[Calvin&Hobbes]

Thank you, gentlemen.

Are you considering more mods (is there still more SQ potential in the V-DAC that is easy to realise?). Or would this be the way to move forward then?!

In general: I am already very pleased with the V-DAC as is; it's simply giving in to temptation for something hopefully still better.

 

[josep]

It does exist something called 'point of diminishing returns' and one must be well aware of it.

We can use an overkill PSU for the V-DAC and it will be grateful (our ears too), say a Sigma11 or something like that. But at or over 200ukp, is beyond that point.
I too want to try a different output stage (passive transformer based) but, again, just each of the (two) needed transformers cost around 90ukp, so...

'So' when you have already the unit, and have a box full of things lying around (and time and will to 'play' around) there are many things that can be done to improve it, but as I said it is important to keep a bit an eye on the thing original price, specially when posting in forums, to avoid non-advised people getting wrong impressions.

Let me say this clear: for 400 (or over 500ukp...) there may be better ways to have good sound quality than buying a V-DAC and ultra-modding it.

 

[dukja]

I just got V-DAC yesterday and have been following this thread for a few days. Thanks you all for the wonderful mods. I'll venture into it when I get familiar with the stock sound. PS upgrade will be the 1st easy step.

If you don't mind, I'd like to mention my appreciation to V-dac and ask USB input question for a moment.

My system is
Foobar FLAC (ASIO4ALL) > V-dac > Arietta > DT880,
and this is the first time I start to enjoy music after over a month of hunting, waiting, and buying. When I switch from HD555 to DT880, I immediately like the sound characteristic. At that time, I was using HOTUSB MKVII dac(16-bit)/amp as input and amp. It works magic on 555 but was disappointing for 880. The MKVII + 880 sounds thin, bright, mid laid back, and dry. Then I got Arietta three days ago and it already helps a lot to add juice and clarity into the sound (input from Sansa Clip).

I expect V-dac to add more nice texture and warm sound to 880. Initially, it did not sound amazing (as usual), but then I did several thing at a same time:
1. Install ASIO4ALL and Foobar ASIO plugin
2. change direct-sound output to 24-bit

And suddenly I heard MUSIC. This is the first time I am not aware of any artifact in mid and high (I am not too picky on bass speed since my genre are classical/vocal) and the sound is just pleasing to hear. I expected this combo will be good for 880 and it does! Thanks for the hints from Head-fi!!

Now I can either use Foobar with output setting to DS: USB DAC (with 24-bit setting) or ASIO: ASIO4ALL (grayed out 24-bit display, but the ASIO4ALL configure window actually shows Out: 2x 32-48kHz, 16Bits).

So does that mean USB can only output 16-bit max? Then why direct-sound setting allows 24-bit but ASIO only allows 16-bit? I saw some pictorial show 24-bit for SPDIF. Does that mean I need to use other source to escape USB 16-bit limit?

Thanks for your experience!

 

[ADD]

Quote:

Originally Posted by josep /img/forum/go_quote.gif It does exist something called 'point of diminishing returns' and one must be well aware of it. We can use an overkill PSU for the V-DAC and it will be grateful (our ears too), say a Sigma11 or something like that. But at or over 200ukp, is beyond that point.

I made the decision yesterday to change my V-DAC power source to a sealed lead acid battery. I bought a 12 amp hour version as I felt this would be the most cost effective and would easily fit on the bookshelf

($69 AUD plus $30 AUD for the charger).

I had previously been noticing that the results I was getting from my regulated mains adapter were not terribly consistent. Sometimes things would sound excellent, but then I would sometimes feel that some of the smoothness, clarity and lack of grain I normally experienced was missing.

Anyway, the lead acid battery seems to have not only solved that, but it has literally peeled away yet another viel from the music - this time I can hear clearly right into the noise floor, I can hear the tiny tinkering of page turns, etc even at quite low volume levels. the overall presentation seems to be smoother as well - but what I mean by that is it's as smooth as the mains adapter was - but only when the mains adapter was behaving at it's very best so to speak.

But this SLA battery just gives this uncanny black, velvet background of absolute nothingness from which the music comes through. It is hard to describe, but imagine wearing glasses and giving them an absolute, thorough clean when they are dirty.

Based on my original lantern battery experiments, I am surprised that the SLA battery holds it charge as long as it does. I listened for several hours yesterday and the voltage barely even moved - unlike the standard 2 x 6 volt lantern batteries that lost two volts after two hours.

Hopefully I can get away with charging the SLA once per week. Anyway, it seems to be something worthy of consideration given the cost of the battery and charger is far less than the cost of any audiophile quality aftermarket PSU (or the projected cost of the V-PSU before the project was allegedly aborted).

 

[josep]

Hi ADD,
Nice to hear this. Somewhere in this thread I put my measurement of the V-DAC current from the PSU, if memory is good it was around 300mA or 0'3A. So your 12Ah battery will last for around 40 hours (12/0'3) before being deeply discharged.
However I will advise you to charge it every night. SLA batteries do like small cycles (very different from NiCd or NiMh chemicals), and definitely do not like at all deep discharges (once deep discharged they are never the same). If every night seems too much ok but do not it let discharge too much (not more than 50%=around 20hours working).
If the charger is a good one you can let it connected all the time, he will put itself in maintenance mode after charging, just unplug it before listening and replug after listening. This way the battery will be with you until the end of the days.
Regards
Josep

 

[iszatso]

Could someone recommend a ps for the vdac that it is extremely well regulated that I can buy over the internet here in america that will give me the sound that ADD talks about in his battery post? I need 120vac here.

These reason I am reluctant to use the battery approach is the constant off and on for the equipment can't be all that good for it. (Convince me the battery is the way to go..)

 

[T_K]

So I received mine this morning and am running it now with a 1700mA 12V universal psu I already had. The unit was surprisingly hot when I first ran it with the stock psu but now it's at room temp.

I'm too tired to do extensive A/B tests but it looks like this will be my main source for the next few months (what I really want is something with the ESS Sabre...) Unfortunately I'm a noob and my dictionary of music-descriptive terms is pretty limited... I can say that my modded X-Fi is more aggressive and so far has a lot harder hitting and more controlled bass... probably more enjoyable for metal/rock music. But the V-DAC is more realistic and I feel I can keep listening to it for hours. I'll get a LME49860 next week, hopefully that will improve it as much as the LM4562 transformed my X-Fi... I wonder if the op-amp could be altogether bypassed though? I kinda compromised when I chose this DAC, I really wanted one with a passive output but I was spending so much time reading about different DACs (damn you head-fi...) that the other day I just said that's it, I choose one tonight.

On a side note I couldn't get it to work with the optical interface from the X-Fi... probably am doing something wrong.

 

[spore]

I am using Meanwell switched medical desktop power supply MES30A-3P1J bought from 1st power. Medical Desktop Power Supply. The psu is universal and can be used worldwide. Unfortunately it is not a SLA battery.

I am their first customer that got the psu and they had to specially indent from taiwan. Take note that they do not have stock on hand although it is not reflected in their website.

You may be able to get the same psu cheaper at other websites but their sales and customer service is first class and I strongly recommend them.

Reason why I choose a medical grade power supply was that the psu has several safety certifications unlike others. I have peace of mind knowing that the meanwell psu wont suddenly burst into flames unlike others which are just CE certified only or have no safety certification at all. Also, in my opinion, i think medical grade products are much better than non-medical ones.

I am pleased with using this psu as my v-dac runs cooler and there was an improvement in the sound quality but your mileage may varies. Take note that an external dc to dc converter plug is required for the v-dac as the psu output plug is 2.1mm and much bigger than the v-dac which is around 1.1mm or 1.3mm. Try to get those plug coverter made in taiwan as they are a perfect fit. Some other dc plug converters that I tried having the same size as v-dac plug, do not fit at all.

If anybody have other cheap/reasonable modifications that will improve the v-dac further, please kindly share them.

 

[dukja]

Interestingly you mentioned about medical grade PS. In one of my R&D project working on high-resolution low-noise power detection, one senior engineer suggested highly about medical grade PSU. It didn't solve all the problem, but it was non-audio related issue anyway. I am glad to see that it work for you.

I just swapped in the Blue Jeans cable and was surprised how well it improved the sound. I wasn't believing that cable can change sound much, but would like to make as less distortion as possible on the upper analog stream. And it did help quite apparently in my system (FLAC >Foobar >V-DAC >Arietta >DT800). For example, the organ in the overture of the Phantom of the Opera was quite bright and "blinking" with Monster 300 MKII (I knowed, it was uneducated random choice...). Blue Jeans cable smooths it out and the speed seems to be improved as well. Soundstage is deep and wide and positioning is clear and solid. I was kind of lazy and did not do too much swapping to compare. But with only $32, Blue Jeans cable is very worthy.

I only use stock PS. The problematic thing is to find right sized plug for the V-DAC. Are there some adapters to convert the size? Or DIY is needed to reconnect the right plug? Anyone has some good suggestion with good Performance/Cost value? Thanks!

As for USB input, it seems that there is not much difference between DS: USB DAC (24-bit) and ASIO4ALL v2(32? 16-bit?). Some reading suggests that it was only conversion between 16-bit (FLAC) -> 32-bit ASIO -> 24 or 16-bit out to DAC, and there is little effect with this type of conversion (zero padding/truncation to the binary representation). Did anyone use USB and would you please share your experience?

Thanks!

 

[spore]

you can get this type of dc plug adaptor for the v-dac and do not need to diy. I bought mine locally and not sure where to get one on internet that fits the v-dac. I tried various dc plug adapter from various shops and only managed to find one dc plug adapter from a local shop that fits well. The shop imported it from Taiwan and I guess only made in taiwan dc plug adapter fits the v-dac perfectly even though the size may be correct.

 

[Calvin&Hobbes]

+1

A decent PSU rated at least 50W will do, one 90-120W unit runing at 12 to 13'5V is perfect and you may have it for (well) under $50 (ePay).

Based on this kind advice I went to the local electronics shop yesterday and bought a switchable power supply delivering 5000mA at 12V (i.e. 60W). The package contains six output plugs, one of which fits the V-DAC. The guy in the shop connected the output plug in the correct polarity for me (crucial), so nothing could go wrong.

And things couldn't have turned out better!! The PSU works like a charm. All my reservations are now gone! My original source has a big PSU and this turns out to be the missing element with the V-DAC.
No more questions from my side concerning prat, impact, attack, upsampling downside or what-so-ever..
The sound has become spot-on with more control and punch (strong and taut bass).
Instruments are loaden with energy.
And there is improved definition, with velvet-black background (poetic terminology from ADD) and no more "small fruits splashing against the wall" (also proza from this forum) as was evident from a somewhat blurred sound before.

Thanks again for this recommendation

. For only 30 Euro I am now completely satisfied.

Here is a link to the PSU I use:
Best switch mode power supply 6V - 15V (up to 5 Amp) at e.g.:
AC/DC Adapters

 

[davidcotton]

Was just wondering how people found the vdac for stuff like rock music? Considering this along with a couple of other possibilities.

 

[ADD]

Quote:

Originally Posted by Calvin&Hobbes /img/forum/go_quote.gif For only 30 Euro I am now completely satisfied.

The ability to completely change the power source delivery is a reason why I think the V-DAC is a better bet than it's competitors. For all the magazines that tested the V-DAC, most of them came to their conclusions based on using that horrid wall wart. It bascially makes the V-DAC functional and that is it (lights turn on, sound comes out).

Going from the wall wart to a great PSU or even better an SLA battery, and the upgrade is as substantial as, say, upgrading from a $2 vacuum tube to your favourite $150 NOS vacuum tube in your amp.

Given how the V-DAC with the wall wart came out in testing by professional mags (it did not really come out badly at all), just imagine it being retested with a top notch PSU.

The competitor's PSUs are all inbuilt requiring an A/C connection. Nothing like the tweaking available for V-DAC owners.

The V-DAC reminds me of cult classics like the old Celeron processors that could be overclocked to (in those times) insane levels, or pocket rocket cars like the original Cooper S or (in more recent times - Swift GTI) that were far more than the sum of their parts. These things were all giant killers in the right hands.

So yeh, I think the V-DAC will become a cult hi-fi classic too.

 

[josep]

Paul,

Nice to see you so happy! A good, no necessary overkill, PSU is enough as the V-DAC has it own internal regulators.

Quote:

Originally Posted by ADD /img/forum/go_quote.gif Going from the wall wart to a great PSU or even better an SLA battery

Batteries are not bad but not the best PSU, they do have low level noise (yes!) and a 'top' PSU can be quite better even if connected to the mains. But as I said, it may be overkill: the cost of a SLA unit or a PS like the one mentioned above is fair (both in absolute terms and in relation to V-DAC own price) and the upgrade well worth it.

Regards

 

[Oskari]

Quote:

Originally Posted by josep /img/forum/go_quote.gif Batteries are not bad but not the best PSU, they do have low level noise (yes!)

They do? How much?