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V-dac modifications - Page 9

post #121 of 196

Wima folie is too big they will not fitt.

You came to my place and did removed replaced some components.

Hope it will bring more music to your V dac 

post #122 of 196

Hi Martin and all others,

 

Yes it did!

There is really more music comming from the DAC!

Everything is more detailed, more precise, more transperant more musical more everything! Did someone removed the curtains in front of my speakers?!

This is the right upgrade to do for your DAC!

 

I contacted Dutchamp because I didn't know what to do with al the information regarding upgrading and tweaking. (I couldn't see the forest anymore because of the trees ). But if there is someone like me who likes just the finishing touch upgrade for his V-DAC these improvements are ok to do.

 

I'm not in to it but maybe Dutchamps can tell me/ us what precise did we changed yesterday?

We've replaced one OpAmp in the analogue section and two condensors also in that section.

But I forgot about the specific values of those components.....

 

Grtz,

 

Jordi

post #123 of 196

NE5532 replaced with Opa270FZ better opamp

Two output caps replaced from 47uF bip elco to 3,3uF Mkp intertechnik audyncap

 

So like i mentioned befor Bip elcos doesnt conduct high freq so good as mkp types

Other mods i didnt found greater improvements to the time and money can spend.

Offcourse a good and better PSU is highly recommended.

 

Goodluck Jordi with the modified Vdac 

post #124 of 196

Hello, all! I am trying to determine how to hook up a V-DAC with a Pyramid PSU. The problem is that I am unable to get a confirmation on the polarity of the tip/center that is required to power the DAC. There is no mention of the polarity in the manual and I do not have the old wall-wart to go off of. (When I have the 'H' lined up with 'Tip' on the cord, the barrel/exterior appears to be negative and the interior/tip positive. The end of the cord is raw wire, but I assume that I attach the side of the cord with the rib marker as 'negative'.) At one point in a thread here, someone mentioned that the V-DAC power supply is center-positive (+ tip), but I just came across the following on hawkee.com about proper setup of the Pyramid PSU (http://www.hawkee.com/shop/prod/9908174/):

 

"First, this unit is awesome. I have a Pioneer SX-980 receiver (circa 1978 or so) and for two years could not figure out why the sound coming from my ipod/computer through it sounded like crap. Hours of research on the internet led me to the DAC solution, and then to this unit in particular. I researched a lot of different units and this was definitely the most highly recommended for the price. So I bought it along with the suggested pyramid power supply. Little did I know I would have to know a little something about electricity to hook the two up. More hours of research on the web ... and now I'm back from the other side to save you some time if you are/were just as clueless as me. Step one, go to Radio Shack and find the aisle with all the different sized plug tips (ones that look like the tip of the wall wart). Look for the green packaging and brand "enercell". You want the "H" sized tip. Next get a Enercell Adaptaplug power cord. Go home, snip off one end of the power cord. The strand with the white stripe is negative, solid black is positive. Cut off some of the plastic to expose each wire and wrap around the terminals of the power adapter. Now take your "H" plug and plug it into the other end. Which way? This I found out the hard way. The wall wart plug would suggest it is positive tip polarity. NOPE! It's NEGATIVE tip polarity. So line up the "negative" symbol on the H tip with the word "tip" on the end of the power cable. Plug into your v-dac. Congrats, you're home free brotha!"

 

So what is the true story here? I certainly do not want to wreck the V-DAC before using it. What is the best way to know how to set up the connections? Thanks in advance for the advice! :)


Edited by sampson_smith - 7/21/10 at 8:19pm
post #125 of 196

I am very surprised, even over a relatively short period of time, that I haven't received a response to the above. Essentially, boiled down, the main question that needs answering is:

 

"Is the V-DAC power supply which inserts into the DC port of positive (inner) tip polarity, or is it negative?"

 

Thanks for the help! *Fingers crossed* :)


Edited by sampson_smith - 7/21/10 at 8:37pm
post #126 of 196

Do you have a multimeter?

You can measure the current polarity with that device.

 

Also you can do a polecheck.

Make sure your device is not grounded.

With the multimeter in VAC measure the voltage between the clinch (groundpoint of the DAC) and the ground of the wall socket.

Try again with the blank-face connector turned around. Measure again and choose for the setting with the lowest voltage leakrate.

 

Hope this is usefull for you.

 

post #127 of 196

Thanks for the info, jordi81. I do have a autoranging multimeter, so I guess I am in luck. I am not sure where the clinch of the DAC is, however, although I assume the ground point of a wall socket is the bottom hole of the plug-in. (I assume that the top two holes provide mains power and I should never stick anything in there, apart from a plug.) What do you mean by 'blank face connector' and 'leakrate'? It appears that I will likely have some Googling to do!   

post #128 of 196

I saw that post you quoted from Amazon too. What's not obvious is that there are two replies to it on the original Amazon page, that are revealed only after clicking through further. Basically, the replies slammed the post for being dangerously wrong about the polarity. So the balance of opinions now tips (haha) towards positive polarity.

 

Best to still verify with your multimeter though.

post #129 of 196

Haha. Thanks for checking, Yoga Flame. I was actually the one who 'flamed' the post in the second comment, out of frustration. I have since seen what appears to be a V-DAC wall-wart in a post here and it appears to be (-)---(o---(+) which I assume means positive tip polarity. However, in addition to that amazon.com review, which indicates it is actually negative to save us trouble - (I have no idea how the poster's V-DAC would have survived if he first hooked it up as + tipped and that was truly incorrect, and then went on to figure out the - tip worked better assuming the V-DAC survived) - there is actually the following series of posts from the thread (with the wall-wart picture) here:

 

http://www.head-fi.org/forum/thread/477392/good-power-supply-for-v-dac

 

Essentially: "FYI - the plug is NEGATIVE TIP polarity. Not positive as the wall wart plug would suggest, or maybe I'm just ignorant." - from a poster with a single post, so perhaps he is indeed 'ignorant'.

 

Followed by: "Is the tip Positive or negative.....Polarity is important, please advise." to which there was no confirmation made.

 

Confusing to say the least. So, in order to use a multimeter to get to the bottom of this - if there is really no one out there with a Pyramid PSU and V-DAC that actually knows the tip polarity that they are using - what setting do I need to use and to which connections do I place the two multimeter contacts? I am at work now, but will try my best to find a demonstration on the net when I get home if no one has an easy answer here.

 

Thanks again for the feedback and advice! :)

post #130 of 196

I'm afraid that this post might not help, but I did post about my experience on some forum of how I hooked up my Pyramid PS3 and V-DAC. I'm sure if you google those terms and even my first name (Dave) you'll probably find it. I probably also had pictures--this was 7 months ago or so.

 

In essence what I did was simple: I had a USB to power tip that exactly matched the tip of the V-DAC's wall wart (from a USB portable hard drive). I then cut it, leaving about 2 inches of lead. It has two wires and a foil wrapping, which is part of the ground and shielding. I used a 3 wire extension cord as my lead, twisted the red and white together with the red and ground on the stripped tip, black on black. I then added two banana connectors (one black one red) on the other end of the extension keeping them with their same colored wires. I plugged the tip into the V-DAC and the banana plugs into the binding posts of the Pyramid and it worked perfectly.

 

I later purchased the V-LPS and did the exact same thing for it, but bought a Tripp-Lite PR-3 for that one (I had an amazon coupon so it only cost me $10 for that one).

 

Good luck.

DT

post #131 of 196

For confirmation's sake to help out future V-DAC users that want to use a Pyramid or related PSU to improve performance, the tip is most certainly center-positive or '(-)---(o---(+)', as is correctly written on the supplied wall-wart. I am currently loving the V-DAC with my Gilmore Lite amp and HD600's, using this upgraded power supply option.

 

Thanks again all for helping me get to the bottom of this! :)

post #132 of 196

Is there any V-DAC project somewhere that proposed a major change to the power supplies?

 

Particularly eliminating the DC-DC supply, that apparently only powers the quad and dual analog output chips. Does it power anything else?

 

Is there a schematic anywhere to be found?


Edited by carlmart - 8/2/10 at 5:55pm
post #133 of 196

Hi, I am using Two SuperTeddyRegs for power up analog stage. You can find schematic of STR on Teddy Pardo's website. In my case they are feed from separate transformer. Dc-DC converter is not used any more. The improvement was much bigger then all other capacitor changes, opamp swaping and and external power supply together. To be honest only after this power mod you can "REALLY" hear other changes eg. opamps replacements. Now V-DAC outperforms NAD C545BEE without any problems.

post #134 of 196
Quote:
Originally Posted by barmanekm View Post

Hi, I am using Two SuperTeddyRegs for power up analog stage. You can find schematic of STR on Teddy Pardo's website. In my case they are feed from separate transformer. Dc-DC converter is not used any more. The improvement was much bigger then all other capacitor changes, opamp swaping and and external power supply together. To be honest only after this power mod you can "REALLY" hear other changes eg. opamps replacements. Now V-DAC outperforms NAD C545BEE without any problems.


Thanks for your suggestions. I do agree that after a very good supply upgrade will you really listen to other improvements. I will have a look at STR's supplies.

 

The schematic I was referring to was the V-DAC's. Can I find that anywhere?

 

Thanks!

post #135 of 196

The schematic I was referring to was the V-DAC's. Is there a V-DAC schematic anywhere to be found?

 

The STR's look interesting, but wouldn't a Sulzer or Jung regulator improve over it?

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