[MASantos]

Quote:

Originally Posted by doctorkelsey i am SURE this has been discussed but I dont know how to search within a single thread and 30 pages is too much to look through , so here is my question: How much current does the alien draw from batteries? thanks a bunch!

Well I'm not going to answer your answer but I'll help:

go to TI's website and search for the PCM2702 and the both reg's. Download the datasheet and read it. You should find the current draw of each of the IC's. Be sure to also check the DAC's website to check which other IC's and components draw current with you desired configuration. THe overall current draw should be equal to the sum of all the current draws of different IC's.

One of the most rewarding aspects of DIY is learning this kind of stuff. At least for me and that's what I learned with other DIY headfiers.

Manuel

 

[splaz]

There I was naively thinking that my wallet had gotten a well deserved break.

 

[doctorkelsey]

Quote:

Originally Posted by MASantos Well I'm not going to answer your answer but I'll help: go to TI's website and search for the PCM2702 and the both reg's. Download the datasheet and read it. You should find the current draw of each of the IC's. Be sure to also check the DAC's website to check which other IC's and components draw current with you desired configuration. THe overall current draw should be equal to the sum of all the current draws of different IC's. One of the most rewarding aspects of DIY is learning this kind of stuff. At least for me and that's what I learned with other DIY headfiers. Manuel

Thanks Manuel,

Got it. It looks to be around 30 mA or so! Can't wait to build one... or five.

 

[robzy]

Hi guys,

Im sorry for coming into the thread so late with a very noob question, im not after a very indepth answer, just a quick overview (one or two lines will do me ):

How does this differ from the original guzzler DAC? What improvements have been made?

Rob.

 

[MisterX]

Quote:

Originally Posted by robzy How does this differ from the original guzzler DAC? What improvements have been made?

http://www.myexposition.com/diy/usbdac/overview.html

 

[theexec]

Lets have an Australian group buy for the parts

I'm a newbie, so not sure where to source parts in Australia, jaycar doesn't seem to have the rarer parts... and I saw that digikey shipping is very expensive for less than 1lb of components. If we group buy say 1lb of component and just send it around by aust post it'll save us heaps

 

[robzy]

MisterX: Thanks for the links (shoulda thought of looking there first, RTFM rob). Would i be correct in stating that RevB consists of an upgrade to its PSU, as well as a better layout of parts?

Quote:

Originally Posted by theexec Lets have an Australian group buy for the parts

Sounds like a very good idea to me! We should get in contact with some other Australians too.

Rob.

 

[splaz]

Well I may be building 1 or 2. Probably a USB one then some sort of battery powered one.

Unlike a certain someone I don't feel the need to purchase 10 boards...

RS components might and Farnell definitely stock parts according to Alf. Of course there may be slight differences in stock with their Australian counterparts.

Unless digikey or mouser or whoever else is significantly cheaper a group buy might not be needed. Although it could be cheaper even after shipping. BUF634 as an example are atleast double the price over here as compared to America and Asia.

 

[MASantos]

Quote:

Originally Posted by robzy MisterX: Thanks for the links (shoulda thought of looking there first, RTFM rob). Would i be correct in stating that RevB consists of an upgrade to its PSU, as well as a better layout of parts? Sounds like a very good idea to me! We should get in contact with some other Australians too. Rob.

The layout around the pcm2702 was improved, the dac can be powered from an amp. Ps filtering was inproved, board size was optimised to fit the smallest 1455 hammond enclosure. I think that was it!

 

[Alf]

Quote:

Originally Posted by splaz BUF634 as an example are atleast double the price over here as compared to America and Asia.

The board also accepts OPA551, which tends to be cheaper and easier to find.

 

[splaz]

I have some SO8 BUF634 already. Just noting that they're a tad expensive here.
I didn't mean to actually say I'd buy from America/Asia just for them. Just using them as an example of how expensive some parts can be over here.

 

[NeilR]

Hmmm... I'm looking at the footprint of the Hammond 1455C cases and looking at the board, which is 2" wide, and the USB jack, which has to be flush with the back panel, putting the board against the back panel, and that huge 1" (maybe) left on the panel and thinking about where I'm going to put a pair of RCA jacks. Never having worked with this case before, maybe I'm missing something. I'm curious what others are doing for output jacks and their rear panel layouts.

Edit: the way I see it, there is only about 5/8" clear space between the side wall and C23 for any additional jacks...

 

[robzy]

As was being discussed in a thread i created about output caps for the Alien DAC: Is there any reason i cant hook up ground on my output RCA jacks to Vcom on the PCM2702 and forget about output caps?

Assuming there is only 1-2mV of dc offset from vcom im sure my Dynalo (Gain ~6) will be able to handle it.

Thanks,
Rob.

 

[Alf]

Quote:

Originally Posted by robzy As was being discussed in a thread i created about output caps for the Alien DAC: Is there any reason i cant hook up ground on my output RCA jacks to Vcom on the PCM2702 and forget about output caps? Assuming there is only 1-2mV of dc offset from vcom im sure my Dynalo (Gain ~6) will be able to handle it. Thanks, Rob.

I have 18.6mV and 13.1mV dc offset relative to vcom.

 

[robzy]

Quote:

Originally Posted by Alf I have 18.6mV and 13.1mV dc offset relative to vcom.

Well..... there goes that idea. Methinks ill just splurge on some nice caps then.

[edit]: Shoulda said thanks for doing the measurements. Thanks muchly, 'tis apreciated

[edit2]: I do realise that while this is an awesome DAC it might not warrant fancy-ish caps, but i cant resist.

Rob.