or Connect
Head-Fi.org › Forums › Equipment Forums › Dedicated Source Components › Chameleon DAC listening and modifications
New Posts  All Forums:Forum Nav:

Chameleon DAC listening and modifications - Page 22

post #316 of 1144
Thread Starter 

great tip

Quote:
Originally Posted by Pars View Post
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
Thanks for that tip. That work you did looks beautiful. Thing is that I don't want to work on that board any more than I really have to. Drilling the PCB is something that I know will bring out my inner butcher.
post #317 of 1144
Pat, you might consider just flowing the pins of the board with a tinly layer of good silver solder....might want to check with a similarly treated pin to see what thickness the female part is able to receive.
post #318 of 1144
Thread Starter 

I will try that

marcelnl,

Yeah, I hesitate now to solder the board solid just in case there is an upgrade. Why else have a plug in board? But for stability and fidelity I may just cop to soldering the damn thing in there.

I think I wil thicken the pins like yuo describe _and_ add conductive compound to close any air gaps.
post #319 of 1144
Thread Starter 

a most unstable fellow

Been doing a little swapping back and forth in and out.

K, the wife, drove through for the Doors ~ Strange Days, dug it, and I took the opportunity to trick her into an a/b session. She has little patience for this but the Doors enticed her ... She like the VALAB 8x NOS DAC best saying it was velvety with more er um music. Damn. WTF.

The biggest difference between them at this stage is the 8x has a Lundahl input transformer, PRP IV resisters at output, and that damn up-sampling card. So out comes the up-sampling card and the sound thickened ... like we like ti around here really. Like dropping the crack pipe. Can I get an amen from _anyone_ around here?

The 8x is a little fat handed at 8x vs 12x. Much smoother but there -is- that thinner sound which I know must be that transformer. I remember swapping in the Lundahl and the sound gaining body. Yep even so on the digital input this did happen. And the PRP resisters VS the Caddock were warmer and more full bodied. So my jury is still out.

TX arriving in the mail soon. We'll see. Then remove 4 DACs and swap in PRPs. Less hifi detail on the 8x to be sure. But that magic all still in there in its most rugged but pure form.

EDIT/EDIT: Hey Mike, I did clean the pins on that up-sampling board. I actually scraped then with a small file till I saw them shine then used contact cleaner on them. It did the trick but I think I am dropping that card anyway now.
post #320 of 1144
I got some parts in the mail today, Some new rca jacks, silver wire, 50k prp output resistors (not i/v). And a Multicap 01 uf for the digital input cap. I installed it, but unfortunately im having issues now.

USB works perfect. But when I try digital input, or just leave the dac on with no input at all, no usb, no coax/optical. I get a very high pitch wine sound. It's strange because none of the mods I did should cause a problem like this. And why does it immediately clear up when USB is hooked up? My thoughts, when you plug in USB the Wolfson/Pulse transformer is disabled and the Tenor kicks in. So it seems there is a problem on the digital board somewhere. I suspect a connection problem, but that is hard to trouble shoot, i've wiggled the board around and I can't hear any difference. I took the board out and sprayed some Dexoit gold on it and put it back in, it worked, without noise, turned the unit off and back on, noise was back and i can't get rid of it now.
post #321 of 1144
I get similair whine sounds at different pitches depending on using coax or usb, they sort of oscillate and are loud. Only when I turn everything (restart computer) of, and start again, and sometimes when I fiddile with the power conector sockets pulling them in and out (switched of of course) it clears up. Usb is very finiky. It just happens occasionaly when Im switching different inputs. When it works normaly its just left on ok so Ive never bothered to chase this up. But I would like to know what causes it. Could be a recent mod, because this did not happen before I modded the input board.

Mike did you do the earth to the transformer on the input board yet, might be transformer/cap oscillaton?
post #322 of 1144
Im runing it stock, the only thing i've done to my input board was change the little ceramic cap for a wima. Unfortunately I shorted a cord in the psu and temporarily sent 10vdc to the +5volt rail. Goodbye reclock board, the digital board seems to still work fine, other then the whine issue. I emailed Michael about buying a new reclock and digital input board.
post #323 of 1144
Hi Mike, just been doing some tests, rewired the spidf earth back to the main board, but the intermittent whine came back after swapping from coax to usb and back again. But I discovered, that the whine goes if I unplug the interconnect between my dac and amp and replug it, strange. Perhaps I have a different problem to you.

Sorry to hear about your reclock board, mine mysteriously died early on as well.

Update, I think Ive isolated the problem as noise from the power supply. It has nothing to do with various inputs. Turning the PSU off and waiting for a few minutes seems to sort it. Its a sort of warbling oscilating tone.

Update 2, I have reversed the yellow wire mod and now the noise is gone. Apparently, for me, the yellow wire mod is not a permanent solution. Bass is softer again, but the sound is less agressive, so its not all bad. So roll on Teradak DC-30W2
post #324 of 1144
Texas precision resistors turned up today, 175r for IV, and 75r for Spidf.

In the IV they added clarity and definition, and dynamics. The 75r brought me giant steps closer to a palable reality. Instruments are much more like instruments and not sounds, and you can sense the presence of the musicians. Its now like being there.
post #325 of 1144

Boogie Factor

Quote:
Originally Posted by PatOMalley View Post
like we like ti around here really. Like dropping the crack pipe. Can I get an amen from _anyone_ around here?
The magic is in there somewhere. The thing about the Valab, less is more. Thing about these digital wizardry gadgets, nice place to visit but wouldn't want to live there. Pat you dont need that card, really. You have never been 100% from the start.

So yeah....amen.
post #326 of 1144
Thread Starter 

put your hands on the radio

Quote:
Originally Posted by Wood View Post
The magic is in there somewhere. The thing about the Valab, less is more. Thing about these digital wizardry gadgets, nice place to visit but wouldn't want to live there. Pat you dont need that card, really. You have never been 100% from the start.

So yeah....amen.
hallelujah!
post #327 of 1144

Less is more!

Ok guys,

As told a hundred times before, the "less is more" approach really affects the Chameleon, often in a positive way.

After providing the Chameleon and schematic to a friend of mine he mentioned that the 74HC04 buffer found on the digital board is not needed at all.
As you can see on the schematic this 74HC04 is a buffer between the XO output of the TCXO (X201) and the S/PDIF receiver WM8805 (U101) and the USB receiver TE7022L (U201).
The 74HC04 only adds jitter (which we all try to prevent) and the TCXO can easily drive both receivers at the same time.

I've contacted Teradak about it and he gave it a try by shorting the two 100k & 100R resistors and bypassing the second inverter gates (U204E and U204F).
He told me it worked but he didn't hear any difference.

I think it is up to us now to do this mod and check if we hear differences. There must be!

I will try to make a detailed picture of the exact mod to do tonight.

The 74HC04 (and 100K/100R resitors) are found on the top left of the board.


I've 'photoshopped' the schematic a bit and it should look like this:


The 100R resistor should be replaced by two 47R resistors to avoid reflections between the S/PDIF receiver, USB receiver and TXCO.

Oh boy, I love soldering SMD...
post #328 of 1144
Thread Starter 

pix

I gotta see a picture of the mod.
Show me a picture and I am in.

Quote:
Originally Posted by rhodes54 View Post
Ok guys,

As told a hundred times before, the "less is more" approach really affects the Chameleon, often in a positive way.

After providing the Chameleon and schematic to a friend of mine he mentioned that the 74HC04 buffer found on the digital board is not needed at all.
As you can see on the schematic this 74HC04 is a buffer between the XO output of the TCXO (X201) and the S/PDIF receiver WM8805 (U101) and the USB receiver TE7022L (U201).
The 74HC04 only adds jitter (which we all try to prevent) and the TCXO can easily drive both receivers at the same time.

I've contacted Teradak about it and he gave it a try by shorting the two 100k resistors and bypassing the second inverter gates (U204E and U204F).
He told me it worked but he didn't hear any difference.

I think it is up to us now to do this mod and check if we hear differences. There must be!

I will try to make a detailed picture of the exact mod to do tonight.

The 74HC04 (and 100K resitors) are found on the top left of the board.


I've 'photoshopped' the schematic a bit and it should look like this:


Oh boy, I love soldering SMD...
post #329 of 1144

Get rid of

Quote:
Originally Posted by rhodes54 View Post
He told me it worked but he didn't hear any difference.
In that case he can take it out in the next version (along with providing space for bypass cap)

Count me in as well on that.
post #330 of 1144
Quote:
Originally Posted by PatOMalley View Post
I gotta see a picture of the mod.
Show me a picture and I am in.
I will definitely make clear pictures. It is a very simple mod but the smd makes it a bit hard to do for some.
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Dedicated Source Components
Head-Fi.org › Forums › Equipment Forums › Dedicated Source Components › Chameleon DAC listening and modifications