This board will be before Kali otherwise you will introduce jitter. While Kali has some noise, its its really much much smaller than and RPI/SBC that has Ghz CPUs sw.
This looks great! I can't wait
How should I power the pi and Kali? At this moment I have already separate powers for the pi and Kali. Do I need another power for this board, or will it feed the Kali?
For a few months I listen to music via the Raspberry PI/Boss Dac combination (with two linear PSU's), which I like very much.
Yesterday and today I tried the Piano 2.1 in dual-mono setting, Volumio RPI image 25th april. (I didn't try the dual-stereo setting.)
In my experience the sound is special. The Piano 2.1 in dual-mono setting is somehow exiting, I want to listen more and more. It is a powerful sound and very open. Does someone recognise this?
Yesterday and today I tried the Piano 2.1 in dual-mono setting, Volumio RPI image 25th april. (I didn't try the dual-stereo setting.)
In my experience the sound is special. The Piano 2.1 in dual-mono setting is somehow exiting, I want to listen more and more. It is a powerful sound and very open. Does someone recognise this?
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I've got one cooking, but won't post comparisons yet or here... see Soundcheck's thread in a few weeks:
http://www.diyaudio.com/forums/digital-line-level/304004-my-new-boss-another-pi-hat-3.html
But for 1st impressions, I'll PM you directly.
Very curious what you did to your HFBD+P... can you post details of your mods in this thread:
http://www.diyaudio.com/forums/digital-line-level/285811-hifiberry-dac-pro-hw-mods-anybody-11.html
I posted a lot about what I did to mine on this thread in the early 2016 timeframe.
Greg in Mississippi
5.9V is on the high side. I have a diyinhk 0.8uV Ultralow noise DAC power supply regulator suppling a nice clean 5V using the same regulator. Can't I use this anymore? Or should I power the Kali direct and leave the power jumper of the Kali? This way only using the ground separation of the isolator board?
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DJ & Jonners,
Thanks for tip. I now have a Boss in slave mode on a Kali breaking-in in one system and a Piano 2.1 on a Kali in 'Twinned' mode in the other. Both are good, the Boss' bass is stronger and more impactive along with more pure and sweet trebles, the imaging of the Twinned Piano is very impressive tho.
I'd forgotten how much the Piano is a baby Boss without all the filtering (to keep noise from the Pi from getting through when they share the same power supply) and minus the .33F Supercap and the PPS capacitors. But otherwise very similar with the same regulators and similar bypassing, the main architecture difference is the PCM5142 on the Piano 2.1 versus the PCM5122 on the Boss, but they have the same specs, likely use the same internal path minus the DSP added in the 5142, and should basically sound VERY similar... See here for comparison: PCM5142 2V RMS DIRECTPATH 112dB Audio Stereo DAC with PCM interface and fully programmable miniDSP | TI.com
Maybe Allo can update the Piano 2.1 with:
1. The ability to fairly easily insert separate power.
2. The Supercap and PPS capacitors (or at least change the appropriate caps' spacing and pad size so adventuresome DIY'ers like myself can replace them ourselves).
3. A driver that still uses the basic I2S feed in slave mode, but offers the option of inverting one channel on each DAC so one could use a dual RCA->XLR adapter and run them in balanced mode. Oh, and switch between the built-in filters too!
At this point it would be a good companion to the Boss with a little more flexibility, but only slave mode and needing a Kali to sound its best!
I'm gonna go poke around in the Piano 2.1 and see if I can easily add a feed to power it separately from the Kali.
Update... I can see no easy way to power the Piano 2.1 separately short of cutting pins on the 40-pin expansion header. I cannot find the trace between the 5V input of pins 2 & 4 and the J19 5v pins / input cap on the inductor filter. Ioan, is the Piano 2.1 a multi-layer board?
Greg in Mississippi
Thanks for tip. I now have a Boss in slave mode on a Kali breaking-in in one system and a Piano 2.1 on a Kali in 'Twinned' mode in the other. Both are good, the Boss' bass is stronger and more impactive along with more pure and sweet trebles, the imaging of the Twinned Piano is very impressive tho.
I'd forgotten how much the Piano is a baby Boss without all the filtering (to keep noise from the Pi from getting through when they share the same power supply) and minus the .33F Supercap and the PPS capacitors. But otherwise very similar with the same regulators and similar bypassing, the main architecture difference is the PCM5142 on the Piano 2.1 versus the PCM5122 on the Boss, but they have the same specs, likely use the same internal path minus the DSP added in the 5142, and should basically sound VERY similar... See here for comparison: PCM5142 2V RMS DIRECTPATH 112dB Audio Stereo DAC with PCM interface and fully programmable miniDSP | TI.com
Maybe Allo can update the Piano 2.1 with:
1. The ability to fairly easily insert separate power.
2. The Supercap and PPS capacitors (or at least change the appropriate caps' spacing and pad size so adventuresome DIY'ers like myself can replace them ourselves).
3. A driver that still uses the basic I2S feed in slave mode, but offers the option of inverting one channel on each DAC so one could use a dual RCA->XLR adapter and run them in balanced mode. Oh, and switch between the built-in filters too!
At this point it would be a good companion to the Boss with a little more flexibility, but only slave mode and needing a Kali to sound its best!
I'm gonna go poke around in the Piano 2.1 and see if I can easily add a feed to power it separately from the Kali.
Update... I can see no easy way to power the Piano 2.1 separately short of cutting pins on the 40-pin expansion header. I cannot find the trace between the 5V input of pins 2 & 4 and the J19 5v pins / input cap on the inductor filter. Ioan, is the Piano 2.1 a multi-layer board?
Greg in Mississippi
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The isolator is meant to give the best power to above HATs. It needs to be powered (cannot take power from above hat). Of course you can power your Kali independantly or your dac as long as you dont feed power to HATs below
I wondered about that too, but won't there be addedd distortion if you take + and - signals from different DACs because the Vouts may not exactly match?
Jonners,
I'm sorry I was not clear, I meant having one channel of each DAC chip inverted so that you could take a balanced signal's + & - sides from each chip, one channel per chip. They still won't perfectly match, but this configuration is very common in the industry.
Greg in Mississippi
P.S. AND if this can be done, when using it in single-ended mode, one could swap from one set of RCAs to the other to get phase-inverted mode... something I miss from a previous player I used.
I'm sorry I was not clear, I meant having one channel of each DAC chip inverted so that you could take a balanced signal's + & - sides from each chip, one channel per chip. They still won't perfectly match, but this configuration is very common in the industry.
Greg in Mississippi
P.S. AND if this can be done, when using it in single-ended mode, one could swap from one set of RCAs to the other to get phase-inverted mode... something I miss from a previous player I used.
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Hi.
I'd 100% agree with JeffreyD.
IMO HATs got to be 5V.
Most of us own high quality 5V supplies. Pretty much everything runs @ 5V nowadays.
That keeps the whole playground flexible.
And there are numerous high quality 5V options around.
Early attempts of certain HAT DAC manufacturers (MamboBerry/Audiophonics/??) to run at higher voltages turned out not to be the best choice.
Even you guys run all your boards at 5V -- except this isolator !?!?
Good luck with the product.
Perhaps there'll be an isolated Kali one day. IMO GPIOs should be isolated on the
DACs. That would require just a simple I2S isolator on the Kali.
Cheers
I'd 100% agree with JeffreyD.
IMO HATs got to be 5V.
Most of us own high quality 5V supplies. Pretty much everything runs @ 5V nowadays.
That keeps the whole playground flexible.
And there are numerous high quality 5V options around.
Early attempts of certain HAT DAC manufacturers (MamboBerry/Audiophonics/??) to run at higher voltages turned out not to be the best choice.
Even you guys run all your boards at 5V -- except this isolator !?!?
Good luck with the product.
Perhaps there'll be an isolated Kali one day. IMO GPIOs should be isolated on the
DACs. That would require just a simple I2S isolator on the Kali.
Cheers