gommer
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Post by gommer on Jan 4, 2015 19:11:38 GMT
Hi Javier,
In your last post you recommend adding an isolator to the Amanero board. I'm wondering if these isolators might add extra jitter to the I2S master clock that could be worse than not having galvanic isolation on the digital lines?
Cheers, Marc
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Javier
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Post by Javier on Jan 4, 2015 19:47:18 GMT
Indeed they do Marc! but the Buffalo doesn't use the master clock from the Amanero anyway, it uses its own 100MHz XO to async reclock incoming signals as most ES9018 based DACs do so no probs whatsoever. Even my (very) modest 9023 based DAC does the same but with slower 50MHz XO. BTW, I have the isolator I linked between my Amanero board and the DAC thanks to Dave's generosity.
Worse case scenario, where you want to run sync'ed XOs from the DAC, the Amanero board can be configured as a salve to the DAC's XOs and that way jitter also become's a non issue when going through the isolator.
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Post by drumdrym on Jan 4, 2015 23:40:56 GMT
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solderdude
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Post by solderdude on Jan 5, 2015 21:04:42 GMT
The USB isolators have the limitation of 24/96. I suspect (don't know for sure) that the one behind the Amanero board can go a lot higher in resolution (bit-sample rate).
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solderdude
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Post by solderdude on Jan 5, 2015 21:23:35 GMT
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Javier
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Post by Javier on Jan 5, 2015 21:25:42 GMT
Your are correct, the isoltaors used in these adapters are not in the USB path but behind the decoder inserted in the I2S/DSD lines so the limitation is max. Mbps and there are plenty 150Mbps chips available Like TI's ISO7640FM, ISO7240M, NVE IL715E, ADUM3440, SI8640, SI8645, etc.
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Post by chinook9 on Jan 6, 2015 5:15:25 GMT
Thank you all for your input.
Given that I don't want to try and solder the tiny parts on the free DIYINHK PCB I expect I should give up on the Amanero and go with the Isolated XMOS DSD DXD 384kHz high-quality USB to I2S/DSD.
Javier, do you know of a ventilated Hammond enclosure that would provide plenty of room and ventilation for the BIIISE? I have found a couple that might work but ventilation was poor. I would prefer to be able to do the build on an aluminum sheet that can be mounted inside the enclosure after the building and testing is complete. Does this make sense?
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Javier
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Post by Javier on Jan 6, 2015 9:42:08 GMT
Here is an image of a very tidy Buffalo build that can give you some idea of the proyect scope: another: Plenty more at Twistedpear's forum (registration is necessary to see most images, it is free): twistedpearaudio.com/forum/yaf_topics12_Project-Gallery.aspxMost people use enclosures from these people: www.modushop.biz/ecommerce/index_l2.phpThey are Italian very high quality aluminium cases and can be, at a cost, very nicely customized. Bear in mind a rather big enclosure is needed, probably of at least the same size of a regular standalone CD player.
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solderdude
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Post by solderdude on Jan 6, 2015 13:45:42 GMT
And just now this comes crawling out of the woodwork: www.prettygoodsoftware.net/DIY/VeritasFlyer.pdfcompletely built PCB with everything already on it (better than loose PCB's) for around $ 600.- Only needs a case, trafo's and connectors.
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Javier
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Post by Javier on Jan 6, 2015 15:46:29 GMT
Looks nice, shame he didn't use the AK4490 instead of the AK4495 which has 19dB lower THD+N than the Buffalo's ES9018 (120dB Vs 101dB). I'd say it should be far easier to build and should have very good performance but IMO the Buffalo is way more flexible when it comes to configuring and has even better numbers, horses for courses. Can't find any info other than the PDF, do you know if it has an onboard a uController or an I2C input header for adding one? In hardware mode the AKM can't do DSD, only PCM. The uC also enables playing with internal filters, digital volume and many other interesting functions.
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solderdude
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Post by solderdude on Jan 6, 2015 16:20:50 GMT
Its still in development. here there is some prelim info: changstar threadThis DAC part starts about at the bottom of page 6, everything before it is about the smaller DAC All the different filter settings etc. can be selected as well as other functions.
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Post by chinook9 on Jan 6, 2015 19:03:07 GMT
The new JLSounds DAC looks very interesting. I will check out the changestar thread and follow its progress.
Initially I will not plan on buying a commercial enclosure. I have access to a sheet metal shop so I will plan on building two a temporary working platform to use for the build and testing. It will be a simple platform with no sides or top. I'll take a sheet of aluminum and bend it so I have a front and a back only leaving around 35cm x 40cm working area for the installation of components. I'll do some checking to confirm the 35 x 40 size will work. Later, if everything goes well I'll either buy or build a better permanent enclosure.
I now have to go through the Extended Bill of Materials in the Buffalo III Integration and figure out what else I need to order. Any recommendations would be appreciated.
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Javier
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Post by Javier on Jan 6, 2015 21:33:08 GMT
Do you have basic stuff like soldering iron, nice soldering wire (1mm or .5mm), desoldering pump, small screw drivers, different colour wires, loupe/magnifying glass, etc.?
Setting up the BIII is a piece of cake. The 3 Tridents and AVCC boards snap in on the DAC board, this in turn snaps in on top of the IVY and then you have to wire the single Placid HD (5.5V) to the 5.5V input of the DAC and the Placid HD BP (Bipolar) to the +15/-15V inputs. Up to this point no soldering is required, just a screw driver. Next would be wiring the outputs to either RCA (Single Ended) or XLRs (Balanced) or even both should you want to, The wires are screwed to the terminals of the IVY so no soldering required there but probably the RCA or the XLR females will need soldering the wires to them. Next is the inputs, if you want SPDIF you could start by soldering a couple of wires (twisted) from the DAC board to an RCA female connector. For USB it really depends on the adaptaer you get, if it has uFL connectors it'll be a walk in the park because you just snap the uFL cables in place on each side, if it doesn't you'll need to do some soldering.
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Post by chinook9 on Jan 7, 2015 6:47:41 GMT
I have a soldering station and all the basics. Actually I'm pretty adequate at soldering and I have done some desoldering.
I will come up with questions concerning the specific supplies I need such as types and sizes of wire.
I have sent an e-mail to WaveIO, DIYINHK, and JLSounds to check on availability of boards with express shipping. I don't want to wait 2-3 weeks to receive the board.
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Post by chinook9 on Jan 8, 2015 15:47:06 GMT
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