Chameleon DAC listening and modifications
May 9, 2010 at 5:22 AM Post #917 of 1,158
If anybody is brave enough they can get improvements by tapping the 5v from the DC 30W to replace the 5v from your computer. You would have to leave the earth wire intact to keep the ground loop to the pc, so no  true galvanic isolation. I tried this with the Musiland with good results, But I do know of at least one unlucky guy who got it wrong and fried his Hiface. Also not all usb cables have the correct colour wiring so you have to be very careful. This was an experiment that jkeny came up with a while ago, when we where trying to find ways to improve the Musiland.
 
May 9, 2010 at 9:47 AM Post #918 of 1,158
Well, guys, it looks like the ADUM does not work with the Hiface, (as I suspected might be the case - see you made me build it & waste my energy ) - it gives "device not recognised" message - I know this is a reported problem on the circuits@home site & the solution is posted there but I've tried it a number of different ways & no go. 
 
Correction: It looks like my ADUM is not working - no device is recognised even USB 1 devices
 
Yes, Wood, this will improve the sound somewhat - how much depends on how bad your PC PS is because this is what is currently powering things. BUT I thought that the Chameleon only used 5V Vbus for led light?
 
BTW, the Green & White are reversed Green=D+ White=D- (not that it matters for this PS exercise.) 
 
May 9, 2010 at 12:27 PM Post #919 of 1,158
The Ultravox ADUM works up to 24/96, with the Musiland, i couldn't test if it can go higher then this. We will know soon enough if it works with the Hiface, and if so, if its a benefit.  Yes the Chameleon just uses the usb 5v for the led, the suggestion to try the usb cable mod was for users of usb powered SPIDF convertors. I found it benificial, but as you say it may be that my pc is noisy, it certainly sounds noisy mechanicaly. Your noticing the wrong colour coding on the diagram further underlines that the modder need to be very cautious if trying this.
 
May 9, 2010 at 1:32 PM Post #920 of 1,158
Quote:
No, The HiFace gets it power from the USB computer 5 volts.

I meant galvanic isolation on the Hiface SPDIF output, isolating the Hiface from what follows.
 
Jkeny, one more thought about clocks on SPDIF.  The Valab used a DIR9001 without a local clock and it performed very well, especially after the pins 13 and 14 to 3.3v mod.  That was the DIR9001 example behind the request for a simple input board from Teradak.
 
I have an Ultravox on the way to use with the Off Ramp.
 
May 9, 2010 at 2:35 PM Post #921 of 1,158
Hey, Wood.  What did you use for connections on both sides of your Ultravox?  Did you mod the standard USB A/B ports?  Wondering what you used between your computer USB out and the Ultravox input.
 
May 9, 2010 at 3:06 PM Post #922 of 1,158
Hi, I am using a 1m Belken pro for the input and a 30cm cable for output to the dac, that was stock supplied with the Musiland. Both are standard A/B types.  I'm waiting for a usb a/b adapter I found on ebay to eliminate the second output USB cable. My Ultravox is  powered by a 12v SLA and the only mod is cap changes to BG FK, I have not tried any other mod at this point.  I would like to try LiFeP04 cells to power it. I have ordered 3 from jkenny, so will give them a whirl with Ultravox as well. 
 
May 9, 2010 at 3:14 PM Post #923 of 1,158


Quote:
Quote:

I have an Ultravox on the way to use with the Off Ramp.


I just noticed this. i would be very interested if you tell us what you find. I  noticed on a forum (was it you?) being advised by (was it Steve N?) that the an ADUM device would only introduce jitter to their products.
 
May 9, 2010 at 4:03 PM Post #924 of 1,158


Quote:
Hi, I am using a 1m Belken pro for the input and a 30cm cable for output to the dac, that was stock supplied with the Musiland. Both are standard A/B types.  I'm waiting for a usb a/b adapter I found on ebay to eliminate the second output USB cable. My Ultravox is  powered by a 12v SLA and the only mod is cap changes to BG FK, I have not tried any other mod at this point.  I would like to try LiFeP04 cells to power it. I have ordered 3 from jkenny, so will give them a whirl with Ultravox as well. 


I ordered a 9.6 Volt LiFePO4 to run my Ultravox on:
 
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260599783306
 
May 9, 2010 at 4:52 PM Post #925 of 1,158
Quote:
I just noticed this. i would be very interested if you tell us what you find. I  noticed on a forum (was it you?) being advised by (was it Steve N?) that the an ADUM device would only introduce jitter to their products.

Yeah, that was me in the AC Empirical Audio forum.  I asked SN about the Ultravox right after you first mentioned it.  He said the output on the Off Ramp was already isolated and I left it at that, but the question really applied to what isolation from the other (input) side could do for the Off Ramp. From my limited POV the Ultravox will provide a cleaner USB source for the Off Ramp to work on, the typical audiophile application of the ADUM circuit.  I decided to try it anyway because it certainly seems like a logical, cost effective step for an improvement in the signal path.  (Not to challenge SN, but his reply didn't seem to apply to the intent of the question.)
 
The Ultravox will be here Tuesday but I realized I didn't have a USB connection solution between the server and the Ultravox input.  I need to be careful because the other USB cable is a pricey Ridge Street Poiema (cryoed silver conductors).  I imagine I may end up using silver wire (on hand) and hardwiring it straight to the PCB for a port on the USB card in my server.  For the time being I ordered one of the stubby no-cable USB male A/B adapters like described at Circuits@Home.  As SN has said, USB cables is not an issue on async devices, but adaptive USB benefits from better cables.  The Off Ramp is a reference grade reclocker on adaptive USB.  It's 24/96 so higher resolution on the Ultravox isn't an issue.
 
I'll be powering the Ultravox with the 12vdc wall wart that was supplied with the Off Ramp.  (I'm using a different PSU on the Off Ramp now.)  I don't use batteries as many of you do because my system is for ambient music playing almost constantly.  The same reason I won't consider tube gear.  Too many hours for components that wear.
 
 
May 9, 2010 at 5:19 PM Post #926 of 1,158


Quote:
I ordered a 9.6 Volt LiFePO4 to run my Ultravox on:
 
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=260599783306


I don't know about these particular LiFePO4 batteries but they are not all made the same or will give the same sonic results - the particular ones I use are 3.3V, 2300mAh & will output 120Amps for 7 second bursts or 70Amps continuous, <8mOhm internal resistance (impedance) - better than 99% of capacitors.They have been tested against a number of well respected commercial regulators & found to easily beat all regulators http://sites.google.com/site/hifacemods/home/announcements/batteryreview
 
Have a look at 4 of these batteries starting a car at -21C in Quebec http://www.youtube.com/watch?v=qcvmvrmTMMk
 
May 9, 2010 at 5:39 PM Post #927 of 1,158
Hi jkeny, I hope you have a large stock of them, I'm looking at the rest of my system and having disturbing ideas at where I could put them.
 
Your comment about the LiFePO4 batteries being than better than 99% of capacitors caught my eye because if using the SLA's its very essential to decouple them with a good cap, for my amp and the Ultravox, I use1000uf 50v  BG FK recovered from another project. I will be interested to find, if I will need  BG when using the LiFePO4.
 
May 10, 2010 at 2:54 AM Post #928 of 1,158

 
Quote:
Quote:
 
 
The Ultravox will be here Tuesday but I realized I didn't have a USB connection solution between the server and the Ultravox input.  I need to be careful because the other USB cable is a pricey Ridge Street Poiema (cryoed silver conductors).  I imagine I may end up using silver wire (on hand) and hardwiring it straight to the PCB for a port on the USB card in my server.
 

Experiment with positioning a bit first before committing , the Diypardise advise is;
 
" Best way is to install Ultravox as near to your USB Monica as possible, keeping this link between them as short as possible. Better still, install in your USB Monica! "
 
 
May 10, 2010 at 5:04 AM Post #929 of 1,158

 
All SPDIF receivers need clock to recover the I2S signal either from external clock source or in-chip PLL-VCO clock source.   For the V2.5 DAC (Valab), the Dir9001 used the in-chip PLL-VCO to decode a biphase input signal with a sampling frequency from 28 kHz to 108 kHz.  For the wm8805, it uses the external clock and its internal PLL to decode the biphase input.   The quality of clock source and the internal PLL loop therefore determine the recovered digital audio quality.  ^-^
 
The pins 13 and 14  of Dir9001 are to select the clock source for system clock.  For pins 13 and 14 to 3.3v mod, it is to set the system clock to 512fs.  It may means the internal PLLed 512fs is better than the other frequency.

 
Quote:
Quote:
I meant galvanic isolation on the Hiface SPDIF output, isolating the Hiface from what follows.
 
Jkeny, one more thought about clocks on SPDIF.  The Valab used a DIR9001 without a local clock and it performed very well, especially after the pins 13 and 14 to 3.3v mod.  That was the DIR9001 example behind the request for a simple input board from Teradak.
 
I have an Ultravox on the way to use with the Off Ramp.



 
May 10, 2010 at 6:10 AM Post #930 of 1,158

 
Quote:
 
Experiment with positioning a bit first before committing , the Diypardise advise is;
 
" Best way is to install Ultravox as near to your USB Monica as possible, keeping this link between them as short as possible. Better still, install in your USB Monica! "
 


Hi Wood,
 
did you notice any problem with your ultravox at first? mine didn't work, wired it up with 12 volt, the lights lit up but no data signal to the DAC. My window 7 didn't recognise the DAC? weird.
 
 

Users who are viewing this thread

Back
Top