"E Bay boards" by itself says little to nothing; there are hundreds of different products there. (if not thousands).
Some very good, some ludicrous, many in between; you can´t put them all in the same box. 🙄
You can´t test them all one by one, of course, but I guess if you detect one or two are clones of established good designs, you should be safe.
In any case, I bet "established good designs" also have their boards made in China 😛
"E Bay boards" by itself says little to nothing; there are hundreds of different products there. (if not thousands).
Some very good, some ludicrous, many in between; you can´t put them all in the same box. 🙄
You can´t test them all one by one, of course, but I guess if you detect one or two are clones of established good designs, you should be safe.
In any case, I bet "established good designs" also have their boards made in China 😛
I have yet to find an LM3886 PCB on eBay that is "very good". The one by XY is one of the better ones, and even it has flaws (lacking decoupling caps and such). I can usually pick out several flaws in the various LM3886 boards on eBay just by looking at the pictures. That doesn't mean you can't cobble something good together around one of XY's boards, but why? Why not just get something that works out of the box?
Tom
Tom
Agreed entirely.. But THE underlying theme in here seems to be "something for nothing" Or more precisely for as little $ as humanly possible.
Currently Chi-Fi junk via Ebay et al.
Clearly.. human nature at it's best .
But how many times can one buy / try such before making the inevitable value correlation ?
In the least these Forums provide perennial entertainment 😀
Currently Chi-Fi junk via Ebay et al.
Clearly.. human nature at it's best .
But how many times can one buy / try such before making the inevitable value correlation ?
In the least these Forums provide perennial entertainment 😀
True. And an opportunity for me to push my Taming the LM3886 article series, which I completely forgot above. Let me correct that... 🙂 Here's the link:
Taming the LM3886 Chip Amplifier
Tom
I'm sure some do. I'm sure all the cheap eBay folks do. The problems I'm seeing in the eBay designs are not related to the raw PCB material. They're related to the circuit design, which I can glean from the pictures: Lacking decoupling caps, inadequate decoupling if it is there (too low capacitance), no Zobel or Thiele networks, etc. Basic "read the data sheet" stuff. Then you add the crappy layouts, such as those where the power supplies come in from opposing edges of the board. That's a recipe for rail-induced distortion.
There's no doubt that you can find good quality coming out of China. I have no problems with my China-assembled MacBook Pro, for example. Also, nothing stops a western designer (such as Apple or myself) from submitting a quality PCB layout to a PCB manufacturer in China and getting a quality board. I did that for a while. The main challenge there is to find a quality PCB manufacturer. They vary in quality too...
Now all my PCBs are made in Canada. They're slightly more expensive to have made domestically than by a good quality Chinese manufacturer, but the quality is better. The domestic manufacturer also throws in stuff like electrical testing of the boards for a very reasonable fee. This means all my boards are now electrically tested. I charge a premium, but I also deliver a premium product. I also sleep better at night knowing that they were manufactured at Western environmental standards.
Tom
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Thanks for the replies, much appreciated.
I read the same that the amp sounds bad at first but if you strip off all of the components and replace with genuine, also create star ground, it improves a lot. Do you think this enough to take it into audiophile territory have you heard anything about this
Also, there are also a few boards with 5532 opa, people are doing the same and replacing 5532 with Burr-Brown 2134, again saying it sound much better but how much of an improvement i can't make out, they just say it loses that lazy muddy sound
Thanks.
I read the same that the amp sounds bad at first but if you strip off all of the components and replace with genuine, also create star ground, it improves a lot. Do you think this enough to take it into audiophile territory have you heard anything about this
Also, there are also a few boards with 5532 opa, people are doing the same and replacing 5532 with Burr-Brown 2134, again saying it sound much better but how much of an improvement i can't make out, they just say it loses that lazy muddy sound
Thanks.
A ground star is usually among the worst performing implementations, though. You want the lowest ground impedance possible. A ground plane offers the lowest impedance, so you want that. You also want a quiet signal ground or reference ground. This reference ground should also be low impedance (i.e. a plane or pour). You want to join these two grounds at one point. Since all "grounds" will be referenced to this point, you need to pick a point you care about. If you're into high performance, you care the most about the speaker output ground, so you join the planes there. I show why in my Grounding article: LM3886 chip amp grounding.
Bruno P.'s article on ground is a worthwhile read as well: https://www.diyaudio.com/archive/bl...d1460406090-bruno-putzeys-micropre-g-word.pdf
To take the LM3886 close to audiophile territory, you need to follow all the current best practices such that you get the data sheet performance out of the part. A regulated supply will help too. To take the LM3886 into audiophile territory, you need some form of error correction to drive the distortion below audible. Error correction will remove the softness in the bass and the harsh highs and you're left with a super clean amp.
Sure. The '5532 is 40 years old now. The OPA2134 is probably close to 30 years old. Improvements happened during those ten years. They are both excellent opamps for their age. You can get an even more dramatic improvement if you replace them with an LME49720 (or OPA1612, but that requires an adapter as the OPA1612 is surface mount). The improvements are quantifiable by measurements.
Tom
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Thanks!
My feeling is that the parts on the ebay lm3886 boards are fake, replacing with a " superior " op amp may do something simply because it works as it should.
Just difficult to understand how they are knocking out these boards at that price including their mark up, tax, international shipping. Looking at the price list i could not populate these boards with legit parts from digikey mouser for what they are charging for everything. Parts must be fake, low performance
My feeling is that the parts on the ebay lm3886 boards are fake, replacing with a " superior " op amp may do something simply because it works as it should.
Just difficult to understand how they are knocking out these boards at that price including their mark up, tax, international shipping. Looking at the price list i could not populate these boards with legit parts from digikey mouser for what they are charging for everything. Parts must be fake, low performance
Probably govt. subsidised power, low taxes, mass production, No service after sales, Weak Labour laws and labour costs. Readily available schematics. Recycled materials.
My TPA 3116d2 amp stopped working just after couple of days. They are only good to get the feel/taste of the product which later on can be acquired with genuine and well made stuff.
Regaqrds
I've never owned a high-end amplifier, just some consumer A/v receivers, and I've played around with some Class D amps. Last year, I built an amp based on the XY LM1875 board, and I was really impressed with the sound quality - it sounds better than everything else I own. In layman's terms, how are chip amps deficient to the best audiophile amps? Or is it as simple as saying that a well implemented chip amp can be on par with the best? In other words, how much better can it get?
Well, that´s a feeling, isn´t it? 🙂
Any actual measurements to back it?
* to begin with raw parts cost is way lower than what we pay because they are inside China and buy straight from original Factory, no shipping/distributor/salesmen involved whatsoever.
To ship internationally goods must be packed properly, sent by truck to nearest port, loaded into a container, shipped thousands of kilometers, go through US Customs, then by truck to Mouser/Digikey (who also add their own markup and sales tax) , then shipped to you.
A Shenzen or Shanghai manufacturer gets them from across town delivered by a truck paying peanuts.
That alone is a HUGE difference.
Important detail: those parts are exact same as those you can buy in USA, only they chop a ton of deadwood by buying locally.
* salaries are way lower (which does no automatically mean worker quality is lower).
When I started checking because I started being hurt (I manufacture Musical Instruments Amplifiers and Speakers) around 2004/2006, Chinese salaries were around U$60 a Month.
They have been steadily rising, reaching some U$240/270 a Month a couple years ago ... at which time they became "too expensive" 😱 and factories started being pulled out of China and moved to cheaper salary Countries such as Vietnam, India, etc.
Sorry but wrong assumption.
Exact same Chinese made Op Amp from a top brand which you get for, say, $2 in small quantities costs, say, $1,20 if bought by the 100 and 80 Cents if by the 1000. Just check Mouser price lists 🙂
I´m quite certain a Chinese manufacturer pays , say, 45 cents or less if bought across town or at least inside China.
Always for the exact same part.
OF COURSE you can not buy in small quantities, add regular US shipping plus tax, and spend as little as what a large Chinese manufacturer does.
Just to have a glimpse of all that´s involved "all together" please watch this YT video about EÜPA, the World´s largest coffee machine, pressing iron and home grill manufacturer.
They make *all* of fhem, from the $20 ones to the $850 ones, for any Brand you can imagine and then some, some of which you believe are made in Germany, Denmark or Japan.
Think again.
YouTube
It´s a very sobering Video, and it´s already OLD, from 2009, go figure.
Apparently this monster very efficient Factory was moved to "S. E. Asia" (Vietnam?) around 2015 or so.
But the main point is that they work WELL, not a sweatshop at all , quite the contrary, an "Industrial Engineer´s paradise" where "anybody" can work well, any task is split into as many small bits as needed so worker neither needs to be specially skilled nor required to "think", simple tasks are easy to learn, done well, and lend to simplified quality control.
All you need is a lot of workers so tasks can be atomized and a lot of production/sales so they all work efficiently with no waste of time.
Imagine same applied to Audio or Electronics products, from spare parts to fully assembled and you´ll understand the cost differences which today baffle you.
As a side note, no backroom operation done by cheap labour using bad equipment ("poor quality fakes") can compete with these monsters; even if paying/spending more the sheer scale of production makes individual part cost unbeatable.
Do you think a small cheap Factory can make, say, Op Amps for less than what, say, TI can?
I don´t think so.
Only if that is cheaper than a bicycle.
Which was common cross-town transport in China until not so many years ago. (or trike with cargo box.)
Trucks for small goods (chips, not pianos) become/became lower cost because truck companies got better at scheduling consolidation and because a 15mph truck makes more trips per day than a 5mph bicycle.
OTOH, when a *small* package (documents) really-really has to get there before the office closes, in most large cities a bicycle-messenger is still faster than a staffer in a taxi.
Thanks for the replies, much appreciated.
So the lm3886 needs error correction for best results.
Are there any chips that have high performance and don't need it. I am trying to keep the board as simple as possible, low component count.
I have two . Ebay: 123310569845 ( LM1875 )
and 262608980751 ( lm 3875 ) This second board is more complex as it has power supply and output protection built on but the amp itself is simple.
Or have i got it all wrong and all chips need error correction.
What do you think or do you have alternative suggestions.
Thanks.
So the lm3886 needs error correction for best results.
Are there any chips that have high performance and don't need it. I am trying to keep the board as simple as possible, low component count.
I have two . Ebay: 123310569845 ( LM1875 )
and 262608980751 ( lm 3875 ) This second board is more complex as it has power supply and output protection built on but the amp itself is simple.
Or have i got it all wrong and all chips need error correction.
What do you think or do you have alternative suggestions.
Thanks.
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Mr JmFahey:
They fake products.
A few weeks ago I watched a show about life in big cities in China , a guy was selling fakes iPhones , they were so well made that even apple had problems identifying the fake from the authentic.
The guy was selling them for like 66% of the retail price , he was the last piece of the puzzle, those phones were made for 10% of the actual iPhone price ...
They fake products.
A few weeks ago I watched a show about life in big cities in China , a guy was selling fakes iPhones , they were so well made that even apple had problems identifying the fake from the authentic.
The guy was selling them for like 66% of the retail price , he was the last piece of the puzzle, those phones were made for 10% of the actual iPhone price ...
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