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Old 4th April 2011, 03:10 PM   #251
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Thanks exa065.

I am on your waiting list!
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Old 4th April 2011, 03:30 PM   #252
Bunpei is offline Bunpei  Japan
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Originally Posted by exa065 View Post
May I kindly ask you to allow me to handle the support questions for exaU2I myself?
As a vendor offering a competing device obviously you have a conflict of interest when you post here. I've been restraining myself from using the SD card player discussion thread as a platform for publicity for exaU2I. These forums are created for the benefit of the genuine DIY users and we as vendors have the responsibility to respect each-other's boundaries.
Oh, I'm sorry. I will withdraw from this thread.

I just wanted to promote 352.8 kHz/24 bit play and the use of I2S and to help people not to get involved in known problems.
You are a commercial vendor while ours is just a diy project as a hobby.
I misunderstood that this thread is left for diy people and you have already created another thread in a verdor area.

I'm sorry again.

Last edited by Bunpei; 4th April 2011 at 03:33 PM.
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Old 4th April 2011, 03:57 PM   #253
AR2 is offline AR2  United States
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I was just wondering if anyone uses exa device as a crossover for multiway stereo? If yes, than what software are you using / planning to use? I am currently using Allocator which is really great software, but requires input / output loop and I am not sure how that would work with exa device. Allocator uses ASIO drivers, does exceptional job but requires to export signal from output to input, and in my case that is SPIDIF in out loop. So maybe the question is if there is a possibility to create loop with exa device? If not, is it possible to create it on the software level?
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Last edited by AR2; 4th April 2011 at 04:00 PM.
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Old 4th April 2011, 04:02 PM   #254
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I am planning to use convolver VST with cPlay. For other program, we can use Console as a host as well
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Old 4th April 2011, 10:27 PM   #255
rsdio is offline rsdio  United States
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Originally Posted by soundcheck View Post
3. SPDIF or USB

Doesn't matter what I tried. I could not find any device which decouples
propery from the PC side. Let me know if there's an interface out there.

I used to use an USB-reclocker from EC-Designs btw.

It's a myth that asynchronous USB is the holy grail of slaving/decoupling a transport.

Slightest variations on the PC will have an impact on the output. You can find tons of info and experiences about it on AA and elsewhere.
Personally, of all the computer DAC hardware that I own, FireWire interfaces are preferred. I own a few USB DACs, but they were all purchased for comparison and are not really used in critical listening setups.

But, again, if you are using a USB-reclocker then you are misunderstanding the proper solution. Reclocking is different technology than having the DAC run as master clock. USB-Audio offers too many options, I suppose, because this should not be so confusing.

As for FireWire, I am interested in designing a proper FireWire DAC, perhaps with I2S output for maximum DIY options. Unfortunately, where USB offers free documentation, cheap chips, free software libraries, and more community experience; FireWire documentation is more expensive than building your own board, chips typically cost a little more, software libraries seem to be nonexistent, and I do not know of anyone in the DIY community who has developed a FireWire solution.

I suppose there's no guarantee that FireWire would automatically perform better than USB, but the commercial products that I have compared definitely put FireWire at the top. At the very least, I would like to see DIY options using FireWire technology, especially with brand new FireWire products being announced this year such as: Sonic State - News WNAMM11: FireWire DSP Accelerators For UAD-2, UAD-2 Satellite DUO and QUAD allow plug in and play operation on Macs - no PCIe card required
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Old 4th April 2011, 10:37 PM   #256
rsdio is offline rsdio  United States
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Originally Posted by Bunpei View Post
One concern is there is no volume function in exaU2I nor miniAMP.
You need to use digital volume function in your player program on PC.
That is not the only option. A product such as one of the Goldpoint level controls would allow you to run your DAC at full bit-depth quality, and then reduce the volume with precision, low-noise attenuators. See Goldpoint Level Controls

Also, if you want digitally-controlled volume instead of a manual control, then the exaU2I is the wrong place for the technology. Even if the exaU2I incorporated a digital volume function, it would be equivalent to using your player program volume. That's because the exaU2I is ahead of the DAC in the digital domain only, but quality attenuation should be placed after the DAC in the analog domain. In other words, if you need digital-controlled volume, then you should select an I2S DAC board that offers that feature, and then connect it to the exaU2I.

Granted, the one weak link is how to communicate between the PC and the digital potentiometer circuit, since the exaU2I only passes audio samples and not control messages. A full USB-Audio implementation would allow the PC to control volume via Audio Control Parameter Block USB messages, out-of-band from the audio stream. But this would require a totally different product design.
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Old 5th April 2011, 12:21 AM   #257
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Originally Posted by rsdio View Post
That is not the only option. A product such as one of the Goldpoint level controls would allow you to run your DAC at full bit-depth quality, and then reduce the volume with precision, low-noise attenuators. See Goldpoint Level Controls

Also, if you want digitally-controlled volume instead of a manual control, then the exaU2I is the wrong place for the technology. Even if the exaU2I incorporated a digital volume function, it would be equivalent to using your player program volume. That's because the exaU2I is ahead of the DAC in the digital domain only, but quality attenuation should be placed after the DAC in the analog domain. In other words, if you need digital-controlled volume, then you should select an I2S DAC board that offers that feature, and then connect it to the exaU2I.

Granted, the one weak link is how to communicate between the PC and the digital potentiometer circuit, since the exaU2I only passes audio samples and not control messages. A full USB-Audio implementation would allow the PC to control volume via Audio Control Parameter Block USB messages, out-of-band from the audio stream. But this would require a totally different product design.

I could not agree more than what you explained particularly when it comes to volume control. It is certainly very simple digital implementation of volume on the DAC like Sabre and makes life much easier for anyone with multichannel set ups, but it could never compare to analog version of the same. The price for analog version is much higher than digital version, but quality is there, particularly when you have to dramatically turn your volume down.
Also, FW is the best, but unfortunately as you described not for DIY. Do you have any knowledge if LightPipe / Thunderbolt is going to be friendlier when it comes to DIY? FW is from Apple, and later belongs to Intel, so maybe that will give some more room for DIY?
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Old 5th April 2011, 01:12 AM   #258
rsdio is offline rsdio  United States
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Also, FW is the best, but unfortunately as you described not for DIY. Do you have any knowledge if LightPipe / Thunderbolt is going to be friendlier when it comes to DIY? FW is from Apple, and later belongs to Intel, so maybe that will give some more room for DIY?
Maybe we can start another thread for DIY FW.

FireWire itself is Apple's branding of IEEE 1394, it is not exclusively 'from' them or Intel. Sony and Texas Instruments also have compatible brand names for the same technology. Texas Instruments makes IEEE 1394a chips such as the TSB41AB2 and TSB12LV32 available without Apple's involvement.

I would be highly suspicious of the feasibility of building a LightPipe / Thunderbolt audio interface in the DIY world before anyone has launched a successful product in the commercial world. It would be much cheaper to leverage existing, proven technology that is a few generations old, and where the chip market has at least some competition on price and established engineering experience. FireWire 400 is capable of at least 54 bidirectional audio channels, or 108 channels at 96 kHz. Existing commercial product implementations have 48 channels at 192 kHz, so there is certainly no need to look to new interfaces that are any faster than FireWire 800, which should support 48 channels at 384 kHz.
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Old 5th April 2011, 01:41 AM   #259
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Maybe we can start another thread for DIY FW.

FireWire itself is Apple's branding of IEEE 1394, it is not exclusively 'from' them or Intel. Sony and Texas Instruments also have compatible brand names for the same technology. Texas Instruments makes IEEE 1394a chips such as the TSB41AB2 and TSB12LV32 available without Apple's involvement.

I would be highly suspicious of the feasibility of building a LightPipe / Thunderbolt audio interface in the DIY world before anyone has launched a successful product in the commercial world. It would be much cheaper to leverage existing, proven technology that is a few generations old, and where the chip market has at least some competition on price and established engineering experience. FireWire 400 is capable of at least 54 bidirectional audio channels, or 108 channels at 96 kHz. Existing commercial product implementations have 48 channels at 192 kHz, so there is certainly no need to look to new interfaces that are any faster than FireWire 800, which should support 48 channels at 384 kHz.
Yes I do agree with all points, but I think, it is just a matter of time to see all kinds of implementations since LP/Thund. is so wide. The beauty in it is that it will carry all previous technologies such as FW, USB, ePCI.... you name it all through the same pipe. So how I see it, all previous technologies will continue to exists and will be just piped all together through the same device, which will also enable Apple to make smaller and smaller units that will be offloading tasks to an external device. We will be plugging monitor, FW device and USB through the same unit that will carry it back to the main machine. That way as you explained all of the development could continue for existing technologies.
Sorry exa, for the interruption with sort of unrelated disscussion, but I am positive I will be plugging exa device to a LP/Thunderbolt pretty soon.
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Old 5th April 2011, 01:46 AM   #260
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I am planning to use convolver VST with cPlay. For other program, we can use Console as a host as well
Thank you ackcheng for the response - I will check that out.
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