Computer Audio Blasphemy, nige tries Another SD Card Player

[Sligolad]

I agree with Nige on the AMS Randy, heat the Vin leg on the AMS and lift it off the board and it will be enought to isolate it and feed 3.3v in direct.
I am using an LT3045 from Ldover with 5v DC in out of the Lampi to get the 3.3v and it does sound way better than my PC setup.

I have the reclock board with clocks on it already built but have not put it in yet, still using the original reclocker i had without clocks and using MCLK off the SD Player and it sounds amazing.

I am going to throw out some thoughts here hoping others with better knowledge might set me straight!!

Was wondering since if the fact that we are not using these small decoupling caps on these remote clocks would degrade performance.

Also wondered if the quality of reclocking is all about the other lines getting all aligned by the masterclock and at the same time isolated from any noise on the MCLK. Would any phase noise on the MCLK's from the SD Player board still affect the DAC after we have reclocked the other lines.

Very little knowledge in this area so just wondering if the good implementation of the decoupling caps on the clocks on the board would offset any phase noise that would get to the DAC from these onboard clocks.

One final improvement Randy on the SD card, if you can pick up an SLC card you should hear a nice improvement over MLC.
Well done on the Blog, will help a lot of people.

[nige2000]

Was wondering since if the fact that we are not using these small decoupling caps on these remote clocks would degrade performance.

100nf-1uf np0 ceramic or some of the plastics pps or acrylic should be a decent bet to try as bypass caps
whether it will yield improvement will be up to experiment
previous experiments proved that electrolytic or larger bypass caps <10uf caused bottlenecks and it was easier to do more harm than good by adding "mediocre" caps
an engineers view is the bypass caps are necessity

Also wondered if the quality of reclocking is all about the other lines getting all aligned by the masterclock and at the same time isolated from any noise on the MCLK. Would any phase noise on the MCLK's from the SD Player board still affect the DAC after we have reclocked the other lines.

think thats hard to answer,
i think its mostly the mclk realignment, there might be a partial isolation effect from signal i2s in to i2s out
anyway theres no doubt the potato reclocker works well,
also think the clock replacement is well worth the 20€, it will provide a finer resolution

[Sligolad]

i think its mostly the mclk realignment, there might be a partial isolation effect from signal i2s in to i2s out
anyway theres no doubt the potato reclocker works well,
also think the clock replacement is well worth the 20€, it will provide a finer resolution

Thanks Nige, must have a go at wiring in the full reclocking board with clocks now that I finally received 2 more SD player boards yesterday.

[randytsuch]

Those NDK clocks are kind of tiny, but with the adapter board Nige found it's not too bad since it has the right pad layout for two clocks.

I'll try playing with the 3.3V reg when I have a chance, maybe this weekend. The regulator tab is also 3.3V, so the entire part will need to be removed from the board, unless I cut traces, but should be easier to remove the reg, and reinstall by the battery.
Along this line, may be time to play with supercaps here. Since its only one voltage, 3.3V, cost isn't too bad. Probably still a future mod for me.

I'm still hoping to get wifi working, although I'm not as optimistic as I was a week ago on this :\
Holding off on Panny SLC's until I resolve this, one way or the other.

Its nice having a remote with hard buttons. I do find the remote buttons don't always do what they are supposed to, sometimes I push a different button, and it acts like I pushed the same button again. Pretty sure its a software bug but I can live with this. I'm thinking about buying a learning remote, and I'll have that as a spare remote. But I'm not really motivated to look at ESP's or anything else like this since the remote works fine for me.

A larger display would be nice, not sure its worth it to buy the chassis version just for a larger display, although its cheap compared to lots of stuff in the hobby. At some point, I'll at least buy another SDP board as a spare/backup.

Randy

[Sligolad]

Will stick this handy link on i2s connections here for those working on connecting to various hardware.
https://docs.google.com/spreadsheets/d/ ... /htmlview#

[tapatrick]

Thanks very much @randy for sharing your mods so clearly.

I have a spare McDualXO that I want to try with the SD player and some Crysteks when I have some time.


Sent from my iPhone using Tapatalk

[Fran]

I got a bit of a chance to have a look inside the chinese boxed version of the SD card player. The SD board does look very similar alright, and has the same chips and clocks on there. I immediately went to see the pinout of the cable running to the DAC and I think I have it figured out but could probably do with someone elses eyes on it. I might get a chance to go back at it tonight to hook up to a 5102a DAC to test. The AK dac in it is nothing special, competently laid out etc, but with bog standard supplies and so on. What I plan to do first off is run the SD player and 5102a off a battery and then think about reclocking etc afterwards.

Pic shows the pinout - I think its right but I'll confirm when I get a chance.

Fran

[Sligolad]

Looks right from my initial tests Fran, I have not gone near it since as I ordered some ribbon cables so that I could do an i2s out as well to the Big7.
Once I get the cables i will butcher them to test properly and report back.

I messed a bit with the Op amps after letting the unit burn in for a lot of hours playing tracks which helps.
Taking out the back single Op amps drops volume but I think it sounded better when volume corrected but not sure, it did however add a loud pop between tracks so stuck them back in.
Since then I changed the front dual op amps for Burson V6 classics and they do sound better after putting some hours on them but not sure they are worth the cost for the improvement.

[Fran]

I must root around and see if I have a bit of ribbon cable knocking about that might do.

[seeteeyou]

Hi nige, my setup is raspberry pi 3 - diynhk 768 isolated xmos - potato -cs4396 dac diy with transformers output...
Sounds good..
Now i connected amanero with potato and the sound is much more clean..

Greg posted something very interesting back in July:

http://www.diyaudio.com/forums/digital- ... ost5478850

Finally, on SD-card player versus computer playback... I am VERY interested in what the guys at TirNaHiFi are working on to make the SD-Card players less user-hostile. Most of what they are working on should be applicable to the SDTrans... I am running mine with a low-end remote relay board and find that a great add-on (with no sonic impact). BUT I also reached a watershed recently... I modified an RPi with linear regs replacing the onboard DC-DC converters and with that as the base of an RPi -> IsolatorPi -> Kali Reclocker stack, the SQ was in the same realm as my SDTrans with one of the lower-end power setups. At least good enough to live with all the time now. So while I'm definitely keeping my SDTrans, I'm also definitely working to get that computer playback setup as close as possible as it offers a LOT more convenience in terms of music selection.

We still dunno whether SDTrans384 (with full-blown LT3045 mod) is superior to the STM32F407ZET6-based SD Card Player at the moment. However, we'll have quite a bit of work to do before either one is able to offer a LOT more convenience in terms of music selection.

OTOH, we could already get a really nice Katana DAC from Allo (for $249) while they're also working on an even better isolator for RPi. Granted the current design might not be exactly the best for an audiophile setup (actually it's a better bet to go for RPi 2 without on-board Wi-Fi for the sake of SQ) but we could always pay someone to design our own carrier board for their Compute Module 3 instead:

https://www.newark.com/raspberry-pi/rpi ... p/02AC9992

According to the datasheet, 3.3V / 2.5V / 1.8V are required to feed Compute Module 3:

https://www.raspberrypi.org/documentati ... df#page=15

In that case, we could simply feed double-regulated LT3045 / triple-regulated LT3045 / quadruple regulated LT3045 to 3.3V / 2.5V / 1.8V respectively based on the advantage mentioned below:

https://www.mpaudio.net/faq

05 Why do some people use the HPULN's in series?

It could be something similar to Mezzanine Power from Alexey:

http://www.ldovr.com/product-p/mpower.htm

I kept an eye on the manufacturers / sellers of Compute Module 3 carrier boards in China, so far two of them seemed to be fairly promising. First one is Shenzhen Tongban Technology:

https://geekworm.taobao.com
https://item.taobao.com/item.htm?id=575337147031
http://www.geekworm.net
http://www.sz-partners.com
https://shop8t302e4699t19.1688.com
http://www.raspberrypiwiki.com/index.php/CM_IO_Board
https://trademarks.justia.com/872/41/ge ... 41171.html
https://trademarks.justia.com/owners/sh ... d-3434995/
https://geekworm.aliexpress.com/store/1048722
https://www.aliexpress.com/item/Raspber ... 15978.html
https://www.aliexpress.com/item/Ultra-T ... 85098.html
https://www.aliexpress.com/item/Raspber ... 64740.html
https://www.amazon.com/stores/Geekworm/node/14104341011

Another one is Herman Liu and he should be fairly well known in the RPI scene:

https://ukonline2000.taobao.com
https://item.taobao.com/item.htm?id=565860030573
http://ukonline2000.com
https://twitter.com/ukonline2000
https://sourceforge.net/projects/u-geek/
http://www.shumeipai.net/?133
http://www.eeboard.com/bbs/space-uid-154.html
http://www.eeboard.com/bbs/thread-31153-1-1.html
https://ugeek.aliexpress.com/store/1954241
https://www.aliexpress.com/item/Officia ... 48426.html

Basically the carrier board should be a headless one without stuff like 4-pole A/V jack / USB ports / Wi-Fi / Bluetooth / HDMI etc. It's gonna provide only Ethernet and I2S audio in order to keep everything as simple as possible. Absolutely no voltage regulators whatsoever since we won't bother with anything less than LT3045.

Once we modify both I2S isolator and reclocker with Pulsar Clock or even NDK DuCULoN, that kinda insane combo should be tough to beat as long as we're able to get our hands on a great slave DAC. Something like dual-mono Buffalo-IIIsePro could be an interesting choice.