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Twisted Pear Audio Opus DAC - Page 11

post #151 of 987
10/21/07 at 4:29am
MrMajestic2

Do you have pics?
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post #152 of 987
10/21/07 at 5:11am
Quote:
Originally Posted by fordgtlover View Post
MrMajestic2

Do you have pics?
Here it is, in a very temporary case. Its even complete with blutac and cardboard panel express backpanel I just ordered a much bigger case for it so I can have space for upgrades.

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post #153 of 987
10/21/07 at 6:20am
Thanks heaps This is very helpful.
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post #154 of 987
10/21/07 at 8:18am

Burning DAC pics

Here's a few pics of the one I just built for the Burning Amp festival (www.burningamp.com).







More pics of the build here: http://www.twistedpearaudio.com/user...y/_burning_dac

It is a dual mono dac with both USB and S/PDIF inputs (switched with a hand etched relay board), two ballsies (one with filters, one without, for comparisons) and the first build of the ASRC module (Metronome).
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post #155 of 987
10/21/07 at 8:39am
D@mn, that's nice!
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post #156 of 987
10/21/07 at 9:16am
Quote:
Originally Posted by BrianDonegan View Post
Here's a few pics of the one I just built for the Burning Amp festival (www.burningamp.com).

It is a dual mono dac with both USB and S/PDIF inputs (switched with a hand etched relay board), two ballsies (one with filters, one without, for comparisons) and the first build of the ASRC module (Metronome).
Thats beautiful Brian. Does the Ballsie to anything for the balanced output as well, besides passing it thru the filter? Also, can you give any specs on the ASRC module, Im dying to know more
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post #157 of 987
10/21/07 at 9:49am
It provides a current buffer for the balanced outs. Not really needed in controlled circumstances, when you know what's going to be connected to it. Also, the filtered Ballsie provides the 500kHz 6dB filter to both balanced and SE signals. Another reason to tap both balanced and SE from the ballsie (when used) would be for both to have the same output level, and also because it is easier.

Another note on wiring. I was doing some tests on the workbench last night, and found it's not too hard to get the I2S clock lines to induce noise in both power and analog signal lines. It's best to stack the I2S components, or keep them somewhat isolated, and keep clock lines as short as possible. In the pics above, I kept all the digital stuff to the left, analog on the right. If I had that one to do over again, I would have done two digital stacks and left more space between them and the Ballsies. It worked out fine this time, but will be more careful after last night's tests. Also, as always, best to make power wiring as straight and short as possible.
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post #158 of 987
10/21/07 at 10:16am
Brian wins the prize for both having the sexiest DAC I've seen in a long time and using it with the cheapest digital cable!

Very, very nice.
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post #159 of 987
10/21/07 at 10:35am
Very nice indeed...what case is that?
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post #160 of 987
10/21/07 at 10:51am
Thanks! Cheap wiring too. Mostly SPC (Newark) 24gauge stranded PVC wire I got on closeout. XLR wire is retwisted (to 3) cat5, and the rca coax is the center of a triple-shielded car audio cable I had laying around.

It's a Par-Metal 12x12x3 case with custom front and rear panels, and knob (all machined by my brother - that's why all the closeups of the switch and such in the photo library - part of our discussions).
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post #161 of 987
10/21/07 at 11:55am
Quote:
Originally Posted by BrianDonegan View Post
Thanks! Cheap wiring too. Mostly SPC (Newark) 24gauge stranded PVC wire I got on closeout. XLR wire is retwisted (to 3) cat5, and the rca coax is the center of a triple-shielded car audio cable I had laying around.

It's a Par-Metal 12x12x3 case with custom front and rear panels, and knob (all machined by my brother - that's why all the closeups of the switch and such in the photo library - part of our discussions).
Nicest Opus I've seen so far! The front panel is awesome, very clean.

Are you considering selling front panels?
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post #162 of 987
10/21/07 at 12:45pm
Quote:
Originally Posted by Clutz
No, because the DAC chip that they have used has both the oversampling filter and the DAC itself integrated into a single chip solution. In order to make use of a non-oversampling DAC, you need to use a DAC chip that doesn't have a digital filter integrated. To the best of my knowledge, all current DAC chips have the digital filters integrated, except maybe the AD1853?

Brad
Sigma delta DACs are by nature oversampling, it is the very principle on how they operate. AD1853 is a sigma delta DAC.

Some examples of non-oversampling DACs are AD1862, AD1865, TDA1541, TDA1543 and PCM56, PCM63.
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post #163 of 987
10/21/07 at 12:54pm
Quote:
Some examples of non-oversampling DACs are AD1862, AD1865, TDA1541, TDA1543 and PCM56, PCM63.
none of which are still available. Coincidence?
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post #164 of 987
10/21/07 at 2:08pm
Despite some current family affairs which take almost all my time from DIY,

I'm still studying all the options about the OPUS. I will be using the USB input.

Then I thought about the option of using the USB input module by itself and saving both the $ and the space of the extra module, PS an transformer, which is quite important as I will be sharing a place with other people soon and won't have much private space to have a big rig.

I will be using the DAC with a CK2III and what I am thinking is how much better will the extra $ and space sound when paired with the CK2.

I know all the yadayada about only subjectivity of sound and only me being able to judge if it is worth it. I am looking for your experiences and opinions.

Also, if anyone compared both, how does the USB module form Twisted compare with the Alien DAC?

If using the SUB module alone I could put it in the same enclosure as the Amp thus saving more space and $
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post #165 of 987
10/21/07 at 2:12pm
The DAC you built, Brian, is very pretty. Props to your brother for the panels.

I think the USB module is similar to the Alien DAC in that it will be 16-bit still.

How about an FPGA for USB?
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