My experience with SMSL 1955 DAC

[BBRN]

I just wanted to post my experiences with the SMSL 1955+ DAC and was wondering if anyone else was using this inexpensive DAC from China. I bought one of these a few months ago via the bay, and within 2 weeks it started producing static from the left channel. Unfortunately, I purchased it from a 3rd party vendor, and it was a bit of a hassle shipping it back to China, but the seller did offer a full refund. When it worked, it worked quite well, and was very detailed. I then thought maybe it was a one-time fluke, and decided to purchase another directly from SMSL. Unfortunately, once again the exact same thing happened, but this time only using the USB and listening to 24/192 files. I contacted SMSL, and I must say they do offer a good service to their customers, and replied back in a timely manner. I was instructed to open the unit up and check the opamps to make sure they were seated correctly...they were. The company then decided to send me a complete board without the casing as a replacement with no hesitation, and most likely due to the high cost of shipping and headaches of China post they didn't even require me to ship the original back. After reading some posts in other forums, it seems this is a common issue with these, and others have had luck with different opamps. So, now I had an extra board and decided to do some experimenting. The unit contains 2 5532DD and 1 OPA275, which are both decent opamps, but I am guessing that in order to cut some cost, the opamps are china reproductions, and may not be quite up to par. I replaced the 275 with a Burr Brown 2107, and the 2 5532's with the reliable Burr Brown 2134. WOW! what a difference. The DAC sounds even better than before, and its been around two weeks with absolutely no issues...it seems much more stable. It really is a decent DAC especially for the $, but looks like it may need either better quality, or different opamps to be stable. Anyways, just wanted to report my results, and see if anyone else here on AK was using this DAC with any luck.

-BB

 

[BigElCat]

How's the SMSL 1955 working now days? I almost bought one of these.

 

[BBRN]

Working very well, it is much more stable with the new opamps than it was previously. It's obviously not the best piece of equipment, but for the money I have no complaints. When funds allow I think I'll be getting an even better piece of shiit...thinking the bifrost.

 

[89grand]

I've never owned that DAC, but I have a SMSL SA-36A amp, and so far it's great, so much so that I also ordered a SMSL SA-98E.

 

[stoN_Cold]

I just want to ad my two cents.

My 1955+ arrived few weeks ago. My intention was to connect plasma TV Panasonic p42st50 optical out to my beloved Pioneer sx-950. Up to that point the TV was connected to the receiver through some crappy Hama SCART to RCA adapter. As I figured that the TV is now my main source of music through DLNA server, I reckon that it is necessary to improve line out of the source. I even bought some nice VDH interconnects for this occasion.

At this point I must say that I love my sx-950 for having very open, detailed and gutsy sound. It gives sparkle to music, and this is something that I don't hear with new amps, for example some H/Ks that my friends have. As for control I'm not that sure. That is why I have hi hopes for this DAC.

Well, the moment of truth. Both adapter and SMSL are connected to separate inputs on the receiver, so I can compare the sound as close as possible. The first thing is, the line out is a bit quiet on this DAC. The other impression is that it just cuts the balls off the sound. Everything is restrained, the punch is gone and the bass is not going as deep as before. We listened to Carmina burana (to see where the bass is ), Steely dan, ZZ top old and new, Morphine, Christian McBride and many more. All music is lossles, needless to say. It made my Pioneer sound like those H/Ks.

After some time I came to realize that this is all on moderate levels of volume, like up to 9 o'clock. When we turn up the volume to 12 o'clock it becomes interesting. The bass becomes more apparent, the details emerge and the neighbours begin to bang on the walls (I'm on the 15th floor).

Well, that was entertaining. I didn't try it with some other sources like CD player, and I'm looking forward to test it in other systems, so I'll post my findings after that. As of now I can't wrap my mind around it. We need to spend some more time together ;-)

 

[ToniCH]

I bought mine in dec 2012 and after few months it started distort sound. I found out its op amps had fried and later I have found out that many from dec 2012 had this same problem. I too considered shipping back to China too expensive so I decided to try to fix it.

I replaced the two identical op amps with new ones. Didn't find any info on the third chip so I could not choose a correct replacement. The two were only few euros (or dollars) so I swapped them in and crossed my fingers. Well, it worked ok for few minutes and then the distortion was back.

Tossed it to scrap pile and moved on. But few days ago I found it again and started googling. It seems that the official word is that they shipped the DACs with bad Sanyo caps which might be the root cause for the op amp problems (?). Luckily, they are also easy and cheap to replace.

The unit contains 2 5532DD and 1 OPA275

Mine was other way around. 1 5532D and 2 OPA275's.
.
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[ToniCH]

Update: I today replaced the Sanyos with Nichicon KA -series with same values. I also replaced the big 20V 3300uf one just because it looked cheap, didn't find 20V 3300uf so I used 25V 3300uf. And I replaced the op amps with BB 2134s and TI 5532. And I also used a new power supply. Now it plays music again and sounds pretty good1 I hope it will last.

I also ran the Sanyos and Nichicons in my cap tester. the 47uf Sanyo came out 22uf, the 330uf Sanyo was 400+uf. Nichicons were spot on their rating.

Sanyos out, Nichicons in: http://i43.tinypic.com/11bnqqd.jpg
Also the big one changed: http://i40.tinypic.com/b6rl8h.jpg
Test run: http://i40.tinypic.com/p25oj.jpg

 

[BigElCat]

Thanks for the pics. Let us know if it keeps working :thmbsp:

 

[ToniCH]

Last time when I only changed the op amps it only lasted for minutes. Now its been playing music for several hours and really does sound good. So far so good - but it has been unboxed (the original SMSL box has 0 holes for air circulation) so its not realistic.

I have been monitoring component temps and nothing reaches 36°C (96.8°F). However I today decided to add cooling fins to the op amps with heat conductive glue and then I drilled 3 holes to the top and bottom of the box to allow hot air out and cool air in. Cannot really help it any more, hope the problem really was the Sanyos.

Like this:

 

[stoN_Cold]

Thanks. Now I'll be ready.

 

[stoN_Cold]

After several days of listening I have to say that my DAC is getting only mildly worm.

Do you have some good power supply to recommend?

 

[ToniCH]

I am jusing just a general adjustable powersupply, nothing fancy.

Update: I today upgraded the TI 5532 op amp to LM4562. I also swapped the remaining no name caps to Nichicon KA -series. After only 15min of listening I must say it sounds very nice for a DAC with less than 100 euros invested. Hope it gets even better over some time