Amplifiers and Price

[Czepa]

I'd love to build my own amplifier but now is not the time. id learn every detail of how they work, build it then probably forget majority of it. so im starting out buying good solid hardware and just building some speakers like ive wanted to do for many years (http://www.troelsgravesen.dk/Faital-3WC-15.htm#SPEAKER-KIT if you're wondering)

THREAD: Cheap amplifiers, ive tried them, i like them, they are cool and its amazing how much amplification you can get out of such compact (fist sized) devices that cost less than a carton of beer. this latest one i have is a AU$43 TPA3116D2 amp and it drives my 10" vintage peerless main 3-way floorstanding large volume vented boxes very close to their limit. the problem is (I THINK) they are running the chips as series rather than having one run as a filter and the second as amplification like i read somewhere... or they are doing some simplified circuit to keep it compact and simple, but its not bad like the last one which used to bleed electrically between the channels. there is a terrible hiss between 50-80% volume though which limits my ability to leave the computer output at a set volume and not be auditorily fatigued after leaving the speakers on standby for hours whilst reading or browsing forums. this has pushed me to change everything and buy a COMPLETE new setup- the plan: computer -> Zoom UAC-2 as a DAC, headphone amp and mic input -> Balanced TRS out to XLR input of (most likely) Behringer A800 -> 8 Ohm floorstanding loudspeakers

QUESTION: When is cheap(er) nasty and how would i know, is brand name everything? i know a brand being well known and reviewed gives insight and a path already walked, but if you were to go in blind you could equally make a mistake on the well known budget brands (nobsound? SMSL? AudioEngine?) as you may on a chinese no-brand. I know more components on boards, more chips etc. does not necessarily equal better. however, to the untrained eye how would you tell something is worth putting down cash or staying away from? i hear 'good capacitor brands' 'higher voltage caps' is there anything else?

To my eyes the berry A800 looks maybe a little bland and simple on the inside, but it has a good review here and is even labelled as a 'REFERENCE' amplifier so im inclined to lock it in but there are 2 very solid contenders in my mind, if not for the increased component count, the independent volume control is desirable (keeping "set" gain early in the chain) and having a dual mono architechture or the idea of DASH makes me curious (Class D chips feeding power to Class AB) if i can get the best of both worlds and still have audiophile grade performance and FLAT response. so what shall it be? ditch the idea of being able to deafen the neighbors and make more practical and probably better sounding speakers with one of the chinese amps? or go for broke on the behringer A800? why SHOULD i stay away from the chinese amps? im kind of tempted to just buy the qiushuo in addition just to test it cause the dual design mono looks so cool.

being my first thread please move it if this is the wrong section. photos included below:
AU$43 TPA3116D2 claimed 50W+50W

AU$<400 Behringer A800 220W+220W 8Ω

chinese ¥1288/AU$268 Qiushuo Amplifier dual mono LM3886 120W+120W(8Ω ???) im sure is running this: https://www.ebay.com.au/itm/LM3886-...-120W-120W-HiFi-Stereo-2-channel/272913081255

AU$500+ but could probably find cheaper somewhere Nobsound PA-10 45W+45W(8Ω) suspected DASH AB amp stating:
Amplifier IC: Sanken SK18752*4 balanced working voltage 54V
Op amp IC: NE5532*5+NE5534*2 |-------| Volume IC: JRC-NJW1194

IF instead of this thing having bluetooth (why?) and XLR inputs, it had a USB input -> DAC chip and separate amp circuit for headphones with its own volume knob this would be a computer hifi killer and everything could be settled lol. many people would pay exotic prices for such a piece of kit. FYI: im looking for clean flat accurate reproduction of sound in my setup and im trying not to compromise on quality.

I hope you find this interesting, its been fun putting all these questions together. even for different use cases, what advice should the beginner take heed of to either avoid garbage or score audiophile grade gear with low cost in mind?

 

[JeffS7444]

I think in the case of first-rate products, you are paying for expertise in PC board design and attention to detail, like not using X7 ceramic capacitors in situations where C0G is called for, but I'm no expert at judging by visual inspection.

But having said that, in the case of the Behringer, I see what appears to be a bare folded aluminum chassis which might provide excellent shielding, and I see where they've masked off paint along the top edge of the case to provide good electrical connection to the top cover and front panel, which are exactly the sorts of details I like to see.

In the case of the Quishuo, if all parts are anodized aluminum (I can't tell from the photo) and simply bolted together, that's kind of crappy as far as shielding is concerned, because anodized surfaces are poor conductors of electricity, and I'd want to see some signs that anodizing has been ground away in key areas, like the earth connection to the chassis.

And when socketed opamps are marketed as an audiophile feature, I think it smells a little like B.S. . Really the only legitimate reason for putting opamps in sockets is to facilitate future servicing, not that they should need any.

 

[somebodyelse]

The TPA3116D2 is the specific TI amp chip not an indication that there are 2 of them.

I don't have any easy answer for the rest. Until they get measured we can only guess and generalize, or check out reports from a subset of skilled customers. You'll find threads here and at diyaudio.com going into some detail about specific models, and some people measuring them. It seems to be a truely mixed bag with some excellent and others appaling or even unsafe.

You'll find manufacturers that seem to take more of an interest in quality and even publish measurements - you'll find representatives from 3E Audio and Aiyima here for example.

Behringer are big enough to be (more or less) a known quantity with a reputation for value engineering, occasionally to the detriment of later versions of their products. Remember that anyone can slap a 'reference' label on something, and that a proper reference needs to be consistent, not necessarily good. The A800 has been measured here so there's no need to guess about its performance.

 

[Vini darko]

I'd trust the berhinger most out of that lot. Plus it's a well backed up global pro brand. But they're £169 in uk so much better value.

 

[Czepa]

@somebodyelse thanks for the correction, i edited the original post
@Vini darko when i found it i knew my search was over and i didnt have to take a risk. plus the immense power gives so much future expand-ability, plus being able to operate in bridged mono, it will be something i use for a long long time.

In the case of the Quishuo, if all parts are anodized aluminum (I can't tell from the photo) and simply bolted together, that's kind of crappy as far as shielding is concerned, because anodized surfaces are poor conductors of electricity, and I'd want to see some signs that anodizing has been ground away in key areas, like the earth connection to the chassis.

And when socketed opamps are marketed as an audiophile feature, I think it smells a little like B.S. . Really the only legitimate reason for putting opamps in sockets is to facilitate future servicing, not that they should need any.

well theres nothing stopping me from taking sandpaper to it myself and if it were to sound off in any way id certainly be investigating it, plus there is a ground through the power socket which looks like is being utilized. this is a better closeup of the suspected board being used (from another source) except the caps actually say RK12 not RI14

In the case of the Nobsound @JeffS7444 the OP-Amp chips might be being used as filters? could this nerf the sound at all?
going balanced input i hope will be worth it cause its been really hard finding anything that has XLR input except the SMSL DA-8S but i assume ANY balanced amp will be better and utilize the balanced inputs with appropriate circuits.

the zoom UAC-2 has 34ohm headphone output which should drive my 250ohm (actually 267) DT990 headphones just fine and i dont have a desire to be able to deafen myself with them. so i consider myself very lucky to be able to get a sweet setup for under 1000AUD before speakers everything considered.

 

[JeffS7444]

View attachment 91779
In the case of the Nobsound @JeffS7444 the OP-Amp chips might be being used as filters? could this nerf the sound at all?

I cannot tell just by looking at it. There are excellent Chinese amplifiers out there, and others which might be better as the basis of a fix-it project. But of the amps you've listed, I too would opt for the Behringer A800.

 

[Czepa]

ok but the main problem i have... the behringer amp is sold out EVERYWHERE. it could be at my house by christmas at the earliest.. whereas the chinese dual mono amp i could maybe have here before december. -- ive searched everywhere for a schematic of that lm3886 board pictured and cannot find it. if someone experienced can give me a positive opinion of the qiushuo i am thinking of just pulling the trigger. if something like this is a bomb audio setup i could see myself building amps and speakers to sell as cheap bundles for people wanting good audio here in western australia, if i get the itch for learning over the next year as i get this setup working and sounding great. does this chine any light on the pedigree of the chinesium?
two mono modules, each integrating 2 LM3886 amplification chips in Class AB, coupled to 2 AOP NE5532D mounted on DIP8, for a total of 4 amplification chips. With these components, the amplifier is able to output 2*120W

 

[somebodyelse]

The named components can give an idea of the best case performance but not the worst - the implementation is everything, and some are easier to screw up than others. Neurochrome has a guide on how not to screw up the LM3886 for example. Note that it's not just about the schematic - layout matters, and some datasheets suggest PCB layouts for the critical bits, but designers don't always take any notice. Occasionally someone does something unusual to surpass datasheet performance (Neurochrome composite amps handily beat datasheet LM3886 performance for example) but that's very much the exception rather than the rule. Falling short of datasheet performance is common. Without measurements it's near impossible to tell one from the other, and we don't have measurements of the Qiushuo. It's up to you whether you want to gamble with an unmeasured one, or go with something that's been measured like some in the TPA3255 threads.

 

[Bob-23]

"Chips are alright" - I use the 5532A in headphone amp builds and in eq builds: it's good and proven, wide(st) spread technology. They woudn't be necessary in such an amp, it's a very minor contribution to the amplification. 'Socketed' is always good, exchange is easy.

I used the 'weaker brother' of the LM3386: the LM1875 for a 20W amp build, and I was astounded by its good performance.

Rod Elliott (on his great ESP-site) praises the LM3386, similarly:
"The sound quality is very good indeed - as I said at the beginning, I would call it audiophile hi-fi, but with caveats." His schematics is close to the datasheet's 'typical applications'.
https://sound-au.com/ >Project 19
But read about the 'caveat'.

But, of course, as "somebodyelse" said, we don't know the respective implementation in your case, in particular, as they have apparently deviated from the (relatively uncomplicated) 'typical applications' (paralleled the chips & coupled with 5532).

Nontheless, I, personnally, wouldn't hesitate using the LM3386 as such (knowing the LM1875). You might take the risk, or you find another amp, including the schematics, with that chip (more closely to the typical applications.)
https://www.ti.com/lit/ds/symlink/lm1875.pdf?ts=1604865874538&ref_url=https%3A%2F%2Fwww.google.be%

In any case, make sure, your coming amp is equipped with a muting- and dc-protection circuit (by relays).

EDIT:
Just've reread Rod Elliott's project 19:
"While parallel operation is often recommended, I absolutely do not recommend that you run the amps in parallel. (...) This causes overheating and will invoke the wrath of the protection circuits. I know this from personal experience working on a 'product' that used LM3886 ICs in parallel - it was a disaster!"

So, you'd better not get that amp!