Try to improve R-2R Holo Spring3 sound quality by HdmiPiPro/FifoPiQ7 DDC (4) Clocks Phase noise comparison
1.To compare phase noise, oscillators have to be at the same frequency.
2.45.1584MHz is selected for the comparison because 45/49 MHz clocks can cover the full digital audio ranges from 44.1 to 384KHz
3.SC-Pure phase noise was measured recently by a calibrated E5052 phase noise analyzer from a third party.But all other phase noise numbers are collected from published datasheets or websites.So please correct me if there is anything wrong.
4.No doubt, phase noise numbers have a big impact on the DAC sound quality, but it may not be 100% related.It could be because of the limitation of the fundamental frequency only phase noise measurement method. DAC runs by the square wave clock, not the sine wave. However, each harmonic frequency has its own phase noise and they all contribute to the final phase noise of the square wave clock. That’s why clocks with the similar phase noise numbers could still sound differently.
5. I could be the one who did the most listening tests to different clock oscillators besides Doede. Based on my own experiences of the listening tests, I've found that the close-in phase nose, the phase noise floor and the phase noise in between (Leeson’s equation applied) are all significant to the sound quality. An oscillator can not achieve a higher grade sound quality if it doesn’t have good close-in phase noise even though its noise floor is great. On the other hand, a good close-in phase noise oscillator can also sound a bit fat, less sound stage any dynamic if the noise floor or the phase noise in between are not great.
6.45.1584MHz Neutron Star2 is a pretty expensive clock. But I found it just uses a fundamental non SC-CUT cut crystal (not the 3OT SC-CUT) . It does have a heater on the PCB but just to keep the crystal temperature stable at around 40 degree C regardless of the ambient temperature. Don’t know why NewClassD didn’t publish the phase noise specifications.
7. Normally SC-Cut crystal oscillators have both better overall phase noise performance and better sound quality than AT-Cut crystal oscillators.
8. Limited by the noise floor of a phase noise analyzer, oscillators with great far off phase noise may not correctly show from the measurement results.
Previous posts:
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-405#post-7220567
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-410#post-7237245
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-411#post-7245259
PhaseNoiseComparison by Ian, on Flickr
ClocksToTest by Ian, on Flickr
1.To compare phase noise, oscillators have to be at the same frequency.
2.45.1584MHz is selected for the comparison because 45/49 MHz clocks can cover the full digital audio ranges from 44.1 to 384KHz
3.SC-Pure phase noise was measured recently by a calibrated E5052 phase noise analyzer from a third party.But all other phase noise numbers are collected from published datasheets or websites.So please correct me if there is anything wrong.
4.No doubt, phase noise numbers have a big impact on the DAC sound quality, but it may not be 100% related.It could be because of the limitation of the fundamental frequency only phase noise measurement method. DAC runs by the square wave clock, not the sine wave. However, each harmonic frequency has its own phase noise and they all contribute to the final phase noise of the square wave clock. That’s why clocks with the similar phase noise numbers could still sound differently.
5. I could be the one who did the most listening tests to different clock oscillators besides Doede. Based on my own experiences of the listening tests, I've found that the close-in phase nose, the phase noise floor and the phase noise in between (Leeson’s equation applied) are all significant to the sound quality. An oscillator can not achieve a higher grade sound quality if it doesn’t have good close-in phase noise even though its noise floor is great. On the other hand, a good close-in phase noise oscillator can also sound a bit fat, less sound stage any dynamic if the noise floor or the phase noise in between are not great.
6.45.1584MHz Neutron Star2 is a pretty expensive clock. But I found it just uses a fundamental non SC-CUT cut crystal (not the 3OT SC-CUT) . It does have a heater on the PCB but just to keep the crystal temperature stable at around 40 degree C regardless of the ambient temperature. Don’t know why NewClassD didn’t publish the phase noise specifications.
7. Normally SC-Cut crystal oscillators have both better overall phase noise performance and better sound quality than AT-Cut crystal oscillators.
8. Limited by the noise floor of a phase noise analyzer, oscillators with great far off phase noise may not correctly show from the measurement results.
Previous posts:
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-405#post-7220567
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-410#post-7237245
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-411#post-7245259
PhaseNoiseComparison by Ian, on Flickr
ClocksToTest by Ian, on Flickr
Does it show the isolated side after the reclocking? Or before reclocking Ian? Ed, I would buy a cheap oscilloscope and measure the signals at the GPIO (both) and UF/L connectors
Hello,
This is what is says in the Monitorpi manual:
Play music and then the real time digital music signal information will be displayed on the OLED screen. I could check if turn of the power supply going to the Italian clock circuits.
@Doede i will try to a VERY easy handheld oscilloscope on amazon. Any suggestions?
By the way i think that using these Italian circuits is a nuisance. It will be ok on the big workbench where everything can be positioned in an easy way and both hands can reach all parts in an easy way. Once it is in a rack that cannot be moved i already start swearing before doing anything.
SO a good idea to have new Ian's clocks which can be installed very easily. Maybe there will be some modifications popping up to stop vibrations reaching the clocks.
Using grommets while connecting circuits with sturdy cables will be like a suspended turntable with a massive cable plugged into the armbase. Are the clocks sensitive to airborne vibration or do vibrating transformers spreading their movements by sturdy stand offs used everywhere having more negative effects.
Of course Ian will not state that his clocks are the best. We, the buyers should do that.
Now i am using station pi but i am thinking about switching to shieldpi pro mk2 when using technical identical power supply set up which one will be the best? Using Raspberry Pi3+ and Q3 but will get Q7 this week. If i can create extra space by doing this i will ditch the big lifepo4 board and get a pair of Eaton to use with the first UCpure board to supply the 3.3 Q7 side
Probably when using clocks inside the chassis you should not use any switching power supplies.
Greetings, eduard
This is what is says in the Monitorpi manual:
Play music and then the real time digital music signal information will be displayed on the OLED screen. I could check if turn of the power supply going to the Italian clock circuits.
@Doede i will try to a VERY easy handheld oscilloscope on amazon. Any suggestions?
By the way i think that using these Italian circuits is a nuisance. It will be ok on the big workbench where everything can be positioned in an easy way and both hands can reach all parts in an easy way. Once it is in a rack that cannot be moved i already start swearing before doing anything.
SO a good idea to have new Ian's clocks which can be installed very easily. Maybe there will be some modifications popping up to stop vibrations reaching the clocks.
Using grommets while connecting circuits with sturdy cables will be like a suspended turntable with a massive cable plugged into the armbase. Are the clocks sensitive to airborne vibration or do vibrating transformers spreading their movements by sturdy stand offs used everywhere having more negative effects.
Of course Ian will not state that his clocks are the best. We, the buyers should do that.
Now i am using station pi but i am thinking about switching to shieldpi pro mk2 when using technical identical power supply set up which one will be the best? Using Raspberry Pi3+ and Q3 but will get Q7 this week. If i can create extra space by doing this i will ditch the big lifepo4 board and get a pair of Eaton to use with the first UCpure board to supply the 3.3 Q7 side
Probably when using clocks inside the chassis you should not use any switching power supplies.
Greetings, eduard
@iancanada : What price range should we expect for the SC-Pure and what release date for Europe (Audiophonics)?
@ eduard,
for quick Check of Signals are ok (voltage level and rough shape and existence) this will certainly do.
Amazon Link
for quick Check of Signals are ok (voltage level and rough shape and existence) this will certainly do.
Amazon Link
I finally scored a RPi and was able to complete this phase of my build. Thanks to Gabster for the inspiration, redjr for some tips and tricks (and inspiration) and of course to Ian for the great engineered boards and know how sharing. Now it is time to listen and fine tune. Attached some pics.
BTW: As you can see, I am using Ivan's large I/V transforms and the stack is about 1 mm above the internal height of the case. This was a design decision I (had to make) made from the start as I did not want to go with a higher case that would not fit my rack. Looks odd but came out OK.
BTW: As you can see, I am using Ivan's large I/V transforms and the stack is about 1 mm above the internal height of the case. This was a design decision I (had to make) made from the start as I did not want to go with a higher case that would not fit my rack. Looks odd but came out OK.
Attachments
Looks good @MartinJohn Odd looking can be okay in the DIY realm. 
As long it works right and the sound is to your liking. Unlike a lot of other audio hardware, DACs and streamers are made to be tweaked - especially Ian's suite of products. He's opened a whole new world, or customization and innovation. From RPis to pure battery operation to clocks, and every conceivable I/O shield to quiet PSUs. Good stuff.
As long it works right and the sound is to your liking. Unlike a lot of other audio hardware, DACs and streamers are made to be tweaked - especially Ian's suite of products. He's opened a whole new world, or customization and innovation. From RPis to pure battery operation to clocks, and every conceivable I/O shield to quiet PSUs. Good stuff.Hello,
Just a basic question when using Q7 board with the raspberry Pi3+ and technically the same power supplies which '' set up '' will give the best result two stacks on a stationpi ( pro) or Raspberry , Q7 separated with a shieldpi pro MK2.
Most of the '' information cables/connections '' look to tricky to me so having information shared by using bigger terminals feels better to me.
Greetings, eduard
Just a basic question when using Q7 board with the raspberry Pi3+ and technically the same power supplies which '' set up '' will give the best result two stacks on a stationpi ( pro) or Raspberry , Q7 separated with a shieldpi pro MK2.
Most of the '' information cables/connections '' look to tricky to me so having information shared by using bigger terminals feels better to me.
Greetings, eduard
Hello Simon,
I know about the importance of good power supplies. In the eighties i had the Hiraga 30 watt amp with the crazy power supply and the MC prepre designed by Hiraga with big sealed lead batteries.
This time i am just curious about the interference between circuit boards using stationpi or shieldpi.
Of course there is the use of Hirose u.fl connectors with are not designed for lots of mating/unmating cycles.
Greetings, eduard
I know about the importance of good power supplies. In the eighties i had the Hiraga 30 watt amp with the crazy power supply and the MC prepre designed by Hiraga with big sealed lead batteries.
This time i am just curious about the interference between circuit boards using stationpi or shieldpi.
Of course there is the use of Hirose u.fl connectors with are not designed for lots of mating/unmating cycles.
Greetings, eduard
Ian, I check this forum like its Christmas morning every day waiting to hear your impressions of the clocks. No rush on the SC-CUT release, rather wait until you are 100% satisfied with it, but even a sneak preview would be much appreciated. Just want to hear how they compared to Accusilicon. Similar but slightly better or do they just blow the Accusilicons away?
@MartinJohn,
Looks very nice your setup. Raising the output transformers to mimic a tube amp would also be nice.
What case did you use?
Looks very nice your setup. Raising the output transformers to mimic a tube amp would also be nice.
What case did you use?
That is a beautiful looking setup, glad I sparked some inspiration.
Feels amazing to build and finish your own Dac. Congrats and thank you for sharing.
UcPureMkIII New features
#41C github.com/iancanada/DocumentDownload
• Add a powerful SYNC UC charging function. Can re charge the UCs during music stops. T his
feature can avoid the output voltage drop or trigger the protection mode even if you listen to music
for a very long time. SYNC control signal can be connected to the MUTE signal of a FifoPiQ7. M ore
UcPure MKIII can work together with this signal as a control chain This signal is isolated from
UcPure MkIII so it doesn’t affect the power supply performance at all.
• Upgrade to higher capacitance, higher voltage and ultra low ESR smoothing capacitors. Make the
UcPure MKIII works better for both AC and DC input and tolerance more to different input power
supplies.
• Upgrade to heavy duty high performance 10A fast acting standard 5*20 mm glass fuse
• Optimized for both DC and AC inputs
• Bigger and stronger ON/OFF switch on top side of the PCB
• More than one UC group s can be in parallel to improve performance more
UcPureMkIII by Ian, on Flickr
#41C github.com/iancanada/DocumentDownload
• Add a powerful SYNC UC charging function. Can re charge the UCs during music stops. T his
feature can avoid the output voltage drop or trigger the protection mode even if you listen to music
for a very long time. SYNC control signal can be connected to the MUTE signal of a FifoPiQ7. M ore
UcPure MKIII can work together with this signal as a control chain This signal is isolated from
UcPure MkIII so it doesn’t affect the power supply performance at all.
• Upgrade to higher capacitance, higher voltage and ultra low ESR smoothing capacitors. Make the
UcPure MKIII works better for both AC and DC input and tolerance more to different input power
supplies.
• Upgrade to heavy duty high performance 10A fast acting standard 5*20 mm glass fuse
• Optimized for both DC and AC inputs
• Bigger and stronger ON/OFF switch on top side of the PCB
• More than one UC group s can be in parallel to improve performance more
UcPureMkIII by Ian, on Flickr
Last edited:
I'm finally getting around to assembling UcPureGen1 and hoping for some confirmation before plugging into the wall outlet.
I'll take some photos when there's some Sunlight.
I only use Solid Core wiring as I believe it's more difficult for RFI to seep in since it's solid. Traditional wiring has gaps for RFI to sneak into. Ian's products are already solid as they isolate from Mains, but I consider traditional wiring a weakness so I standardised on Solid Core Wiring.
I'll take some photos when there's some Sunlight.
- Attach bussbar on -+ to Series Eaton 3000F.
- + - needed on other side, so they each have their individual bussbar.
- Attach - bussbar to - J7 with 18G Solid Core Cooper.
- Attcach + bussbar to + J7 with 18G Solid Core Cooper.
- Confirm with community it's good to go.
- Plug in with Medical Grade Mean Well 19V SMPS.
I only use Solid Core wiring as I believe it's more difficult for RFI to seep in since it's solid. Traditional wiring has gaps for RFI to sneak into. Ian's products are already solid as they isolate from Mains, but I consider traditional wiring a weakness so I standardised on Solid Core Wiring.