That would result in dropouts/stuttering, not a subtle change in audio quality.
Reasonable hypothesis... IMO no amount of jitter would cause the Pi to drop bits. It is simply reading data into its buffer, then handing off to FIFO to stock pile into its buffer. All is happening in bursts and buffers are big enough to not run dry while FIFO carefully sends it out in a steady jitter free sequence.
Hi'
Is it really possible?
I asked about memory of the FifoPi buffer and never had an answer. Iir not in the FifoPi manuel either. It s perhaps not that important ?!
MC board was able of high buffer, but what about FifoPi?
I don't think there are bits loss due to the Rpi... nothing hard to acheive for any computer...
Is it really possible?
I asked about memory of the FifoPi buffer and never had an answer. Iir not in the FifoPi manuel either. It s perhaps not that important ?!
MC board was able of high buffer, but what about FifoPi?
I don't think there are bits loss due to the Rpi... nothing hard to acheive for any computer...
I try to think out of the box, it's the only way to evolve
I also have a twisted pear conus/hermes. This was developed to make it possible to use as master clock for the attached beagle bone black (this one can take an external clock, rpi can’t). Why all this trouble if reclocking provides similar results?
The same accounts for async usb receivers like the one from Lorien. This would be able to reconstruct bit perfect data stream. But I never got such good results as with the hermes/cronus setup.
In my view it is probable that there is an influence.
Ha ha, I was wondering when this would show up here, on another forum people already claim improvements by running 2 reclockers in series.
Have you tried separating the DAC from the FifoPi? Markw4 reported that improved sound, maybe there is some interference from the clocks, they do sit quite close to the board above.
The BBB can't play 44.1khz based material without an external clock and Lorien's receiver (all of the USB receivers really) has the isolation after the Xmos chip so the chip is exposed to all the noise coming from the USB lines. That is why the BBB needs the cronus and all USB interfaces need a reclocker.
Have you tried separating the DAC from the FifoPi? Markw4 reported that improved sound, maybe there is some interference from the clocks, they do sit quite close to the board above.
The BBB can't play 44.1khz based material without an external clock and Lorien's receiver (all of the USB receivers really) has the isolation after the Xmos chip so the chip is exposed to all the noise coming from the USB lines. That is why the BBB needs the cronus and all USB interfaces need a reclocker.
Hi Supersurfer, I could not agree more. Fun to debate the possible cause.I try to think out of the box, it's the only way to evolve
I took a similar path. SBC to WaveIO. Love the WaveIO, but could not totally shake off the influence of the source computer or the USB cable.
Then BBB to Acko S03. Big improvement, and I could be convinced that I did not need to worry as much about the settings on the source computer.
Now same clocks but on a FIFOPi. Really have not worried too much about the Pi. Just built a good linear supply for it based on general principals. But I do read posts about the positive impact of an SSD drive vs HDD. Also some concerns about how many interrupts generated by the NAS and even should I not go to optical cable to isolate all the noisy PS on NAS and router. All of this points to impact of noise coming into the Pi and still impacting digital stream generated by the FIFO. I think the real area for improvement remains the isolator which could explain everything, even the perceived improvement of 2x isolator in series. Just my hunch..
Also could be noise getting through to FIFOPi/acko/hermes etc affects the quality of the clocks. My next step is an off board clock (Well tempered master...) with its own PS, chassis etc. If the FIFOPi is then immune to the Pi, then I have my answer.
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A great question, and one that is worth considering. In my experience, it is constrained by how you chose to build your chassis. But it is worth considering the body of experience available to mechanical engineers and also take a look at the methods that the crazy people who buy crazy priced audio devices use to dampen vibration and then emulate some of it within your self constrained design. Some elements that I find beneficial:
1. a blob of some dampening material right on the clock/pcb. Mac tack, silicone your choice.
2. mount Rpi stack on a base that has some mass and then isolate the base. Effective choice is a wooden base like a butcher block. Then borrow from audiophile devices. Put butcher block on a layer of rubber and then put all that on a layer of stone or something else heavy.
3. While you would think that is enough, more dampening will pay dividends in my experience. My Rpi/FIFO is on a wood block with its standoffs mounted in silicone in the wood. It is mounted inverted on a metal plate inside a wood chassis. Above the metal plate is a layer of sand around DAC PCB (it is separated by the metal plate to electrically isolate FIFO/Rpi from the DAC). Above, the top of the chassis is also hardwood. I like wood because it does not have the same tendency to ring like metal. The entire wooden chassis music server sits on a granite slab with some foam between the wood and the granite.
One would think all of this is more than enough. But last week I piled bags of sand across the top of the chassis. This provided a positive impact on sound. All the things you get from having a better clock like improved image and separation of sound sources. Not for your living room system, but in the man cave, it is perfect.
Next, I plan to have a separate chassis for the clock. I imagine putting the clock PCB inside a grounded metal box, and burying the metal box in sand inside a wooden box. I want the clock to be in its own little bubble immune from the world around it.
Given the clock will be oven controlled, I might need to experiment to find the right oven temp to maintain the target 185F temp for the oscillator, but hey, why not? This is DIY after all.
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I have a ground plane between the fifopi and dac.
The bbb can play redbook material but it will not be bit perfect, rpi has the same issue. That is where the fifopi comes in (or the cronos).
A nice idea to stack reclockers, I might try this one!
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Hi Supersurfer, I could not agree more. Fun to debate the possible cause.
I took a similar path. SBC to WaveIO. Love the WaveIO, but could not totally shake off the influence of the source computer or the USB cable.
Then BBB to Acko S03. Big improvement, and I could be convinced that I did not need to worry as much about the settings on the source computer.
Now same clocks but on a FIFOPi. Really have not worried too much about the Pi. Just built a good linear supply for it based on general principals. But I do read posts about the positive impact of an SSD drive vs HDD. Also some concerns about how many interrupts generated by the NAS and even should I not go to optical cable to isolate all the noisy PS on NAS and router. All of this points to impact of noise coming into the Pi and still impacting digital stream generated by the FIFO. I think the real area for improvement remains the isolator which could explain everything, even the perceived improvement of 2x isolator in series. Just my hunch..
Also could be noise getting through to FIFOPi/acko/hermes etc affects the quality of the clocks. My next step is an off board clock (Well tempered master...) with its own PS, chassis etc. If the FIFOPi is then immune to the Pi, then I have my answer.
I have walked the same path: starting with a laptop on wave io to the dac, then an alix board, than rpi, than bbb-cronos, then again rpi with added acko reclocker (the software for rpi is much better developed than bbb; moodeaudio with sound tweakes is the best at the moment) later switched the acko for the allo kali and isolator and now the fifopi.
I never liked the quality of pc with usb interface, all other boards without any kind of reclocker sounded already better.
I also received 4 sc-cut clocks (45 and 49 MHz but also 5,6 and 6,1 MHz) with driscoll boards and oven from Andrea. Started smd soldering yesterday
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I forgot to mention the Alix. We have had similar path and observations.I have walked the same path: starting with a laptop on wave io to the dac, then an alix board, ...
I never liked the quality of pc with usb interface, all other boards without any kind of reclocker sounded already better.
I also received 4 sc-cut clocks (45 and 49 MHz but also 5,6 and 6,1 MHz) with driscoll boards and oven from Andrea. Started smd soldering yesterday
I look forward to hearing your reports on the SC-cut clocks with FIFOPi. Mine seem to be taking slow boat across the Atlantic so I'll be trailing your experience. I have the 45/49 coming and passed on the 5/6 for now (regrettably). Ultimately will benefit from hearing your report on 45 vs. 5. The 5,6 has amazing specs for redbook.
I am not so fast with building the pcb’s. It is a lot of smd soldering and I learned to take it easy to prevent mistakes.
The 5/6 mhz clocks are bigger and need a new board and oven, this is in the design phase by Andrea so will take some time.
Your boat might be faster than me
Hi !
I build FifoPi stransport to SPDIF and HDMI .
1 _ RASPBERRY PI2 .
https://item.taobao.com/item.htm?sp...CBykL&id=585598597518&ns=1&abbucket=16#detail
2 _ WM8805 I2S to SPDIF .
https://item.taobao.com/item.htm?sp...MYHbd&id=545250959553&ns=1&abbucket=18#detail
3 _ I2S HDMI .
https://item.taobao.com/item.htm?sp...l8Ijf&id=542491572010&ns=1&abbucket=16#detail
4 _ FIFOPI UTIMATE + CRYSTEK CCHD-957 .
https://www.diyaudio.com/forums/gro...us-i2s-pdif-fifo-kit-buy-318.html#post5726311
CRYSTEK CCHD-957 Ultra Low Phase Noise Crystal Femtosecond Clock 22.5792 24.5760 | eBay
I build FifoPi stransport to SPDIF and HDMI .
1 _ RASPBERRY PI2 .
https://item.taobao.com/item.htm?sp...CBykL&id=585598597518&ns=1&abbucket=16#detail
2 _ WM8805 I2S to SPDIF .
https://item.taobao.com/item.htm?sp...MYHbd&id=545250959553&ns=1&abbucket=18#detail
3 _ I2S HDMI .
https://item.taobao.com/item.htm?sp...l8Ijf&id=542491572010&ns=1&abbucket=16#detail
4 _ FIFOPI UTIMATE + CRYSTEK CCHD-957 .
https://www.diyaudio.com/forums/gro...us-i2s-pdif-fifo-kit-buy-318.html#post5726311
CRYSTEK CCHD-957 Ultra Low Phase Noise Crystal Femtosecond Clock 22.5792 24.5760 | eBay
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I tried the "tack-it" over the Pi3 clock; I don't have the Fifopi yet as it is out of stock; but I definitely hear the improvement: everything seems to fall in a more correct position therefore all music is more musical; and sounds a bit warmer and smoother and much less harshness in the treble.
I put more Tack-it on the Amanero384 clocks and the main dac PCB clocks. Amazing result!
For a $0.5 tack-it tweak, my system seems to have a 200 dollars sonic improvement.
My audiophile friend says I am imagining thing. He does not believe it and does not want to try it. I wonder if anyone would try it and report back. It does not cost much!