MicroSD Memory Card Transport Project

Jump to Latest
diyiggy

diyiggy

Disabled Account
Joined 2019
Julf said:
I understand that that is what you believe, but do we have any actual evidence to support your view?



Of course, but I also understand the difference between personal preference and accurate, transparent reproduction of sound - any sound.
Click to expand...


It's an evidence all curious guys can do easily. I do myself : take 2 similar pcbs : amp, pre, dac, what you like : just populate it with few different passive parts or simply the same passive parts but change the voltage of caps by a close voltage not too change ESR/ESL too much (for instance 25V instead 16V) and it doesn't sound the same. Do a controlled ABX and indeed you can conclude it doesn't sound the same.
 
diyiggy

diyiggy

Disabled Account
Joined 2019
Julf said:
Indeed. Claims and opinions are cheap, being evidence-based takes more effort. It is one of the fundamental problems of modern society.
Click to expand...


Is not that a claim and opinion as well ;)

Please try first before critisize people so easily, it's not worthy from you doing what you critisize yourself. You like Science, so please, experiment first then come back with some reliable evidences too. You may even find something you're able to measure cause of your tech background and bring us some new food with more than salt & pepper quantity as some already shared like Cyril Bateman caps papers and others did with resistors. Maybe ears can hear some difference we don't know how to measure or maybeb there is nothing to measure but the whole listening result. It seems more complicate that the simple clear sound idea and noise floor.

Nobody here is saying passive parts are the alpha & omega of audio design, people here just are trying to say it is one of the parameter and it is important for ending result to reach our common goal. Too bad people who claim to have a scientist approach and whom have "only" an engineering reflex want to burn them all as witches.

I understand they are prudent. we are again & again here in a dreadful atavism : "we Know, you stupid ignorant"... if Sapiens was like that, Earth will be flat yet !

well, it's my opinion and claim at least :) .Enough said, last post for me. There is nothing bad in the fact people experiment and set up their system for a better sound. And at the end take two people in ABX finding the sound is best, you may also be in the biased psychoacoustic preference both is sharing at the same time. But what's wrong, it's like the tube vs the silicon; tubes measure not so good but may befound more musical by musicians themselves or not. Many ways to skin a cat be it dead and alive at the same time...(joke)
 
Last edited:
J

Julf

Member
Joined 2011
diyiggy said:
It's an evidence all curious guys can do easily. I do myself : take 2 similar pcbs : amp, pre, dac, what you like : just populate it with few different passive parts or simply the same passive parts but change the voltage of caps by a close voltage not too change ESR/ESL too much (for instance 25V instead 16V) and it doesn't sound the same. Do a controlled ABX and indeed you can conclude it doesn't sound the same.
Click to expand...

Can you describe your ABX setup?
 
J

Julf

Member
Joined 2011
diyiggy said:
Too bad people who claim to have a scientist approach and whom have "only" an engineering reflex want to burn them all as witches.
Click to expand...

Questioning claims and asking for evidence is not the same as burning someone as witches.

diyiggy said:
And at the end take two people in ABX finding the sound is best, you may also be in the biased psychoacoustic preference both is sharing at the same time.
Click to expand...

ABX tests don't tell us anything about preferences - all they tell is if someone can hear a difference or not.
 
diyiggy

diyiggy

Disabled Account
Joined 2019
... but a difference is already a quality judgement in mind... I just said you two people may notice a difference and subjectivly may prefer it which can be seen as an objectivism... whether we ask their aesthetic preference or not.

We are not going into dialectic like two old men Julf. I have respect for your opinions and claims. But please try and experiment yourself on that: it's the better and the only way which can change or not your mind.
best regards,
diyiggy.
 
B

bitinhvi

Member
Joined 2007
Hi,
Finally I could try my SDTrans384 with LifePO4.
Connection is like this:
Single 3.3V LifePO4 -> CN1, CN5, CN7
Single 3.3V LifePO4 -> LT3045 LDOVR -> 2.5V -> CN10
-> LT3045 LDOVR -> 1.2V -> CN13

I got sound via I2S to Soekris, however Nothing is on SDTrans's LCD. Anyone can advise where should I check? Or I still need 5V power supply for LCD?

Thank you.
 
B

bitinhvi

Member
Joined 2007
Hi Sumotan, after feeding 5VDC, the LCD is up.
So now the the SDTrans384 is running with both LifePO4 and 5VDC shunt. It is not the thing I want but there is no solution yet.

I got one issue is suddenly Soekris DAC output level is very low, so have to deal with it first, before keep exploring the SDtrans.
 
X

xerogravite

Member
Joined 2005
hello all,

I have become quite curious about sd card readers. I have an unmodified qls qa550. my question is this....
given the additional formats / resolutions that the sdtrans384 can do .. does that make the circuit more complicated and could a 16/44.1 wav. only play possibly sound better because it is so simple?

just an innocent question? purely theoretical this does not account for designs execution .

thanks in advance
 
B

Blitz

Member
Joined 2002
Greg Stewart said:
Time for an SDTrans384 Mk2?

In post #224 of this thread dated November 13 2010, Bunpei announced the release of the current HW version of the SDTrans384, then only supporting 192. Several firmware upgrades have enhanced the functionality of the unit, including DSD functionality AND increasing the maximum bit rate to 384.

I've been using an SDTran as my reference digital source for several years now. I have it connected to a highly modified Soekris DAM DAC and listen to it on a nearly daily basis. I've also done some modifications/upgrades to my SDT by using the 5 included external power feed points (3x3.3V, 2.5V, 1.2V) as insertion points for ldovr.com LT3045 boards, along with a quick and dirty 4-relay board remote functionality and a backlight jumper switch. I also added u.fl jacks directly soldered on the bottom of the TTL I2S output pins.

I love this unit and expect it will be in one of my systems for a long time. I especially like the use of distributed power regulation which helps improve the SQ by reducing interaction between different sections of the unit via their power rails.

BUT the platform is now almost 10 years old. I'd like to start a conversation calling for an upgraded hardware platform for the SDTrans. Here is my wishlist for the hardware side:

- Upgrade each of the local regulators to LT3045 or equivalents. Consider adding another regulator and external power feed point to exclusively power the SD Card.

- Upgrade the clocking inputs/outputs and TLL-level I2S outputs to include at least pads for installation of u.fl connectors for better signal integrity. Include dual sets of u.fl pads for the TLL I2S output to simplify use with dual-mono DAC board setups.

- Upgrade the on-board clocks... at the very least go to the lower-phase-noise SDA version of the NDK clocks on the board. Better yet might be to go with a plug-in carrier board similar to what Ian Canada uses on his FIFO setups to enable less invasive clock upgrades / replacements.

- Consider flip/flop style synchronous reclocking of the 2 I2S outputs right at the output connector points for the highest signal integrity.

- Look at upgrading the S/PDIF output chip to one of the later ones. That world has seen some improvements in the last 10 years. Also look at the LVDS conversion chip used to create the LVDC I2S output. There might be better (adding less jitter) ones available today.

- Plug-in add-on boards to enable easy remote operation (via relays or custom solutions), synchronous clocking (similar to what Chaiki did for his DAC designs), momentary switch for backlight (similar to what I did with a custom header), remote display operation.


AND here are some thoughts on some SW upgrades. NOTE that I would not want to see any of these implemented IF their implementation compromises the SQ we get from the SDTrans. It is currently and always will be a bit of a hair-shirt affair to use. While these could provide some useful upgrades, nothing will make it an easy-to-use unit appropriate for every digital playback setup. SO if any of these requires either HW or sufficiently extensive SW upgrades to compromise the SQ, I personally would not want them. BUT if they can be done with no compromise in SQ, here's my thoughts:

- FLAC decoding

- Higher PCM & DSD samplin rates

- Larger SD Cards... at least 64Gb

- Output signal phase reversal

- I2C signaling of output type (PCM or DSD), bit-rate, bit-depth, AND if possible, de-emphasis flag (used in a very small number of CDs)


Any thoughts?

Greg in Mississippi
Click to expand...

Is it a contradiction to ask for a Linux/MPD version of it ? I love to have cover artand my ipad to control my music library. And my Alix 1D Board with Sotm USB Card does not sound bad either, but I can fully see the benefit of goong smaller in terms of hardware and direct i2s...
 
diyiggy

diyiggy

Disabled Account
Joined 2019
Hello Greg,


What gave you the best sound till today as a source : SD Trans or FiFoPi (or else)???


I assume you have benchmarked it subjectivly in your system with the same I2S input DAC ? And btw what is today your reference dac at home (the one you prefer to compete to the others ?


thank you for your help
 
B

badrisuper

Member
Joined 2012
Hi

I have this transport for long time. I am planning to add a power supply. Anyone what transformer I have to go for? I am going to use power supply board built by Chiaki. Here attached the picture as well.

Thanks
Badri M
 

Attachments

  • 01.jpg
    01.jpg
    288.5 KB · Views: 352
B

badrisuper

Member
Joined 2012
diyiggy said:
R core traffo...if you find...somegood suppliers wheteyou live
Click to expand...

Thanks. I am in Nederlands. I will try to search for R Core Transformer.

sumotan said:
Hi Badrisuper,
Im running individual supplies on mu SD Trans. With LDO regs including the 5v supply,
7v ac trafo will suffice. Im not aware of what Chiaki ps board is like but I would recommend that you power each point individually which means total of 6 locations.

Cheers
Click to expand...

The power supply board I have is built by Jack Yamazaki from Tachyon. It has 2 out. One is 5v and the next one is 3.3v. So I have to limit myself with that.

Is there any cabinet available for sale for this transport?

Badri M
 
You must log in or register to reply here.
Top Bottom