Hi Ian
I managed to get hold of a IsolatorPI from a fellow DIYaudio member. The board is very nice and have already installed it with great succes.
I have been messing a bit with the master/slave jumbers on the IsolatorPi. I can only get it to work in slave mode. I have connected the I2S signal to a SRC4192 ASRC module from Twisted Pear(Metronome). The board is set to output master mode at 256fs. That signal is passed on to a PCM1794a COD DAC also from Twisted Pear.
Maybe i have misunderstood the Master/slave idea but do you know why the master jumper setting is not working?
Thanks in advance
Btw: Your new FifoPi looks really good! That could be the newt upgrade
Thank miklau,
The IsolatorPi master mode was designed to work with master mode RPi DAC HAT such as Hifiberry Pro +. Those master mode DAC HATs usually need Linux driver to run.
For external high-end DAC, to improve sound quality, you will need FifoPi to make audio master clock local and asynchronized with clocks from RPi.
Regards,
Ian
@jonners @iancanada
Thank you both for the help and fast reply I will keep an eye out for the FifoPI
I have also tried a KALI Reclocker in master, but would this be same regarding the Linux Driver?
I am trying to make a mute function and the PCM1794s soft mute requires a pin set to high.
I would like to use the isolated GPIO pin for this since I have a shared ground between the DAC power supply and the Isolator Pi. The ground to the RPI is not shared.
I have tried to use Pin 15,22,31 but they seem to be always pulled high? Can I control these pins or would you recommend a relay/transistor and then use the unisolated side?
Regards Mikkel
Thank you both for the help and fast reply
I will keep an eye out for the FifoPI I have also tried a KALI Reclocker in master, but would this be same regarding the Linux Driver?
I am trying to make a mute function and the PCM1794s soft mute requires a pin set to high.
I would like to use the isolated GPIO pin for this since I have a shared ground between the DAC power supply and the Isolator Pi. The ground to the RPI is not shared.
I have tried to use Pin 15,22,31 but they seem to be always pulled high? Can I control these pins or would you recommend a relay/transistor and then use the unisolated side?
Regards Mikkel
@jonners @iancanada
Thank you both for the help and fast reply
@miklau
FifoPi has built-in isolator and an isolated mute signal output(active high). I think it works for your application.
FifoPi also doesn't need any special Linux driver. It works with any external DAC including PCM1794 with providing local MCLK.
Regards,
Ian
Hi Ian
Thanks again Sorry if I ask wrong but would I be possible to control the Isolated pins 15,22,31 on the IsolatorPi? I just took this from page 4 at the IsolatorPi User manual where they are listed as pull up with the 4.7k resistor. But not sure if they are controllable or always high?
Regards Mikkel
Thanks again
Sorry if I ask wrong but would I be possible to control the Isolated pins 15,22,31 on the IsolatorPi? I just took this from page 4 at the IsolatorPi User manual where they are listed as pull up with the 4.7k resistor. But not sure if they are controllable or always high? Regards Mikkel
Thanks again
@miklau,
That's no any problem. You can use GPIO pin31 on my IsolatorPiII as the mute signal. It's 100% isolated from RPi ground.
Regards,
Ian
@miklau
Yes, it's possible. IsolatorPi I has a reserved GPIO pin15 for isolation function. But it was not standard equipped. You need to assemble a SMT optical isolator by your self. Please let me know if your really want to do so. However IsolatorP II can be used directly for this feature.
Regards,
Ian
Yes, it's possible. IsolatorPi I has a reserved GPIO pin15 for isolation function. But it was not standard equipped. You need to assemble a SMT optical isolator by your self. Please let me know if your really want to do so. However IsolatorP II can be used directly for this feature.
Regards,
Ian
Power sequence of Isolator Pi and RPI
Hi Ian
I was just wondering if everthing is fine if I power the isolator pi and my raspberry pi simultaneously? Your manual just state to power the Isolator first and then the RPI. If there is sound is everything fine or would SQ improve if powering the RPI with a 1-2 sec delay?
Thanks
Hi Ian
I was just wondering if everthing is fine if I power the isolator pi and my raspberry pi simultaneously? Your manual just state to power the Isolator first and then the RPI. If there is sound is everything fine or would SQ improve if powering the RPI with a 1-2 sec delay?
Thanks
I am trying to understand whether I should wire my ODroid C2 directly to my DAC by I2S, or if there would be a major benefit by going to something like the isolator hat, FIFO board, McFifo? There are quite a few choices here so it's difficult to determine which is the best one. I do not wish to use RPI because of its slow Ethernet connection. I want to keep the ODroid C2 because of its GbE and eMMC storage. I must find the best choice for ODroid C2.
I was planning on making a cable to run from my C2 7 pin I2S header to the RJ45 input of my Audio-GD NFB7.77 according to the photo attached. The NFB7.77 should be able to clock the signal without the MCLK present. Without the MCLK, do I need to worry at all about poor clock quality from the C2? Would there be a vast improvement by going with a McFifo or I2S isolator hat? All input is appreciated.
I was planning on making a cable to run from my C2 7 pin I2S header to the RJ45 input of my Audio-GD NFB7.77 according to the photo attached. The NFB7.77 should be able to clock the signal without the MCLK present. Without the MCLK, do I need to worry at all about poor clock quality from the C2? Would there be a vast improvement by going with a McFifo or I2S isolator hat? All input is appreciated.
Attachments
Hi everybody.
I have used the isolatorPi with an IQaudio Dac+ working in slave mode.
I have now bought an Allo Boss 1.2, which works in master mode.
Therefore on the isolatorPi I should reverse the jumper settings on J11 and J12 to make it works with master mode dac, correct?
My second question is about powering.
Should I use the J1 power input on the isolatorPi or could/should I use the USB type c connector on the Allo Boss Dac?
On the Boss Dac I have already removed the J25 jumper because I'am already powering the Boss and the RPI individually.
In this situation, does indeed make sense to add the isolatorPI or the separation already implemented in Boss 1.2 powering already provides galvanic isolation?
Thanks for any insight on this!
Franz
I have used the isolatorPi with an IQaudio Dac+ working in slave mode.
I have now bought an Allo Boss 1.2, which works in master mode.
Therefore on the isolatorPi I should reverse the jumper settings on J11 and J12 to make it works with master mode dac, correct?
My second question is about powering.
Should I use the J1 power input on the isolatorPi or could/should I use the USB type c connector on the Allo Boss Dac?
On the Boss Dac I have already removed the J25 jumper because I'am already powering the Boss and the RPI individually.
In this situation, does indeed make sense to add the isolatorPI or the separation already implemented in Boss 1.2 powering already provides galvanic isolation?
Thanks for any insight on this!
Franz
Hi Ian
I was just wondering if everthing is fine if I power the isolator pi and my raspberry pi simultaneously? Your manual just state to power the Isolator first and then the RPI. If there is sound is everything fine or would SQ improve if powering the RPI with a 1-2 sec delay?
Thanks
The power up sequence is only related the initialization timing of HAT on top of IsolatorPiI or IsolatorPiII. Because of the pretty slow RPi boot up time, I don't think there is any problem to power them simultaneously. I didn't see it has anything to do with sound quality.
Regards,
Ian
Please refer to IsolatorPi or IsolatorPiII user's manual for settings running whith master DAC.
Powering RPi from GPIO would be always better than from a USB cable.
Regards,
Ian
Thanks for your replay Ian
I am still planning on adding an extra isolated pin connector on the IsolatorPi I. Could you please direct me to what type of small SMD components I should buy to build this?
Thanks in advance
Apologies for my dumb questions... if I power the IsolatorPi through the deicated J1 connector, the IsolatorPi will then in turn power the connected audio board, Allo Boss in my case.
But the raspberry will always be powered through its micro-USB port (connected to a USB cable), so I'm not sure I understand your answer above.
Unless I'm missing something....
If you have an IsoaltorPi II, you can power RPi through J2 on IsoaltorPi II rather than from micro-USB. This is a better solution.
Regards,
Ian
FifoPi doesn't have Odroid I2S port. If you really want to use it with FifoPi, you will need a IsolatorPi or IsolatorPiII in between.
Regards,
Ian