Cheap DAC working well

Feanor:
Adaptor mod - I refer to the post #76 above. Useful ?
SMSL 1955+ has been launched over 1 year , Feb 2012. I had one in Feb 2013 and the 2nd in Apr 2013 with both labelled "1955+". The 2nd one may have the DAC enhanced for a little higher gain than my 1st one ( in 2 months' time.)

When I first hooked up the SD-1955+ to the Visio TV set S/PDIF output, it was loud static noise only. The problem was solved by switching the output from Dolby Surround 5.1 to PCM.

Do I miss anything using the PCM instead of Dolby Surround? The DAC output is fed through an Adsom GSA-700 in my main audio systme.

Are there a cheap DAC option with native Dolby Surround 5.1 support?

Yes, you're correct. The SMSL SD-1955 decodes stereo (2 channel) PCM signals only -- this is the case for almost all audiophile DACs. The SMSL only outputs stereo so you don't get any surround, but the 2 channel sound is just as good quality as Dolby Digital 5.1's.

There are two basic types of Dolby "surround", Dolby Digital and Dolby Prologic. Dolby Digital requires 5.1 channels of discrete input whereas Dolby Prologic synthesizes 5.1 channels from stereo input; in principle you could feed the SMSL's stereo output to a Dolby ProLogic decoder to get synthesized 5.1.

There are relatively inexpensive DACs that decode Dolby Digital but I have no recommendations.

Hi all,
i'm also interested in the Teralink-X2 / X1 U9VA Linear Low noise Power Supply (230vAC version) for the SMSL 1955+.

what are peoples opinion on it?

thanks

Quote:

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Originally Posted by half5777

Hi all,
i'm also interested in the Teralink-X2 / X1 U9VA Linear Low noise Power Supply (230vAC version) for the SMSL 1955+.

what are peoples opinion on it?

thanks

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Do you have a link for that power supply? I might be interested. Many people insist the linear power supplies are superior to switching power supplies.

http://www.teradak.com/en/product_view.asp?ID=209but i just realised that the polarity is different, can anyone suggest a cheap alternative?



i was thinking about this Amazon.com: Anker Pro 10000mAh Multi-Voltage (5V 9V 12V) Output Portable Power Pack External Battery Charger for iPads, Samsung Tablets (Samsung 30-pin adapter not included), iPhones, Android Smart Phones, Camcoders, Digital Cameras / DV Recorders, P batteries are a clean source of power.


what do you think Feanor?

Quote:

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Originally Posted by half5777

[URL]
i was thinking about this Amazon.com: Anker Pro 10000mAh Multi-Voltage (5V 9V 12V) Output Portable Power Pack External Battery Charger for iPads, Samsung Tablets (Samsung 30-pin adapter not included), iPhones, Android Smart Phones, Camcoders, Digital Cameras / DV Recorders, P batteries are a clean source of power.

what do you think Feanor?

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That Anker Pro device is interesting because -- if I understand it's capabilities -- it provides a battery power source for the attached device, (e.g. an SMSL SD-1955). Battery power, in principle, is the lowest noise power source possible. If you get one, definitely let us know how it works out.

Half5777 and others,

I'm linking this thread that casts a lot of doubt on the supposed benefits of battery power for DAC and, also I guess, phono preamps, etc. ...

"Battery driven DACs" at AudioAsylum, see HERE.

Quote:

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Originally Posted by kaushik741

Hi Feanor ,

Thanks for the reply and mail . I had also reverted back to your mail .

Just to be clear about the FR/EMI factor , as the PSU is outside the unit shall RF/EMI still can affect the audio output if same PSU is Used .

For OPAMP , did you tested LM 4562 or LME49720 ?

....

Regards

Kaushik

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So I tried replacing the OPA2134 opamps in my SMSL SD-1955 with LME49720's. The LME49720 is a recently, highly touted opamp especially developed for audio applications.

I listened for about 4 hours in total which ought to be enough to burn in a tiny component such as an opamp. My strong impression is that while the LME49720 is sounds transparent, the top highs are far too shrill for my liking -- this might not be the cases with a different downstream amp than my Class D Audio SDS-258. As typical of class D amps, (I'm sure there are exceptions though), the SDS cuts no slack for harsh records or upstream components.

So I wasted no more time listening to the LME49720 and rolled two of the three, i.e. the I/V / gain pair, for my trusty paired OPA627's. Yes, opamps do sound different from each other. The OPA627's are distinctly smoother on the top end and much more listenable at least in combo with my components. I suspect I do loose some resolution and perhaps transparency with the LME49720 though.

I'm thinking the OPA627's are maybe just too smooth and I might go back to the OPA2134's as the best compromise.

By the way, I'm currently using my SMSL SD-1955 because my Schiit Bifrost is back at Schiit Audio being fitted with the Uber Analog upgrade. See the August '13 edition of Stereophile where in the reviewer stated that the Bifrost offered the best value for money of any component he had reviewed.

Quote:

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Originally Posted by Feanor

So I tried replacing the OPA2134 opamps in my SMSL SD-1955 with LME49720's. The LME49720 is a recently, highly touted opamp especially developed for audio applications.

I listened for about 4 hours in total which ought to be enough to burn in a tiny component such as an opamp. My strong impression is that while the LME49720 is sounds transparent, the top highs are far too shrill for my liking -- this might not be the cases with a different downstream amp than my Class D Audio SDS-258. As typical of class D amps, (I'm sure there are exceptions though), the SDS cuts no slack for harsh records or upstream components.

So I wasted no more time listening to the LME49720 and rolled two of the three, i.e. the I/V / gain pair, for my trusty paired OPA627's. Yes, opamps do sound different from each other. The OPA627's are distinctly smoother on the top end and much more listenable at least in combo with my components. I suspect I do loose some resolution and perhaps transparency with the LME49720 though.

I'm thinking the OPA627's are maybe just too smooth and I might go back to the OPA2134's as the best compromise.

By the way, I'm currently using my SMSL SD-1955 because my Schiit Bifrost is back at Schiit Audio being fitted with the Uber Analog upgrade. See the August '13 edition of Stereophile where in the reviewer stated that the Bifrost offered the best value for money of any component he had reviewed.

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Hi Feanor

On the opamp issue I followed your upgrade for the SMSL using the 2134 and 2604. I can honestly say I prefer this improvement in sound, its maybe a little more melow but I am hearing more detail with nice soundstage. This opamp upgrade is staying in place for me. I measured the SMSL case temps using a 3M IR meter and after running the unit for a couple of hours the temp was 28- 32 oC. This is more than acceptable. I have fitted some PC RAM heatsinks to the opamps just to dissipate the heat away from the opamps more effectively. You can buy these from Maplins, they are self adhesive.

The Teralink (Teradak U9VA) power supply has also made a difference. Even before upgrading the opamps the bass sound was the area of improvement, it is tighter with a more defined bassline! I can verify the Teralink U9VA PSU as a good alternative. It is well put together and appears a quality Chinese item like the SMSL.

Cheers
Andy

How much shall I expect to pay for the OPA2227 in the US? There are so many seller of the opamp on Ebay, how do I know whether I am getting a real one?

Is this a reliable seller? OPA2227P High Precision Low Noise Audio Op Amp OPA2227 | eBay

Quote:

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Originally Posted by keilau

How much shall I expect to pay for the OPA2227 in the US? There are so many seller of the opamp on Ebay, how do I know whether I am getting a real one?

Is this a reliable seller? OPA2227P High Precision Low Noise Audio Op Amp OPA2227 | eBay

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Sorry for my delay in replying.

Personally I would prefer to buy any sort of electronic component from a well-established North American supplier of possible; this way you will be assured that the component is legitimate and not counterfeit. Reputable suppliers ...

• Mouser.com, HERE
• Newark, HERE
• DigiKey, HERE.

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Originally Posted by Feanor

Sorry for my delay in replying.

Personally I would prefer to buy any sort of electronic component from a well-established North American supplier of possible; this way you will be assured that the component is legitimate and not counterfeit. Reputable suppliers ...

• Mouser.com, HERE
• Newark, HERE
• DigiKey, HERE.

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It is a good reminder. It would be good if I can order from Newark Electronics and pick up from their local office. But they have a minimum order of 150 pieces. So it does not work.

OPA2227PAG4 - TEXAS INSTRUMENTS - IC, OP-AMP, 8MHZ, 2.3V/ us, DIP | Newark

Digikey seems to still take order for small quantity. I ordered 2 pieces at under $11. But there is no shipping estimate for the order. I will check later to see if the shipping cost is manageable. Thanks again for the reminder.

Quote:

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Originally Posted by keilau

It is a good reminder. It would be good if I can order from Newark Electronics and pick up from their local office. But they have a minimum order of 150 pieces. So it does not work.

OPA2227PAG4 - TEXAS INSTRUMENTS - IC, OP-AMP, 8MHZ, 2.3V/ us, DIP | Newark

Digikey seems to still take order for small quantity. I ordered 2 pieces at under $11. But there is no shipping estimate for the order. I will check later to see if the shipping cost is manageable. Thanks again for the reminder.

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The shipping for the 2 opamp from Digikey turned out to be $4.99 which is for any package less than 1 pound. This worked out very well for me.

The problem with Digikey order is that they cannot provide a shipping estimate before you hit the proceed buttom because it depends on the package weight. And they cannot provide an estimate of the package weight either. From 1.01 pound to 5 pound, the shipping is a flat rate $10.

Quote:

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Originally Posted by keilau

The shipping for the 2 opamp from Digikey turned out to be $4.99 which is for any package less than 1 pound. This worked out very well for me.

The problem with Digikey order is that they cannot provide a shipping estimate before you hit the proceed buttom because it depends on the package weight. And they cannot provide an estimate of the package weight either. From 1.01 pound to 5 pound, the shipping is a flat rate $10.

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I'm glad it worked out well from Digikey. Let us know your impression of these opamps.

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Originally Posted by Feanor

I'm glad it worked out well from Digikey. Let us know your impression of these opamps.

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I finally got around swaping out the OP275 with the OPA2227. But I am not sure that I like the sound better. It seems to sound boomy as my first impression.

I may swap them a few time before I decide. What would be your first choice opamp that can be obtained from DigiKey?

Quote:

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Originally Posted by keilau

I finally got around swaping out the OP275 with the OPA2227. But I am not sure that I like the sound better. It seems to sound boomy as my first impression.

I may swap them a few time before I decide. What would be your first choice opamp that can be obtained from DigiKey?

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Something that ought to give you a very smooth, musical sound would be these pair OPA627's, (the OPA627 is single opamp, unlike the majority which are dual). I replace the two dual opamps at the I/V stage with Chinese-sourced versions and the result was as described; (buffer stage I left with the one LME49720) ...

http://www.partsconnexion.com/media/...mp_64358md.jpg

I don't think Digikey, Newark, or Mouser sell them. If you want to be sure they are authentic, you could get them from Parts ConneXion, HERE.

Or you could try the eBay, such as HERE, but there is a some risk that they are counterfeit.

Quote:

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Originally Posted by Feanor

Something that ought to give you a very smooth, musical sound would be these pair OPA627's, (the OPA627 is single opamp, unlike the majority which are dual). I replace the two dual opamps at the I/V stage with Chinese-sourced versions and the result was as described; (buffer stage I left with the one LME49720) ...

http://www.partsconnexion.com/media/...mp_64358md.jpg

I don't think Digikey, Newark, or Mouser sell them. If you want to be sure they are authentic, you could get them from Parts ConneXion, HERE.

Or you could try the eBay, such as HERE, but there is a some risk that they are counterfeit.

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Wow!! $110 (for 2) vs. $18 from Hong Kong. I think that I will take an Ebay chance. Thank you for the links again.

I have only one signal source for the DAC now which is the low quality cable TV. Most channel, including the music channels, has so compressed signal that the stock OP275 sounds ok. After failing with the OPA2227, I wonder why I bother.

Any other experience with the OPA2227? Why does it sound boomy? Or it is just my system?

Quote:

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Originally Posted by keilau

Wow!! $110 (for 2) vs. $18 from Hong Kong. I think that I will take an Ebay chance. Thank you for the links again.

I have only one signal source for the DAC now which is the low quality cable TV. Most channel, including the music channels, has so compressed signal that the stock OP275 sounds ok. After failing with the OPA2227, I wonder why I bother.

Any other experience with the OPA2227? Why does it sound boomy? Or it is just my system?

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I've never heard the OPA2227.

I've tried the SD-1955 with three OPA2134; this was a very small improvement over the OPA275. As mentioned earlier, I tried three LME49720's: the sound was very well resolved but also very bright with my class D amp, (might complement a warmer sounding amp, though). The best sound I've had is two twined Chinese-sourced OPA627's, plus a LME49720 in the output position.

Quote:

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Originally Posted by Feanor

I've never heard the OPA2227.

I've tried the SD-1955 with three OPA2134; this was a very small improvement over the OPA275. As mentioned earlier, I tried three LME49720's: the sound was very well resolved but also very bright with my class D amp, (might complement a warmer sounding amp, though). The best sound I've had is two twined Chinese-sourced OPA627's, plus a LME49720 in the output position.

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I picked up the idea of the OPA2227 in posts exchanges between you and TLCW in May. I mistakenly thought that you recommended it.

I don't know how the Chinese sources can sell the OPA627 so cheap. I went to DigiKey to check their price. A pair of OPA627 needed to replace one OP275 will cost $50 at DigiKey. I will need 4 for the SMSL1955 which is pricier than the DAC itself!!

I ordered the OPA627 with the single to dual adapter from this Ebay seller.

Quote:

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Originally Posted by keilau

I picked up the idea of the OPA2227 in posts exchanges between you and TLCW in May. I mistakenly thought that you recommended it.

I don't know how the Chinese sources can sell the OPA627 so cheap. I went to DigiKey to check their price. A pair of OPA627 needed to replace one OP275 will cost $50 at DigiKey. I will need 4 for the SMSL1955 which is pricier than the DAC itself!!

I ordered the OPA627 with the single to dual adapter from this Ebay seller.

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I made a mistake. Those are single OpAmp, not the dual. It took 3 weeks to ship. I am giving up and will go back to the OP275.

Quote:

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Originally Posted by keilau

I made a mistake. Those are single OpAmp, not the dual. It took 3 weeks to ship. I am giving up and will go back to the OP275.

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Ah! That ad is confusing although the when one looks closely, it's clear enough that all the adopter does is convert a single surface-mount to DIP. What we actually want is TWO surface-mounts convert to a single DIP; (these are available). The extreme cheapness of these Chinese OPA627 makes me suspect that they are counterfeits but the ones I have work well just the same.

Does anyone have an opinion on how ES9023 compared to the SD1955?

In Case ES9023 TE7022 192K 24bit USB DAC Coaxial Fiber DAC 110V or 220V | eBay

Price is comparable. This ES9023 box uses internal power supply.

I have an expensive RME fire face and an very cheap Behringer Dac UCA 200.
I do not think I can tell the difference when playing back through my Sound Devices HP amp.
Is there a DAC blindfold A/B test?

Quote:

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Originally Posted by peterBj

I have an expensive RME fire face and an very cheap Behringer Dac UCA 200.
I do not think I can tell the difference when playing back through my Sound Devices HP amp.
Is there a DAC blindfold A/B test?

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I have no experience with any of these components.

As for a blindfold test, there has been endless debate about the validity and relevance of so-call "DBT" -- double blind testing. In my opinion, scientifically rigorous testing is not necessary for practical purposes in audio.

It's sufficient that the 'A' and 'B' that the components being compared are the only ones that are different, and that the listener is completely unaware of which of the component he/she is listening until several trials (listenings) have are completed.

Quote:

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Originally Posted by Feanor

Ah! That ad is confusing although the when one looks closely, it's clear enough that all the adopter does is convert a single surface-mount to DIP. What we actually want is TWO surface-mounts convert to a single DIP; (these are available). The extreme cheapness of these Chinese OPA627 makes me suspect that they are counterfeits but the ones I have work well just the same.

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I have now replaced the opa2134(s) with opa2107(s) in my sd1955+ DAC. The opa2107(s) are not cheap but not as expensive as the opa627, in the Uk £30 for two opa2107 from RS Components. I can advise that the opa2107(s) have given the sd1955+ a more natural detailed sound. The bass is more defined but not quite as deep as the opa2134(s) sounded. The highs are sweet the midrange very much the same. I can also tell an improvement in the soundstage a little, its wider.

To sum up my SMSL SD1955+ is now as far as I wish to upgrade, I am very pleased with the results. Some might say upgrading the power supply (Teradak 9VA) and OpAmps (2 opa2107, 1 opa2604) is false economy and they are most likely right but I have enjoyed the tweaking exercise and improvements along the way :yesnod:

cheers
Andy

HAPPY 2014 :3:

Quote:

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Originally Posted by a0r0a7

I have now replaced the opa2134(s) with opa2107(s) in my sd1955+ DAC. The opa2107(s) are not cheap but not as expensive as the opa627, in the Uk £30 for two opa2107 from RS Components. I can advise that the opa2107(s) have given the sd1955+ a more natural detailed sound. The bass is more defined but not quite as deep as the opa2134(s) sounded. The highs are sweet the midrange very much the same. I can also tell an improvement in the soundstage a little, its wider.

To sum up my SMSL SD1955+ is now as far as I wish to upgrade, I am very pleased with the results. Some might say upgrading the power supply (Teradak 9VA) and OpAmps (2 opa2107, 1 opa2604) is false economy and they are most likely right but I have enjoyed the tweaking exercise and improvements along the way :yesnod:

cheers
Andy

HAPPY 2014 :3:

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Happy New Year to you too, Andy

Yes, the opamp swapping exercise was a lot of fun and a good deal cheaper than, say, swapping interconnect cables. With more discernible results too I'd say.

Hi all,

I have been following this thread with interest and hope i can contribute something to the discussion.

I purchased my first SMSL SD1955+ over a year ago and intended to use it in USB INPUT mode with a Samsung NC10 netbook (Windows XP)/external HDD as a music server. I experienced lots of problems connecting the SD1955+ USB to the netbook,
it was not reliable and would often crash when I was using my preferred audio player WINAMP. When it did work, it sounded really good and I agree with other reviewers comments here that for £70 ($100) it is very good value and has a sound quality that is worthy of a DAC several times the price. Anyway, the regular system crashes finally got to me and I moth-balled the SD1955+ until I could upgrade my netbook.

Fast forward a year later and I have finally replaced the Samsung with an Acer Aspire One running Windows 7 Ultimate. Even better, the Windows 7 has a proper device driver and the SMSL is recognised as "SMSL SD1955+" and works perfectly! No unexplained audio drop-outs and computer crashes!

OK, the tweaker in me got the better of me and I did a bit of op-amp substitution, replacing the JRC5532 output buffer with a selection before finally choosing the LM4562. It sounded better - better sound stage, top-end and tighter bass. I kept the other two I/V converter op-amps (OP275) the same. Intrigued by this apparent beneficial change, I looked more closely at the DAC to see if there was room for further improvement. An obvious area is the +9V SMPSU. Why would the manufacturer of a high quality DAC compromise its quality with a cheap, noisy switching power supply? To answer that question, I coupled a linear +12V DC supply to a very basic hand-made LM317K linear regulator, output DC adjusted to 9V. The results were very impressive sound-wise, and I can only agree with other reviewers that the SD1955+ sound is much improved, mostly by the marked reduction in digital "hash" appearing on the analogue output signals.

At about the same time, I was trawling on eBay and spotted an SMSL SD1955 (the original, first version) starting at £28 in auction. No-one else bid, so I got it for that price :-) . The specification of the original SD1955 looks better on paper (more dynamic range and lower distortion) but there is another significant difference - it comes complete with a linear 24VDC supply instead of the cheap, nasty 9V supply provided with the SD1955+. On listening tests, it did sound very good but not markedly better than the SD1955+. I popped open the lid and found there were 3 off OP275 fitted (not sure if it was tweaked by previous owner or if that was factory build) and so I substituted the output buffer for an LM4562, so I could compare the two DAC's in the same configuration. The result was pretty impressive - before the op-amp swap, the bass had been quite boomy and the top-end very muted and thin. After the swap, it sounded more like the SD1955+ but to my ears so much cleaner and musical. I could not resist opening up the SD1955 power supply case and not surprisingly found a hefty transformer, PSU capacitor and an LM317T regulator on a heatsink - quelle surpris! So, the moral of the story (if there is one) is that it would appear that SMSL manufacturer has probably compromised the performance of this lovely little DAC over the past few years for purely commercial reasons, cheap (and lightweight!) SMPSU versus low noise linear regulator (heavy, so increased overseas postal charges) and cheap, low-cost (even by Chinese standards) op-amps.

I hope I have added something informative to this thread. Keep on listening to that lovely (when sympathetically modded!) DAC. :-)

roclite

Quote:

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Originally Posted by roclite

Hi all,

I have been following this thread with interest and hope i can contribute something to the discussion.
...
roclite

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Yes indeed, roclite,

You comments are very interesting indeed, and welcome to AR Forums.

My original recommendation for the SD-1955 was for S/PDIF only, specifically coaxial connection. I found the USB connection unsatisfactory.

I have documented my opamp substitutions above in this thread. The smoothest had dual OPA627's in the I/V stage; (or they were from China so maybe they were counterfeit, but they work pretty well).

I always used the power supply that originally came with the SD-1955 that is a SMPS, so I have no experience with linear supplies. There is a school of thought that SMPS are actually better with DACs of the modestly price variety, but I don't recall the explanation which beyond my limited technical understanding.

Thanks for warm welcome Feanor.

I was just happy that I quickly found a sound component combination that I am very happy to listen to and engages me with my music. I was surprised at the difference in tonal quality of my sound system by making a few simple component substitutions. OK, not that simple if I had to replace the SMSL DAC with the original 2010 version. The OPA627 might offer some further improvements but probably a bit too pricey for my budget. As to why you would want to connect a high frequency "switching" mode power supply to a low noise digital-analog amplifier (the DAC), I would probably think that a linear PSU has intuitively less additional noise that can find its way onto the analog outputs. Maybe the school of thought that a SMPS is better with cheaper DAC's is that the additional switching noise generated in effect competes with the digital noise produced by the DAC itself to mask the amplitude of certain dominant noise frequencies. I really don't know either :-). Suffice it to say, the early adopters who bought the first version of the SD-1955 were the lucky ones who bought a really nice sweet sounding, well-designed piece of audio kit. As for the second version SD-1955+ and probably its latest incarnation, the "Sanskrit", the performance has already been compromised for commercial reasons in my opinion. I hope other people like me get lucky on eBay.

roclite

I need clarify that the SD-1955 that I have, (which is not labelled SD-1955+), came with the 9VDC 2.0 amp SMPS, not the the 24V linear supply. So it seems that some changes were made before labelling was changed to the latter designation.

Nowadays I'm using a Schiit Audio Bifrost DAC with Uber analog upgrade. It is more transparent and airy than the SMSL but, of course, several times as expensive. I still believe the SMSL SD-1955, and probably also its successors, are great value for very little money.

I agree that the SD-1955+ is a very good DAC and if I had not stumbled across its predecessor, the original version SD-1955, I might have been very satisfied. It does appear that SMSL quietly made several changes or "upgrades" to the design from the first version. Whether these changes enhanced the sound of the DAC is a matter of opinion. I attempted to make the SD-1955+ sound like the SD-1955 by replacing the supplied 9V, 1.5A SMPS with a home-brew LM317K regulator powered by a Stontronics 12V linear regulated PSU (14W).
I also followed your lead by using the S/PDIF Coax output from my NAD C542 CD Player. It does sound very good, and the more I listen to it the more I like it. However, when I switch to the original SD-1955 with its 24VDC regulated supply, I am listening to a different DAC. The sound-stage is wider with far more depth, instruments and vocals are much more precise with greater clarity, without being clinical. I can hear the percussion of instruments as well as the resonance. I am hanging off every note waiting for more. By comparison, the SD-1955+ just sounds good. I am now happily re-discovering over 7000 tracks from my HDD music collection. The newer SD-1955+ may shortly appear on eBay as I don't need 2 DAC's. I will leave the last words to the eBay seller who sold me the SD-1955 DAC, "older better version" as he described in his listing. He knew too. Thanks for giving your insight to this discussion.

Very interesting, roclite,

There might have some change to the SD-1955 prior to the introduction of the SD-1955+. My SD-1955 (if such it is) looks like the SD-1955+ on the left of the first picture even though it is labelled SD-1955; also, as mentioned, the power supply that came with it is the 9 VDC SMPS variety.

Possibly my SD-1955 is actually the SD-1955+ before the maker got around to correcting the model number -- who knows? Anyway, I'm keeping my SD-1955 (+ or whatever) as a backup for my latest DAC.

Feanor, you are probably correct and you have SD-1955+ electronics in an SD-1955 labelled case. From experience, Chinese Quality Assurance leaves a lot to be desired and lots of different versions of the "SD-1955" probably exist with different op-amp configurations and other key components, depending on the actual manufacturer, not necessarily SMSL :-) i.e. the manufacture may be sub-contracted out to other Chinese electronics manufacturers. This probably explains much of the variability in other SD-1955 users listening experiences.

For the benefit of others who might be reading this thread, it would appear that the original SMSL SD-1955 with 24V PSU may still be available direct from some Chinese suppliers as opposed to the newer revisions currently being sold on UK/USA eBay and Amazon:


Smsl Sd-1955 Dir9001 Ad1955 Dac Optical Coaxial Decoder & Power Adapter - Buy Optical Coaxial Decoder & Power Adapter,Digital Audio Decoder,Digital Amplifier Product on Alibaba.com

If nothing else, the internal pictures serve to show that there are considerable differences in the design, layout and components on the circuit boards. Therefore, you might expect them to sound different, because they are.

Hi all ,

Unfortunately the DAC is now powering on but not emitting any sound output .

I mailed couple of times to smsl<wbr style="color: rgb(119, 119, 119); font-family: 'normal arial', sans-serif; font-size: 12px;">@smsl-audio.com m about the problem but there is zero response from them , not even a auto mailer .

Local technician told the DAC chip gone bad and its tough to get it in Kolkata .

Chinese are imitating good but I believe the components are 3rd grade and protection circuits are not there .

Too much disappointed with the failure and behavior of the manufacturer .

Regards
Kaushik

Quote:

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Originally Posted by kaushik741

Hi all ,

Unfortunately the DAC is now powering on but not emitting any sound output .

I mailed couple of times to smsl<wbr style="color: rgb(119, 119, 119); font-family: 'normal arial', sans-serif; font-size: 12px;">@smsl-audio.com m about the problem but there is zero response from them , not even a auto mailer .

Local technician told the DAC chip gone bad and its tough to get it in Kolkata .

Chinese are imitating good but I believe the components are 3rd grade and protection circuits are not there .

Too much disappointed with the failure and behavior of the manufacturer .

Regards
Kaushik

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I have no useful advice, unfortunately. Support for products bought from Chinese is poor to non-existent, which we need to understand before we buy from there. Could be you'll just have to order another one or some other DAC.

hi Kaushik,

Assume you have done the usual fault-finding process and checked all 3 inputs (S/PDIF, OPTICAL, USB) and verified your amp is OK. In that case, either DAC or power supply/standby circuit feeding the DAC - the Power LED being lit does not tell you much. Its a cheap audio DAC from China, not part of a human life support system :-). Probably not worth trying to fix, unless you happen to have the proper surface-mount repair tools. As Feanor said, just buy another one or really blow your budget and buy a better quality Schiit Bifrost Uber like me :-)

Quote:

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Originally Posted by Feanor

I have no useful advice, unfortunately. Support for products bought from Chinese is poor to non-existent, which we need to understand before we buy from there. Could be you'll just have to order another one or some other DAC.

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The performance per price ratio of Chinese electronics is hard to resist. I have had good luck the last few time. I live in the US. I buy the Chinese electronics only from Ebay seller that provide reasonably good protection in DOA parts. Extended warranty? Forget it.

help please ,

im using smsl 1955+ dac

my amp is akai aa39, pc win 8

dac is connected to the computer using usb cable..

while playing music, when i power off the amplifier (only amp), the dac stop working, showing like it stuck (or in a loop like state) , in the window play back device list......also the winamp shows the same , stuck!! no sound when switching on amp back...TOTALLY STUCk


only way i find is to power off/on the Dac, or in the play back device list in windows , just disable and then enable the DAC device , it will work ..

any USB driver update available

Help please

Quote:

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Originally Posted by muralikundoli

help please ,

im using smsl 1955+ dac

my amp is akai aa39, pc win 8

dac is connected to the computer using usb cable..

while playing music, when i power off the amplifier (only amp), the dac stop working, showing like it stuck (or in a loop like state) , in the window play back device list......also the winamp shows the same , stuck!! no sound when switching on amp back...TOTALLY STUCk

only way i find is to power off/on the Dac, or in the play back device list in windows , just disable and then enable the DAC device , it will work ..

any USB driver update available

Help please

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Hello, welcome to AR Forums.

It is strange that turning off only the would should cause the DAC to stop working -- actually it's your computer music player that stops working, not the DAC itself.

The SMSL uses only the standard Windows USB audio device although this really should not be a problem. If your computer has S/PDIF output, either coax or optical, try that. If not try one of the music player tweaks below; I believe that Winap and some other players will accommodate either of them. Also, in principle the either of the following ought to improve the sound though they might -- or might not -- fix your particular problem

Try a WASAPI plug-in. WASAPI simplifies the sounds' path from the player to USB or S/PDIF output versus Window's standard "audio stack" interface. When installed, you would select it as the output device in your music player

Along the same lines you might try using ASIO4ALL, (see HERE), which also replaces the standard Windows audio stack with a simpler path to audio output, either USB or S/PDIF.