SMSL I just got their PL20 CD transport. Looks great and wasn't expensive. Very good for the money.
New world of HiFi with Chinese Class D Amps.
- Thread starter P.M.B.66
- Start date
tadawson
Well-Known Member
"Garage sale"? Hardly! Newer is rarely better (other than in the minds of the sales and marketing pukes that try to convince folks to $pend more on an actual downgrade. . . ) Why do you suppose that the FTC just released new regs to reign in the bull$h1t in Class-D (and other amp) advertising?
And Chinese stuff sounding better . . . Bwahahahahahahah! Do you listen to cow flatulence as well? Specs (that are met) exceeded the ability of human hearing to differentiate decades ago . . . and falsified specs have sucked since the dawn of time . . .
And *EVERY* amp I own will meet it's specs! Whenever I rework something, it gets a full test - sustained load, etc.
And never said that Class D can't be decent . . . I said that *THIS* class D appeared to be a streaming turd based on published tests (no matter what the price) and that the offshore non-name brands are notorious for utter BS specs.
tadawson
Well-Known Member
If I'm putting it on the road, the size and weight matters. If it sits in the house, I could care less, myself . . . and switch mode amp specs are not using the same metrics - there is a difference, just not as much as it appears. The Cl-D is using very short term peak power ratings, and more "classic" amps were using long term continuous (as the FTC has now mandated for all).
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knotscott
Super Member
I bought an Aiyima A07 Premium with the 48V 5A PSU in hopes of replacing my ailing B&K ST-140 as a woofer amp in my bi-amped system. Even with an opamp upgrade and the beefier PSU, the bottom end just didn't have the impact and control that the bass from the ST140 had. I was pretty disappointed that it wasn't going to be the cheap fix I had hoped for. It now resides in the basement as a bench amp. I'm sure there are better examples of excellent Class D amps out there that have higher damping factor and the ability to drive woofers hard in the bottom octaves.
I ended up springing for a Linn LK140 that really hits hard with excellent control....it was quite a bit more money, but I got the performance I wanted.
I ended up springing for a Linn LK140 that really hits hard with excellent control....it was quite a bit more money, but I got the performance I wanted.
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The variables are different to a certain extent indeed.
I'd happily run my home rig on class D, but the current mix of HiFi and PA amps (all class A/B) serves me well too. The main benefit of the smps stuff I'm eyeing to me is that I could run my main system through one device that feeds all speakers (which requires an internal crossover next to amplification).
Chances are I'll experiment with both boat anchor amps + external crossovers and class D (or H) integrated solutions.
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Hammett
Active Member
I am just impressed that your ears are so finely tuned that you can tell the national origin of the amplifiers that you use.
RVT1K
Super Member
My experience is with the Fosi V3 Stereo w/ the 48V - 5A power supply.
First impressions were that it felt solid and well made with good fit and finish. My second impression was that the speaker terminals will not fit standard double-banana jacks. I wound up soldering copper ring connectors on my speaker cables.
I used mine as the top end of a bi-amp system with a Adcom GFA555 II on the bottom. The speakers were B&W DM604 S3. I can't say I heard anything different than with bi-amping with another Adcom GFA555 II on top.
I found my Fosi amps were dead quiet and never got very hot even after extended periods of rockin the house.
It does seem to me that many of the recent crop of class-D amps often show a rated total power output that is higher than the rated output of the included power supply. I knew that going in so it was not a concern to me. I was more interested in experimenting and the price-point made it attractive to me.
First impressions were that it felt solid and well made with good fit and finish. My second impression was that the speaker terminals will not fit standard double-banana jacks. I wound up soldering copper ring connectors on my speaker cables.
I used mine as the top end of a bi-amp system with a Adcom GFA555 II on the bottom. The speakers were B&W DM604 S3. I can't say I heard anything different than with bi-amping with another Adcom GFA555 II on top.
I found my Fosi amps were dead quiet and never got very hot even after extended periods of rockin the house.
It does seem to me that many of the recent crop of class-D amps often show a rated total power output that is higher than the rated output of the included power supply. I knew that going in so it was not a concern to me. I was more interested in experimenting and the price-point made it attractive to me.
It's a Brave New World...
I am not personally using any Class D amps but I gave a friend a Fosi and it works quite nice for what he does at his place. I think he likes the ability to send music via bluetooth from his computer to the Fosi. And then it also can do TV sound and CDs.
I am not personally using any Class D amps but I gave a friend a Fosi and it works quite nice for what he does at his place. I think he likes the ability to send music via bluetooth from his computer to the Fosi. And then it also can do TV sound and CDs.
Variety is the spice of life, isn't it.
But anyhoo, back to fun with class D: I'm running my ZK1001b with a battery to test a speaker I just swapped a new tweeter into, only to notice the tweeter die again after a few hours of playing.
Or at least I thought it died initially. Remembered that some of these amps drop down in high frequency response depending on presented load fast plus that it's been ages since I charged the connected battery, so figured I might as well try charging the battery before opening the speaker again. And hey, presto, a charged battery means my tweeter is back in business again.
You can't even see the amp on the picture.
The battery on top of it is holding it down so it will stay put, the speaker cable might drag it off otherwise.
But anyhoo, back to fun with class D: I'm running my ZK1001b with a battery to test a speaker I just swapped a new tweeter into, only to notice the tweeter die again after a few hours of playing.
Or at least I thought it died initially. Remembered that some of these amps drop down in high frequency response depending on presented load fast plus that it's been ages since I charged the connected battery, so figured I might as well try charging the battery before opening the speaker again. And hey, presto, a charged battery means my tweeter is back in business again.
You can't even see the amp on the picture.
The battery on top of it is holding it down so it will stay put, the speaker cable might drag it off otherwise.
You waste power about 2-7% on low but at high the number is up to 50%. So yes if there is no power there is no high. Commonly the understanding is that low is more power hungry but it seems that no one is talking about the waste at high most as heat.
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I agree about the power to a point. 300W for example is a peak power with the max power supply. For example Aiyima A07 Premium with 48V 10A is rated 300W peak and 250W nominal. Hmmm maybe or maybe not. I think it might preamp has some effect and the speakers used. Maybe in a perfect world in a controlled test but I think the nominal is closer to 200W. That's already a good number and if it sounds good that's all that matter.
I have two Aiyima A07 Premium's (2 x 48V 10A power supplies) Bridged and Bi Ampling low and High separate. $55 amp + power supplies it does a good job well over it price.
80's kit amp would sound very different. I'm guessing that you have had it for a very long time and your ears are custom to it. It will take possibly weeks to train your ears to something else.
That said mono block setup gives you power but no control of the high and low. Next time try two stereo amps one for the high and second for the low. This will give control for the subs and tweeters separate.
PTL-Pioneer
Super Member
I'm all for trying out something of that ilk,I was always just concerned if they blow up, they might take legitimately take my speakers out with them. Do they all have speaker protection?
There are lots of people on here running different Chi-Fi Class D amps. I have not read about any bombs going off. I have 2 in regular rotation and/or use, no booms.
And what do you mean by blow up? maybe some hyperbole
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PTL-Pioneer
Super Member
Sorry, I should clarify, I just meant if they developed a fault and something shorted or whatever that they might not have a speaker protection circuit, which could damage or destroy speakers.There are lots of people on here running different Chi-Fi Class D amps. I have not read about any bombs going off. I have 2 in regular rotation and/or use, no booms.
Amd what do you mean by blow up.aybe some hyperbole
I have not read any reports of Chinese hifi explosions!
Note these are from $50 up. Expensive also fails. If you have some specific brand in mind or model you can Google for example with these words. "brand word" fails. It will give you some sort of answer what can go wrong and all the brands have something $50 to thousands.
Power supplies are one of the main fail when using no brand bricks. Also because most of these have swappable op amps user error can damage the amp. Over powering another issue that will shorten the life.
Compared to your vintage gear Class D sounds very different. More modern sound maybe. Today just as good. But if your ears are custom to older amps it might take few weeks to train your ears to a new sound. This is maybe the biggest hurdle after years of listening vintage amps.
J English
Super Member
Have and use several, with good results. Started with the original Aiyma A04 and A07 amps. Use a SMSL AO100 bluetooth amp in the dining room system; not a ton of power, but perfect for that medium size room where we want soft to moderate volumes. I am currently using the new Fosi BT20A MAX in my bedroom system, perfect for that setup, has two RCA inputs plus Bluetooth. I also use two Aiyima A07 MAX amps as monoblocks in a summertime porch system. I also have the Fosi V3 stereo amp, nice volume control with that one. I also use and love my small Schiit Gjallarhorn amp (class AB) paired with their Saga 2 preamp for my main workroom system.
With my smaller size rooms, multiple systems, and listening at light to moderate volumes, these amps work perfectly. I have established nice relationships with the Aiyima and Fosi audio support folks, they are very responsive to questions and suggestions.
All of the op-amp rolling is unnecessary for good sound, that was more of a marketing ploy. I think these smaller amps are not ideal for speakers that are very demanding or where people want to play continuously loud. For that, the best class D option are Hypex or Purifi amps ($500 and up).
With my smaller size rooms, multiple systems, and listening at light to moderate volumes, these amps work perfectly. I have established nice relationships with the Aiyima and Fosi audio support folks, they are very responsive to questions and suggestions.
All of the op-amp rolling is unnecessary for good sound, that was more of a marketing ploy. I think these smaller amps are not ideal for speakers that are very demanding or where people want to play continuously loud. For that, the best class D option are Hypex or Purifi amps ($500 and up).