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Hi, I want to use 4 I2S sources with Buffalo32s, tell me please, can I use simple 4 sections 4 position rotary switch ?
Peace, Me.
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You probably could, but honestly switching I2S can be problematic because it always increases the length of the I2S transmission line and introduces the possibility of crosstalk. It may work fine for you, but it may not.
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Hi, Russ.
I have modified VIA Tremor 5.1 sound card, (simple I'm extract from $12 Tremor I2S (Philips standart) bus), and I have LVDS line. LVDS transmit I2S to 12 meters via UTP without any loss (may be longer, I'm not check max cable leight).
1. You mean, I can use, but I need to place LVDS receiver near rotary switch?
2. Can Buffalo32S support I2S by Philips?
3. What best idea for switch 4 I2S lines? May be relay with terminator?
Thank you.
Peace,
Me.
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This is actually an interesting topic. What I want to do is have a I2S, DSD and SPDIF connection on my box. Therefore I would like to modify my SACD player to be able to transport DSD an I2S to the DAC. So I have to: 1. be able to switch I2S, DSD and SPDIF to the buffalo 2. be able to extract I2S and DSD form the SACD player 3. be able to transport the signals Well, as for 1: I might imagine that some AND/OR logic might be used to make this possible? As for two, that is easy, just solder some wires on the DAC where the signals are.. Three is maybee a difficult one. I'm currentl looking for some way to transport the data balanced over SPDIF. Maybe a RS485 receiver and line driver might help, for instance LTC1688. It can do 100MBPS over a few meters without problem. I'm a bit afraid of phase differences between the line drivers though.. Has anyone an idea if this might work?
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Dear Voodooless, question three is not diffecult at all :) I use pair LVDS SN65LVDT41/14 for transfer I2S on 16 meters (!!!) via standart UTP cat5. No lags, lossless signal. Voodooless, I have few devices, write me email if you have an interest. Edited by user Sunday, August 30, 2009 10:33:15 AM(UTC)
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I'm in a somewhat similar situation. I need to switch two I2S sources (DSD/PCM) and TPA MUX (SPDIF, AES/EBU, Toslink, USB). I'll try a different route - use ELMA 06-4264 rotary switch. It's a 8 poles, 6 position non-shorting switch. 4 poles will be reserved for D2,D1,DCK,GND lines, 2 poles for MUX input selection, 1 pole for LED input indicators and the last free pole probably for DAC digital power. The idea is that with slow rotation during input switching the power will be momentarily disconnected thus providing DAC resetting and locking onto the new source signal (though maybe won't be needed).
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ustas wrote:Dear Voodooless, question three is not diffecult at all :) I use pair LVDS SN65LVDT41/14 for transfer I2S on 16 meters (!!!) via standart UTP cat5. No lags, lossless signal. Voodooless, I have few devices, write me email if you have an interest. Hi Ustas, It would be great if I can use differental signal transfer between B32 and PC!!! I have a Julli@ soundcard, and it outputs only single ended I2s signals. How did you make inverted I2S signals for differental signal transfer? Could you show me how you modified your soundcard to make it possible? Thank you.
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Good day,hkminn !
You have another trouble on that way, how I know Juli@ have Philips format I2S output, first of all you need to convert: I2S bus Philips > Sony. You can write to me letter I can explain you about converter schenematics.
Peace, Me.
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Karlosak wrote:power will be momentarily disconnected thus providing DAC resetting and locking onto the new source signal (though maybe won't be needed). Main "ELVIS" is RESETTING. If you look to board of Buffalo32 u can see "RESET" pins. May be easy way is just connect two poles of switch to reset pins ... and you do not need shutdown power by every click. Peace, Me.
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resetting is not required when changing input formats. But you may want to mute during the transition to prevent any noise.
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Russ, is the muting really needed? I thought that the Sabre chip utilizes soft-mute feature when powered up and locked. I've even tried a simple test - with SPDIF signal active I toggled the DAC's main power switch on and off and there was no noticeable noises. As a bonus there is a nice "fade in" to music when powering on ;-) Now if the muting during input switching is really useful, how it could be easily done without any fancy logic?  Edited by user Tuesday, September 1, 2009 2:35:58 PM(UTC)
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Needed? No not really. But I have found in my own experience going between DSD and I2S I sometimes get a little white noise in the transition, but it is only about 1/4 second. :) So if that would not bother you, then don't give it a second thought. :) It was not even particularly loud. Maybe -24db.
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Needed was a strong word, unless you are perfectionist ;-) I'll let others know how it goes when I receive the (pricey) ELMA rotary switch. The success is not granted, since I already had DSD locking problems when connecting my opened SACD player to the Buffalo. Now, after I tapped the signal at a different place, closer to the player's DAC (after 200R series internal resistors), it works reliably every time, but we will see. An oscilloscope would definitely be a welcomed addition to my DIY bench. Without it, I can only speculate. I see that there are impedance matching resistors between signal and ground on Buffalo's I2S inputs, though I cannot measure their value since the board is now fully wired and difficult to get to. Russ, could you tell us their value, and then what's the ideal impedance of the I2S interconnect? Any other idea why the series 200R resistors helped to lock the signal? Maybe the I2S/DSD signals generated by the decoder chip are really weak and cannot drive the termination load? Thank you for your time and kind advice, and keep up the great work! Edited by user Friday, September 4, 2009 9:50:56 AM(UTC)
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I do it ! My way is: ASUS Essence STX > I2S 24bit 192kHz.> LVDS > 15 meters cat.5-e UTP > LVDS > ADUM > Buffalo32s > GREAT sound !    Also I can select between SPDIF from SONY CD and I2S from my PC by onboard K1, but with short noise (resampling?) about 1/4 sec. May be same "sound" what was written by Russ White. My next project to build digital preamp with 4 lines I2S commutator, I2S format converter, SPDIF, TOSLINK inputs, digital volume control, and i think about touch screen control ... In the future. Thanks a lot Russ and Brian!
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