no they are 0.01 resistors,I dont care about price,I thought this Soekris miracle could possibly be best dac currently on this planet but your comment make it seem like just buget bang for buck
Looking at HIFIDUINO's idea of using the vias next to the shift registers for adding capacitance makes me wonder - why not solder to the vias? Is there the possibility of some diode effect with those wires touching the vias passing through?
Is there any reason NOT to solder at the vias?
Another question comes to mind - would there be any advantage using film resistors here instead of the polymers? I have added polymers at the regulators. There is room for film caps there. I know next to nothing about digital circuits and realize I am thinking analogue with the film cap question.
They would be much more expensive than polymers so I hope the answer is that it would gain nothing using film caps.
Any thoughts?
Is there any reason NOT to solder at the vias?
Another question comes to mind - would there be any advantage using film resistors here instead of the polymers? I have added polymers at the regulators. There is room for film caps there. I know next to nothing about digital circuits and realize I am thinking analogue with the film cap question.
They would be much more expensive than polymers so I hope the answer is that it would gain nothing using film caps.
Any thoughts?
If you use non-audiopile real low inductance stacked film caps, is OK, since you need to decouple some fast signals (the rise/fall commutating is decoupled by onboard SMD caps). But the DAM also benefited from low freq decoupling so polymer caps have the desired characteristcs: low ESR and high capacitance.
I have soldered some caps and solder goes to vias, but maybe some vias don't have soldering "pads" and not adhere to solder...
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Thanks for your note, DIYBras.
I do not have the board in front of me - if there is nothing to solder to then there is nothing to worry about but my memory seemed to remember some metal around the hole - and HiFiduino said something about checking continuity from the via to the existing cap ...
I would much rather use the polymers.
Luckily audiophile caps are too big and expensive so they were not a consideration. I was thinking of WIMA PPs.
I do not have the board in front of me - if there is nothing to solder to then there is nothing to worry about but my memory seemed to remember some metal around the hole - and HiFiduino said something about checking continuity from the via to the existing cap ...
I would much rather use the polymers.
Luckily audiophile caps are too big and expensive so they were not a consideration. I was thinking of WIMA PPs.
after detail listening sessions, in my particular case and in the analogue part of DAC [plz look on the former report], polymer caps gave me decreasing of tonal balance and muddy air... and PP caps improvements only. For sure an amount of PP caps is not enough often and you have to compensate it through another cap types..
Thanks, alecm,
I have 1000 uf at the opamps and would use the WIMA PPs at the shift registers.
Not that I want to do this without reason - those PPs would be much more expensive as you know.
I think I can squeeze the 10uF 100v WIMA MLP4s on the board. Would probably require placing them below and atop the board. Do you think 80 uF of film caps would be enough to be noticed?
Do you think this is something worth pursuing?
Take care,
I have 1000 uf at the opamps and would use the WIMA PPs at the shift registers.
Not that I want to do this without reason - those PPs would be much more expensive as you know.
I think I can squeeze the 10uF 100v WIMA MLP4s on the board. Would probably require placing them below and atop the board. Do you think 80 uF of film caps would be enough to be noticed?
Do you think this is something worth pursuing?
Take care,
No one has tried to use the analog stage without the SE-BAL op amp LME49724? Since by default the DAM is SE out.
It would be interesting to see potential of:
- removing LME49724
- replace LME49710 with OPA627/AD797
- supply OPA627/AD797 with +-15V, if possible
- direct SE buffered out from OPA627/AD797
It would be interesting to see potential of:
- removing LME49724
- replace LME49710 with OPA627/AD797
- supply OPA627/AD797 with +-15V, if possible
- direct SE buffered out from OPA627/AD797
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This was as power line filtering/bypass?
Hard to argue with what someone hears, but film caps as bypasses should improve things only at very high freq, based on impedance characteristics.
Does the film ones have much better transient absorbtion capability then?
I have bunch of 0.47u films laying around, i should try these on top of the polymers.
I see no spec for dielectric absorption on the PANASONIC spec sheet for polymers.
Of course, this is specified for the WIMA PPs - .05%.
I would think the polymers would be closer to aluminum electrolytics than to PP film. The answer to be found is whether a "fast" capacitor would make any difference here.
MOUSER has a "new" WIMA 4.7 uF MKP4 for $2.93 each so that would not be too bad at all. Not the best WIMA MKP but has to be better than a polymer in all parameters but capacity.
Of course, this is specified for the WIMA PPs - .05%.
I would think the polymers would be closer to aluminum electrolytics than to PP film. The answer to be found is whether a "fast" capacitor would make any difference here.
MOUSER has a "new" WIMA 4.7 uF MKP4 for $2.93 each so that would not be too bad at all. Not the best WIMA MKP but has to be better than a polymer in all parameters but capacity.
Got my 0603 0.1R resistors and though I could barely see them I thought between that time and when I got home that I might be able to do this substitution.
Started trying to get them out of whatever it is they were in and when I could not do that I figured I was way over my head.
Contacted a audio technician fellow I have known for awhile and asked if he would do this for me and the groan he emitted ... but he said he would give it a try. He has the gear for it and I hope he will, after seeing the board, be willing to do this. I take the board to him Saturday so I hope to hear what this does Saturday evening.
Seems to me it might be better to run a wire between the appropriate pins of the opamp for the feedback loop. Peter Daniel was adamant about keeping the loop as short as possible and it has to be easier.
Hope 30 gauge wire will fit through the vias. Ordered some silver wire in that gauge for the additional capacitors "extenders" per HIFIDUINO.
I have Panasonic polymers and Silmics on hand - tempted to use the Silmics. Can always add a PS bypass later on.
Any comments would be appreciated.
As an aside - I got the SUSUMU resistors based on the recommendation of carlsor, a DIYAudio poster, who has found them to be superior resistors.
Started trying to get them out of whatever it is they were in and when I could not do that I figured I was way over my head.
Contacted a audio technician fellow I have known for awhile and asked if he would do this for me and the groan he emitted ... but he said he would give it a try. He has the gear for it and I hope he will, after seeing the board, be willing to do this. I take the board to him Saturday so I hope to hear what this does Saturday evening.
Seems to me it might be better to run a wire between the appropriate pins of the opamp for the feedback loop. Peter Daniel was adamant about keeping the loop as short as possible and it has to be easier.
Hope 30 gauge wire will fit through the vias. Ordered some silver wire in that gauge for the additional capacitors "extenders" per HIFIDUINO.
I have Panasonic polymers and Silmics on hand - tempted to use the Silmics. Can always add a PS bypass later on.
Any comments would be appreciated.
As an aside - I got the SUSUMU resistors based on the recommendation of carlsor, a DIYAudio poster, who has found them to be superior resistors.
A positive upgrade I did this week was to use batteries to power the DAM. With good sonic results! More fluid and less harshness, remembering the descriptions of who did the main supply upgrade. And now I have reached the output quality level measured by some here in DIYA (ie. better measurements, too).
Remember, batteries have no connection to the electrical network of the residence, so we have less noise coupling point for DAM. Not to mention that before I was using AC direct, and this have ripple, power-grid noise and inherent rectifier commutation noises in board.
Who has not made the upgrade of the main supply, I recommend testing option with batteries, if you have it ready. I used an old Notebook battery (3 internal Li-Ion elements, ~ 11V) for positive supply, and for the negative supply I used 2 old cellphone Li-Ion batteries in series (totaling ~ 7.5V). As the DAM has regulators for all applications, this asymmetric power caused no problem.
Who does not want to use batteries I recommend at least one supply with transformer with good insulation between PRI-SEC (toroidal is no-no!), And with a good snubber in rectifiers. Regulation is not mandatory if you filter decently the raw DC out.
Remember, batteries have no connection to the electrical network of the residence, so we have less noise coupling point for DAM. Not to mention that before I was using AC direct, and this have ripple, power-grid noise and inherent rectifier commutation noises in board.
Who has not made the upgrade of the main supply, I recommend testing option with batteries, if you have it ready. I used an old Notebook battery (3 internal Li-Ion elements, ~ 11V) for positive supply, and for the negative supply I used 2 old cellphone Li-Ion batteries in series (totaling ~ 7.5V). As the DAM has regulators for all applications, this asymmetric power caused no problem.
Who does not want to use batteries I recommend at least one supply with transformer with good insulation between PRI-SEC (toroidal is no-no!), And with a good snubber in rectifiers. Regulation is not mandatory if you filter decently the raw DC out.
This took me a while to try to quantify... seems a lot of folks report changes to how snappy the sound is after the mod, but it's something I never found a problem with. Just so you have some context, I run the SE output of the DAM1021 into ZM's pumpkin as a buffer and for my balanced out.
The best I can describe the resistor mod is that pre-mod, the sound placement was always pinpoint... post adding the resistors, I find the sound placement is still there but now there is better "filling" out of the spaces between them. It just makes the whole soundscape more cohesive and together. Initially, it seemed to make the music seem a little "softer" (not in the volume sense) - not sure if it's what audio media call refined or smoother. I always found it hard to quantify music/sound so I hope that helped.
Whatever the case, I think it's very easy to listen to - not that it wasn't before. I'm trying not to use superlatives... but compared with using a separate low noise 3.3v supply... a separate 5v supply... this presented a bigger change to me. [Of course, you could say that this mod allowed the other mods to perform their duty *shrug*]
Right now, I'm just waiting for my ST-Link V2 to arrive so I can try to recover my second board from a failed firmware upgrade. (hopefully before the new firmware arrives) I'm just enjoying these little tweaks that pop up every now and then
I'll probably have to show a before and after and make clear my measurements are relative, since I use a Asus Xonar sound board, which is unbalanced and has some noise mixed in measurements (I'm not have "professional" lab). I get some -160dB in FFT floor (over 110dB "general" SNR), but with some interference from house supply, PC and monitor. Hence my measurements are subject to interpretation, so I have not showed yet (also a shame to show my "dirty" measurements system
). And note that I said that measurements improved over earlier, but still not outperform the best DAM measurements available.Having said all this, I can post the measurements if people agree to the terms.