Comparing 2 Different LM3886 Amplifier Modules

[spaceman5]

Hi


When searching eBay for LM3886, 2 ready-made modules that appear frequent, are these:

An externally hosted image should be here but it was not working when we last tested it.

As can easily be seen,
the black module has much more components on it, while the green module is quite a minimalist relative to it, in terms of the number of components..


My question:

I unfortunately do not have the circuit for either of these 2,
but from seeing the images, can you predict which one will give a better sound quality?


The easy answer that I could give to myself, is that the black module, since it's richer in components, might be better..

Yet sometimes adding more can do the opposite, when not done right,
and on the other hand doing with little, can bring a purer result..

So the easy answer (the black one) is not necessarily the correct one..

So I hope that from these images you can maybe give a better answer than mine


Thank you very much

 

[Bone]

You cannot assess the quality of sound by the number of components used.
The black module has in addition a speaker protection relay and regulated supplies.
Sometimes less is more!

 

[bullittstang]

I have used the green version and was surprised it sounded as good as it did. Especially considering the price. You will need a toroidal, PSU with caps and maybe a speaker relay/protection as well.
As mentioned the black one is a more complete option, as you only need a toroidal. Can’t comment on the sound though.

 

[spaceman5]

You cannot assess the quality of sound by the number of components used.

Right,
that's why I created this thread.

The black module has in addition a speaker protection relay and regulated supplies.

Right.
The speaker protection relay obviously will not affect the sound quality,
the regulated supplies will.


But there are other components on the black module, that do not exist on the green module,
for example,
there are 4 chips on the black module,
the first pair of them look like 5532,
and the second pair is quite impossible to see from the image..

What is the purpose of them?
(or at least, what is the purpose of the pair that we can see its number.. )

 

[Panelhead]

The black board looks the best to me. Do not like zorbel networks.

 

[spaceman5]

What's zorbel networks?

 

[tomchr]

The speaker protection relay obviously will not affect the sound quality,

That depends on which relay they chose. Some relays do cause audible distortion. Also, relays tend to wear and this wear will cause a degradation in sound quality (audible distortion) over time. Also, relays may not offer any protection when they're needed. Rather, they tend to arc over and self-destruct, usually taking the speaker with them. You can see some examples of that (including some spectacular videos) here: Speaker DC protection with relays

the regulated supplies will.

Regulating the supply for the LM3886 is more likely to improve the sound quality. That part is certainly true.

Tom

 

[spaceman5]

Hi tomchr

Regarding the speaker protection relay:
Scary

BTW, the black module comes as a kit, so whoever buys it, can simply decide not to solder the relay to the board.

 

[00940]

On the black board:
- The lm3886 operating on a lot less than 50V, there's less risk to blow a big relay like that. I woulnd't omit it.
- Regulation is obviously only for the opamps, not the lm3886.
- The overall layout seems much tighter.
- I don't like the fact they omitted the output LR filter.

On the green board:
- The long tracks and the perfectly symmetrical layout don't inspire a lot of confidence in optimal routing.
- Decoupling of the lm3886 doesn't look great on either board but at least the black board has the big caps relatively close by onboard.

Those boards are pretty much low quality stuff. What's the intended use ?

 

[spaceman5]

Thank you very much 00940,
really useful feedback.

On the black board:
...
- The overall layout seems much tighter.

You mean the components are more condensed on the PCB?
It should not matter to the listener in any way.. If I understand correctly..

Those boards are pretty much low quality stuff. What's the intended use ?

Music..

If they are low quality, can you maybe recommend another LM3886 option that is good, if you know one?

 

[neila]

You mean the components are more condensed on the PCB?
It should not matter to the listener in any way.. If I understand correctly..

As Tom, one of our resident experts often says, the layout IS the circuit. A poorly laid out circuit will typically have greater noise than a well laid out one.

If they are low quality, can you maybe recommend another LM3886 option that is good, if you know one?

Er, Tom again... Tom's company Neurochrome has a number of offerings that are extremely well designed and come with first class support from the man himself. See here.

 

[spaceman5]

As Tom, one of our resident experts often says, the layout IS the circuit. A poorly laid out circuit will typically have greater noise than a well laid out one.

Interesting, was not aware of that.
Thanks.


BTW, the black board have opamps and the green doesn't - what difference do they make?
(what do we miss on the green board, due to not having them?)

Tom's company Neurochrome has a number of offerings that are extremely well designed and come with first class support from the man himself. See here.

Nice, but prices are really high,
Hopefully there are other good options..

 

[00940]

Music..

Obviously.

I mean, what speakers will use with them, in how big a room, background music or party level, and so on.

 

[neila]

The prices are certainly higher than a lot of the ebay offerings and I understand that they may be too high for some. I would offer two further comments about the pricing...

If you want to make a presentable amplifier with a decent chassis, then the price of the boards themselves is far from the largest outlay. You've also got to consider the transformer and they are also not all that cheap.

To a very large extent, you get what you pay for in this game. While the ebay offerings seem attractive, they will often come with little documentation, no circuit diagram and you can expect little or no help from the seller if you run into difficulties. Just take a look at this section of the forum to find examples of people that have been tempted by very cheap ebay offerings and then come here looking for help when they run into problems.

I feel that you are probably like I was 12 months ago, in that (reading between the lines), I suspect that you have relatively little experience (I certainly didn't). After much consideration I decided to go with the Neurochrome LM3886DR boards and I am very glad that I did. For me, the extra initial outlay was worth the security that I wouldn't be spending my time on something that I could never get working to my satisfaction.

 

[maty tinman]

I would forget the Chinese LM3886.

From China, only some LJM designs.

L12-2 CFP Output amp 120W*2 8R

by Calvin

...These small modules keep pushing the ELs as if there were no tomorrow and keep cool.

I can confirm ATAUDIOs statements in #15. Transparency, livelyness and control are words I´d use to describe the sonics and are words I got to hear from anybody who gave a listen. These modules are anything but boring.

Since they performed so well not just with dynamic speakers but also with ESLs, we made a small shootout between them and several commercial amps, among them a Accuphase A50.

Well, the King is dead, long live the King. Poor Accu was dethroned within a few beats. Hard to believe but more on the listening panel preferred the small amp (tweaked) instead of the class-A monster. Differences were much smaller with dynamic speakers, but the fact that this amp could sonically cope with the Accuphase was sensational. Not taking build quality and finish into account, those preferring a more relaxed, laid-back performance would still be happier with the Accu. Those liking a lively performance would probabely prefer the small amp modules.

L12-2, powerful, good, low-cost - calvins-audio-pages

L12-2 - modifcations - calvins-audio-pages


L12-2 Power Amplifier - stevesstuffproject

 

[spaceman5]

Music..

Obviously.

I mean, what speakers will use with them, in how big a room, background music or party level, and so on.

6.5", medium size bedroom, placed on a desk, nearfield listening
Using low volume, not high.. The most important thing is sound quality, not volume


neila:
With the prices there, you can buy a fully assembled monitor, not just a module
I prefer to check other options..
Thank you tho.

I would forget the Chinese LM3886.

From China, only some LJM designs.
by Calvin

L12-2, powerful, good, low-cost - calvins-audio-pages

This looks beautiful,
and hopefully sounds as good..

But it is not a module for sale?
Just a PCB design that you download, PCB print, and then you need to buy the parts from elsewhere, and then solder it?

Edit:
Sorry, I now see in the last link, a reference to an eBay seller who sells it....

This looks terrific..
Thank you so much

 

[maty tinman]

Like a good single ended is H2 dominant.

Measurements by vzaichenko

LJM-L12-2-THD-01-kHz-H2-dominance-vzaichenko

[IMG, link] http://maty.galeon.com/WP-imagenes/hum/LJM-L12-2-THD-01-kHz-H2-dominance-vzaichenko.png


LJM-L12-2-THD-20-kHz-H2-dominance-vzaichenko

[IMG, link] http://maty.galeon.com/WP-imagenes/hum/LJM-L12-2-THD-20-kHz-H2-dominance-vzaichenko.png


LJM-L12-2-IMD-14-15KHz-vzaichenko

[IMG, link] http://maty.galeon.com/WP-imagenes/hum/LJM-L12-2-IMD-14-15KHz-vzaichenko.png


And you do not need a preamplifier.

 

[Bare]

Spaceman: Go HERE:
Amp Camp Amp – diyAudio Store
and BUY this... There is an illustrated build guide and a forum dedicated to helping in 'Pass Labs' above.
You will NOT build a better sounding amp..... all brochure babble fanboy claims aside

 

[spaceman5]

maty, thanks again..


BTW
The LM3886 is 2x68W.

For cases where I need much less than that, e.g. 2x15W or 2x18W,
Is there another Class AB amplifier chip, that is the same great quality as the LM3886, but just in lower watt?

But really the same level of Sound Quality like the LM3886..

 

[maty tinman]

Measurements at 15 watts. 8 or 10 watts too.

One thing more, vzaichenko usually takes measures at 15 watts -> I suppose the same with LJM L12-2.

In the real life, in home, we listen at 8 - 10 watts with "normal" speakers off course.

If the speakers have very high sensitivity, with 1 watt is OK.