Cheap DAC working well

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Originally Posted by Feanor

Well, well, what diya know: the hum problem I mentioned wasn't caused by my cheap DAC. The problem is rare & intermittent, caused by some other, undetermined factor.

However before figuring this out I went to good ol' eBay and ordered another cheap DAC, namely this one, also sold by a couple of other eBay vendors ... New design S.M.S.L SD-1955 DIR9001 AD1955 mini DAC Optical coaxial | eBay

http://imgs.inkfrog.com/pix/bluericewin/x195.JPG
http://imgs.inkfrog.com/pix/bluericewin/x19GB2.JPG

It uses:

• Analog Devices AD1955 chip for a DAC; this current chip is capable of 24/192.
• DIR9001 S/PDIF receiver, capable of 24/96; an older chip but well regarded for jitter reduction
• Tenor TE7022L USB interface, capable of 24/96 -- however I only use the S/PDIF coax input
• Two dual OP275 opamps for I/V and one dual 5532 for an output buffer.
• 9 VDC wallwort power supply

The DAC doesn't do asynchronous upsampling but the AD1955 has internal oversampling which feature I presume is used.

Because I had them around I used OPA2134 opamps to replace the OP275's, and an OPA2604 to replace the 5532. I'm considering replacing the cheap wallwort with a regulated PS.

The unit sounds at least as good, probably better, than my previous cheap DAC. BTW, I started to use this DAC the same day as I started with the Magneplanar RFI/EMI choke mentioned elsewhere -- which means unfortunately that I'm not really sure which change is causing such improvement as there might be! :aureola:

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Hi Feanor

I have ordered the SD-1955+, a plus model as it is now known.

Can I ask if the DAC is still giving you good service? Do you still like the sound? After many months of listening do you still feel the Op-Amp upgrade is worth the extra spend? Did you change the PSU and if so did this improve anything in the sound?

I hope I am as pleased as you are and thanks for the great review. This allowed me to give this DAC a try knowing how it performs.

Cheers
Andy

Quote:

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Originally Posted by a0r0a7

Hi Feanor

I have ordered the SD-1955+, a plus model as it is now known.

Can I ask if the DAC is still giving you good service? Do you still like the sound? After many months of listening do you still feel the Op-Amp upgrade is worth the extra spend? Did you change the PSU and if so did this improve anything in the sound?

I hope I am as pleased as you are and thanks for the great review. This allowed me to give this DAC a try knowing how it performs.

Cheers
Andy

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Hello, Andy,

Yes, I'm still enjoying this DAC very much. For air & resolution in particular it is the best I've tried. I should remind you that I'm using only S/PDIF inputs, not the USB.

I have not changed the original PSU which is a smallish wall-wort. I believe it is switching mode but it isn't specific and I have attempted to take it apart. I would be fun to get construct as DC battery supply but I haven't gotten around to this, nor do I feel much need.

Among modern opamps the differences are subtle so you might not hear any significant difference. On the other hand, even very good opamps are cheap. The unit requires three dual opamps, so for example, a set of OPA2604 can be had for about $15 (plus shipping) from an electronic component supplier such as Newark.com, or LME49720's for about half that.

The opamp long popular with audiophiles is the OPA627 which is a 'single' opamp. You would need three paired OPA627's. From a highly reputable source such as Parts ConneXion, (HERE), this would run about $165 which makes the value dubious. Or you could try a less reputable eBay source, such as HERE, for a lot less money, but you risk getting counterfeits.

Hello Feanor

Thanks for the prompt response to my questions.

That is reassuring to know it is working well and it sounds great. I will be using the Co-Ax S/PDIF input on the DAC as well. I will try the DAC first straight out the box and compare the sound quality to my CD player internal DAC. I will most likely buy the Op-Amp upgrade you have made as its plug-n-play and your results are sucessful for minimal outlay!

My CD player sound is very detailed but, I do wish the highs were more refined, I guess 'harshness'. Your experience with this DAC seems to prove a positive in this respect and other areas as well, a real bonus ;)

I will keep you posted on my results with the SD-1955+ when I have the DAC in place. Just waiting for it to arrive in the UK :(

Cheers
Andy

Quote:

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Originally Posted by Feanor

My old Assemblage 1.5 DAC is pretty decent

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I used to really like those Assemblage units and all the different options you could choose from...

Quote:

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Originally Posted by Feanor

I'm very pleased with this latest cheap DAC -- my third eBay special and they just keep getting better & better.

I believe this is the best sounding DAC yet -- not necessarily by a huge margin but by some margin. The instrument timbres seem clearer, (notably strings and brass), imaging more precise, the soundstage deeper, and the mid-range somewhat fuller-bodied.

I attribute these improvements to a greater freedom from grain and sonic crud. Get rid of the hash and the music is liberated. Where does the hash come from? Possibly ...

• Jitter (if a digital source)
• Digital filtering, e.g. "pre-echo"
• Opamp noise and/or negative feedback
• RFI/EMI

But the result, IMO, is much of the "harshness" attributed to digital. Minimize the harsh and you'll find your CDs sound a lot better than you ever thought they could. This isn't the first case in my experience that improving my reproduction chain, (not just the DAC), as made CDs relatively listenable that I'd previously figured were a sonic write-off.

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Hi Feanor,
I'm watching this thread for some time, because I was also interested in some cheap DAC. My goal was to use it with my TV, as it has no analog output and also with AirPort Express+iPad, as a better alternative to the built-in DAC in the AE, in both cases using the optical line.
Finally I bought the DAC, but … it just won't work I hope it would. I can get sound only if I connect it to my computer and switch it to USB. When I switch it to "digital output" it's dead, no sound.
I get the same result when I connect it to my TV, STB or AirPort Express - simply no sound.


I expected some problems with my TV, as I read somewhere that it should be switched to PCM stereo (correct me if I'm wrong) and I couldn't find any switch in the set-up of the TV for PCM stereo, but why it doesn't work with optical output at all?


I send an email the seller about this problem, but I'm not expecting much help from him, so any input in this issue from you would be much appreciated.


Sorry for my english, but it isn't my first language :)

Quote:

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Originally Posted by Dag

Hi Feanor,
I'm watching this thread for some time, because I was also interested in some cheap DAC. My goal was to use it with my TV, as it has no analog output and also with AirPort Express+iPad, as a better alternative to the built-in DAC in the AE, in both cases using the optical line.
Finally I bought the DAC, but … it just won't work I hope it would. I can get sound only if I connect it to my computer and switch it to USB. When I switch it to "digital output" it's dead, no sound.
I get the same result when I connect it to my TV, STB or AirPort Express - simply no sound.


I expected some problems with my TV, as I read somewhere that it should be switched to PCM stereo (correct me if I'm wrong) and I couldn't find any switch in the set-up of the TV for PCM stereo, but why it doesn't work with optical output at all?


I send an email the seller about this problem, but I'm not expecting much help from him, so any input in this issue from you would be much appreciated.


Sorry for my english, but it isn't my first language :)

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Hi, Dag,

I'm sure I understand your problem entirely; (your English is fine though).

To cover the basis, the SMSL DAC has three inputs: USB, S/PDIF optical, and S/PDIF coaxial. There is a front panel button you have to push to select the input that that you want to used. (Personally I use both S/PDIF inputs, but mostly the coax.)

Do your TV and AirPort Express have S/PDIF digital outputs? (Often TVs don't have digital outputs. If I'm thinking of the right model, the Airport Express has some sort of weird combined digital/analogy output.) Of course, only digital outputs will work with the DAC's inputs.

If you are using proper digital outputs from these devices and you have selected the appropriate input on the DAC using the front panel button, then you ought to have sound. It's possible your unit is defective.

Hi, Feanor,
thanks for your quick reply, although not very pleasant for me :)

Well, yes I did everything like you suggest - my TV has optical out and also the AE has it (indeed it's a combined analog/digital output and you need a small converter for 3,5mm jack if you use it with optical cable) and I switch on the front panel of the DAC to optical output, but with no joy.

I will try also the coaxial output just to see if this works, although it wouldn't help me as I need optical outputs to work for my setup, but I'm just curious if it would work.

The seller answered my email, so I will see how it will end up.
I will leave feedback later.

Again, thanks for your suggestions and Merry Xmas and a Happy New Year for You and Your family.

Dag

So it does sound like your unit is probably defective; I hope you get satisfaction from the dealer at some point.

Best of Christmas season to you & yours.

The SMSL DAC arrived. A nice Xmas pressie. I have made a switch fuse UK adapter so I can power down the PSU rather than leave the SD1955 in standby. Although I see no issue with the unit being left in standby.

I hooked up the DAC to my CD player SPDIF CoAx out and moved the RCAs off of the CD player onto the SD1955. Turned the SD on, very quiet in standby. The moment of truth!

I have sound. Now my thoughts on the SD1955.

Wow! Out of the box the sound is open, smooth, detailed with tight controlled bass with nice pace. This DAC out of the box is an improvement over my CD players DAC. I compared track for track on a number of my favs and the SD1955 has the edge in a way I was wanting.

The DAC arrived in 9 days, was really well packed. The unit is built very well with a nice finish and not only sounds great but looks fab!

Thanks Feanor a great find that has allowed me to upgrade my system when funds were tight.

Quote:

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Originally Posted by a0r0a7

The SMSL DAC arrived. A nice Xmas pressie. I have made a switch fuse UK adapter so I can power down the PSU rather than leave the SD1955 in standby. Although I see no issue with the unit being left in standby.

I hooked up the DAC to my CD player SPDIF CoAx out and moved the RCAs off of the CD player onto the SD1955. Turned the SD on, very quiet in standby. The moment of truth!

I have sound. Now my thoughts on the SD1955.

Wow! Out of the box the sound is open, smooth, detailed with tight controlled bass with nice pace. This DAC out of the box is an improvement over my CD players DAC. I compared track for track on a number of my favs and the SD1955 has the edge in a way I was wanting.

The DAC arrived in 9 days, was really well packed. The unit is built very well with a nice finish and not only sounds great but looks fab!

Thanks Feanor a great find that has allowed me to upgrade my system when funds were tight.

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I'm glad the SMSL is working well for you at last. It was my impression from the start that it would be a very fine DAC for several times the money. It is certainly a better DAC that what is in my older Sony SD-CE775 SACD/CD player -- so much so that on hybrid SACD discs, CD layers sound better through the SMSL that do SACD layers through the Sony.

Hi Feanor

Further listening has revealed just how detailed this DAC is. I agree with how well instruments are defined and separated in the soundstage. The best part for me is the smooth balanced sound, nothing lost but really nice to listen to. As I said before my CD players DAC was just a little to forward for my liking. The SD has rid my system of that trait.

Now, do I change the OpAmps? I really do like the sound now. Will I be more amazed at the gain?

Cheers
Andy

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Originally Posted by a0r0a7

Hi Feanor

Further listening has revealed just how detailed this DAC is. I agree with how well instruments are defined and separated in the soundstage. The best part for me is the smooth balanced sound, nothing lost but really nice to listen to. As I said before my CD players DAC was just a little to forward for my liking. The SD has rid my system of that trait.

Now, do I change the OpAmps? I really do like the sound now. Will I be more amazed at the gain?

Cheers
Andy

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Andy, any change for swapping opamps will be relatively small. It's unlikely that you'll be amazed but you might hear some difference.

Hi Feanor

I must admit for now I will listen to the DAC as it came out of the box. It has made the refinement in sound I wanted.

It is a gamble changing the OpAmps as one person may like the subtle change v the other person may not.

Cheers
Andy

I have decided to get an Anedio D2 DAC when a AN 3.1 Sig comes up for sale on Agon. Any comments? I'd use a USB/spdif converter until I could install WaveIO | Luckit in the AN.

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Originally Posted by Happy Camper

I have decided to get an Anedio D2 DAC when a AN 3.1 Sig comes up for sale on Agon. Any comments? I'd use a USB/spdif converter until I could install WaveIO | Luckit in the AN.

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Forcing one to do homework sometimes opens other options. My new darling (and one I like for it's capabilities) is the Lynx Hilo. Call for pricing as I've been given 25% off list quotes. It's a pro audio co. with a good reputation in the industry.

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Originally Posted by Happy Camper

Forcing one to do homework sometimes opens other options. My new darling (and one I like for it's capabilities) is the Lynx Hilo. Call for pricing as I've been given 25% off list quotes. It's a pro audio co. with a good reputation in the industry.

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Hi, Happy,

Since you mention it, I looked up the Lynx Hilo. It looks pretty sweet but definitely isn't in the "cheap" category. B&H Photo Video is selling them for $2500: HERE

http://static.bhphoto.com/images/ima...345/768851.jpg

I've been quoted $1850 for a new one. You see all the front end capabilities this thing has?

Based on this thread I ordered one of the S.M.S.L mini DACs. Should be an interesting experiment.

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Originally Posted by SkiFastBadly

Based on this thread I ordered one of the S.M.S.L mini DACs. Should be an interesting experiment.

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Should work out well for you. Are you presently using a DAC?

From this thread we see there occasional quality control problems but they have been solved.

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Originally Posted by Feanor

Should work out well for you. Are you presently using a DAC?

From this thread we see there occasional quality control problems but they have been solved.

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Yes, I'm currently using an Adcom GDA 700 with which I'm quite pleased, but I wanted to try something with higher bit rate capability to take advantage of some of the high definition music available, for example, from HDTracks. I intend to split the signal coming out of my computer and do an A/B comparison. Should be interesting.

Quote:

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Originally Posted by SkiFastBadly

Yes, I'm currently using an Adcom GDA 700 with which I'm quite pleased, but I wanted to try something with higher bit rate capability to take advantage of some of the high definition music available, for example, from HDTracks. I intend to split the signal coming out of my computer and do an A/B comparison. Should be interesting.

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I just connected a new SMSL 1955+. I agree to all threads here about the SQ of 1955+. The sound is impressive. My beloved CDP is still better but not much. I had only 3 hrs of operation and the RCA & Toslink are new too, 1955+ is definite a steal at US$100. I am sure it will be much better soon.
I am interested to know how far it is when comparing with Adcom GDA 700 or some other DAC. I like it for upgrading CAS for 2.0 and feed to preamp.

SMSL is a comparatively newer Chinese company (nearby me ). The set up has Germany and Japan running. The interior components and external finish are very seriously productions. I bought the matching Class D (T) amp, same box as DAC 1955+ with unbelievable power of 80W !!

BTW, folks, I've temporarily reverted to the WM8740+DIR9001+CM102S-based DAC that started this thread; (picture below). (See more of the DAC's specs HERE on eBay.)

I had to do some computer redeployment and end up with using an old XP computer for my music server; this machine doesn't have S/PDIF output. Thus I am constrained to output to my DAC using USB.

The bad news is that my SMSL DAC doesn't handle USB properly, at least in that the DAC's output is reduced to an unacceptably low level when using USB input. The better news is that this previous DAC of mine with its CM102S USB receiver works quite well. I used the AUDIO4all music player => device interface software presently whereas I used my S/PDIF-capable sound card's custom ASIO driver before the computer switch.

I won't say that this setup sounds as good as the SMSL+S/PDIF but it's quite acceptable for now.

http://gallery.audioreview.com/data/500/WolfsonDAC.jpg

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Originally Posted by Feanor

B

The bad news is that my SMSL DAC doesn't handle USB properly, at least in that the DAC's output is reduced to an unacceptably low level when using USB input. The better news is that this previous DAC of mine with its CM102S USB receiver works quite well. I used the AUDIO4all music player => device interface software presently whereas I used my S/PDIF-capable sound card's custom ASIO driver before the computer switch.

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SMSL manufacturer is here:

Shenzhen shuangmusanlin electronic Co., LTD

You may contact them about the USB issue. They may have a USB firmware update for download- now is empty in the download section.

Quote:

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Originally Posted by TLCW

SMSL manufacturer is here:

Shenzhen shuangmusanlin electronic Co., LTD

You may contact them about the USB issue. They may have a USB firmware update for download- now is empty in the download section.

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Thank you for this information about the SMSL manufacturer of whom I wasn't aware.

As for a downloads, there might be computer driver USB for the SD-1955 DAC although it isn't available at the moment. I'm not aware of any firmware as such since the DAC itself is apparently all hardware.

BTW, the website is a classic example of "Chinglish" language usage.

I tested the USB input. As the manufacturer stated somewhere. It works for Windows XP and Windows 7. I found it is not working in Vista. For me, I cranked up my pre-amp from 10 o'clock ( Optic) to 12- 1 o'clock for USB on XP notebook, the volume is fine. The USB interface seems OK for my audio setup.
The Web and user manual are bad BUT the products are quite GOOD. This is common in MIC electronics. even bearing Western brands - Frigidaire, Toshiba, Delonghi. Same as the English translation in my Italian made electric oven manual.

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Originally Posted by TLCW

I tested the USB input. As the manufacturer stated somewhere. It works for Windows XP and Windows 7. I found it is not working in Vista. For me, I cranked up my pre-amp from 10 o'clock ( Optic) to 12- 1 o'clock for USB on XP notebook, the volume is fine. The USB interface seems OK for my audio setup.

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I'm glad it's working for you. My machine is an XP but it doesn't work well in my case.

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Originally Posted by Feanor

I'm glad it's working for you. My machine is an XP but it doesn't work well in my case.

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Hello Feanor,

Im new here. Ive been reading alot from your Thread. I too am looking for a cheap DAC, not too cheap(sound quality).
Here's my situation; I just got a new Panasonic VT50 plasma and like all 2012 and newer models they are removing analog outs. I have an optical cable running to my reciever(Pioneer Elite SC-27). Works great together. The problem I have is I am using Zones in my home and in order to send audio to zone 1 or 2, they must be analog. Except for the ipod input. Im guessing the internal Wolfson WM8740 handles that.
I am lookin at the DAC you recommended SMSL AD1955+ and also the SMSL SD-793II

My goal is to stream pandora and other services to other zones or hear TV shows in diff rooms. So i am focused on a quality chip. The "cheap" DAC is only needed for the TV. I also was looking at the HA INFO DA1 due to its Optical out that i can reroute to the receivers optical. Hence allowing me to run RCA's to the zone and Optical for the main TV room?

Thanks for your help.
Elite

If your plasma TV has digital out ( optical or coaxial ), SMSL 1955+ is DAC (all : optical, coaxial , USB ) sd-793II is DAC with headphone amp but not for USB input . 1955+ has very good SQ (sound quality -image and sound stage ). They may serve
serve your purposes. Especially, 1955+ is really better than many many separate / built-in DAC in AV receivers.
BTW, In Elite Sc27 user manual: "It is possible to play (selected source) when using the main zone and ZONE 2 or the main zone and ZONE 3 " ( P. 91-92)

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Originally Posted by TLCW

If your plasma TV has digital out ( optical or coaxial ), SMSL 1955+ is DAC (all : optical, coaxial , USB ) sd-793II is DAC with headphone amp but not for USB input . 1955+ has very good SQ (sound quality -image and sound stage ). They may serve
serve your purposes. Especially, 1955+ is really better than many many separate / built-in DAC in AV receivers.
BTW, In Elite Sc27 user manual: "It is possible to play (selected source) when using the main zone and ZONE 2 or the main zone and ZONE 3 " ( P. 91-92)

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I wish that were the case, unfortunenately with these receivers only Analog Audio inputs can be outputed to Zone 2 or three 3. And I have confirmed this via self testing and calling the Elite support team at Pioneer. All HDMI, Dig Co-ax, optical audio can not be sent to Zones. For that same reason I'm using an OPPO BDP-83SE with the upgraded dacs and power supply, so that i may get the most from the stereo outputs(analog). For $450-500USD used these universal disc players are superb. It uses 8-channel Sabre32 Ultra (ES9016) DAC chip by stacking 4 DACs for each of the Left and Right channels.

The Elite uses a Wolfson Wm8470 DAC. In your Opinion do you think the 1955+ will better the DAC in the SC27?

Thanks,
Elites
It looks like Ill take your recommendation and get the 1955+ dac for the plasma.

Based on good reports from "inmates" over at Audio Asylum, I decided to try a Schiit Audio MODI DAC, (see HERE).

http://schiit.com/cart/images/modi_04.jpg

This DAC is a USB-only, USA made product from a cutely named maker. It features an up-to-date AKM4396 DAC, C-Media CM6631 asynchronous USB receiver, and low-voltage AD8616 opamp filter/output stage. This for US$ 100. The obvious limitation is no S/DIF input.

The C-Media CM6631 USB receiver is notable. It's an asynchronous and therefore potentially very low jitter device -- that's the good news. Mildly disappointing is that Schiit doesn't provide the custom driver that would be necessary to support 24/192, so the MODI is limited to 24/96. They say that at the $100 price point they can't provide the support necessary to offer a custom driver.

The MODI is probably the best "cheapo" DAC I've had so far, (I've reported four if you're counting). It has almost the detail and resolution of the SMSL DL-1955 I report few months back, but more than compensating for any minuscule loss there is a significantly smoother presentation (or greater "musicality" as some would describe it). I'm quite certain that the majority of enthusiasts/audiophiles will prefer the MODI over the SMSL, and that includes me.

I can endorse the MODI without reservation at the price provided you need a USB only interface.

However MODI will be my last "cheapo" DAC for a while: I have decided to upgrade to medium priced DAC, Schiit's BIFROST DAC which I will comment in a separate post.

Quote:

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Originally Posted by Elitesc27onribbons

The Elite uses a Wolfson Wm8470 DAC. In your Opinion do you think the 1955+ will better the DAC in the SC27?
It looks like Ill take your recommendation and get the 1955+ dac for the plasma.

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The WM8470 is good for sure. I like 1955+ as it is good, cheap and allows optical, coaxial and USB inputs.
I throw in a source: cheapo DVD transport, Computer DVD drive, CAS USB via foobar2000 on downloaded files, all provide me good music listening.
Let us know how you like it if you do have it for plasma TV.

hi Feanor ,

After going thru the review of SMSL SD1955 by yours , I bought a same piece .

just out of the box , it performed well . What I observed that , Its clear but having the gain down by atleast 4 DB. The sound is bit thin ( Bass ) , high are bit rolled off at the end , mid is clear .

I am using Yamaha Receiver RX-V450 with Usher V-601 BS and for source I am Using Pioneer DVD and also Desktop ( Reaktek HD Chipset ) taking the onboard SPDIF .

Peculiarly the sound degrades while I connect to Desktop compared to DVD Digital Out . In Desktop the bass has a mechanic sound seems cracked , High are not so clear , Mid are OK .

To Be noted , that same SPDIF from Desktop when connected to the Receiver Digital-IN , it perform very fine .

Can you please help me by referring OPAMP no. which can help me to upgrade the sound ?

I like a bit of heavy thick lows with balanced mid and high , and a bit of laid back spreaded soundstage .

Does upgrading the capacitors can improve the sound ?

Having a better PSU other than the supplied one can improve the sound ?

In another forum I have seen that the capacitors and OPAMP are changed which soothes the sound .
troca de OpAmp (DAC SMSL SD-1955 rev.B) OP275G - algumas duvidas - Página 2


In India / Kolkata its bit difficult to get OPAMPs in shop or by Ebay still wanna try that .

I don't have complete electronics knowledge but minor changes if suggested can be done for the DIY purpose .

I emailed you on this subject, relying in some detail.

My experience with the SMSL hasn't given rise to the issues you seem to have. On the whole the SMSL sound is well-resolved & transparent but perhaps a bit bright on the top high frequencies, (not at rolled off as you experienced).

I think some of you problems are related to your other equipment.

A well regarded opamp is the OPA2134, but the change will be fairly small. An upgrade power supply might bring more improvement, but in this regard it's as important to have good RFI/EMI filtering as anything else. Capacitor upgrades might yield some improvement but I have no suggestions.

Bear in mind that the SMSL is an inexpensive DAC and I don't think spending a lot of time, effort, or money to upgrade it worthwhile (unless your hobby is electronics).

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Originally Posted by Feanor

I emailed you on this subject, relying in some detail.

My experience with the SMSL hasn't given rise to the issues you seem to have. On the whole the SMSL sound is well-resolved & transparent but perhaps a bit bright on the top high frequencies, (not at rolled off as you experienced).

I think some of you problems are related to your other equipment.

A well regarded opamp is the OPA2134, but the change will be fairly small. An upgrade power supply might bring more improvement, but in this regard it's as important to have good RFI/EMI filtering as anything else. Capacitor upgrades might yield some improvement but I have no suggestions.

Bear in mind that the SMSL is an inexpensive DAC and I don't think spending a lot of time, effort, or money to upgrade it worthwhile (unless your hobby is electronics).

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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 ?

Neither its my hobby or have surplus money and time , but still have a keen knack to have a better output by small changes possible .

I will let the forum know the results what I am testing today .

1. Changing OPAMPs ( dont know which are will be available in market today ).

2. Also change to dedicated sound cards like SB Audigy and Yamaha 744B .

3. Thought of changing the capacitors but the after the above changes .

Regards

Kaushik

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 ?

Neither its my hobby or have surplus money and time , but still have a keen knack to have a better output by small changes possible .

I will let the forum know the results what I am testing today .

1. Changing OPAMPs ( dont know which are will be available in market today ).

2. Also change to dedicated sound cards like SB Audigy and Yamaha 744B .

3. Thought of changing the capacitors but the after the above changes .

Regards

Kaushik

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Kaushik,

See my second email.

I haven't tried the opamps you mentioned; I've only tried the opa2134 and paired opa267's. The latter opamps are very expensive unless you get them from China -- and the Chinese ones are very likely to be counterfeits !!!

Quote:

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Originally Posted by Feanor

Kaushik,

See my second email.

I haven't tried the opamps you mentioned; I've only tried the opa2134 and paired opa267's. The latter opamps are very expensive unless you get them from China -- and the Chinese ones are very likely to be counterfeits !!!

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Hi Feanor

I have not posted in a while but thought I would provide an update on the SMSL SD DAC. I am still loving the sound of this DAC. I have not changed the OP amps as I cannot fault the sound performance but decided to change the power supply. I did some research and found a PSU by Teralink. It was adjustable in voltage to suit the SMSL 9 volt requirement.
See the spec below:

Teralink-X2 / X1 U9VA Linear Low noise Power Supply (230vAC version)

1.EMI AC filter.
2.EI Transformers.
3.CLC Low ripple DC filter.
4.MJE15030 , BC550 low noise linear voltage circuits
5.And high accuracy reference voltage output.
6.STTH8S06 fast diodes.
7.High quality Panasonic FM caps.
8.DC output : 0.25V -9 V adjust ( Default DC 8.5v/1A in no loading for TX2/TX1)
9.AC input :AC 115 or 230V
10.Aluminum body , size is W101 x D115 x H46 mm
11.Aluminum panel.
12.Includes DC cable for connect Teralink - X2 / X1
13.Weight :700g 1pc
14.High level of silent background and detailed sonic performance can be achieve

Now I am not sure if I am suffering from 'I have improved the PSU so the sound must be better' or not. At this early stage in the change of the PSU on the SMSL DAC I am really pleased with the detail and imaging, its fast, open and punchy. I did have to solder the original SMSL PSU cable end to the Teralink PSU cable end to join the two units together checking polarity, + middle - outer at 9v DC. I also had to pop the lid off of the Teralink PSU and adjust the voltage from factory 8.5v to 9v. The Teralink is all aluminium construction and is substantial in weight.

I will continue to listen and update you with my thoughts over prolonged use and advise if there really is a difference with the Teralink PSU + SMSL DAC.

Cheers
Andy

I like to join the talk about the cheap SMSL 1955+ DAC.
Every since acquired it in Feb, I am still enjoying it very much. I now use it in my CAS setup via USB port from my Dell desktop. . I like to retain the warranty so I have no plan to swap opamp - though OPA227PG4 is around US$8 from RS Components, H.K. I carefully chose a short RCA and after a week of burn-in, I don't hear the harshness coming from either CAS & Main systems. The manufacturer uses 9VDC adaptor for the newer products quietly as I just bought 1 more for my sitting room main system for some CDR with my Pioneer BD player as transport. The DAC may have the gain been further improved For around US$100. delivered to your door in US, it is a steal.

Quote:

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Originally Posted by TLCW

I like to join the talk about the cheap SMSL 1955+ DAC.
Every since acquired it in Feb, I am still enjoying it very much. I now use it in my CAS setup via USB port from my Dell desktop. . I like to retain the warranty so I have no plan to swap opamp - though OPA227PG4 is around US$8 from RS Components, H.K. I carefully chose a short RCA and after a week of burn-in, I don't hear the harshness coming from either CAS & Main systems. The manufacturer uses 9VDC adaptor for the newer products quietly as I just bought 1 more for my sitting room main system for some CDR with my Pioneer BD player as transport. The DAC may have the gain been further improved For around US$100. delivered to your door in US, it is a steal.

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I'm glad to hear you're still enjoying the SMSL 1955+. For $100, delivered, it is indeed a steal.

If you inclined to try an opamp swap, I'd say go for it -- if installed properly, i.e. with the correct orientation which is easy to determine, the new opamps won't harm your unit. If you don't care for the sound or you have some other problem for which you want to claim under warranty, just swap back the original opamps. N.B. You will need a dual (two-channel) opamps, so you'd need the OPA2227 version of the OPA227PG4.

In any case for only $60-65 excluding shipping, I personally wouldn't be much concerned about warranty.

Feanor: Thanks for advice and notes. I shall order opamp 2227 on my next RS purchase. Only 9 VDC supply, do you agree the mod ?
I like to let you know that SMSL is modifying 1955+ continuously . May be after I notified them about your gain problem earlier through email, they released a higher gain version quietly.

Quote:

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Originally Posted by TLCW

Feanor: Thanks for advice and notes. I shall order opamp 2227 on my next RS purchase. Only 9 VDC supply, do you agree the mod ? ...

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What mod are you referring too? Yes, SMSL 1955 requires 9 VDC; I assume the 1955+ is the same. One could try a linear, full-regulated AC-input power supply or a battery power supply. Actually, battery power would be interesting: I suppose six 'D' cell cells in series might work, or several 9V batteries in parallel.

Quote:

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Originally Posted by TLCW

... I like to let you know that SMSL is modifying 1955+ continuously . May be after I notified them about your gain problem earlier through email, they released a higher gain version quietly.

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My gain problem was only with the USB connection; I had no problem with either S/PDIF input.