There will be two AES/Spdif inputs:
1: Balanced into LVDS Receiver, can be connected directly to transformer and can be run single ended for SPDIF Coax, just a capacitor and two resistors needed when single ended 75R. To keep it isolated I recommend to always use a transformer for AES Balanced and SPDIF Single Ended inputs.
2: 3.3V CMOS level input, can be connected directly to SPDIF Optical Toslink receiver.
There will be example schematics in the manual.
Selection between I2S and AES/SPDIF sources can be automatic or manual with two pins that can be connected directly to a control switch. For more sources you can also just switch the inputs.
Those PCB mount Talemas are also available from Digikey in the U.S., for example:
70040K Talema Group LLC | 1295-1040-ND | DigiKey
Hi Søren.
I'm not going to be a first wave adopter but I'm developing plans to use two of your DAC boards in the near future.
My plan is to use the forthcoming digital crossover filter option offered by your boards so I will have one Soekris DAC board per channel (L & R), using one side of each board for bass and the other for mid/treble. Using this configuration is there a possibility of the L & R DAC boards getting out of sync. because of their completely separate reclocker sections.
Thanks
Ray
I'm not going to be a first wave adopter but I'm developing plans to use two of your DAC boards in the near future.
My plan is to use the forthcoming digital crossover filter option offered by your boards so I will have one Soekris DAC board per channel (L & R), using one side of each board for bass and the other for mid/treble. Using this configuration is there a possibility of the L & R DAC boards getting out of sync. because of their completely separate reclocker sections.
Thanks
Ray
I don't always read carefully, so please forgive my ignorance if this was mentioned prominently somewhere else, what forthcoming digital crossover filter option ?
Thanks.
Hi Palmito, check out this article (digital crossover reference is towards the end);
https://hifiduino.wordpress.com/2014/10/12/r2r-for-the-rest-of-us/
Ray
No problem, but note the question about sync'ing that I posed...
May be a non-issue but worth checking.
Ray
Thanks Soren,
May an experienced member testimonie if these ref are good enough please ?
SE spidf pulse transformer : PE-65612NL Pulse Electronics Corporation | 553-1580-5-ND | DigiKey
or a Newava S22083 Newava Technology Inc | 470-1003-ND | DigiKey
May an experienced member testimonie if these ref are good enough please ?
SE spidf pulse transformer : PE-65612NL Pulse Electronics Corporation | 553-1580-5-ND | DigiKey
or a Newava S22083 Newava Technology Inc | 470-1003-ND | DigiKey
As these DAC board contain both reclocking and isolation I would recommend toslink as the preferred way of connecting the source if possible.
This provides the advantage of galvanic separation between the units which means that a foul earth on the source would not contaminate the DAC.
Transfer limit is however typically 24/96 and no higher fs...
384=USB?
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This provides the advantage of galvanic separation between the units which means that a foul earth on the source would not contaminate the DAC.
Transfer limit is however typically 24/96 and no higher fs...
384=USB?
//
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First firmware release will NOT support digital crossovers, although there will be 14 available biquads, already tested in order to support de-emphasis on SPDIF inputs.
As somebody already noted, there is issue of syncronization.... I have a couple of ideas how to connect multiple boards together, but I don't have time to implement and test before shipping the first batch.
But as I already said, all firmware on the board is upgradable though a std PC serial port, I will implement it soon as my big speakers are already designed for electronic crossover use....
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I don't really have much opinion on trafos, just got a couple of Murata DA101C, planning to test those tonight, I should hopefully get 192 Ksps though those. The used AES/SPDIF digital receiver core should support 192 Ksps, but I couldn't get more than 96 Ksps using Toslink, but that's probably due to the receiver, didn't look that sharp on the scope....
Thanks Søren, I'm in the early stages of planning a multi-Soekris implementation with digital crossovers so I'll await your developments around digital crossovers and sync'ing multiple dacs.
Ray
The DA101C seem to be widely used in commercial and DIY projects.
At least one user how has tested and said the DA101C is "good, not junk".
http://www.diyaudio.com/forums/digital-line-level/165978-s-pdif-input-transformer.html#post2172094
TwistedPear use them on their SPDIF boards for the Buffalo II and III for example.
The fact that they are cheap, and that Farnell/Element14 has 100's in stock, makes them an attractive choice.
cheers
Paul
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I bought 4 of these because I was told here it would be possible to use them together in a multichannel configuration so I hope it doesn't take too long to get that information sorted out...Thanks....
Yes, as Soekris advised above, an isolation transformer is better than without, also with the isolated entries of the DAC.
In this particular case and not talking of the level of upsampling frequencies, I would advise more a passive traffo than the Tolinsk because the active devices which translate the signal in pulsed light are most of the time a source of crap despite the isolation it provides ! Could it be local ground loop, etc ? I don't know but many listeners can listen to it when he has the choice on the same device between spidf and toslink
At least this is my understanding and experience.
I asked for spidf mainly because I'm Squeezeboxed and twrak it with true 75 ohms plugs and wire. But this Squeezebox allows also toslink, but before a prove of concept if me, I will choose spidf first !
two cents,
in any case USB rreaders allows more than 96 Khz upsampling... if you have such materials in your own library of if your oversample red book with your computer on the fly before sending it to the USB streamer !
We clearly lack clear testimonials about respective advantages between this two ways !
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That's not what I said, as "datas" is not the word because both are bit perfect in regards to datas and stay time multiplexed (not frequency multiplexed). I'm just saying than the devices at each side of a tolinsk signal are not good and it's well known : often a spidf sounds better than a tolinsk. Is it because active devices, local ground loop, decoupling caps of the local devices (often a LT chip), impedance, I don't know the origin, but many diyers tested it and many have choosen spidf for a long time over tolinsk !
As here there is an isolation circuit in the Soekris'Dac: I really don't know in the particular case of Soekris DAC, but for sure you will not find a better result with the toslink on the spidf, that's what I wanted to say... At minimun it should be worst and at maximum will give you the same result than spidf ! If your device has just a tolinsk, well it's an other story !
As here there is an isolation circuit in the Soekris'Dac: I really don't know in the particular case of Soekris DAC, but for sure you will not find a better result with the toslink on the spidf, that's what I wanted to say... At minimun it should be worst and at maximum will give you the same result than spidf ! If your device has just a tolinsk, well it's an other story !
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