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Chameleon DAC listening and modifications - Page 21

post #301 of 1144
yeah, I saw that, it looks like he put a couple 2k resistors on there. But I don't know what value his original SMD resistors are. It looks like 680 is the correct value? It's confusing. There's another set of resistors above these, that are also labeled

300R
3k3x2

and these resistors actually have the proper values of SMD 332 (3.3k) 680 is definitely not 3k3. But the board could be wrong.
post #302 of 1144
Quote:
Originally Posted by MikeW View Post
yeah, I saw that, it looks like he put a couple 2k resistors on there. But I don't know what value his original SMD resistors are. It looks like 680 is the correct value? It's confusing. There's another set of resistors above these, that are also labeled

300R
3k3x2

and these resistors actually have the proper values of SMD 332 (3.3k) 680 is definitely not 3k3. But the board could be wrong.
680R is what TeraDak is using now. Both Pat and mine were the early adopter version which had incorrect resistors there. Back to your noise, if you are hearing hissing sound without any music playing then what you are hearing is the background noise from the DACs and it is unlikely that it is a defective DAC chip. I believe what you are hearing here is the noise from 16 chip DACs?
post #303 of 1144
Yeah, I think im hearing the dac noise, however it still does not explain why it is dramatically cut when I remove the Reclocker board. Should I experiment with putting more resistance at that position? Am I not understanding something, pat said he made his resistance 1.2k. That's still almost twice what 680 is.
post #304 of 1144
Quote:
Originally Posted by MikeW View Post
Yeah, I think im hearing the dac noise, however it still does not explain why it is dramatically cut when I remove the Reclocker board. Should I experiment with putting more resistance at that position? Am I not understanding something, pat said he made his resistance 1.2k. That's still almost twice what 680 is.
Ok. I am not an expert in this area. It won't hurt to try as long as you don't remove existing 680R SMD, instead shunt with higher value resistor that will result in slightly higher overall resistance. Michael is the best person to answer this question.
post #305 of 1144
Just wanted to give an update on listening impressions. My Silmic 2 Dac coupling caps have got some burn in time now. A good 120 hrs or so. Wanted to make some comments about how they effected the sound.

The stock Tantalum caps to me, sounded a bit "edgy" on the high end, these Silmic 2 are warm in comparison, but not overly so. The high's sound much more refined, and real. Cymbols sound right, more textured and less glass like. less shattery, and more metal. The last dac I heard that had high end texture and grit like this was a 600$ Channel Islands VDA-2. This is not something the old valab had ever done for me, perhaps it could have if modded to a higher level then I had taken mine. The Silmic 2 are "smoother" then the Tantalum, but I would say, not in a negative way. They are still not fully broken in. I can hear farther into the music, and the background is a notch blacker. Bass feels impactful, yet well rounded, and a similiar effect to the high end is noted here, in the fact that you can hear texture of instruments better.

A cheap(~10$ shipped), and very worthwhile upgrade. Im quite pleased with how this turned out.
post #306 of 1144
I like silmics, over the next 100 hours they get more and more transparent, more detail will come through, but they still maintain that natural warmth. Right at the very end of burn in the bass comes in, deep but very tight and detailed. very realistic balanced all round. Blackgates take a good 6 weeks before you hear them at there best. They are more transparent/dense in the midrange and the presentation is more dramatic. I cant say one type is superior to the other, they both are the best caps at what they do. Although it may be heresy in the BG world to say this, I suspect silmic, in direct comparison have a less dramatic presentation then BG (thats not to say the silmics are not dramatic), but the silmic are more seductive/musical for long term listening. Ive used silmic now I am trying BG, I might even try mixing them. Its all great fun!

Just my opinions of course,. AudioNote use both Silmic and Blackgate in their very highest end gear.
post #307 of 1144

TDA1543 SMD swap

After testing on my Valab, I replaced the 0.1 smd on the chips to Wima. First checked it with no 0.1 caps. Big no no, the sound loses focus, becomes soft and to warm. With the replacement Wimas the attack on bass is very fast, much faster then before. The bass seems deeper as well, and more spatial detail.

Basicaly the dac now sounds more open energetic and faster, with more definition in bass instruments. Soundstage seems larger too. But it is less soft/cuddly sounding.

However the Wimas will need time to settle in, I can hear some very slight grain in vocals and although there is more detail, there appears to be a loss of transparency overall. Could also be that I am hearing better the BG burn in character. Overall I prefer it now, but expect it to improve in the next few hours. Will report back

Do not do this mod if you are not 100% sure, once the tiny dust size smd are off they are not going back on!!!

UPDATE Turns out the slight grain, etc were due to a loose oscon on the spidf board. Sounds great now.
post #308 of 1144

Bypass

Pic
LL
post #309 of 1144

stock vs mods

hifi2001, since you have my stock chameleon dac do you care to talk about how far you've gone in terms of sound quality with the mods you've done on yours, and give your analysis of big change mods vs smaller ones? and wonder if you've had a chance to solder in the 16 coupling caps yet. Thanks.
post #310 of 1144
Quote:
Originally Posted by hifi2001 View Post
Ok. I am not an expert in this area. It won't hurt to try as long as you don't remove existing 680R SMD, instead shunt with higher value resistor that will result in slightly higher overall resistance. Michael is the best person to answer this question.
Shunt = parallel... the resistance will never get higher than 680 ohms. Rt = 1/(1/Ra + 1/Rb)

Putting a 100K in parallel results in 1/(1/680+1/100000) = 675 ohms
post #311 of 1144
Thread Starter 

MikeW and upsampling noise

I added the resistor to drop resistance and that cleared up the noise I had at that time.
A short while ago I had a little noise that sounded like a cracked transducer/cone on a speaker. took the upsampling board out and cleaned the pins, put it back in and noise all gone.

Now I flip it on and get the weirdest noise yet. A lot of static and kind of a woo woo kind of thing on transients. Weird right? Knowing I had those noise issues before with the up-sampling board I just reached in and rocked it and noise all gone. I am going to solder that thing in place. It will probably increasing to fidelity as well. Daughter boards s. u. c. k.
post #312 of 1144
It would be nice to have it fixed, but im not all up in arms about it really. It is tolerable, might see if I can just buy a new board from michael sometime. Sure would be nice to get the noise level down to what they are without the reclocker.

It looks like one of my dac chips might be slightly wonky, since I messed with them. I think im going to ignore it though, when the Voltage drops below 8.00 going to the dac chips I get a slight buzz(only audible at non-listenable levels), as soon as voltage hits 8.00 it go's away though. Michael actually shipped this set at 8.20 volts to the dac chips.

I have been afraid to try the Yellow wire mod, so im still runing blue wire. My yellow wire is really short, I will have to skin it, solder a new wire to it and heatshrink it.

I replaced that little ceramic coupling cap on the Pulse transformer. This only effects SPDIF input though right? Probably won't do me much good as USB is primary source, though I did it for good measure. It was actually pretty easy, I clipped the leg of the old ceramic cap, soldered in the new one, and lined up the 2 legs and very carefully and quickly dropped a bulb of solder on them. Got a pic below. it looks like it's shorted to the pin 3 of the pulse transformer, but it is not. it's just close.

edit: hey pat what do you think about treating the pins with some kind of contact enhancer aka ~ deoxit gold.
LL
post #313 of 1144
Thread Starter 

upsampling board noise second thought

Maybe solder those boards in place is a baaaad idea, right?
So I am off to fetch some silver conductive compound. Put some on both plug in boards. Yeah, that's it.
post #314 of 1144
If you sometimes have to wiggle the board around, that would indicate that the connector (the board mount receptacle) isn't the greatest. You could solder them in and that should be much more reliable. If you really want them to be removable, one thing I have used (for 7 pin dual FETs and for transistors) are pin receptacles from Mill-Max. Note that you would need to mic the pins on the board, and order the appropriate size of these. You most likely would also have to enlarge the holes in the board (PCB drill), which if it is a single sided board, or if all connections (traces) are on the bottom of the board is not that big of deal (with a drill press).
http://dkc3.digikey.com/PDF/US2010/P0547.pdf

Example:
post #315 of 1144
Keep up the good work gents !....I'm waiting patiently for the PSU mods to begin to see where that takes things

Peete.
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