Chameleon DAC listening and modifications - Page 30

How would you ensure its 75ohm, or is this irrelevent when using 2 trannies?

I've never really worried about the 75 Ohm, as it seems impossible to me to get that right and its the combined geometry of the cable that matters.

Capacitance is key, and the beauty of DIY is that you can tinker until you find a local optimum for your setup.
You could use HQ Satellite dish coax or the likes but the results I have heard by just using f.e two lengths of twisted inductor wire outperformed most fancy coax cables I have heard including high End interlinks (vdHull and the likes also buy off the reel)


The 50 ohm story DKD Instruments (about coax impedances)

Velocity factor (VF) of common coaxial cables (Coaxial cable velocity factor information)

Transmission line problems Transmission line problems. solutions that help in understanding


Practical Line-Driving Current Requirements Practical Line-Driving Current Requirements

Impedance matching for microphones Shure - Professional Audio - Products

s/pdif interface epanorama.net/S/PDIF Interface

marcelnl, just made up a 25cm litz 4 silver wire cable, its certainly an considerable improvement over the bog standard copper digital interconnect I was using. Didnt try before because of the 75 ohm fuss. But then I am a sucker for silver in the sig path.

Update: Interesting, after some listning, I noticed the sound was too smooth/polished, switched back to the bog standard 75 ohm cheapy cable and more texture.

don't mess with Litz....what cable geometry did you use and what insulator?

A digital cable needs to break in for a good long period and the silver (any conductor) may be directional.

happy cabling ;-)

wire was burn't in, lose teflon, but will try again later, because those bgs are all over the place at the moment, so I don't know what I am listning to.

No love for poor opamps around here. They are hard to replace for their size and convenience though. Some have tried to make "Discrete" opamps, ala Audio GD's "Moon, Sun Earth" a discrete "Drop in replacement" for your standard opamp. Similar to the Burson Buffer. However, upon listening it's been shown that the best of breed opamps actually perform close or better then these discrete designs. Not saying opamps are better, but they are better then the massive discrete drop in replacements that have been made for them. There have been some real advancements in recent times too, look at the LME 4562, for example. If discrete was the only thing that mattered we would all be listening to 300$ Gilmore Lite's. But why does an M3 that stuffed full of opamps outperform it?

I think we are talking about two distinctly different things here, Opamps stink at phase linearity and TIM due to the high slew rates and high negative feedback emplyed to get specs showing one gazillionth of a percent distortion.

A discrete Opamp is yet another compromise, space, just have a look at the 'L Audiophile and AN designs and you know what it means and if you have half a chance listen to those designs. I'm not familiar with the amps you mention but I'd guess that the one outperforming the other got more things right, discrete is only worth something if the designer knows what he is doing. I've heard (expensive) tube amps that were crap and those were easily outperformed by my daughters chip amp in her HIFI set but that does not mean that tubes suck.


Pat: replacing the standard RCAs is required anyway.

Wima DAC chip caps

I think that 10uF would be fine as well. One might try leaving in the original SMD caps and paralleling the 10uF Wima's if they are worried about total capacitance. I really just hate the break-in stuff and the usual sound of the 'lytics. I finally hit about 350 hours on the BK caps (and the whole unit as well) and the sound really blossomed. Very nice indeed. The whole soundstage opened up, became clearer and a little smoother sounding overall.
I would agree with Marcel about the digital interconnect. Though I did purchase mine I feel the general theories and experiences hold true. Mine are solid silver (flat and polished) and terminated with Silver Bullets as are all my DIY interconnects. I have tried a few others that Bill Allen had on hand and mine were clearly superior. One was an earlier generation of the same cable (Ridge Street). Chris Van Hause at VH Audio told me that just using his silver cable would not quite do the trick for a reason that I cannot remember exactly. Sorry for that brain fade but that does not preclude you finding your own solution. Good luck.
Tony

I hooked up the yellow wire a few minutes ago, out of curiosity. Bass does seem to be slightly better, but it's not a huge difference. Perhaps because of the mods i've already done have made the effect less. I will say this though, I no longer have buzzing noise no matter what I set the dac voltage too. Before anything higher then 7.55 and I had very very slight buzzing noise, with the yellow wire I tried between 7.5 and 8.4 volts and there was not the slightest buzz or noise at all anywhere in between.

Im not sure i'll leave it here, I may set it back to the blue wire and set the dac chips to 7v, i listened to them at 7v last nite and was pretty happy, I think they do sound better there then at 7.5 /w blue wire.

I am concerned with heat though, I don't want to chop my chasis up, woods suggestion was pretty cool with the washers to make an air gap in front/back. I wonder if this is enough alone.

When you lower the dac chips voltage it also lowers the max output voltage. For example at 7.55 volts I can run a 40 hrz test and get exactly 2v output. (no clipping) Lower the dac output to 7v and this drops to 1.85 volts (anything higher will clip). Does this have any negative effect on performance?

Wow it heats up pretty good. To much heat for my liking. I put the blue wire back on @ 7v on dacs. I can't hear much difference tbh.

what heat, the DAC chips use the power and the only thing the yellow wire does is to provide the voltage regs with a bit more space to do their thing. Ifg anything it is the voltage regs that burn off a couple of additional watts.
The voltage you set for the DAC chips will affect heat production and the output current, I'd tinker with that until you have the best sound and be happy .
1.8 V output should be enough for any power amp, I would not worry about the output voltage at all if the sound is better.

yeah im talking about the DC30W chasis gets quite abit hotter. Not the dac.

as long as you do not burn your fingers on it (or the heatsinks) everything should be OK.....