Rank: Member
Groups: Member
Joined: 5/25/2011(UTC)
Posts: 7
Location: Australia
|
I've just imported the first exaU2I USB-I2s device into Australia. Very nice unit and great backup from exadevices.
I'm using it with a Twisted Pear Sabre 2 dac, and using the I2S connection of course.
However I cant get a constant lock on to the dac with any freq over 96K. Works fine at 44, 48, 96 but drops out every 2 secs with 176,192.
I've determined it's not the exadevice, as the same thing happens when using an Evo and Teradak I2S connection.
Even when there is no track selected the "Lock" led on dac flashes every 2 secs when connected via I2S.
It's fine with spdif at all freqs, works very well. Tried all the switch positions, very short 1 inch connections, etc.
Very capable laptop with windows 7, tried JRiver and Foobar, same result, no joy over 96K.
It seems there is an issue with the I2S structure in Sabre chip.
Can anyone confirm this, and is there a fix?
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 10/21/2010(UTC)
Posts: 21
Location: Kyoto
|
Is your dac Buffalo II with 100Mhz TCXO? If so, that might be caused by LOWEST_DPLL_BANDWIDTH setting. Check these related threads first. You would get some useful informations. http://www.twistedpearau....aspx?g=posts&t=1672http://www.twistedpearau....aspx?g=posts&t=1488How long can your dac keep lock while playing 44.1/48/96 khz files? When I'd tried lowest dpll bandwidth setting, I feel it's hard to play one song(about 5-10minites long) without any dropout. Mine are 80Mhz version, one of them has 96mhz clock module(replaced by myself), and both of them are controlled (not at the same time) by Arduino when I was tweaking DPLL_BANDWIDTH setting.
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 4/6/2009(UTC) Posts: 18  Location: Horgen, Switzerland Thanks: 1 times
|
I have 3 Sabre chips (2 Buffalo 24s, 1 Bufallo II) and all of them operate flawlessly with either a Hiface I2S by JKenny / or EVO, using the I2S connection, no disconnects what so ever at all KHz rates using both JRiver and Foobar. I have also used them with the Metro and or the Mux with similar results - all of them have a 80Mhz clock. At least it appears that this is not a general flaw/problem as others are reporting it to be. Just my 2 cents.
Abraham
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 5/25/2011(UTC)
Posts: 7
Location: Australia
|
Well from all the searching i've done it seems a possible solution is to use the 80Mhz oscillator in place of the 100Mhz.
Is that a simple substitution, can i unsolder the 100 and just replace it with an 80 or isnt it that simple?
|
|
|
|
|
|
Rank: Administration
Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA
Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
|
statman wrote:Well from all the searching i've done it seems a possible solution is to use the 80Mhz oscillator in place of the 100Mhz.
Is that a simple substitution, can i unsolder the 100 and just replace it with an 80 or isnt it that simple?
??? How did you arrive at that conclusion?
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 5/25/2011(UTC)
Posts: 7
Location: Australia
|
From the observations on this page. http://www.twistedpearau....aspx?g=posts&t=1672All the users with 80Mhz dont seem to have problems implementating I2S. It seems a reasonable summation to me. I would love to hear your opinion on what may be causing the dropout on freq over 96K.
|
|
|
|
|
|
Rank: Administration
Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN
Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
|
Actually the clock is not anything to do with it. :) In fact the faster clock is more desirable if faster sample rates are required.
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 10/21/2010(UTC)
Posts: 21
Location: Kyoto
|
I think nothing wrong with your 100Mhz TCXO itself.
>All the users with 80Mhz dont seem to have problems implementating I2S. It seems a reasonable summation to me.
It is said that - 80Mhz TCXO version of Buffalo II's onboard firmware sets DPLL_BANDWIDTH setting to BEST_DEFAULT, that makes
dropout-free playback easily (but not so good at jitter-reduction purpose)
, and 100Mhz TCXO version sets it to LOWEST, that sometimes cause a few or many dropouts especially when using i2s connection (but does best at jitter reduction purpose)
I have not experienced 100Mhz version of Buffalo II, but when I tried different controll program (that's not twisted pear product) and lowered DPLL_BANDWIDTH setting,
I had met same problem as yours - less dropouts with lower sample rate files, frequent dropouts with higher sample rate files.
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 5/25/2011(UTC)
Posts: 7
Location: Australia
|
Both administrators leaving short messages saying what isn't the problem- how about something positive - you must have more than a clue about this shortcoming. Connections are provided for I2s so is it reasonable to expect it to work for all of the units, not just some of them?
This was posted on diyaudio, it may or may not be be correct, but a comment would be appreciated.
"However, TPA might have changed ES9018 register setting for DPLL bandwidth parameter at the same timing when they upgraded previous 80 MHz oscillator to new 100 MHz one.
In my case, two new Buffalo II boards with 100 MHz oscillators shipped this year suffered the similar problems. After replacing the new MCU with old one that came with an old Buffalo II board with 80 MHz oscillator, the problem disappeared. "
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 10/21/2010(UTC)
Posts: 21
Location: Kyoto
|
>This was posted on diyaudio, it may or may not be be correct, but a comment would be appreciated. I found Bunpei better answered than me there. He also suggested a way to make sure your problem is whether register setting issue or not - in other words, different register setting cures dropout problem or not. Edited by user Friday, May 27, 2011 6:47:24 AM(UTC)
| Reason: Not specified
|
|
|
|
|
|
Rank: Member
Groups: Member
Joined: 5/25/2011(UTC)
Posts: 7
Location: Australia
|
Received the alternative firmware for the buff2 and happy to report it works exceptionally well in I2S mode with the exaU2I driving it. It's the best sound I've heard from digital, maybe the best sound ever. Thanks to TPA.
|
|
|
|
|
|
Forum Jump
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.
