[zzodhi]

So when will the Chameleon be available? Or is it now?

 

[Wood]

Enough time with the Ultravox to give impressions.

This is a USB isolator, which provides its own power for d1 d2 and 5v+, and completely isolates the downstream component, from the computer gnd, as well. It is based on the Analog Devices Adum4160.

ADUM4160 | Full/Low Speed USB Digital Isolator | Digital Isolators | Interface | Analog Devices

I know of three places you can buy a board using this chip;

Analog devices evaluation board

ADUM4160 | Full/Low Speed USB Digital Isolator | Digital Isolators | Interface | Analog Devices


Circuits and home

USB Interfaces « Circuits@Home


And DiyParadise,Ultravox, the one I am using.

Ultravox - SGD60.00 : Welcome to the diyparadise e-store!

My current setup is a modified Musiland USD 01 async device feeding SPIDF to the Chameleon. My computer source is foobar2000 and music files 16/44.1. I don’t use usb directly, as compared to the Musiland I cannot hear the music for the noise.

As the Musiland is usb powered, I hoped using Ultravox would improve its output signature, although I was more or less happy with the sound representation, I still felt it could be more communicative/ musical.

The Ultravox is a completed component, and only requires a dc voltage supply to the attached red and black wires (as in the pic on the site) so it only took a couple of minutes to wire to a dc jack allowing me to use a SLA 12v or a SMPS 12v.

Trying with the Musiland, well, it worked, it powered it with no problems. But A/B’ing sans Ultravox led to a clearing of considerable congestion in the midrange, which I had not noticed at all previously. This congestion was not trivial,had I really been listening to for all this time without noticing?

So success, in this respect, but I can’t say the Musiland was more musical, as I had hoped it might be using the Ultravox.

But then the fun started when I tried the Ultravox directly into the Chameleon usb. In comparison to the Musiland/Ultravox combo, it was like comparing an original recording to digitally re-mastered recording. It’s clear that the Musiland is somehow hyping up the sound.

Direct, the Ultravox, is the most musical and engaging sound I have heard from digital. Its ‘clean’ and ‘messy’ at the same time. The ‘mess’ is all coming from the recording, dirty organic life forms. if you like, doing their thing. The ‘clean’, is just garbage that’s not there, as opposed to ‘clean’ meaning a polished presentation.

Swapping the two caps for Blackgates made for a richer presentation, tonally natural. Using a SLA Battery also pushed the sound slightly more to the organic.

If you use usb on the chameleon you have to get one of these for sure. I don’t know if is better to use this as a replacment for all usb/spidf convertors like a hiface, but I can’t go back to the hyped sound of my Musiland, even when using it in conjuction with the Utravox.
Obviously music direct from a pc is a non-starter, using the Musiland was a big help, and is improved further with the Ultravox. But somewhere along the line, something is degrading the signal. With the Ultravox sans Musiland, the sound is just,..... well,..... normal. Its like I just added the Texas IV resistors again.

 

[Bill Allen]

Wood-Nice work on the isolator, glad to hear it works.

I am now thinking about adding one to my Pace Car to isolate the USB input. I am getting a pesky ground loop on occasion with the Pace Car and Chameleon I2S.

I found this device that may be able to be adapted to the OEM HiFace I2S card to provide the required 5V output.
3.3V to 5V DC-DC converter. « Circuits@Home

Perhaps JKenny could put together a ADuM4160 isolator, OEM HiFace USB card with I2S output with 5V conversion and battery power supply all in nice neat package.

My next project is to "stack" solder 16 DAC chips then simply apply power and I2S source signal. The Paved Penny DAC. Perhaps even power the DAC chips with LION battery power and some of the newly available super capacitors to FRM things up ... or should I say SCRM!

My main goal to yet again state that this is now the best sounding DAC I have ever heard in my system.

 

[Wood]

Bill, I noticed a marked increase in soundstage and natural realism as I put back the dac chips, in the Chameleon, from 12 to the full 16. You know where I'm going with this don't you.......

Jkenny is a bit worried that the Adum4160 doesn't have the bandwidth for the higher data rates for his twisted Bovine. I will get some high rate flac samples and see what the Adum4160 can handle. But the ground loop isolaton is the key here, not just external supplies that still have to maintain the usb gnd loop, will see if I can bring him over here to discuss this.

 

[mmerrill99]

Thanks, Wood for contacting me.

I have to admit that I don't know anything about the Chameleon & it's internals - any link to this info, particularly the chips that I2S could be fed into? Not much on the Teradac site - 16 stacked TDA1543 DAC chips & ASRC function - how is this ASRC implemented ?

Currently there is a USB input board? which feeds I2S to where? What chips?

About the ADUM4160 - it has a bandwidth limitation so you won't be able to get 24/192 out of it but interested to hear what yo do get - I could do the maths for the theoretical max bandwidth but what you get in practise can be less!

Given a I2S board could be done based on my modded Hiface? what are the numbers interested & what would be your target price? What is Steve Nugent's I2S selling for?

 

[Wood]

Hi jkeny, welcome aboard, Ive got 24/96 out of the adum4160 which is plenty enough for the Chameleon nos dac. Most of us are 99.9% 16/44.1.

The Adum4160, diyparadise Ultravox now replaces my Musiland usd 01, its simply does a better job at jitter reduction, and then some. So partnered to your modded Hiface could be something else, and higher rates are simply not a bottleneck here.

see pm for schematic. Michael at Teradak is very responsive to input from users, in fact thats why this dac exists at all, so who knows where this might go?

The picture is of mid price nos dac, Chameleon, which has enormous potential. Very creative input on this thread, has produced a great dac, but more can be done on the data input side, yet its tricky to do that in a price range that comesurate with the dac. So thats where your modded hiface fits so nicely.

Bill would have to fill you in on Steve's input, as it is at present a strictly bespoke job. But I could see a modded hiface installed inside the Chameleon itself, if it can be figured out.

 

[mmerrill99]

Quote:

Originally Posted by Wood /img/forum/go_quote.gif Hi jkeny, welcome aboard, Ive got 24/96 out of the adum4160 which is plenty enough for the Chameleon nos dac. Most of us are 99.9% 16/44.1.

Me too

Quote:

The Adum4160, diyparadise Ultravox now replaces my Musiland usd 01, its simply does a better job at jitter reduction, and then some. So partnered to your modded Hiface could be something else, and higher rates are simply not a bottleneck here. see pm for schematic. Michael at Teradak is very responsive to input from users, in fact thats why this dac exists at all, so who knows where this might go?

Waiting for PM schematic. The Chameleon has it's own USB input? Which has the biggest effect replacing the 5V USB supply with an external 5V (I currently have a modified USB cable which allows this) or galvanically isolating the USB signals?

Quote:

The picture is of mid price nos dac, Chameleon, which has enormous potential. Very creative input on this thread, has produced a great dac, but more can be done on the data input side, yet its tricky to do that in a price range that comesurate with the dac. So thats where your modded hiface fits so nicely.

OK give me an idea of the prices we are talking about?

Quote:

Bill would have to fill you in on Steve's input, as it is at present a strictly bespoke job. But I could see a modded hiface installed inside the Chameleon itself, if it can be figured out.

How much are people willing to connect up I2S wiring/cabling i.e. is there some sort of DIY ability or are people looking for a plug & play system?

 

[Wood]

The modified usb cable has no effect here as the dac only uses the power for an led. The galvanic isolator has drasticaly reduced jitter for me. The question is can it contribute anything to a modded hiface? I found it improved the musiland and without a doubt, more so then a modded usb cable. But ironicaly in the case of the musiland, the isolator is superiour to it and so I have now dropped the musiland out of my system altogether.

The other interest is, as you say, to find a way to do direct I2S as in the case of Bills rig, but using your modified hiface, in place of the very desirable but much more pricey usb Pacecar.

As Bill says 'Perhaps JKenny could put together a ADuM4160 isolator, OEM HiFace USB card with I2S output with 5V conversion and battery power supply all in nice neat package.' Bill would have to supply the heads up on the I2S connections, or the simpler option would be to use your modified hiface and the spidf interface.


The skills here are varied of course but with the clear guidence given by the regulars even newbies visiting here have excelled.

 

[mmerrill99]

I just looked back at the posts of Steve's work & it would seem there a lot of board modifications needed & provisos - If people can work out what's needed on the boards I can supply a modded Hiface with I2S out - perhaps somebody could send me the board & I could test it for strength & integrity of I2S signalling?

Quote:

The difficulty is that the mod to add the I2S interface to the Chamelion is non-trivial. The board has very poor transmission-line characteristics as-is. This is evidently why the designer "scabbed-on" several ad-hoc terminators at various points in the net. An obvious lack of understanding of transmission-lines and termination techniques. As a result, quite a few traces are cut and 12 "blue-wires" are added to do the mod, as well as removing lots of terminations and changing one group. Even with these mods, the I2S driver at the source device, in this case the Pace-Car USB, must have serious drive strength in order to drive a parallel termination. If you have a PMC270X or something similar that you want to drive it with, it will not have enough drive, nor will it be 5V logic levels. Also, I discovered that it craps-out after 96. You dont get 176 or 192. Another thing that all of you must understand is that I2S done properly is not simply a matter of connecting the three signals and returns to the circuit. This configuration ignores the need for muting. This means that if you unplug the USB or I2S cables on your device or lose power to the device or the DAC, that a really loud pop can propagate to the speakers, causing potential amp and speaker damage. This means that if you have this configuration, you must be very careful about connecting the I2S cable before powering anything on and then power-on the DAC last. Then power-down the DAC first. If a reworker is interested in doing this I2S mod so that it is compatible with Off-Ramp or Pace-Car USB with 5V I2S output option, I can give this information freely. Just contact me.

 

[regal]

Quote:

Originally Posted by Bill Allen /img/forum/go_quote.gif If the OEM M2Tech I2S card could be modded for 5 volt output I have no doubt this would offer the "lowest cost" option for eliminating interface jitter on the Chameleon or Valab. But remember with just a USB input now we're talkin' computer audio only. Of coarse if you have the cash the Pace Car USB would still be the superior choice. I sent the information about the OEM M2Tech board to Michael in the past but once again its a demand vs price point thing. However given the superiority of direct I2S input and looking at the simplicity in the pictures above ... there is a strong argument for a M2Tech I2S/USB input only version of the Chameleon.

I think you will need a reclocker of some sort like the pace-car to convert from 3.3V I2S to the obsolete 5V I2S the old DAC chips require.

 

[mmerrill99]

The I2S signal generator needs a strong current outptut to drive the parallel terminations on the I2S lines on the Chameleon board, it seems, according to Steve.

However, the other I2S transmission line issues identified by Steve would be a problem - there is no sense in installing a bad I2S implementation, you lose all it's low jitter advantages & it can even be worse than SPDIF implementation! It's all about implementation & less about the underlying theoretical superiority of one digital communication over another.

 

[mmerrill99]

It looks to me that your best option is to go for a modified Hiface (SPDIF output) with a ADUM front end!

Here's what I suggest:
A modified Hiface (3.3V supplies optimised) with a front end ADUM that also supplies 5V to the Hiface for the final 5% improvement on the USB transport feeding SPDIF to the Chameleon.

 

[Wood]

jkeny, did you try your adum from 'circuits and home', yet on your modded hiface? I am very curious to see what this combination can do, isolation from pc and clean power to the clocks.

My Blackgated Ultravox, running of a 12v SLA battery, has blown away the jittery hash and its not even async, just a psu.

Yes there is no doubt that your suggested option will bring a lot of improvement.

Even more would be garnered from a redesign of the input board on this dac, if a practical implemention of the modded hiface is via spidf and not I2S.

https://sites.google.com/site/hifacemods/home

 

[mmerrill99]

Quote:

Originally Posted by Wood /img/forum/go_quote.gif jkeny, did you try your adum from 'circuits and home', yet on your modded hiface? I am very curious to see what this combination can do, isolation from pc and clean power to the clocks.

No, I haven't tried it yet because I haven't stuffed the board yet - now might be a good time to consider it when I get a free minute. I have another isolation option which I'll be comparing it to & this may allow high-speed 480mBps operation

(I know it's not needed here but hey-ho)

Quote:

My Blackgated Ultravox, running of a 12v SLA battery, has blown away the jittery hash and its not even async, just a psu.

Yes, good PS can work wonders on equipment - the secret is finding good quality PS. My batteries have been reported to be easily better than a lot of very highly regarded series & shunt regulators: Battery Review (Hiface USB Transport Modifications & Ancillaries)

Quote:

Yes there is no doubt that your suggested option will bring a lot of improvement. Even more would be garnered from a redesign of the input board on this dac, if a practical implemention of the modded hiface is via spidf and not I2S. https://sites.google.com/site/hifacemods/home

I already have a version of the modified Hiface with I2S output only (NO SPDIF) if you want to try it Vs the Modified Hiface with SPDIF - full refund on return? This was designed for inputting to the Sabre DAC boards (Buffalo & AckoDac) or any boards that have provision for I2S input.
DAC options (Hiface USB Transport Modifications & Ancillaries)

My thoughts are as above about the sub-optimal I2S implementation issues but it might be interesting to compare. I'm not so sure that the I2S signal needs level shifting from 3.3 to 5V to operate but it may need more drive capability. However, the existing USB chip in the Chameleon is a Tenor TE7022 chip - I can't get any data on this chip but the I2S output from this chip might be the logical place to feed in I2S from a Hiface. As far as I can see this is a 3.3V chip & so no level shifting would be needed to feed I2S in at this point. The level shifting happens after this at the ASRC chip or at the multiplexer chip.

 

[mmerrill99]

A further thought - by connecting external I2S via the I2S-out of the Tenor chip we are retaining all the existing functionality of the Chameleon device, so SPDIF input is still intact, asynch function is till intact.