Asynchronous I2S FIFO project, an ultimate weapon to fight the jitter

[Lso]

Hi Ian
I have the es9028 dac and opa861, i have measure it and there is quiet large amount off distortion, a have THD measurement around 65% at 0db and 80% at -3db volume, is it a problem between tha es9028 and the opa861?
Kind regards Lars

 

[iancanada]

Do you have other DAC, such as a ES9038Q2M DM?
You can use a known good DAC to figure out if it is a DAC issue or the I/V issue.

 

[Lso]

I have measured the Topping D90 with the same equipment and there a have a tHD around 120%, i have a suspicious to a problem with your es9028 and opa861, will it be better with the es9038 dac. I have the FIFOQ7 in the setup too.

 

[iancanada]

Ian,

First, thank you for your designs, they are wonderful especially for what they cost and work as advertised, or better! I recently installed the FifoPi Q7, which replaced a FifoPi Ultimate, and also installed a UCPure Mk II.

A few questions on the UCPure Mk II. I want to power my DDDAC with it and 15V is too high, the DDDAC needs 12V input. I tried connecting the positive wire to my DAC at the point bypassing the last battery of the 6 series connected supercaps, to give me a 12.5V supply. This worked for a while but caused the last battery not in use to eventually go over-voltage. The red LED on the protection board came on after a few charging cycles. Is there a way to effectively drop the max charge level to between 12 and 12.5V by using a different combination of jumpers S2, S4, S6?

Also, I noticed the voltage was at 15.6V fully charged, and drops all the way down to about 12.5 before it would start the charge cycle, is this normal? And if so, is there a way to change that to about 13.5 - 14V to start the charge cycle? But, ideally I would want to have 12.5V fully charged and start charging at 11V.

For now I'm using 3, hexfet 8 amp rectifier diodes in series to drop the voltage, but I'm not sure that is the best solution. BTW, it sounds AMAZING powering the DAC and Q7 reclocker with the 6 supercaps, very noticeably better than simply powering your FifoPI Q7 with 2 supercaps and leaving the DDDAC powered by Doede's regular PS. With the 6 supercaps powering the DDDAC, the FifoPi Q7 gets "clean" power from an ADM7150 3.3V regulator I installed on the DDDAC mainboard.

Thanks in advance for any help on this DAC setup.

Richard

Just a more or less educated guess:
If the DAC Chip has to drive 2 instead of 1 output, for sure the distortion will increase as the ideal operating point of the output stage of the DAC has now changed into a non-optimal zone.
Seems you are looking for a (passive) preamp, which is then connected to a headphone amp and the power amp?

Hi guys,

Sorry for my late update. I was tied up with design SC-PURE clocks.
I figure out the 12V UcPure configuration, the solution is here:
https://www.diyaudio.com/community/...fight-the-jitter.192465/page-421#post-7330696

Good weekend.
Ian

 

[Heathkit]

12V configuration for UcPure MkII/MkIII

UcPure with 3000F ultra capacitors could be the best low noise power supply in the real world. I know a lot of people want a 12V configuration to upgrade their DDDAC, So the solution is here:

1. Replace S2 with a 390K 0603 resistor, can be RT0603DRE07390KL
2. Keep S4 OPEN
3. Replace S6 with 232K 0603 resistor, can be RR0816P-2323-D-36D

Under this configuration, the UcPure will be:
12.6V: fully charged
10.3V: Trigger the protection mode to re-charge the UCs
12.33V: Back to pure mode when reach this voltage

Please make sure all the voltages are correct before connecting to your DAC if you want to change to this configuration.

Implemented and working great! Thank you Ian for bringing this 12V solution!

 

[iancanada]

@Heathkit

I'm glad the 12V UcPure solution is working for you. Congratulations!
For 12V solution, you can use only 5 ultra capacitors, one UC cell can be saved.

Ian

 

[Heathkit]

Ian,

I thought the UC's had to be used in pairs to retain the balancer PC board that is between each pair of cells. I have all 6 in series and it appears to working fine. Charging turns on at 10.25V and stops at 12.6V. But if you think 5 cells is better I'll connect it that way...

 

[iancanada]

@ Heathkit

I think it's better to stick with 6 cells configuration if the balancer boards have to work for pairs. 6 and 5 cells, the performance differences are very small.

 

[BogdanS]

Is the any possible to add a USB DVD ROM to make it having a CD player function?

​

Regards,
Ian

I use Moode with https://github.com/TheOldPresbyope/moOdeCDPlay

 

[JanDH]

Ha Ian,

Misschien niet het juiste onderwerp voor deze vraag:

Kan je mono dac worden gebruikt met hqplayer in dsd-modus? Kan het dac-filter worden doorgegeven en kan de dac rechtstreeks vanuit hqplayer worden gevoed.

Bedankt,
Jan

 

[Batenet]

@ Batenet,

Your streamer project looks awesome, you did a good job. Congratulations!

What external DAC are you using? How do you like the Neutron clocks?

Ian

Audio-Gd R-7HE r2r dac,have Neutronstar 3 ref. clock. Very resolving clocks,with high transparency/clarity.

 

[iancanada]

True OCXOs, SC-CUT crystal
45.1584/49.1520MHz Audio frequencies
RFX UK made
Could be the only available real audio frequency OCXOs that can be touched so far.
5V DC input. UcPure with two 3000F UCs could be the best possible power supply.


OCXO_RFX_Audio by Ian, on Flickr

 

[SimonJ]

Fantastic Ian and I look forward to hearing all of the capabilities and integration to FiFoPi

 

[alecm]

Ian, this is a game-changer!!!!

 

[alecm]

Nice noise plot for the 10mhz version of the clocks. The result should be much much better than CRYSTEK

 

[crm75]

True OCXOs, SC-CUT crystal
45.1584/49.1520MHz Audio frequencies
RFX UK made
Could be the only available real audio frequency OCXOs that can be touched so far.
5V DC input. UcPure with two 3000F UCs could be the best possible power supply.


OCXO_RFX_Audio by Ian, on Flickr

Very nice! I suppose should be connected to SinePi. Will be a newer version of SinePi also?

 

[ctpirn]

Just had an update from mouser. The BCAP0325 P270 S17 used in Ian's designs is now Obsolete.
They canceled all of my pending orders 🙁

 

[SimonJ]

There will be alternatives you can use which is good news 🙂

 

[crm75]

Just had an update from mouser. The BCAP0325 P270 S17 used in Ian's designs is now Obsolete.
They canceled all of my pending orders 🙁

Seems like the new version is BCAP0325 P270 S19:

 

[redjr]

Thanks @crm75 for this info. It all makes sense from Maxwell's standpoint - offering a new product replacement that's plug-n-play compatible. Just wish Mouser had offered us a less restrictive return/replace policy.