Guys, anybody tried this here?
OCXO constant temperature crystal oscillator clock board For Raspberry Pi 4B
OCXO constant temperature crystal oscillator clock board For Raspberry Pi 4B | eBay (just one link)
I am intrigued but would like to hear some reviews:)
Never experienced or will with these type of clocks. The theory makes sense and fully depends on the DAC that your using, This clock will reduce jitter, as the jitter on a rPi is bad. The rpi was never designed as audio player.
However, the majority of DAC’s have their own internal clocks and use PLL to deal with the jitter. If yoiu have a DAC, that doesn’t have this feature, or a really crappy rPi, you will benefit from it.
But then again, all boils down to the user experience/perception.
We can’t measure the difference between the std clock or a temp controlled OCXO clock vs the output audio as the most DAC’s have the clock and PLL integrated in a chip.
Some people will claim there is a world of difference, or that the 1000 euro USB cable produce a world of more clear sound, that a printed e-mail has better information than the same mail online.
It’s seems pointless and risky. Risky because it replaces the the existing onboard clock on the RPi4. You will need to be pretty handy with a soldering iron.
Pointless because DACs usually have their own clocks. Both USB DACs and I2S DAC HATs control the flow of data from the RPi; they don’t care about variations in the RPi4 clock.
Well, i do have a good clock on my es9038Pro dac, with its own PSU.
I did modify PC components before with huge success, where the USB clock and the Mobo clock where replaced with newtron star clocks - these are completely different league and price of course.
Soldering it on the Pi is something I can manage yet always a risk as the eyes are not what they used to be:)
I just cannot see in this case that a simple OCXO should make all the difference as the frequency is actually generated through the PLLs.
Well, on the rPi it will make the crystal frequency stable, as the crystal itself is very responsive to temperature changes, hence that’s why put it in a controlled oven. So the temperature is stable and as a result the frequency. (so far the theoretical part)
So if you use the rPi 3,5mm jack or HDMI, you might notice some differences. If you hear a 100 euro differences…
that’s always the question:) is it worth the money:)
Just noticed that i have 2 netronstars in my toolbox (NewClassD NeutronStar 3) the older version though so i just ordered 25 and 54 Mhz fundamental crystals. If for nothing else, just to see what is all the fuzz:) and have some fun doing it. I will replace the master clock and the Network clock, I have already done that on my LAN switches. As the DAC connects through I2S i guess i dont need to do anything with the USB clock.
Problem to fit them in the enclosure though:)
Well just to play around, why not.
However, I am pretty convinced that as long as we stay in the digital domain, it will not give much benefits. As all that is being transported is data. If this was relying on accuracy of the clock al lot of network retransmission would occur, making the network unfit to use.
I am very curious on the results.
Many Pi Hats use their own crystals because the Pi crystal is very prone to jitter.
I have a 5122 Hat and a 3038q2m Hat and both have their own crystals.
Also I just got a TeraDak player which is basically a nice enclosure with a Pi4. It has 2 TCXO’s (which is a lesser form of the OCXO).
As was mentioned, believe ALL modern DACS have their own timing crystals so if you connect via USB you’ll be all set.
I’m not sure if having the Pi have a OCXO or TCXO is any better than some cheaper options (like the one shown on the 5122).
My unscientific opinion is that you need to go way up the audio food chain (streamers >$2k and Chinese DAC > $750 or European / American DAC > $2k) along with a good integrated amp and very nice speakers for it to make a difference).
You missed the point, my dac has also its own clock. THis here is for the clocks of the PI itsself. USB / network and system clocks.
But you miss our point. Except for the slight possibility of some improvement of audio and video over the HDMI ports, there is no advantage in improving the Raspberry Pi clocks.
that was what i wanted to try;) But I do not expect much either.
As I cannot get a Pi4 anywhere at the moment, i will wait to play with the clocks until i have a spare one, cause there is a chance that i will break the PI, eyes not what they used to be.
good weekend you all
So for interest I purchased [this] (LHY Raspberry Pi 4B Verbeterde en gemodificeerde OCXO Ultra Low Phase Noise Constante temperatuur Kristaloscillator Klokbord - AliExpress 44)
I have run it in for a couple of days, and compared to another unmodified Pi4B as a music server playing LMS, and sending the music stream via ethernet to an ALLO USBridge for playback to a USB DAC, I can confirm the following. (I know this is a volumio forum, sorry!)
Playing the OXCO clock with a separate 5V supply, [ either a Linear Power Supply from China measuring 2mV ripple or a 12VDC SMPS powering a 5V super regulator also measuring 2mV ripple under load ] the standard Pi unmodified sounds considerably better.
All are using the same Pi4 5V supply, which itself makes a large difference to the sound compared to other supplies.
I am going to try taking the 5V from the Pi to the OXCO clock as a last step, so not using a separate supply.
In all cases a common ground between Pi and OXCO was required to make it function.
Oh well, worth a try!
I am trying to find the TeraDak twin oscillator board to try, but can’t seem to get a reliable link on Ali Express, anyone know where they might be available?
Thanks
