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Chameleon DAC listening and modifications - Page 51

post #751 of 1144
Quote:
Originally Posted by Wood View Post
I see no reason why Teradak could in the future provide a board without a clock for those of us with a high quality spidf input, be it cdp, or exteral reclocker etc, the choice would be the provided at purchase. Or for that matter 12s input, though that would require a new chasis design.
Michael would have to be convinced it's worth his time and cost to develop the extra board. I imagine the development would be easy enough but he'll have to pay out to have a minimum number of the boards made. I suspect he would dismiss it for the same reasons he's convinced the input board needs the USB and SPDIF running into the clock, being that most people considering a Chameleon would benefit from it. That's really too bad because there are some people with high end systems looking straight at the stacked TDA1541 NOS DACs as a high end solution. Michael needs to see that perspective. Maybe the coming 6Moons Chameleon review will sway him.

My little dream board would be no more than the pulse transformer and a tried-n-true DIR9001 (with the Valab established mod already done) and the associated components necessary to complete the circuit. All the USB stuff could be omitted. If that suddenly materialized I'd buy a Chameleon in a heartbeat. I won't hold my breath.

Does Michael monitor this thread? I know he's made revisions using some of the great mod ideas you guys have pioneered in this thread. I assumed it was because some of you keep in contact with him.
post #752 of 1144
Hello, all, first post here. Interesting thing you've got going here.

I was inspired by the momentum here to order a chameleon on 3/29, and I'm very intrigued to see what transpires when it gets into my system.

Question : What are those big BLUE block-y cap looking components in the new chameleon output stage where the orange wima caps used to be ?
Anyone know ?

Thanks for responses, and thanks for an intersting read, mod-men ....
post #753 of 1144
Thread Starter 

BLOCKS

Those are the filter caps which block high end distortion. They also block the kick on SQ. Removing them is the primary step after opening the chassis lid.
post #754 of 1144

What say you Rhodes54, how about it?

Quote:
Originally Posted by Newk Yuler View Post
Michael would have to be convinced it's worth his time and cost to develop the extra board. I imagine the development would be easy enough but he'll have to pay out to have a minimum number of the boards made. I suspect he would dismiss it for the same reasons he's convinced the input board needs the USB and SPDIF running into the clock, being that most people considering a Chameleon would benefit from it. That's really too bad because there are some people with high end systems looking straight at the stacked TDA1541 NOS DACs as a high end solution. Michael needs to see that perspective. Maybe the coming 6Moons Chameleon review will sway him.

My little dream board would be no more than the pulse transformer and a tried-n-true DIR9001 (with the Valab established mod already done) and the associated components necessary to complete the circuit. All the USB stuff could be omitted. If that suddenly materialized I'd buy a Chameleon in a heartbeat. I won't hold my breath.

Does Michael monitor this thread? I know he's made revisions using some of the great mod ideas you guys have pioneered in this thread. I assumed it was because some of you keep in contact with him.
I would buy that input board at the drop of a hat and I think many here would to, if there are enough of us it might even be worthwhile for him to make up a minimum run. Barring that perhaps Rodes54, could figure out how to bypass that clock when via the spdif.
post #755 of 1144
Thread Starter 

i'd buy one too

but i never really like the daughter board setup.
i think a premo rendition would be a solid pcb with TX output.
post #756 of 1144
Quote:
Originally Posted by Wood View Post
I would buy that input board at the drop of a hat and I think many here would to, if there are enough of us it might even be worthwhile for him to make up a minimum run. Barring that perhaps Rodes54, could figure out how to bypass that clock when via the spdif.
I just emailed Michael asking about a simple alternative input board and suggested the components I mentioned here. I'll let you know how it goes.
post #757 of 1144
Michael replied text below. What do you guys think?

The back panel changes and omitting jacks, etc are unnecessary. Simplifying the original input board will require the use of the same receiver IC with its hardware mode limits. Does the WM8805 require the TCXO to operate? He's apparently not immediately familiar with the DIR9001 mod on the Valab.

Hi,

Thanks for your suggestion. Actually we would also like to do the simple input. What we concerns are the market. If there is a lot of request for the simple input and it doesn't make us lose money, we of course will try it. For the simple input, we should also modify the back faceplate not including the USB socket, which is also a time-consuming process. Maybe we should consider how to fulfill it as simple as possible. The simplest way is to use the original board and not to solder the USB related parts. Otherwise, we should consider re-making the simple input board.

If we consider making the simple input board, what functions can you suggest? Do we need to support SPDIF and Toslink? For the IC used for SPDIF receiver, we are using the combo of WM8805 + 12M TCXO. Was this combo not better than our previous Dir9001 solution? Can you tell us what the Valab have modified, too?

Michael,
post #758 of 1144
Quote:
Originally Posted by Bill Allen View Post
Steve Nugent has successfully added an I2S jack and terminated it directly to the DAC chips of my Black Chameleon. I will now drive the DAC I2S direct from my Pace Car via a Northstar I2S cable. This is as clean as a digital interface gets my friends. I have working towards this point since the day the first Valab DAC showed up. My Black Chameleon is stock so it will take time to mod it & break in, but I will eventually report back with the results.

Since the Valab days I have been drilling home the message that lowering Jitter is the name of the game with these stacked NOS DAC's. Short of my solution I think Rhodes has the simplest low cost solution for lowering the jitter on the Chameleon. Add a Tentlabs or Audiocom Super Clock on the upsampler board. Nice job! You could even power the new clock board with a battery. I run the Pace Car on a Lithium-ion laptop external battery pack, I simply unplug the charger for critical listening. Something like this. Amazon.com: TOSHIBA Satellite 2105CDS External Battery: Electronics

For those that are ready to consider computer audio may I suggest you look into an M2Tech Hi-Face with direct I2S connection to the DAC chips. This will be a bit of an adventure but should provide superior results at very low cost. Right now they don't make an I2S output version but that may change soon. M2Tech
The Chamelion that I modded for Bill is stock, not modded, and yet the result is unbelievable. The I2S interface feeding it is from my new Pace-Car USB, this one with 5V I2S interface. I was frankly surprised at the bass and dynamics. Highs need work is all.

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.

Steve N.
Empirical Audio
post #759 of 1144
Newk Yuler, I must admit I am a bit puzzled by Michaels reply, I guess he is thinking of the whole product, and a spidf version only, but if removing the usb part of the input board works, and avoids the clock, I would be happy to have this as a second board, and use the original board if I have to use usb only. I am assuming the WM8805 works without the clock, and works as well as the dir90001.


Steve, excellent 'proof of concept' achievement. So a future iteration of the Teradak series could/should incorporate a I2S input of the bat and so it would be far easier to use with the Pace car and off-ramp, and even Teradaks own reclocker which uses I2S output (I think). But its good to know that this very valuable upgrade path is possible!

Any chance of pics, or shall we wait for Bills update?
post #760 of 1144
Quote:
Originally Posted by Wood View Post
Steve, excellent 'proof of concept' achievement. So a future iteration of the Teradak series could/should incorporate a I2S input of the bat and so it would be far easier to use with the Pace car and off-ramp, and even Teradaks own reclocker which uses IS2 output (I think). But its good to know that this very valuable upgrade path is possible!
This would require a mux/selector be inserted by Teradak

Quote:
Any chance of pics, or shall we wait for Bills update?
I have to post pics on a URL here, so I have put them here:

I2S mods for Chamelion DAC

Steve N.
Empirical Audio
post #761 of 1144
Very neat Steve, would there be any advantage, do you think, of putting the I2S input connector at the front of the dac thus reducing cable length?
post #762 of 1144
Quote:
Originally Posted by Wood View Post
Very neat Steve, would there be any advantage, do you think, of putting the I2S input connector at the front of the dac thus reducing cable length?
Perhaps a small advantage, but inconvenient in the rack.

Steve N.
post #763 of 1144
Thread Starter 

two questions

anyone know the "what's up" on the 6moons Teradac review?
and anyone hooked up their Cinemags and want to tell about it?
post #764 of 1144

Coax connection

Quote:
Originally Posted by rhodes54 View Post
I've been curious for quite a while if the Chameleon would benefit from a better clock.
The Chameleon has 2 XO's on board: 1) a 12 Mhz XO for the S/PDIF and USB input and 2) a 24.576 Mhz XO for the upsampling board.
I decided to go for the upsampling board first and I've replaced the XO by the Tentlabs XO 2.2 tonight.

Connecting the clock is easy:
1) Remove the 47uH choke
2) Remove the 100R resistor located in the middle at the top of the upsampling board.
3) solder the XO output of the tentlabs to the upsampling board as shown in picture 3 and you're done :-)

It has been on for 30 minutes only so I can't give a detailed description on the sound yet. One thing that was obvious right away: No more grainy highs coming from the upsampling board! ahhhh!

As usual some pics for you:
Hi Rhodes,
First off, thanks for doing this mod. I have been thinking about doing something along this line but I wondered about the efficacy as the sound I am getting is pretty impressive but after seeing your scope shots the choice is made pretty clear. Again, it means spending somewhere close to the price of the unit to get better sound but I am willing to do it at this point. Just like laying out the money for the Dueland caps, sometimes you just have to bite the bullet.
That being said, I could not see in your photos where the coax shield is connected. Could you help me out there?
Thanks,
Tony
post #765 of 1144
Quote:
Originally Posted by PatOMalley View Post
anyone know the "what's up" on the 6moons Teradac review?
and anyone hooked up their Cinemags and want to tell about it?
Last I checked 6Moons for the review (recently) it was in the 'next up' section from one of the reviewers. Probably not too long to wait.
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