Experience with this DIY DAC ?

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Bill Fuss

RIP
Joined 2005
WDYSUN said:
I don't get this. If you set M2 and M3 on 1 it should upsample the digital stream.



what's PS3?


I am not sure I got your replay. I think I was asking a different question. My question is about the upsampling frequency.

When the upsampler board is installed, does the gigaworks always upsample at the same frequency? Which one? The quartz on the upsampler board has a frequency which is a multiple of 48KHz so I guess that either it upsamples to 96KHz or to 192Khz. I wonder whether the upsampling frequency is fixed or it rather depends on the input signal.

Cheers
Pietro
Click to expand...

Hi all,
The 8421 is configured to upsample to 192 from any sample rate.
 
noSmoking

noSmoking

Member
Joined 2010
difference between new blue board and old red BIG dac?

Hi All,
I am looking to buy the new 2010 blue board from Ebay:), but I am new to DAC"s but learning fast thanks to all the great posts!!!!!
So what do you think of the new blue big dac board good investment and sound after mods discussed here?
use his R transformer or a E-I type ?:confused:
Could anyone give me a list as what to modify on this board, I am reading but you have had more time to listen than me!!!! and these pages are growing,LOL


Thanks ahead of time!!!!!:eek:
 
S

sendler

Member
Joined 2004
mysite.verizon.net/vze4c5pt/id2.html
Pass

gabanyayaya said:
Been reading and searching all I/V board possibly to used with PCM1794 chip and there's plenty of them..unfortunately all of it use opamp for single end and discrete for balance differentiate output....is there a full discrete circuit for SE out there..????
Click to expand...

Pass just presented an article about his open source I/V.
 
J

jrockhead

Member
Joined 2006
WDYSUN said:
I don't get this. If you set M2 and M3 on 1 it should upsample the digital stream.

Whats not to get? With the upsampling board installed this is how it processes the higher sample rates.I did not try M2 and M3 in the 1 position without the upsample board so I don't know what will happen.

I did play with M0 and M1 in various positions but the DAC would only work in the I2S mode. It has to do with what edge the data is decoded on.


what's PS3?

Playstation3 from Sony.


I am not sure I got your reply. I think I was asking a different question. My question is about the upsampling frequency.

I am answering your question. You asked what frequency the DAC is sampling at and I told you how to find out.

When the upsampler board is installed, does the gigaworks always upsample at the same frequency?

No.


Which one? The one that the source is sending to the DAC.


The quartz on the upsampler board has a frequency which is a multiple of 48KHz so I guess that either it upsamples to 96KHz or to 192Khz.

Like I said the DAC samples at whatever the source is sending to it. With my PS3 with different settings I can send either 44Khz. 48Khz. or 176.4Khz. without changing any switches on the DAC.

I wonder whether the upsampling frequency is fixed or it rather depends on the input signal.

No, Yes.

Cheers
Pietro
Click to expand...

Cheers to you also Pietro
 
B

Bill Fuss

RIP
Joined 2005
Usually it's the Chinese stealing other's designs, now they are afraid we are stealing theirs. Decware has started buying these dac boards, packaging them in a cheesy case and selling them for $875 in the US.

There are some questionable areas on them but overall they are a great buy and pretty good quality. The latest version looks to be the same as the old ones except for a few component values.

We all have the manuals so if you want the schematic just email me or someone else.
 
B

Bill Fuss

RIP
Joined 2005
Yeah, I've been following that too, looks quite interesting. I would think you would need to decide which dac chip you want to use, then start asking questions. It is hard to get a grasp of how a dac chip output can be fed into what is basically a virtual ground and get an output out of it, but it apparently works very well.

I used an output circuit somewhat similar, designed by Spencer, a forum member, in a Rotel player with PCM63s. It was a big step up from opamps. I'll see if I still have the documentation.
 
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G

gabanyayaya

Member
Joined 2008
Bill Fuss said:
Yeah, I've been following that too, looks quite interesting. I would think you would need to decide which dac chip you want to use, then start asking questions. It is hard to get a grasp of how a dac chip output can be fed into what is basically a virtual ground and get an output out of it, but it apparently works very well.

I used an output circuit somewhat similar, designed by Spencer, a forum member, in a Rotel player with PCM63s. It was a big step up from opamps. I'll see if I still have the documentation.
Click to expand...

I was told the 1794 works well with output traffos and tested just like in the K&K audio website. I works....!!!

But speaking of doing thing in proper manner, an I/V to a buffer is the best way.

I would love to see the output circuit Bill.
 
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