[whiz]

Quote:

Originally Posted by robzy Hrm, to be honest im not sure whether you are joking here or not

looooooooool!

NO WAY you believed that!!! 1 Farad cap is like a bottle of water! i can't image having this for portable use even if it was the perfect cap! (useful though for other needs in car audio)

am i offtopic?!?!

 

[doobooloo]

Quote:

Originally Posted by whiz NO WAY you believed that!!! 1 Farad cap is like a bottle of water! i can't image having this for portable use even if it was the perfect cap! (useful though for other needs in car audio) am i offtopic?!?!

Yes, he could have very well believed that because very small >1F capacitors do exist...

Click here for some available on Digi-Key: http://dkc3.digikey.com/PDF/T062/1091.pdf

You can get a 70F (seventy!) capacitor, its dimensions are only 18mm x 50mm.

 

[Alf]

Quote:

Originally Posted by whiz 3)so many people made that board...why don't you use RMAA to see the results in papers? perfection might be not audiable to our ears due to imperfection, but no one cares to test it and upload some diagrams? except Alf and maybe 1-2 more? if i had the board i'd definitly do it!

The link has been posted earlier in the thread V1.0 vs Rev B

 

[whiz]

Quote:

Originally Posted by doobooloo Yes, he could have very well believed that because very small >1F capacitors do exist... Click here for some available on Digi-Key: http://dkc3.digikey.com/PDF/T062/1091.pdf You can get a 70F (seventy!) capacitor, its dimensions are only 18mm x 50mm.

Nice dooboolooo! you've right! they are known but rearly used...so i forgot them!

 

[doobooloo]

Quote:

Originally Posted by whiz Nice dooboolooo! you've right! they are known but rearly used...so i forgot them!

I wonder if they'll be any better than putting a battery in the signal path, though...

 

[whiz]

I hope someone can answer this...
i understand that the crystal loading capacitors keep the crystal
to the frequency we want. What happens if the loading capacitors
aren't the correct value? what are the consequences to the operation of the alien dac?

I'm talking about "frequency pullability"

Thanks!

 

[whiz]

Quote:

Originally Posted by whiz I hope someone can answer this... i understand that the crystal loading capacitors keep the crystal to the frequency we want. What happens if the loading capacitors aren't the correct value? what are the consequences to the operation of the alien dac? I'm talking about "frequency pullability" Thanks!

anyone kindly enough to answer my question please?

 

[dakotart1984]

Still off topic whiz, but commonly higher value caps are seen common, one typical example is in the original xbox, in wich i believe it holds "cmos" type settings. More specifically its a 2.5v 1F Powerstor cap, wire a few of them in parallel and you can make some neat projects. I recall this link I read on hackaday.. http://www.hackaday.com/2005/12/06/supercap-9v-battery/

 

[stevodude]

Woot, got pcb's,

Not sure if this should be posted here, but trying to organise a bom for australia supplier.

Farnel au does't seem to stock the pcm2702e's neither does Radio Spares in au...

or is there an equivalent I can get here in this backwater place called australia...

I wouldn't mind ordering from a maximum of 2 suppliers, but so far I can't find 1 that stocks the dac, which is the main component I need, neither the REG101UA-3.3 or REG102UA-5, or the buf634 ( which I will probably have to build a custom buffer anyway, so thats not a worry).

cheers, stevodude.

 

[Andrew*Debbie]

Quote:

Originally Posted by guzzler /img/forum/go_quote.gif C1 doesn't really have an optimum value unless you calculate all the parameters for the filters and coupling to USB line, 1uF will do fine.

Why is a C1 a high capacitance ceramic? ESR is kinda high at frequencies over 100MHz for a typical one.

Would a low value high frequency part be better here? One that has low ESR up to at least 1GHz. I'm thinking about using something like a muRata ERB21 or GQM21 at 50-100pF.

My 'scope only has a 60MHz bandwidth, so I have no idea what kind of high frequency noise is on the USB power lines.


ERB ESR graph

 

[picklgreen]

What other DAC chips is the Alien DAC compatible with? I am curious if there are benefits from using any of the other PCM270x family chips.

Nevermind..I see the pinouts are all different.

 

[cutun1217]

hi everybody, im new in this forum. i want to ask whether i have any chance to get this board or do u guy have to eagle file or board layout so i can etch the PCB for myself?
thanks so much.

 

[GregVDS]

Hello,

I would like to know if the alien dac is working under mac os x? Is there something to instal, like asio driver or something else, or everything is recognized without any problem, or full incompatibility?

Many thanks,

GregVDS

 

[achina]

With at least 10.3 and 10.4 it is plug and play. Shows up as an additional sound device. Haven't tried it with anything older.

 

[GregVDS]

Thanks, I should definitely try to build this one. I plan to use is as source for a SOHA I already finished (with crossfeed, custom built output buffers and Epsilon12 protection). Can I simply join the outputs of the Alien DAC to the RCA inputs of the amp, without fussing with input switch, or the Alien DAC will have a bad influence when not used on the RCA signal? I mean the CL/CR could play for both system, right? I don't remember if the SOHA has DC input protection, I should check that. What is the best choice for CR/CL (discussed at libitum, I know, but a resumé of all the thread would be nice) if I have to put them in? As I understand, the Alien DAC is producing DC offset that has to be blocked, internally, or by the amp, right?

I never soldered SMD, but am reading all tutorials available. Is it ok to go unregulated USB power? What should I expect in comparison with the stock headphone output of my Macbook (sound quality point of view, apart from the SOHA influence)?

All the very best,

GregVDS