digital controlled PWM amplifiers

[Kjeldsen]

That is what I mean. And looking at distortion graph, it's more like 0,1% than less.

When I look at even cheap analog class d it's 0,01% or even less. I know distortions is not everything, but 0,1% does seem to be a lot.
TACT or Lyngdorff can go way below these figures also with equibit technology.

 

[maciekw]

I compared the QLS QA100 amplifier amplifier modules based on Hypex UCD400Hrx. The answer, which amplifier is better is not easy. Sound similar. In some ways, the highs are worse in the amplifier QLS, but on the other hand, the mids sound very transparently and well. QLS has better space and location sound. Bass is comparable. A little weird, because Hypex has several improved specifications.

 

[sharpi31]

My SMSL Q5 arrived today. I connected it via USB to a Raspberry Pi B running Volumio 1.5. After rebooting the Pi it recognised and automatically selected the QAMP playback device (no issues at all). I've successfully tested 16/44.1, 24/44.1 & 24/96 files. There is a minor glitch (very low level) when changing tracks, but nothing when tracks are played in a sequence as part of a play list. I'm very impressed with the Q5. Dynamic, punchy, deep bass, and very layered and detailed mid/top (low level brushed cymbals are crystal clear over louder lead instruments). I'm still using the laptop-style SMPS that came with the Q5. I have a diy 25V linear supply with 750VA toroid and 88000uF caps ready to go, but want to get to know the amp with the SMPS before changing.

For £80 delivered this thing is great, if you have digital sources. I've not tested the analogue input yet. It's funny to think how good the Sonic Impact T-Amp seemed a few years ago, considering how much more you get today from the Q5.

 

[Julf]

When I look at even cheap analog class d it's 0,01% or even less. I know distortions is not everything, but 0,1% does seem to be a lot.

Have a look at the specifications of any of the highly regarded tube amps - it might put things in perspective It is rather unlikely that 0.1% THD would be audible.

 

[bearberry]

...how much more you get today from the Q5.

I agree, seems to be excellent value. I've had a Q5 for about a week. Very well packaged for shipping, and neatly presented/accessorized. See pics (pardon the quality on a few of them!).
Sounding good so far, although three times now the left channel hasn't worked when first turned on. Will be contacting the seller. I think it's probably a bad internal connection. Very nicely made judging from the exterior. A Breeze Audio 2.1 arrived today and the SMSL is clearly better finished, though the Breeze is fine.

 

[bearberry]

Update - the left channel of the SMSL Q5 quits working when the amp is turned off and on again. Pulling the power plug for a few seconds gets it working again. I bought the amp from Shenzhen Audio. They've been very responsive. Latest word is that the manufacturer is going to revise the unit. I noticed the amp currently is not available on the Shenzhen site.
I hope that a fix is coming soon, as it's a nice amp. Pain to use right now though.

 

[sharpi31]

I've had the missing left channel issue a few times, but only when I've broken the USB connection with the amp powered up. After plugging in another USB source the left channel goes until the amp power is pulled then reconnected.

With (both Raspberry Pi & Cubox-I) USB source connected and switched on, and amp powered up, the fault has never occurred (I need to break the USB connection to trigger it). Unless I'm messing about changing things my kit stays powered up for days at a time.

 

[robert1325]

tWould you say the Q5 is a good alternative to buying a TPA 3116/-10 and USB DAC combo? I am looking at having a little minimalist setup and the one box Q5 appeals to me for that reason, even though I haven't found any comparisons with the TPAs.

 

[sharpi31]

I've got both the Q5 and Audiobah TPA3116. Both are very good, but I'd definitely go for the Q5 for use with a laptop if there wasn't a decent USB DAC available (TPA3116 with laptop analog output won't compete with Q5). The Q5 can behave a bit strangely if the USB source is disconnected then reconnected, so I'm in the habit of switching it off with the PC and then on again after the PC boots.

 

[robert1325]

Thanks, I might just order straight from Shenzen to get the newest version. I read they fixed some issues now.

 

[AudioLapDance]

I don't know about 'newer' chips but I have the DDX320 and UD20:



DDX upgrades: "schlocky" (ha, that's what the spellchecker suggested!) diodes, 22,000uf/63V ps on board!, 3x pan FM 1000uf/50V on ps, SM caps and FM electro on ps vias under chips, OSCONS on key digital chips, separate 9V adapter ps for digital section and FM 2700uf on pcb, superclock with own 12V adapter ps, ...

UD20 upgrades: 4,700uf/35V ps on board!, 2x pan FM 560uf/35V on ps, SM caps and FM electro on ps vias under chips, OSCONS on key digital chips, ... and adding individual 3.3V regs for the key digital sections , ...

---------------------------------------------------------------------

The DDX is 2.1, has way more power and lots of cool functions (sub xo, eq) via it's remote.

The UD20 is great if you don't need a lot of power or toys, just good 'ol stereo.

Both work on 12V SLA ... so I'm gonna try 'em in the .... car with my notebook or laptop!



PS What are the "newer" / better digital chips these days?!?
There's so many technologies and similar part#: TDA, TPA, TSP, PTSD, ...

If your up on the industry, can you give us a short list of the current offerings.

Thanks so much and cheers,
Jeff

 

[maciekw]

another pure class d amplifier

I found very interesting chinese PCM2PWM amplifier: d.sound d310.
Specyfication:
Distortion: thd + n = 0.008% @ 10W / 1kHz / 8 Ω / 44.1K coaxial input
SNR: 95dB
Efficiency: "90%
DNR: 103db
Power supply rejection ratio: 80db
3 digital input: USB, coaxial RCA, optical fiber
1 analog input: RCA
Digital format: 44.1k / 48k / 88.2k / 96k / up to 24bit192k
Input power: AC 90-240V 50 / 60Hz
Output Power: 80W & 8Ω 120W & 4Ω / thd <3%
Distortion: thd + n = 0.008% @ 10W / 1kHz / 8 Ω
SNR: 95dB
I compare this amplifier with ucd400hrx based amp and qls qa 100. First is typicał analog2pwm amp, but second amp is pcm2pwm. I find d.sound is better than qls in all aspect of sound. Larger base bass, better treble and improved holographic great location.
There is only one problem. This amp is only on chinese market. My friend was in China last week and bought this amp for me.

 

[mikey_audiogeek]

I would like to buy one of these D.sound amplifiers!

Cheers,
Mike

 

[Kjeldsen]

here is one more

150w pure fiber coaxial digital amplifier USB DAC audio decoder remote small amplifier amp-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

This one is pure T.I. where the D.sound is D2audio+T.I.

 

[mikey_audiogeek]

here is one more

150w pure fiber coaxial digital amplifier USB DAC audio decoder remote small amplifier amp-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

This one is pure T.I. where the D.sound is D2audio+T.I.

Great find - thanks!

 

[lithoc]

Hi ,

Just found out there's more, but things to look out for the is USB audio, some are stuck with 16bit 44.1/48khz sampling rate

HIFI Digital Amplifier Pure Class D Amp No Need DAC TAS5342lA 2x100W 44.1k/48k/88.2k /96k MAX 24bit192k Coaxial Stereo USB Audio-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

D802 pure digital amplifier remote USB / optical / coaxial input 192KHZ 80W +80W 2.0 channel amplifier-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

D302 DC15V 4A 30W+30W 2.0 channel pure digital amplifier /192k Coaxial Optical USB soundcard super TA2024 TA2021-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

 

[von Ah]

These new finds look very interesting. Thanks for sharing!

 

[jamesblonde]

I do not like any amplifier that does not maintain flat response into non-resistive loads (ie real speakers). None of the TI/TacT designs that I know of are load invariant.

Afaik, the impedance of the speaker must be in a certain range because it affects the cutoff frequency of the low pass circuit. If you really want to run 16 ohm speakers, you can just change the value of the capacitor and/or coil in the low pass filter.

 

[jamesblonde]

here is one more

150w pure fiber coaxial digital amplifier USB DAC audio decoder remote small amplifier amp-in Amplifier from Consumer Electronics on Aliexpress.com | Alibaba Group

This one is pure T.I. where the D.sound is D2audio+T.I.

$38 for an Equibit amp? I'm very curious to hear it. Too bad the postage is nearly $90!

 

[abraxalito]

The real price (on Taobao) is something around $100. If you look carefully at that Aliexpress page, the shipping fee they're asking is $153.... Here's one on Taobao - http://item.taobao.com/item.htm?spm=a230r.1.14.4.AUEty4&id=43291747349&ns=1&abbucket=17#detail