if you email charcroft in the uk they can trim you some
Distributor and manufacturer of passive, interconnect and electromechanical components. U.K. Electronic Component Supplier
thats what ill do when im doing my final build
Closer to 13R better, so I would go with 12R (maybe someone with more inside of DAM R2R ladder could pinpoint this, Søren?)
cheers
Danny
Nige your PM box is full, empty it in order to receive msg's.
Hi Nige, 13R are part of the ladder and also LPF and I wouldn't recommend to short them out, it wouldn't damage anything but the R2R ladder impedance will be affected (may make signal worse off?). Taking out c135/c142 is what Søren did in order to improve speed of DAM. Now this is good only for testing purpose but in real application I have replaced them with 470pf polystyrene ones.
cheers
Danny
Trying to connect a usb->i2s interface seems that I have damaged the isolation chips (probably incorrect ISO VDD polarity or overvoltage). Measuring resistance between ISO V3.3 and ISO GND is zero. All voltages on J2 header are OK. The DAC responds to commands sent through RS-232 just fine.
There is no optical damage to the isolation chips but I guess they are fried. Is it safe to assume the only the 3 Si8620 isolation chips are damaged? Should the capacitors on the input side of the isolator be replaced as well?
If any of the other Greek members know of a facility that is able to replace the chips please chime in. As I don't have the equipment to desolder and solder SOIC8.
There is no optical damage to the isolation chips but I guess they are fried. Is it safe to assume the only the 3 Si8620 isolation chips are damaged? Should the capacitors on the input side of the isolator be replaced as well?
If any of the other Greek members know of a facility that is able to replace the chips please chime in. As I don't have the equipment to desolder and solder SOIC8.
As arf already points out, those 13R resistors are part of the R-2R resistor network. They should not be changed, they're not part of any filter as such, but remember that the total R-2R networks output impedance is the R part of the RC output filter.
It's already a high quality thin film resistor, but it's effect on the total resistor network is so tiny that I can't imagine changing it would have any effect at all, unless the value is changed....
Anybody claiming otherwise have either changed other things or are victim to the psyshoacoustic effect of wanting to hear something after spending way too much on otherwise inexpensive parts....
It's already a high quality thin film resistor, but it's effect on the total resistor network is so tiny that I can't imagine changing it would have any effect at all, unless the value is changed....
Anybody claiming otherwise have either changed other things or are victim to the psyshoacoustic effect of wanting to hear something after spending way too much on otherwise inexpensive parts....
yes a few big A123's
i know its very original of me
Nothing wrong with using what works. I wondered if you were using the smaller ones, that's all.
Hi Søren, thanks for clarifying R2R network for us.
Could I ask if November release of DAC1101 will bring long promised DSD capability to DAM1021?
Cheers
Danny
btw
I don't believe expensive parts as per se would make "miracle" in any system, and unfortunately you are right about "psyshoacoustic" effect of expensive parts (some say that gold plated power fuses is all you need!?). However just like special lacquer coating of Stradivary make Stradivarius violin unique, I do believe that adding some of "exotic" components (silver solder, Z foil R and stacked film caps) in DAM's audio path can make for "unique life like" sound.
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After a long break, I'm resurrecting my efforts to fire up my DAC
Been reading about the mods.
So FYI, if you don't want to buy a 0.01 ohm 0603 resistor, a 1.2 inch piece of 30 gauge wire has about that much resistance.
In this application, I think it would be "close enough".
I would think it would be easier to install too, but you still have to get the 499r resistor installed.
Randy
Been reading about the mods.
So FYI, if you don't want to buy a 0.01 ohm 0603 resistor, a 1.2 inch piece of 30 gauge wire has about that much resistance.
In this application, I think it would be "close enough".
I would think it would be easier to install too, but you still have to get the 499r resistor installed.
Randy
Came across John Curl reminiscing on capacitors in audio, maybe some of this could be applied to DAM1021 analog part?
Cheers
Danny
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Cyril Bateman did the best work on capacitor sound, Jan now has them online: Cyril Bateman's Capacitor Sound articles | Linear Audio NL
Thanks for this, interesting reading ........
and in good old DIY saying: best capacitor = no capacitor at all!
that is why I was so drawn to DAM1021, no coupling caps in audio out!!!! not to mention the cost of V-cap Teflon and Audio Note Silver!
cheers
Danny