mowglycdb
500+ Head-Fier
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A WW platinium seems too expensive D: a Chroma seems more logic, given that if he's going to use the minimum length that's 0.3m there shouldn't be much diference.
So I've decided to give the DI-2014/HDMI out to M7/HDMI. Placed my order for DI-2014 with TXCO and HDMI out upgrade and the HDMI input board for DIY install into my M7.
Rest of config is Audio-GD Master 10 amp into Magnepan 3.7R. Double Helix USB and ACSS cables. Source is dual I5 CAPS PC's running WS2012, Audio-optimiser 1.30 and jplay. Currently using Audiophilleo 2 and Purepower for USB to BNC into M7 so will be interesting to compare to DI-2014/HDMI.
This just leaves a decision to be made on HDMI Brand/Model and length in time for the arrival of the kit from Audio-GD. Double-Helix do not do a HDMI cable otherwise I would have stuck with that brand for my cables. Any nominations for HDMI cable ?
Frizzup
However, I'm confused by your statement that each circuit (channel) ground (return) is connected by (in?) the cable. That would seem to defeat to whole purpose of eliminating common mode interference in balanced signal cable. Do you mean at the connector(s)? I would think that the individual channel ground conductors would be grounded together in either the transmitter (e.g. DDC) or receiver unit (DAC), and leave the individual channel cable grounds insulated from each other over the entire exposed cable length. What am I missing?
So I've decided to give the DI-2014/HDMI out to M7/HDMI. Placed my order for DI-2014 with TXCO and HDMI out upgrade and the HDMI input board for DIY install into my M7.
Rest of config is Audio-GD Master 10 amp into Magnepan 3.7R. Double Helix USB and ACSS cables. Source is dual I5 CAPS PC's running WS2012, Audio-optimiser 1.30 and jplay. Currently using Audiophilleo 2 and Purepower for USB to BNC into M7 so will be interesting to compare to DI-2014/HDMI.
This just leaves a decision to be made on HDMI Brand/Model and length in time for the arrival of the kit from Audio-GD. Double-Helix do not do a HDMI cable otherwise I would have stuck with that brand for my cables. Any nominations for HDMI cable ?
Frizzup
OK I will give it a shot. In differential HDMI LVDS there is no ground return on one of the two signal pairs as needed with single ended schemes like RJ45 I2S. The LVDS return current is through the opposite signal wire of the pair - both above ground. Each of the four signal pairs are shielded and these shields are connected to ground on both sides of the cable in HDMI I2S (pins 2, 5, 8, 11) plus pin 17 which is defined as digital ground in HDMI world. The LVDS receiver chip needs the ground reference of the transmitter in order properly decode the state of the presented LVDS signal. LVDS is fast with low jitter due to a large part the signal swing is only +/-350mV around a bias point of about 1.2V above ground. In single ended LVTTL as with RJ45 the signal swing is 10 times as much at about 3V. Lower signal swing means less ambiguity in decoding a logic state change which results in lower jitter. Texas Instruments has a great publication on LVDS and in the back of the document talk about jitter with emphasis on HDMI application. http://www.ti.com/lit/ml/snla187/snla187.pdf
OK I will give it a shot. In differential HDMI LVDS there is no ground return on one of the two signal pairs as needed with single ended schemes like RJ45 I2S. The LVDS return current is through the opposite signal wire of the pair - both above ground. Each of the four signal pairs are shielded and these shields are connected to ground on both sides of the cable in HDMI I2S (pins 2, 5, 8, 11) plus pin 17 which is defined as digital ground in HDMI world. The LVDS receiver chip needs the ground reference of the transmitter in order properly decode the state of the presented LVDS signal. LVDS is fast with low jitter due to a large part the signal swing is only +/-350mV around a bias point of about 1.2V above ground. In single ended LVTTL as with RJ45 the single swing is 10 times as much at about 3V. Lower signal swing means less ambiguity in decoding a logic state change which results in lower jitter. Texas Instruments has a great publication on LVDS and in the back of the document talk about jitter with emphasis on HDMI application. http://www.ti.com/lit/ml/snla187/snla187.pdf
Are you sure HDMI is DC around a 1.2V offset? I always thought the pairs were AC with opposite polarity. Depends on whether the CML rails are +/- or + and GND, but the whole idea of CML is to avoid switching noise by running a fixed current (3.5mA, which over 100ohm at 340MHz translates to 350mV). Also, looking at eye graphs they're always +/- and always indicate the two signals crossing. Maybe I'm misreading... Actually, it may not matter and the 1.2V offset is just the particulars of the output stage, but the two signals need to cross or you'll need a reference ground.
The pink faun should be coming in a week or so. I'm running long lines (15 feet), so not optimized. I can try to compare it to the coax out of my HT claro II. Can also try to compare it vs USB but the USB drivers have been crashing my desktop. I probably don't have the best ears or source material (Google streaming mostly) so my review may be lacking. I would possibly be willing to send it to a respected member with a OR5 for comparison.
One issue though - the left and right channels are switched. Simple enough to switch the cables around but I'm also using the HT claro II for games - would be a hassle to constantly move cables around. I'm emailing the seller to see if I can get that fixed.
It doesn't seem to like the "redmere" HDMI cable I had from monoprice. Replaced it with a another generic HDMI cable I had laying around and everything works now.
Is the pin out on the HDMI input kit fitting the Offramp 5 without changing the pin out and on the homepage it says that on Master 7 no soldering is needed, is this correct?
Thanks for the review. You are having a similar experience as I have with using HDMI I2S. The only solution I have to offer for reversed left and right channels is to swap the HDMI L/RCLK connections on one side of the HDMI cable. This will invert the L/RCLK signal. Would require a cable where you can remove the HDMI connector shells and then resolder the wires. Strange Pin Faun would design it this way but understandable with no standard for HDMI I2S. But Pink Faun claims that the PS Audio HDMI I2S method is incorrect in the PMs you sent to me.
Did it sound bad or just not work at all? I use generic 6 ft. cables on my A/V setup and haven't had a problem. Searching AVS forum seems Monoprice had an issue with Redmere cables in 2012. They claim the issue has been since corrected.