Thanks, Russ.
Wow!. I always trust the datasheet. Must wait to learn the hard way, I think
I am not sure who said anything about trust in the data-sheet.
My advice was to check that the register settings are always what you expect them to be, after all it is your controller that could be changing them. By polling the registers from time to time you can know that all is well and also that some error in transmission or code did not occur. Think of it as a checksum.
Also by checking that they have not returned to their defaults you can see if you had an inadvertent reset. This can happen for a number of good reasons.
Hard way if you must. I prefer preparation.
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Agree. I only have one DAC to control. But for dual mono, all register programming would have to change as well
I am not sure who said anything about trust in the data-sheet.
My advice was to check that the register settings are always what you expect them to be, after all it is your controller that could be changing them. By polling the registers from time to time you can know that all is well and also that some error in transmission or code did not occur. Think of it as a checksum.
Also by checking that they have not returned to their defaults you can see if you had an inadvertent reset. This can happen for a number of good reasons.
Hard way if you must. I prefer preparation.
Good advice. Thanks!.
None.
The only good reason to use a metronome with the Buf II would be if you needed to convert 48fs I2S to 64fs.
Hi Russ,
I've recently purchased a Buffalo II DAC off of audiogon not realizing you would be changing the XO chip. I guess I really did realize it but somehow it didn't register. Anyway I too man wanted to run dual mono mode. Is there anyway I could send in my Buffalo II and get the XO replaced with the new one for a fee?
In addition would there perhaps be any benefit in replacing the current clock with something like a Dexa Neutron Star? Is it even possible to use an external clock with your board?
Best Regards,
Theo
I've recently purchased a Buffalo II DAC off of audiogon not realizing you would be changing the XO chip. I guess I really did realize it but somehow it didn't register. Anyway I too man wanted to run dual mono mode. Is there anyway I could send in my Buffalo II and get the XO replaced with the new one for a fee?
In addition would there perhaps be any benefit in replacing the current clock with something like a Dexa Neutron Star? Is it even possible to use an external clock with your board?
Best Regards,
Theo
@Theo
I am not an expert, but I believe special care was taken to keep clock and power regulation very near to the pertinent circuits.
Although better external clock references might be available (not so sure if better power regulation), it seems crucial to keep the signal away from interferences.
Keeping paths/rails as short as possible seem to play a more significant role than just the clock deviation inherited from its reference source (as long as you have a good enough crystal, which is the case with Buffalo II and even if your external reference is the most stable reference, like an atomic clock...).
Ok, I might be over exaggerating with atomic clocks.
@ twisted pear
Is that right?
I am not an expert, but I believe special care was taken to keep clock and power regulation very near to the pertinent circuits.
Although better external clock references might be available (not so sure if better power regulation), it seems crucial to keep the signal away from interferences.
Keeping paths/rails as short as possible seem to play a more significant role than just the clock deviation inherited from its reference source (as long as you have a good enough crystal, which is the case with Buffalo II and even if your external reference is the most stable reference, like an atomic clock...).
Ok, I might be over exaggerating with atomic clocks.
@ twisted pear
Is that right?
jgazal. You are absolutely correct.
At 100mhz routing parasitics are a paramount concern. YOu simply could never route an external clock as well as the current clock is routed. You will end up completely losing any possible benefit.
Not only that but the custom ordered Crystek clock we are using is already superb.
At 100mhz routing parasitics are a paramount concern. YOu simply could never route an external clock as well as the current clock is routed. You will end up completely losing any possible benefit.
Not only that but the custom ordered Crystek clock we are using is already superb.
1) Yes, you will need a hot air station. It is simply an SMD device.
2) No. I only get enough made for the DACs we are building. You can order one from Mouser though. They usually have a few in stock. CCHD-950-25-100.000 Crystek Crystals XO Oscillators
I want to reiterate that there is not really a need to replace the 80MHz XO.
Over the weekend, the heavens opened, the seas parted, Hades froze over.....(or maybe my wife was just out of town for the weekend) and my BII is actually playing music. Far from optimal, but better than silence. Volumite even works! Woo hoo.
Brian/Russ - going way back to a question I had earlier I'm playing into an original Ivy set up for an Opus. When I asked originally, you pointed me here http://www.twistedpearaudio.com/docs/linestages/ivy_manual_2.0.pdf and kindly sent the 187R resistors. However, you also sent some 10nF caps labeled for C1-C4. The manual indicates 'omit' for this location for the B32S, so I'm just wondering whether the BII is indeed different and I should use 10nF or just leave them out. I guess it's easy enough to try it both ways. (I'm guessing this is related to the filter cap discussion for the Legato)
One other question that might be better in the USB thread. It's looking like I'm going to need/want 2 sources into my BII - I2S from the USB/xmos board which will come from a dedicated music pc, plus an spdif input from the general PC for watching occasional workout videos. Is it possible to switch just the D1 line from LRCK to SPDIF (assuming it's ttl level), or should I expect to use an external spdif receiver and a full Otto style I2S switch for all signal lines? The usb/i2s input would be silent (but still 'on') when using spdif so I would hope this would work, but I'm not sure whether they really should be open when using spdif.
The follow-up to that is if I can just switch D1 I actually have an unassembled Darwin board lying around - could I use this to do the switching, or is the layout likely to introduce some signal degradation of some sort with high speed signals? Quality on the spdif input in this context isn't important, but I'm concerned that messing with LRCK might be a bad idea.
Brian/Russ - going way back to a question I had earlier I'm playing into an original Ivy set up for an Opus. When I asked originally, you pointed me here http://www.twistedpearaudio.com/docs/linestages/ivy_manual_2.0.pdf and kindly sent the 187R resistors. However, you also sent some 10nF caps labeled for C1-C4. The manual indicates 'omit' for this location for the B32S, so I'm just wondering whether the BII is indeed different and I should use 10nF or just leave them out. I guess it's easy enough to try it both ways. (I'm guessing this is related to the filter cap discussion for the Legato)
One other question that might be better in the USB thread. It's looking like I'm going to need/want 2 sources into my BII - I2S from the USB/xmos board which will come from a dedicated music pc, plus an spdif input from the general PC for watching occasional workout videos. Is it possible to switch just the D1 line from LRCK to SPDIF (assuming it's ttl level), or should I expect to use an external spdif receiver and a full Otto style I2S switch for all signal lines? The usb/i2s input would be silent (but still 'on') when using spdif so I would hope this would work, but I'm not sure whether they really should be open when using spdif.
The follow-up to that is if I can just switch D1 I actually have an unassembled Darwin board lying around - could I use this to do the switching, or is the layout likely to introduce some signal degradation of some sort with high speed signals? Quality on the spdif input in this context isn't important, but I'm concerned that messing with LRCK might be a bad idea.
Is there a dedicated thread on the future Twisted Pear USB/xmos product?
High on my wish-list for such a product would be a build-in high-quality I2S mux to allow for selection between different I2S sources (2-3). Or maybe a new lightweight 3:1 digital signal level "Otto" product.
Just my 2 cents while waiting for Ventus, USB/xmos, AC1/2 and company
Edit: Just saw the announcement of MRB1 on the TPA site! Maybe this is the answer.
High on my wish-list for such a product would be a build-in high-quality I2S mux to allow for selection between different I2S sources (2-3). Or maybe a new lightweight 3:1 digital signal level "Otto" product.
Just my 2 cents while waiting for Ventus, USB/xmos, AC1/2 and company
Edit: Just saw the announcement of MRB1 on the TPA site! Maybe this is the answer.
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Dumb question but i thought id ask.
SInce the buff is back in stock, how does the Volumite work with it in terms of quality? Im pretty sure its not like using PC windows volume control were you loose bit depth as you turn the volume down, But how does it work? It would seem to be the ultimate volume control for a buff only preamp since it adds nothing to the signal path and there for should be better then any volume control like a lightspeed.
SInce the buff is back in stock, how does the Volumite work with it in terms of quality? Im pretty sure its not like using PC windows volume control were you loose bit depth as you turn the volume down, But how does it work? It would seem to be the ultimate volume control for a buff only preamp since it adds nothing to the signal path and there for should be better then any volume control like a lightspeed.
The volumite uses the digital volume control of the DAC chip. If like in the ESS chip the internal data width is much greater than that of the signals' data width you'll hear much less degradation than other types of volume control. And L/R balance is much better than using a pot in a classic way. Plus the amount of control over the volume is really, realy nice since the 90x8 chip uses 0.5dB steps over an 127dB range. So in that regard it's much better than an attenuator.
You are wrong about the signal path though: basicly the digital volume control DOES alter the signal, most likely by simply doing a division on the input based on the volume setting. This can lead to rounding errors, so in theory this method isn't perfect either. But given the price and performance of the Volumite, you'll be hard pressed to find something better.
You are wrong about the signal path though: basicly the digital volume control DOES alter the signal, most likely by simply doing a division on the input based on the volume setting. This can lead to rounding errors, so in theory this method isn't perfect either. But given the price and performance of the Volumite, you'll be hard pressed to find something better.
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