[MatsudaMan]

Quote:

Originally Posted by Calvin&Hobbes /img/forum/go_quote.gif Sorry for my ignorance, what does the x-10 v3 do? Is it a dedicated PSU?

It's a tube output stage and buffer. Basically it gives the sound a little tube magic and magnifies everything - sounds a little louder in the process.

 

[josep]

There was a time were budget CD players had somewhat weak analog outputs, and many integrated amplifiers had lowish impedance inputs. This resulted in overload of those CD outs and bad, or less than good, sound. X-10 came within them, offering a very high input impedance for the analog CD outs to see (no load = best sound) and a low output impedance for the amplifiers. Add to this some tube coloration (second harmonics dose someone

) and the result was usually nicer sounds from the same budget gear, like some "magic" interconnect to so say.

However I am surprised you like it on the V-DAC. In my experience this unit is perfectly able to drive anything, ok mine has now a different out opamp, but adding an X10 gives always less transparency (I never liked this added veil and never needed its theorical benefits anyway). Maybe your Atoll is a thougher loud than I imagine, but... you must try a different opamp and get rid of the extra buffer to see.

Yesterday I managed to have some more musical minutes (still too busy

so still no pics, sorry). I like this dac, as I said it is not out of place in my main rig (speakers), it just feels a bit less transparent than my references, there is less microinformations and maybe this causes a small loss of depth, and the bass is too a bit lighter, but I still have the original coupling craps (yups caps) so... there is some road still ahead.
But the sound is warm and nice, one can live perfectly happy with it.

 

[Calvin&Hobbes]

I am not keen on modding the V-DAC, unless you (Josep) would stumble on a major weakness in the configuration that would be easy to fix. In that sense: I have confidence in what I hear (on top of my left-handedness when it comes to electronics).
In addition to my earlier comments I would say that there is some room for improvement when it comes to "authority and impact" of e.g. solid rock music. I compensate for this by slightly turning up the subwoofer level. I suppose that a better PSU could help here, given all the comments sofar. With all the expertise around, I am however a bit surprised that such a thing is not yet readily available and that V-DAC lovers have to await new initiatives such as little pinky. Nobody has yet reported on the sound effect of a better PSU. Or did I miss something?
The V-DAC has no lack of details to my ears (IMHO too many details can cause an experience of lesser coherence, where one starts listening to details rather than the music as a whole). I fully agree with an earlier comment that this V-DAC is more expressive at lower SPL. Since my sealed box enclosure ATC's are somewhat insensitive I previously had to crank up the amp to bring out the music. Now the music is more expressive at lower sound level (although I still crank up when home alone).
Sooo, I am still fond of my V-DAC.

 

[MatsudaMan]

Quote:

Originally Posted by josep /img/forum/go_quote.gif There was a time were budget CD players had somewhat weak analog outputs, and many integrated amplifiers had lowish impedance inputs. This resulted in overload of those CD outs and bad, or less than good, sound. X-10 came within them, offering a very high input impedance for the analog CD outs to see (no load = best sound) and a low output impedance for the amplifiers. Add to this some tube coloration (second harmonics dose someone ) and the result was usually nicer sounds from the same budget gear, like some "magic" interconnect to so say. However I am surprised you like it on the V-DAC. In my experience this unit is perfectly able to drive anything, ok mine has now a different out opamp, but adding an X10 gives always less transparency (I never liked this added veil and never needed its theorical benefits anyway). Maybe your Atoll is a thougher loud than I imagine, but... you must try a different opamp and get rid of the extra buffer to see. Yesterday I managed to have some more musical minutes (still too busy so still no pics, sorry). I like this dac, as I said it is not out of place in my main rig (speakers), it just feels a bit less transparent than my references, there is less microinformations and maybe this causes a small loss of depth, and the bass is too a bit lighter, but I still have the original coupling craps (yups caps) so... there is some road still ahead. But the sound is warm and nice, one can live perfectly happy with it.

I have to disagree. The x10 does not add any veil. I like the x10 because of the added tube richness and the bigger and more stable soundstage.

BTW when are those pics coming? Also, where can you buy the upgraded opamps? Do you have to solder them?

 

[josep]

When you add something to the analog path... there is some transparency to be lost. But as I said the X10 has positive efects too, obviously you got more positive then negative!
I would help to know the input impedance if your amp/pre (on its manual maybe?) to understand why it is so.
Not yet but this afternoon I promish making and uploading pics. Btw yes, the opamps came soldered unfortunately.

 

[MatsudaMan]

Quote:

Originally Posted by josep /img/forum/go_quote.gif When you add something to the analog path... there is some transparency to be lost. But as I said the X10 has positive efects too, obviously you got more positive then negative! I would help to know the input impedance if your amp/pre (on its manual maybe?) to understand why it is so. Not yet but this afternoon I promish making and uploading pics. Btw yes, the opamps came soldered unfortunately.

Josep, here are the specs on my amp:

Power Wrms/channel/8 Ω
100 W
Power Wrms/channel/4 Ω
140 W

Impulse power

180 W
Power supply (VA)
660
Total capacity (µF)
30 000
Number of inputs
4 + 1 monitor
Input impedance (kΩ)
47
Sensibility (mV)
100
Rising time (µs)
2,5
Bandwith
5 Hz - 100 kHz
Output level (0dB)
-
Signal/noise (dBA)
100
Weight (kg)
10
Dimensions (mm)
440x90x270
Remote control
option
Phono stage
option
Silver line
option

 

[josep]

Well 47kOhm is not by any means a low input impedance. Whatever way, if you prefer the X10 "in", so good so far!

And now for the claimed picture... You can see a big cap close to the power input, two big ones in different places of the circuit (Elma Silmic for +V and -V analog) and a smaller one close to one of the Elma (Oscon for +5V digital). The opamp is close to the analog output (an opa2604 here). That, and removing the input diode (ferrite bridge instead) is all I have done (... yet).

Regards

Josep

 

[josep]

I forgot to mention: today I received my HFN&RR, there is a test of the nice Weiss Minerva DAC, wonder what DAC chip does it use? Yes, same here: pcm1792 (and yes just one). It is a 3,000ukp unit btw.

(Note/disclaimer: I am not saying by any means the V-DAC will sound same as this Weiss! But, you know...)

 

[MatsudaMan]

Quote:

Originally Posted by josep /img/forum/go_quote.gif Well 47kOhm is not by any means a low input impedance. Whatever way, if you prefer the X10 "in", so good so far! And now for the claimed picture... You can see a big cap close to the power input, two big ones in different places of the circuit (Elma Silmic for +V and -V analog) and a smaller one close to one of the Elma (Oscon for +5V digital). The opamp is close to the analog output (an opa2604 here). That, and removing the input diode (ferrite bridge instead) is all I have done (... yet). Regards Josep

Hey Josep,
Thanks for the pics. It's cool to see the innards of this little beast. Can you give some impressions on differences you heard after making the "upgrade"? Also, what makes the opamps you replaced better than the originals? I'm totally oblivious to the diy stuff, so any info will help. Thanks

 

[split_brain]

Get a proper source, and hear your recordings like they were meant to be heard.

 

[MatsudaMan]

Quote:

Originally Posted by split_brain /img/forum/go_quote.gif Get a proper source, and hear your recordings like they were meant to be heard.

I totally agree! That's why I love the V-DAC - it really let's you "hear the recordings like they were meant to be heard". Good stuff man!

 

[Calvin&Hobbes]

Comment withdrawn.

 

[spore]

I changed all 4 caps as shown by Josep photo to ELNA audio grade capcitors with the same capacitance value. Some caps are replaced with higher voltage rating as I am not able to get the same voltage rating. I did not change the input diode as I am not sure how or where it is from the photos. I ran the v-dac immediately after the caps change and the bass is more defined and natural sounding.

Next I changed my op amp from NE5532 to LME49860.LME49860 can be used as a direct replacement for NE5532 without any changes to the circuit. As usual I ran the v-dac immediately after the op amp change. Music is clearer and seems like a soft veil lifted off the music. Soundstage width and depth increased slightly. Highs are much airy with greater extension while bass is tight and deep with more slam. More details are heard clearly while vocal/midrange remains pretty much the same. Imaging is slightly improved.

I think it is cheap and good upgrade for v-dac but your mileage may vary.The mod is worth it!

 

[MatsudaMan]

Quote:

Originally Posted by spore /img/forum/go_quote.gif I changed all 4 caps as shown by Josep photo to ELNA audio grade capcitors with the same capacitance value. Some caps are replaced with higher voltage rating as I am not able to get the same voltage rating. I did not change the input diode as I am not sure how or where it is from the photos. I ran the v-dac immediately after the caps change and the bass is more defined and natural sounding. Next I changed my op amp from NE5532 to LME49860.LME49860 can be used as a direct replacement for NE5532 without any changes to the circuit. As usual I ran the v-dac immediately after the op amp change. Music is clearer and seems like a soft veil lifted off the music. Soundstage width and depth increased slightly. Highs are much airy with greater extension while bass is tight and deep with more slam. More details are heard clearly while vocal/midrange remains pretty much the same. Imaging is slightly improved. I think it is cheap and good upgrade for v-dac but your mileage may vary.The mod is worth it!

Ok, so I'm totally a newb at this whole modification thing so....can you show us pics of these modifactions and maybe give some info on where to purchase such things? Also, must you have soldering skills to pull of such a mod? Very interested and intrigued.

 

[spore]

Op amp LME 49860NA - buy from Farnell P/N: 143-3173
100uF 35V capacitor - buy from RS Components P/N: 215-5714
1000uF 16V capacitot - buy from RS components P/N: 215-5663

Search google for Farnell and RS Components to buy online or place orer and collect from the trade counter.

The caps to replace are at location C25, C22, C45 and C61. They are the 3 big brown capacitors and large red one. Take note that these capacitors are polarized and have positive and negative connections. You can differentiate the negative terminal by looking at the capaitor. There is a negative marking on the capacitor.


I am not able to get non polar audio grade capacitors for C3 and C4 both located at the end of the board near the op amp location. If someone could try changing out these caps and report back their findings, that would be great. I think changing C3 and C4 may improve the sound further.

NE5532 is an old om amp design that has been around for more than 30 years old. LME 49860NA is a much better spec op amp which is a direct replacement for NE3552 and it will definitely improve the sound.

Actually this is my first time I am desoldering/solder capacitors and opamp. I was intrigued by Joseph findings and did some rsearch on the net. Fortunately. I did not kill the v-dac.