digikey sells 11.289 Mhz crystals for 0.52 ea
9B-11.2896MEEJ-B TXC CORPORATION | 887-1237-ND | DigiKey
they have 10 ppm accuracy
Replace the osc in the CD or DVD with this family of parts for
a 50x improvement over the 500 ppm part
9B-11.2896MEEJ-B TXC CORPORATION | 887-1237-ND | DigiKey
they have 10 ppm accuracy
Replace the osc in the CD or DVD with this family of parts for
a 50x improvement over the 500 ppm part
I champion the use of high quality high current regulated SMPS for poweramps, where their benefits are quite obvious because making a 500-1000W regulated linear supply for such a task is both prohibitively expensive and double the size. you can forget shunt regs, except maybe for powering input differentials.
it is true that most noise can mostly be kept out of the audio band, but here we are dealing with circuitry that operates well above the audio band, the PSRR of a clock is terrible and its not hard to make a linear, shunt or battery supply for this purpose, so the trade off isnt in its favor.
it is true that most noise can mostly be kept out of the audio band, but here we are dealing with circuitry that operates well above the audio band, the PSRR of a clock is terrible and its not hard to make a linear, shunt or battery supply for this purpose, so the trade off isnt in its favor.
max 500 uW, I think means 3,3V only. The challenge is finding a 5V 11.2896mhz crystal.
check out audiopower.it, the DPS500/S (lower v-out, 800W with 1000W burst)or DPS500/S-64V 800W not my design, but what i'm talking about. custom spec voltages are available for a bit more. i'm using the DPS600 in a custom format (bipolar front end supply at higher voltage than main high current output), they are cut from the same cloth, basically a digital class A amplifier powered by an 'SMPS' with very low noise and differential feedback
watch out for spam on the site, they are redesigning it and adding security, stay away from the datasheet links and you'll be fine =) I have them and can email if you are really keen.
watch out for spam on the site, they are redesigning it and adding security, stay away from the datasheet links and you'll be fine =) I have them and can email if you are really keen.
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There are no specs about motional capacitance and Q in the datasheet.
40 Ohm ESR for a 10 MHz crystal, resistance welded.
Don't expect great performance in phase noise and then jitter.
I thought this was the " Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter" forum...?
someone mentioned using SMPS with this 'asynchronous i2s fifo', I explained my reasoning why not, but where I thought it was not only appropriate, but superior. i've contributed quite a lot of on topic conversation and support on this i2s fifo project over the last 18 months or so. I feel zero guilt for the short diversion.
was your post on topic?
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Back to my SMPS argument 
It would be lighter and more convenient / compact rather then a toroid / battery combo no?
Benefits, would hardly outweigh the use of either if properly setup and filtered in my opinion.
Since no more than 2 or 3 amps is required and voltage is low...
It would be a cheaper or at par ( including an Audiophile filter section on the output ) but a lot lighter and simpler to put in slim case.
It would be lighter and more convenient / compact rather then a toroid / battery combo no?
Benefits, would hardly outweigh the use of either if properly setup and filtered in my opinion.
Since no more than 2 or 3 amps is required and voltage is low...
It would be a cheaper or at par ( including an Audiophile filter section on the output ) but a lot lighter and simpler to put in slim case.
you are free to pursue it for curiosity, I see no benefit and only extra problems to solve, a linear supply to power it is pretty small and dwarfed by the rest of the build. an isolator board was developed for this design with part of its mission being isolating the clock from the USB ground and its SMPS, why would you think people would be interested in putting one back in?
I find it exceedingly doubtful you can produce a quieter SMPS supply, so it can only be noisier. the fifo takes only ~150mA, so it really doesnt need that much space for anything, a tiny transformer, a tiny regulator and 2 x A123 battery cells is nothing. the only thing that would motivate me is higher performance and it just isnt there. lighter? having my dac 250gm lighter? I dont often carry it with me.
it doesnt have to be a battery/reg combo, if you are happy with the sort of performance SMPS gives then you wouldnt need the hassle of batteries, tiny linear regs powering the onboard regs would suffice.
I find it exceedingly doubtful you can produce a quieter SMPS supply, so it can only be noisier. the fifo takes only ~150mA, so it really doesnt need that much space for anything, a tiny transformer, a tiny regulator and 2 x A123 battery cells is nothing. the only thing that would motivate me is higher performance and it just isnt there. lighter? having my dac 250gm lighter? I dont often carry it with me.
it doesnt have to be a battery/reg combo, if you are happy with the sort of performance SMPS gives then you wouldnt need the hassle of batteries, tiny linear regs powering the onboard regs would suffice.
Back to my SMPS argument
It would be lighter and more convenient / compact rather then a toroid / battery combo no?
Benefits, would hardly outweigh the use of either if properly setup and filtered in my opinion.
Since no more than 2 or 3 amps is required and voltage is low...
It would be a cheaper or at par ( including an Audiophile filter section on the output ) but a lot lighter and simpler to put in slim case.
Hi Adrculda,
Here is the noise density plot of TPS7A4700. But the noise performance is still not as good as a decent battery pack. The whole goal of the FIFO is to reduce the clock jitter. It gains neither from the high efficiency nor from the compact size of a power supply. With the isolator board, the power consumption is just around 100mA for the clock board and half of isolator, the only thing helps is the low noise performance of a power supply.
Theoretically a switching power supply is not good at low noise application comparing with linear. The high frequency high power switching noise is very hard to be decoupled, even using multi-stages CLC filter, because there is no ideal capacitor and inductor in the real world. The EMI noise introducing from ground into DAC may even more difficult to deal with.
But I might be wrong. Please let me know if your can really find a switching power supply with competitive noise performance.
Regards,
Ian
Attachments
isolator powered from J9 on the clock board side. It works good with dual xo clock board. To use a single clock board, you have to figure out flying power wire to power the isolator clock side. Please refer to the schematic of the isolator board.
For single xo clock board, yes, if your use 3.2V battery, you have to remove U5 and short the LDO footprint with a 0 ohm jumper.
Ian
Hi,
I am new to this kit, and after reading this thread for a while, some things are still not clear to me, hope somebody could help. Thanks in advance.
What is the delay time since input?
There is a table in the manual: "FIFO half full delay time". Is this the answer?
If there is some delay, then there will be lip sync problem when watching videos. I'm concerned of this.
Is it there a "low latency mode" switch to toggle so the entire buffering process could be bypassed?
I'm not demanding, just asking if this is feasible and easy to implement.
I am new to this kit, and after reading this thread for a while, some things are still not clear to me, hope somebody could help. Thanks in advance.
What is the delay time since input?
There is a table in the manual: "FIFO half full delay time". Is this the answer?
If there is some delay, then there will be lip sync problem when watching videos. I'm concerned of this.
Is it there a "low latency mode" switch to toggle so the entire buffering process could be bypassed?
I'm not demanding, just asking if this is feasible and easy to implement.
toggle entire buffering board? sure, you can put a suitable switch at the input and bypass the entire fifo.....
of course there is a delay, the delay is based on the samplerate, it is how the fifo works, it cannot be bypassed and still have the buffer in circuit. the only thing you can do is delay your video by the same amount.
this is for high quality audio, if you want to make it work with video i'm afraid the ball is in your court.
it would be really good if people would use the 'search this thread' function, the number of times we have answered this question is getting quite large.
of course there is a delay, the delay is based on the samplerate, it is how the fifo works, it cannot be bypassed and still have the buffer in circuit. the only thing you can do is delay your video by the same amount.
this is for high quality audio, if you want to make it work with video i'm afraid the ball is in your court.
it would be really good if people would use the 'search this thread' function, the number of times we have answered this question is getting quite large.