| dddac |
Like to share my new design with you all.....
you can download full document with circuits and pcb designs here:
Download PDF DOCUMENT here
image of the ready DAC Module board |
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| dddac |
| the SPDIF Receiver..... |
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| dddac |
and the USB to I2S converter / receiver / DAC
more details on my site :)
dddac site |
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| maxlorenz |
Well done!
I'm gonna eat it :D
Happy new year for you and your family.
Mauricio |
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| rfbrw |
| Note to Ulas. No RFC. |
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| Jocko Homo |
It has an RCA jack for the SPDIF.......................oy vey.
Waiting on the .pdf to d/l..........and you-know-who to tell us the right way to do it. Cough, cough.
Jocko |
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| ash_dac |
Hi,
Which brand vhc4040 do you recommend or have tried ?
From the datasheet I see that they is quite a bit of difference in their spec's!
Cheers,
Ashley. |
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| maxlorenz |
So, I can directly feed the DAC modules through I2S from the CDPRO-2M that is waiting unbuilt on my living room?
No need for reclock?
I plan to use a few cm of wire, but before I will search how to implement this not to upset Joko :D
Yes, I am an irresponsible hobbist ;)
Best of lucks with your new project :cheers:
Mauricio |
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| Jocko Homo |
I would rather see you use I2S than SPDIF done in an "irresponsible manner".
Not your fault that is is a lousy way to transmit signals.
Jocko |
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| maxlorenz |
Dear Joko:| quote: | | I would rather see you use I2S than SPDIF done in an "irresponsible manner". |
A thousand thanks. That comforts me and reasures me :angel:
Abusing of your kindness...errr...would it be any "must read" paper referring I2S transmision that you can point me to?
In order to save me many hours of google search, that is :angel:
Kind regards.
Mauricio
(Willing to learn) |
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| carawu |
Moin Mauricio,
try this:
http://www.semiconductors.philips.c...ious/I2SBUS.pdf
From memory: max. length for i2s is 20cm. Correct me, if i´m wrong.
For the rest (or most?) of us....spdif AND usb is the way to go. You can use your PC and "cheap" CD-Playa. No need or hazzle to dig in an old playa-model, trying to find a way to squeeze i2s out of it. So Doedde´s concept is right.
For some of us, there is the need to improve this concept. CDM-pro is prohibitive expensive and digging in ~20year old Playa´s isn´t that attractive (for me!). YEMV
Carsten |
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| Jocko Homo |
Nope, don't have anywhere to point you, but...........
If I was going to run I2S from my CDP, I would look at LVDS. National makes several TX/RX chips that should work. If you can't find the info there, I may have propaganda sheet from them with the right P/Ns.
Yes, USB is probably the future. Especially for commerical efforts. This is DIY. Doing it the hard way can be more fun.
Hopefully better sounding, and more educational.
Jocko |
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| carawu |
Just some thoughts:
Soldering these PCM2xxx chips IS the hard way.....
But I hate the idea of booting my CD-playa....so, here is a thread about Digital audio from IDE (CDR->DAE), maybe that´s the way to go.
http://www.diyaudio.com/forums/show...&threadid=50187
Carsten |
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| rfbrw |
| If i had to use the pc, i'd use ADAT. |
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| curva |
| quote: | Originally posted by rfbrw
If i had to use the pc, i'd use ADAT. |
Any idea what happened with alesis-semi? Are they out of business? |
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| rfbrw |
| quote: | Originally posted by curva
Any idea what happened with alesis-semi? Are they out of business? |
The are now Wavefront Semiconductor. http://www.wavefrontsemi.com/ |
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| maxlorenz |
Many thanks to Carsten and Jocko for their help :D
| quote: | | CDM-pro is prohibitive expensive |
It's cheaper than a laptop perhaps?
So, everybody is considering USB as a better option.
Ah! more to study! :bawling:
Regards
Mauricio |
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| carawu |
Moin Mauricio,
no, USB Audio is only the hype of today..... ;-)
It´s better to look what you have, what´s in your partbin and what you can do. Do it, relax, hear some music, cause that´s what you are looking for.... or am I wrong?
Carsten |
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| rfbrw |
| quote: | Originally posted by maxlorenz
So, everybody is considering USB as a better option.
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No, not everybody. |
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| hagtech |
USB is ok. It has jitter too. I believe it is best to reclock both USB and S/PDIF sources. I did with my USB DAC.
jh:) |
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| 12 Cents |
| Is'nt reclocking done at this USB receiver because it requires it in any event? |
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| maxlorenz |
Dear Carsten:| quote: | | Do it, relax, hear some music, cause that´s what you are looking for.... or am I wrong? |
Touche! :D
(oops! no accent here)
I only found theoretical background referring I2S bus, so far. No practical tips. I will search now our forum :eek:
Regards
Mauricio |
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| hagtech |
| quote: | | Is'nt reclocking done at this USB receiver |
Indeed, the USB receiver chip regenerates the clock. But look at how this is accomplished. The bus runs at 48MHz (I think), so the chip starts with a 12.000MHz xtal and multiplies that up to 96MHz (don't for a minute think that is jitter-free). From there, the processing is done and USB reception, etc. Now, from the audio packet timing (dependent on the PC clock, full of jitter) a new 44.1k clock is created. How? A complicated multi-loop PLL synthesizer. Haven't been able to dig deep into this, but probably a fractional loop from a VCO referenced to the 96MHz AND the USB packet delivery. So now you have two system clocks that are not harmonically related (12M/44.1k = 272.1088435...) in one chip. All running from the same supply, trying to spit out clean audio data. Oh, and it also has to decode 32k and 48k word clocks too, so operation is not narrowband.
Nonetheless, TI did a superb job and these USB chips work extremely well. But let's keep in mind the hoops they had to jump through to try and regenerate word clocks.
In my opinion, the USB audio output is ripe for reclocking with a dedicated narrowband VCXO running from a separate clean supply. I have confirmed this with my own testing.
jh |
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| 12 Cents |
| Ok. What's the deal with this USB thing? Made for non-redundant data, it has to have some buffering, some indepandance of the incoming data stream clock or somethin'? |
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| hifi |
Here you can read about the development and workings of "SpAct"
http://www.planetanalog.com/story/OEG20020220S0017
Even if the jitter is plentifull it will not be as heavily signal correlated compared to if its been biphasemark encoded, and thus not as harmfull.
| quote: | | In my opinion, the USB audio output is ripe for reclocking with a dedicated narrowband VCXO running from a separate clean supply. I have confirmed this with my own testing. |
How did you, or how do you suggest to do this? A secondary Pll or mayb a fifo? |
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| Jocko Homo |
Secondary PLL.......the kind of thing us RF guys love to futz with. (Yeah, I know......I'm sick.........)
Anyway, Mr. "making audio fun again" was kind enough to donate one of his thingies for me to delve into........(well, he really didn't expect me to delve into it, but he should have known better, right?)........and I will try to run some graphs on the recovered clock jitter, and compare them to what you get from a typical CDP driving my D/A box. No promises, but I plan to try.
Jocko |
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| ozone_stink |
Cool thread!! -I've been pestering Peter to make one of these thingies. I'm beginning to understand some of his reluctance.
I *did* say _beginning_, right? *wipes brow*
Cheers. :cheers: |
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| hifi |
I got one of tents PLL:s aswell...
Here is a measurement taken of the errorsignal from said PLL when driven by a PCM2902 playing regular music trough a spdif interface you would probably recognice....
I can hear no readily recognisable signal modulation of the errorsignal when i listen to it with a battery powered headphoneamp.
The measurement is taken with a regular soundcard (averaged 10 times).... But compared to the spectra of my Cdplayer I dare attribute most of the spikes to the pcm.
ofcourse a comparision to the clock comming directly out of a pcm27xx would be better...but in the meantime.. |
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| pburke |
| quote: | Originally posted by hagtech
In my opinion, the USB audio output is ripe for reclocking with a dedicated narrowband VCXO running from a separate clean supply. I have confirmed this with my own testing.
jh |
isn't that pretty much what Doede did? His USB board that I am listening to right now has a 12mHz Tent clock on it. Hooked directly via I2s to the 16-chip TDA1543 tower on my last generation DDDAC build, the combo easily outperforms anything else I have played with in recent years (I'll spare you the list of devices, interface, cables, jacks, unless you really need to know)
For me, this little card pretty much marks the day I finally had a strong enough reason to move over to PC-based audio. It just sounds that much better, period.
This interface is also a mile ahead of USB-SPDIF interfaces and I've got two of them, but neither really rocked my boat enough to pull the plug on the CD transport, although they sounded very detailed and possibly better than the CD player, but it was a taste thing and not enough to even contemplate ripping hundreds of CDs to a file server. Now it's just blatantly obvious that I'll have to go and start working on that...
Peter |
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| hagtech |
| quote: | | workings of "SpAct" |
Hey, great article! This reveals a lot. Noticed they found the same 44/45 sampling issue I tried to explain (poorly) in my NONOS DAC white paper.
For testing, I can clean up the audio clock with a HAGDAC. You could do the same thing with a Tent X03.
jh |
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| hagtech |
This will help, but you'll notice most of the problems occur after this. I believe the reclocking has to be on the audio signal, not the USB signal.
jh |
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| dddac |
| quote: | Originally posted by ash_dac
Hi,
Which brand vhc4040 do you recommend or have tried ?
From the datasheet I see that they is quite a bit of difference in their spec's!
Cheers,
Ashley. |
I have tried only one brand and need to look it up. But never the less, I do not expect audible differences by changing the brand.
If any one has time and energy to do so. let me know :cool:
doede |
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| Jocko Homo |
You-know-who will claim otherwise. No, he won't measure it, just assert it.
Jocko |
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| dddac |
| quote: | Originally posted by hagtech
This will help, but you'll notice most of the problems occur after this. I believe the reclocking has to be on the audio signal, not the USB signal.
jh |
JH,
What "most of the problems" are you referring to? This does not help me improving future designs....
YES, the Tent Clock helps, so there is nothing against a 29 Euro option where Audio companies sell upgrades for hundreds (or thousands) of Euros.... :rolleyes: won’t we all agree?
The DAC with USB input sounds just great, and you need to throw a lot of money on the table for commercial DACs or CD players to come close to this result...... that always has been the philosophy behind the DDDAC1543 designs....
I consider it to be very good, that my thread and published design has kicked loose a discussion on what could be even better in USB-audio (which would sound also better than just remarks on what is not good, even without having built and listened.... Short remark: Ulas, where are you by the way??? ) And I hope this will lead to Forum members really (and I mean really!!) work on this concept and come with solutions as well. And than I mean publish circuits which are tested, PCB designs which are actually built and make it available at a very reasonable price..... Than we have all won :att'n:
Look forward to the first improved USB reclocked designs at this forum (really ... :) )
doede |
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| hifi |
If you read the article I linked to in post #25 you will see how the innards of the PCM2xxx works and how its clocking scheme is devised.
Replacing the 12Mhz oscillator with a low jitter one does not buy you all that much, it certainly will not hurt But it would be money better spent if it where used to reclock (synchronous) the i2s stream when it exits the Pcm. |
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| hagtech |
| quote: | | What "most of the problems" are you referring to? |
I spoke to this in post #23.
You can download schematics for the hagdac, hagusb, and chime at my website. The basic topology I chose was to use the S/PDIF output from the USB chip. A step backwards maybe? Or perhaps not. This allows me to run it through a transformer to isolate PC ground and PC power from the audio system. Ground isolation alone I think is worth the conversion. And most of the S/PDIF problems of transmission and connectors are eliminated since I keep the routing all on the same PC board (chime). Then, I do a VCXO-based PLL to reclock the audio right at the DAC, after the digital filter (the more gates you go through, the more jitter added). The PLL loop runs very slow and operates subsonically. It does take a few tenths of a second to lock, though. The flywheel action keeps audioband jitter really low. Biggest drawback is that it may not lock to transports or PCs that are out of the +/-100ppm redbook spec. I haven't seen this yet, but it is possible. Also, older transports were allowed up to 12UI at low frequencies (motor speed control?). The flywheel operation will not tolerate more than 0.5UI (~10ns jitter).
jh:) |
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| Jocko Homo |
Using a CD-80, with a "clocko jocko" inside, the recovered SPDIF clock is 43 dB noisier than "clocko jocko" by itself. This makes sense, as the jitter on the YM3623 is in the 1 nSec range, and "clocko jocko" is probably under 10 pSec. I did not fully calibrate the test set-up, but the close-in noise on "c-j" is around -130 dB/Hz^-2. Not bad, if my calibration is right. Actually, the close in noise on the recovered clock is around 15 dB lower than the HF noise, as it has an exponential rise, starting at around 250 Hz. Still, it leaves much to be desired.
Using a USB-SPDIF thingie, the clock noise is 7 dB noisier than the CD-80. In addition, there are spurious responses, too numerous to list. No, I don't have a way to display them here, so you guys will just have to trust Mr. RF is telling the truth.
Jocko |
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| hifi |
| quote: | | there are spurious responses, too numerous to list |
Where you using a Ti chip? |
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| dddac |
I had some email comments and questions on the windows kmixer. And the possible influence on bit cooretness...
I am not sure about this case. The USB versio sounds so good in comparison to SPDIF and normal CD Player, you would expect no bit pampering.... but not sure....
Any way, I thougt it might be a an idea to create a wav file with a very clear data patern, like a squarewave using bit 14,15 and 16 running at 11025 Hz for example.... and check this data on the digital scope. If tampered, it should look like a prety mess I guess. Any one already some xperience or ideas ? |
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| Jocko Homo |
The TI chip is inside a Mr. "making audio fun again" USB thingie. PCM2704.
Only has SPDIF out, no headphone spigot provided.
Jocko |
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| Elso Kwak |
| quote: | Originally posted by Jocko Homo
The TI chip is inside a Mr. "making audio fun again" USB thingie. PCM2704.
Only has SPDIF out, no headphone spigot provided.
Jocko |
Fun? What fun? I am crying............:bawling: |
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| Jocko Homo |
See, if you had bought a squirrel instead, you wouldn't be sounding like Eric Burdon.
Jocko |
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| Elso Kwak |
| quote: | Originally posted by Jocko Homo
See, if you had bought a squirrel instead, you wouldn't be sounding like Eric Burdon.
Jocko |
A squirrel can SCREAM! |
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| dddac |
ok chaps,
let's be constructive or on-topic .... :rolleyes:
elso, why cry ??? explain !!!
doede |
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| rfbrw |
| quote: | Originally posted by dddac
elso, why cry ??? explain !!!
doede |
That's just elso singing the blues. |
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| toman_9 |
Hi Duede,
After some more reading in your web site, you have convinced me to use the battery as a power supply for my design, as I was unawere of this auto charge battery.
I have 2 questions :
1) Can you give a reference where to get this 29 euro auto charge battery, what make/model is that ?
2) What are the dimensions of the boards ?
I need accurate info as I wan to know whether they fit into my cd player.
Thanks.
Tim. |
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| dddac |
| quote: | Originally posted by toman_9
Hi Duede,
After some more reading in your web site, you have convinced me to use the battery as a power supply for my design, as I was unawere of this auto charge battery.
I have 2 questions :
1) Can you give a reference where to get this 29 euro auto charge battery, what make/model is that ?
2) What are the dimensions of the boards ?
I need accurate info as I wan to know whether they fit into my cd player.
Thanks.
Tim. |
Hi Tim,
no problem :)
to 1) I used the Reichelt one: BCA 12-1
"Ladegerät für 12V 3,4-24 Ah PB-Akkus"
link to reichelt
Reichelt
to 2) usb 50x100 spdif 100x100 dac 90x100 all mm :D
regards
doede |
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| toman_9 |
Thanks! :)
I would assume that the height is 70 mm for the towers, right ?
Tim |
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| dddac |
| quote: | Originally posted by toman_9
Thanks! :)
I would assume that the height is 70 mm for the towers, right ?
Tim |
That will do for sure..... if you add up all very tight, you need 7mm for the board-thickness and mounting underneath. Then the towers are 50mm plus the mutter on top, lets say 6mm, so total is minimum 63 mm
regards
doede |
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| toman_9 |
Thanks for the info... I think it fits...
Looking at your schematics w.r.t battery charger.....
Hmmmmm.....
This means I have to somehow need a power switch which will power on the charger when the DAC is off, and vice versa...
Let's see if I can find a switch... |
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| pburke |
| quote: | Originally posted by toman_9
Thanks for the info... I think it fits...
Looking at your schematics w.r.t battery charger.....
Hmmmmm.....
This means I have to somehow need a power switch which will power on the charger when the DAC is off, and vice versa...
Let's see if I can find a switch... |
look for a "DPDT switch - that's all you need |
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| dddac |
| quote: | Originally posted by toman_9
Thanks for the info... I think it fits...
Looking at your schematics w.r.t battery charger.....
Hmmmmm.....
This means I have to somehow need a power switch which will power on the charger when the DAC is off, and vice versa...
Let's see if I can find a switch... |
the switch is already in the kit :angel:
regards
doede |
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| dddac |
By the way, I just finished my set up for an audio server, streaming into the USB input :)
can be looked at at my site. look for banner dddac1543mk2 than in frame left click USB Server ....
or go straight with this link (no frames...)
USB Audio Server
doede |
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| 12 Cents |
Cool, what is that for a PC? How much did you pay? How much for that 80GB disk?
Regards,
Lukas
edit: ok I saw it. A PC in just that touchscreen case, that would be nice.. |
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| dddac |
| quote: | Originally posted by 12 Cents
Cool, what is that for a PC? How much did you pay? How much for that 80GB disk?
Regards,
Lukas
edit: ok I saw it. A PC in just that touchscreen case, that would be nice.. |
if you follow the links on that page, you can download a datasheet.... it is called the DT166, AMD Geode based 533MHz
I paid 280 Euro. The HD was 91 Euro ....
doede |
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| Elso Kwak |
| Why not a Mini-Mac? What do I know about computers?:eek: |
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| dddac |
| quote: | Originally posted by Elso Kwak
Why not a Mini-Mac? What do I know about computers?:eek: |
MAC is not doing straight bits out, but making some kind of apple format (you see, apple is not my strong side as well :xeye: )
and is more expensive. But for sure it will work.
I have tried the USB-DDDAC on an Apple Notebook, works perfectly and immediately :)
By the way, is there Foobar2000 for Mac ? :devilr:
doede |
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| Zodiac |
After reading so many things about USB - it's amazing, the best thing since sliced bread, etc... I decided I should try it out for myself and compare against my base system to see whether it met it's reputation or whether, like most things in audio, it was a load of hot air. Music used was varied, ripped using Plextools and losslessly encoded. Music played off a Mac Mini
My base set up is Cyrus Diskmaster --> Benchmark DAC1 --> Active XO ---> Pass Labs Aleph3 / UCD 180 --> Linkwitz Orion
I built myself a USB-SPDIF converter using a PCM2706 (thanks to TI sample programme), powered off bus. Sound was long way behind Cyrus/Benchmark combination, bass 'one notey' to the point of being unlistenable and a very high audible noise floor. Positives, a bit more detail it seemed in med / high frequencies, but to be honest I couldn't listen to more than 15mins without switching the damn thing off.
Then I built a USB front end for my TDA1541 nonos dac (PCM2706 outputting straight I2S), which hitherto was using a CS8412 receiver with local clock, I2S reclocking based on Doede's original schematics and DEM clocking. When I was using this with the Cyrus I actually preferred it to the Benchmark. With the USB front end - first impressions are that bass 'one note' sound is completely removed, actually it is more chunky and rounded than that from the Cyrus/Benchmark. Also the high noise floor seems to be ameliorated, but it still seems higher than when fed by the Cyrus. There's more musicality and flow to the music, but less dynamics and less energy. Detail during busy patches seems slurred. Overall a less satisfying experience!
At this stage I can think of a few tweaks I can make to the USB front end - maybe Tent Labs 12Mhz oscillator (ordered, but not yet arrived) and re-implementation of DEM clocking driven off a buffered bitclock will restore things? Power supply is current sourced shunt regulator, so not that much improvement I can make there....
One things for certain though, having all your cds available at the touch of a button is the dogs danglies! |
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| dddac |
It is all about implementing it right.... did you also try PC, or only the mac ?
copied this from BD-Design Forum: interesting:
Hi all,
Being a Mac-user since 1987, and being owner of a pair of DIY Oris horns with AER MD1 drivers, I followed all topics about Mac vs Windows on this forum with more than normal interest. So when Bert asked if someone would like to come and compare, I thought it would be a nice reason to go to Bert, listen to his new things and compare my Mac to the Windows system Bert uses. Problem was that my Mac (Powerbook G4 titanium 400 MHz, 2001) does not support USB2.0, needed for the twindac. I bought a PCI card with 2 USB2.0 outputs (59 euro) to solve this little problem.
More things I arranged in advance: I downloaded the latest version of iTunes, made some space on the only 10 gig harddisk and ripped 3 CD's to AIFF format
Last friday I drove to Bert to compare. Bert's laptop had a broken USB port, so he ripped the CD's I took there on his Windos PC in a few minutes. We made the same playlist on both the Mac and the PC
and started listening to the PC. Not new for Bert, but I was surprised by the sound, being clear, transparant, with a wide and deep stage, things I can reach at home only with certain vinyl records.
after about 20 minutes we switched to the Mac. Soon we were sure that, although the sound was not bad at all, it did not reach the level of the PC. It sounded a bit dull, flat. Bert suggested to try an other format, so I put some tracks on the Mac in WAV format. Listening again. Although better than the AIFF format we still could hear the difference very well. The soundstage being not as wide and not as deep as the PC. You could hear less of the environment on the Mac, the voice of the singer comming from below in stead of from the middle, it missed the feeling of being there.
To make a real fair test we finaly put my PCI card in Bert's PC laptop, so this computer could be connected to the twindac. Listenig again made sure that the PCI card was not the bottleneck. It even sounded a little better than the PC we started with.
So, sorry for me and all other Mac-users:
Mac with iTunes does not sound as good as a WIndows PC configured the way Bert did.
The promblem seems to be that there is no way to configure the Mac/I tunes. Window-users can ajust the amount of memory used, overrule the volume adjustment and so on. On a Mac I at least am not able to. Maybe someone can write/program a Mac-application that lets you configure these things. (What you want in fact is a player that uses as much memory as possible and sends the digital data direct to the USB2.0 port without any interference). Maybe linux offers a possibility ?... |
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| Zodiac |
Haven't tried mac vs windows yet, but note the comparison wasn't apples to apples, as Foobar had some thing called noise shaping turned on:
I quote "Output format set to 16 bit fixed point with strong ATH noise shaping". If noise shaping is used by Foobar obviously this is not a straight comparison mac vs windows, maybe it's more Foobar vs iTunes...
http://www.bd-design.nl/forum/forum_entry.php?id=9603 |
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| 12 Cents |
| quote: | Originally posted by dddac
By the way, I just finished my set up for an audio server, streaming into the USB input :)
can be looked at at my site. look for banner dddac1543mk2 than in frame left click USB Server ....
or go straight with this link (no frames...)
USB Audio Server
doede |
BTW that album (Katie Melua - Piece By Piece), besides being beautiful music, seems very well recorded to me, but also overproduced, have you noticed the slight reverb on the esses (S-Laute in german), the sibilance IMO? |
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| Bas Horneman |
| I think so too..good recording it seems..but overproduced..that sums it up pretty good I think. |
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| Zodiac |
| quote: | Originally posted by Zodiac
After reading so many things about USB - it's amazing, the best thing since sliced bread, etc... I decided I should try it out for myself and compare against my base system to see whether it met it's reputation or whether, like most things in audio, it was a load of hot air. Music used was varied, ripped using Plextools and losslessly encoded. Music played off a Mac Mini
My base set up is Cyrus Diskmaster --> Benchmark DAC1 --> Active XO ---> Pass Labs Aleph3 / UCD 180 --> Linkwitz Orion
I built myself a USB-SPDIF converter using a PCM2706 (thanks to TI sample programme), powered off bus. Sound was long way behind Cyrus/Benchmark combination, bass 'one notey' to the point of being unlistenable and a very high audible noise floor. Positives, a bit more detail it seemed in med / high frequencies, but to be honest I couldn't listen to more than 15mins without switching the damn thing off.
Then I built a USB front end for my TDA1541 nonos dac (PCM2706 outputting straight I2S), which hitherto was using a CS8412 receiver with local clock, I2S reclocking based on Doede's original schematics and DEM clocking. When I was using this with the Cyrus I actually preferred it to the Benchmark. With the USB front end - first impressions are that bass 'one note' sound is completely removed, actually it is more chunky and rounded than that from the Cyrus/Benchmark. Also the high noise floor seems to be ameliorated, but it still seems higher than when fed by the Cyrus. There's more musicality and flow to the music, but less dynamics and less energy. Detail during busy patches seems slurred. Overall a less satisfying experience!
At this stage I can think of a few tweaks I can make to the USB front end - maybe Tent Labs 12Mhz oscillator (ordered, but not yet arrived) and re-implementation of DEM clocking driven off a buffered bitclock will restore things? Power supply is current sourced shunt regulator, so not that much improvement I can make there....
One things for certain though, having all your cds available at the touch of a button is the dogs danglies! |
Well, some progress to report...implemented DEM clocking off the PCM2706 MCLK and swapped out the standard TDA1541 for an S2
Impressions relative to Discmaster / Benchmark:
+ve's: bass more solid and defined, notes have more shape to them. More musical. Low level details not previously apparent now audible.
-ve's: not as transparent, reduced 'air'. higher noisefloor
I actually think the first -ve is related to the old multibit dac vs new deltasigma dac and not related to USB / SPDIF comparison...
All in all I actually prefer the computer as front end now (though the difference is NOT night and day as some would have you believe and my TDA1541 implementation is quite full on in terms of power supplies) !! So big step forward. Next steps are implementation of the 12mhz Tent clock (just waiting for a few bits from farnell). Anyone have any ideas about isolating the computer ground from the dac ground??? BB150's ?? |
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| summilux |
Boy, would I ever WANT this to work the best on a Mac. On my iTunes (6.02) under Preferences/Advanced I can disable the iTunes volume control and increase the streaming buffer, under Preferences/Playback I can also disable two "Sound Enhancers". Maybe this would help?
Jonathan |
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| velicko |
In the file dddac1543mk2ver50.pdf there are layers design for all three boards.
Does anybody have separated layers so I could build PCB-s myself.
If it is not problem, please do send me to velicko@gmail.com.
I could work it out in Photoshop, but it would save me much time if I could get separate pictures for all layers for all three boards.
Thanks much.
:) |
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| pburke |
| quote: | Originally posted by velicko
In the file dddac1543mk2ver50.pdf there are layers design for all three boards.
Does anybody have separated layers so I could build PCB-s myself.
If it is not problem, please do send me to velicko@gmail.com.
I could work it out in Photoshop, but it would save me much time if I could get separate pictures for all layers for all three boards.
Thanks much.
:) |
why don't you just buy a board? We're not talking about a $3000 Levinson product here. |
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| velicko |
| quote: | Originally posted by pburke
why don't you just buy a board? We're not talking about a $3000 Levinson product here. |
I do not live in EU, and I am tired of problems with customs.
For example:
Unfortunately, I ordered free samples from TI, and after few days samples arrived to customs.
I got package after few days, and after I paid more than 80 EUR just for custom expenses.
Maybe for "just PCB" it would be different, but I really do not want to go through all their complications... :(
Never mind, I'll clean the givven picture with photoshop.
Thanks anyway. |
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| fmak |
[QUOTE]Originally posted by velicko
[B]
I do not live in EU, and I am tired of problems with customs.
For example:
Unfortunately, I ordered free samples from TI, and after few days samples arrived to customs.
I got package after few days, and after I paid more than 80 EUR just for custom expenses.
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This is mostly due to the incomprehensive way in which US comapnies manage their postings; applies even to the EU!
If they just put samples in an evenelope with a declaration of neglible value, this would just get thru' the post. Instead, they use these expensive international mailers who actually charge for informing the tax authorities. Some even handle tax like they are part of government!
I am very cautious about ordering from N America. About 10% of the companies are sensible and use USPS which is perfectly good. |
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| pburke |
| quote: | Originally posted by velicko
I do not live in EU, and I am tired of problems with customs.
For example:
Unfortunately, I ordered free samples from TI, and after few days samples arrived to customs.
I got package after few days, and after I paid more than 80 EUR just for custom expenses.
Maybe for "just PCB" it would be different, but I really do not want to go through all their complications... :(
Never mind, I'll clean the givven picture with photoshop.
Thanks anyway. |
not sure what you are afraid of - Doede even sells his stuff for cash in an envelope, and I doubt he'll ever use something like FedEx or UPS that'll force the shipment thrugh silly customs channels.
Why don't you ask him? his DAC chips arrive in the US in a little cardboard box with a few stamps on them. I'm sure a PCB will fit into an even smaller envelope.
Peter |
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