User in Hong Kong build his own OLED display for soekris R2R DAC
adding additional I2S and SPDIF input.
One I2S input either for Chinese famous
TANYU CDM3/4 CD player
???CDM3/4???? - ?Feverhifi ?????? - ??HIFI???? - Powered by Discuz!
or
Stock Fish CDPro2 CD player
another I2S input for Amanero Combo 384
Amanero Technologies
adding additional I2S and SPDIF input.
One I2S input either for Chinese famous
TANYU CDM3/4 CD player
???CDM3/4???? - ?Feverhifi ?????? - ??HIFI???? - Powered by Discuz!
or
Stock Fish CDPro2 CD player
another I2S input for Amanero Combo 384
Amanero Technologies
Attachments
Last edited:
I have to finish to modify the second channel too, then I can respond to this
I removed the .1R over the 10R resistor and the .1R/jumper over the feedback capaitor. So back to the original (except the 47uF cap which I left in place).
Hi There,
Fellow Soekris DiYers
It looks like everybody is playing with DSD/USB interfaces for the DAC, which is quite interesting.
I was thinking to plug the Soekris directly to I2S feed from either RPI2 or BBB via Chronus + Hermes (in the same way as it was implemented for DDDAC).
Has anybody tried this before ?
Fellow Soekris DiYers
It looks like everybody is playing with DSD/USB interfaces for the DAC, which is quite interesting.
I was thinking to plug the Soekris directly to I2S feed from either RPI2 or BBB via Chronus + Hermes (in the same way as it was implemented for DDDAC).
Has anybody tried this before ?
Hi There,
Fellow Soekris DiYers
It looks like everybody is playing with DSD/USB interfaces for the DAC, which is quite interesting.
I was thinking to plug the Soekris directly to I2S feed from either RPI2 or BBB via Chronus + Hermes (in the same way as it was implemented for DDDAC).
Has anybody tried this before ?
Yes, a lot of people are feeding their DAM from the RaspberryPI I2S output. Recklocking is done by tha DAM, so additional reclockers aren't necessary, me think.
have a look at this thread
http://www.diyaudio.com/forums/digital-line-level/271734-linux-servers-soekris-dam1021.html
More measurements, relative to my mod:
I have included graphs for Zero signal "garbage", White noise signal with 48kHz-like (like 96kHz sampling but the sampling is 192kHz) response, FFT from original DAM, and An FFT with my mod (see the attached graphs, but make sure to read the scale):
((((How do they (alecm and zfe) made their posts? I tried to include the illustrations directly in the text (as in posts of zfe and alecm), but it made an error message appears and I could not post ... since I don't know to do that, sorry the mess post))))
UGH, my white noise shows some peaking, need more tuning
(Sorry, I lost the non-modded white noise DAM, but is worse...)
The FFT with my mod, well, a little better...
But now time to refine that.
I have included graphs for Zero signal "garbage", White noise signal with 48kHz-like (like 96kHz sampling but the sampling is 192kHz) response, FFT from original DAM, and An FFT with my mod (see the attached graphs, but make sure to read the scale):
((((How do they (alecm and zfe) made their posts? I tried to include the illustrations directly in the text (as in posts of zfe and alecm), but it made an error message appears and I could not post ... since I don't know to do that, sorry the mess post
))))UGH, my white noise shows some peaking
, need more tuning(Sorry, I lost the non-modded white noise DAM, but is worse...)
The FFT with my mod, well, a little better...
But now time to refine that.
Attachments
First the picture of the modded part.
As most of the vias are covered by the "green paint" at my DAM, I had not the connet-form-below-option, I soldered the capacitors (16V 2700uF Panasonic FM) directly to the main buffer cap. And as my case is not high enough, I had to lay them flat.
The green caps are 360pF WIMA FKP2 soldered directly to the GND and Vcc pins of the shift registers. This was for the 250MHz oscillations (weather they were now in the DAM or oscillations in my oscilloscope), surely they not harm (but the physical connection is a bit fragile ... possibly I will end to remove them again in the future).
So to the sound. I have to admit, that I have not listened to my other modifications a) as I had not always enough parts lying around to modify all rails. b) I was very tight in time and only did the full modification for the most promising version. So I compare only with the unmodified DAM.
I currently only can listen with my headphone (an "vintage" Stax Lambda Pro + SRM1 Mk2). First observation is, with high sample rate recordings, the unmodded DAM and this headphone I sooner or later got some kind of headache. With the modded version this seems to be gone! I suspect that either that 39kHz noise hump either caused distortions it the head phone amp or this high frequency junk in the signal wereas transmitted to well to the ear and although inaudible caused some pain. So good point
The sound has definitely changed very noticeably!!
I hear more details, the sound is even more than before only "there" (in the sense that you don't think it comes from the headphones).
An prominent example is the bass section where in some piece I suddenly hear a very deep drum in the background with clear modulations of its vibrations (before this was more some unarticulated noise). Moreover, with enough volume up, I felt the bass part in the body as never with the headphone before... more like with speakers.
Impulses of piano or guitar snares have more attack and are more well defined impulses, again not covering details.
This changed the sound of this setup that much, that I have to listen a lot more to see if I get "used" to that. I can not say that the tonal balance got wrong. Definitely there are "improvements". But I am not yet decided If I just have not heard the "truth" before or if the effects are overemphasizing at some point and there is now to much of ... many things.
I encourage the people here with more analytic or professional ears to give this mod a try. I would be glad to hear other opinions.
Especially in comparison to the other mods.
As most of the vias are covered by the "green paint" at my DAM, I had not the connet-form-below-option, I soldered the capacitors (16V 2700uF Panasonic FM) directly to the main buffer cap. And as my case is not high enough, I had to lay them flat.
The green caps are 360pF WIMA FKP2 soldered directly to the GND and Vcc pins of the shift registers. This was for the 250MHz oscillations (weather they were now in the DAM or oscillations in my oscilloscope), surely they not harm (but the physical connection is a bit fragile ... possibly I will end to remove them again in the future).
So to the sound. I have to admit, that I have not listened to my other modifications a) as I had not always enough parts lying around to modify all rails. b) I was very tight in time and only did the full modification for the most promising version. So I compare only with the unmodified DAM.
I currently only can listen with my headphone (an "vintage" Stax Lambda Pro + SRM1 Mk2). First observation is, with high sample rate recordings, the unmodded DAM and this headphone I sooner or later got some kind of headache. With the modded version this seems to be gone! I suspect that either that 39kHz noise hump either caused distortions it the head phone amp or this high frequency junk in the signal wereas transmitted to well to the ear and although inaudible caused some pain. So good point
The sound has definitely changed very noticeably!!
I hear more details, the sound is even more than before only "there" (in the sense that you don't think it comes from the headphones).
An prominent example is the bass section where in some piece I suddenly hear a very deep drum in the background with clear modulations of its vibrations (before this was more some unarticulated noise). Moreover, with enough volume up, I felt the bass part in the body as never with the headphone before... more like with speakers.
Impulses of piano or guitar snares have more attack and are more well defined impulses, again not covering details.
This changed the sound of this setup that much, that I have to listen a lot more to see if I get "used" to that. I can not say that the tonal balance got wrong. Definitely there are "improvements". But I am not yet decided If I just have not heard the "truth" before or if the effects are overemphasizing at some point and there is now to much of ... many things.
I encourage the people here with more analytic or professional ears to give this mod a try. I would be glad to hear other opinions.
Especially in comparison to the other mods.
Nicely done zfe! I wanted to see how you did it but couldn't wait and went ahead. Glued them to the backside. Soldered strands from a cable to the vias. Are they to thin possibly?
Only did the output cap mod - no feedback mod- no previous HW mod done.
Sound:
Bass had biggest impact with weight and details - nice. I can play loader without strain - nice. I still wish it was a little cleaner in upper midrange and beyond. But definitely an improvement - maybe its my switchmode DC feed? Need to check with batteries now after the mod.
Used Pana 16V 1000uF 23mohm - 16ME1000WX
//
and went ahead. Glued them to the backside. Soldered strands from a cable to the vias. Are they to thin possibly?Only did the output cap mod - no feedback mod- no previous HW mod done.
Sound:
Bass had biggest impact with weight and details - nice. I can play loader without strain - nice. I still wish it was a little cleaner in upper midrange and beyond. But definitely an improvement - maybe its my switchmode DC feed? Need to check with batteries now after the mod.
Used Pana 16V 1000uF 23mohm - 16ME1000WX
//
Attachments
Last edited:
Vinyl copies often have a superior mastering over the CD release better suited to our high expectations with how things should be done.
I'm actually running my vinyl through my dam via a AD24QS-K ADC (CS5381) and it simply sounds better even without the pure analog path to the amplifier.
Nightwish Imaginaerum is a great example.
It would be great if everyone detailing their experiences with mods would add a short description of their exact configuration in that post: Power supply (trafo only, unregulated but filtered, discrete regulated, batteries etc.), all mods done to the DAM, input used (S/PDIF, IS2, etc.), output used.
Otherwise it's hard to figure out even from skipping through the thread what configuration people are actually listen to.
Otherwise it's hard to figure out even from skipping through the thread what configuration people are actually listen to.
I've been wondering how good these beis converters are. What's your verdict? At a quick glance it seems the ADC doesn't use a special clock, there are no jitter specs availible and the PSU is very basic.
To all the Arduino fans, I'd like to let you know that I have posted my code for controlling the dam.. It can be found here: ArDAM1021 Project | Dimdim's Blog
It is still in the alpha stage of development, but it gets the job done (more or less).
Feedback is more than welcome..
It is still in the alpha stage of development, but it gets the job done (more or less).
Feedback is more than welcome..