Katana Sound Quality Stack
If you have the Sound Quality Op Amp board in your Katana stack have a look at the two green ovals in the attached picture. I noticed that the two standoffs between the Katana board and the Op Amp board on this side were not tight. Any attempt to tighten the standoff would cause the boards to bend. The eight pin connector between these two boards was tight, but the standoffs were not. I believe this is caused by the small board that Allo added to the Sound Quality Op Amp board. This tiny board appears to go under the 8 pin connector.
Changing these two standoffs from 11mm to 12mm solved the problem. However, I found that I needed to leave the two 11mm standoffs on the opposite side of the board as the 12 pin connector on the back of the board didn't seat correctly with 12mm standoffs.
I was not happy with the fit of the acrylic case on my stack and I will not be using it. The middle red oval shows the device heat sink touching the bottom of the top cover while there is almost an 1/8" (~3mm) gap to the top of the posts on each side. The cutout in the top cover of my case does not allow the heatsink to pass through.
The music is great however. I am waiting for my linear power supply parts to arrive and looking forward to the change that it will make.
If you have the Sound Quality Op Amp board in your Katana stack have a look at the two green ovals in the attached picture. I noticed that the two standoffs between the Katana board and the Op Amp board on this side were not tight. Any attempt to tighten the standoff would cause the boards to bend. The eight pin connector between these two boards was tight, but the standoffs were not. I believe this is caused by the small board that Allo added to the Sound Quality Op Amp board. This tiny board appears to go under the 8 pin connector.
Changing these two standoffs from 11mm to 12mm solved the problem. However, I found that I needed to leave the two 11mm standoffs on the opposite side of the board as the 12 pin connector on the back of the board didn't seat correctly with 12mm standoffs.
I was not happy with the fit of the acrylic case on my stack and I will not be using it. The middle red oval shows the device heat sink touching the bottom of the top cover while there is almost an 1/8" (~3mm) gap to the top of the posts on each side. The cutout in the top cover of my case does not allow the heatsink to pass through.
The music is great however. I am waiting for my linear power supply parts to arrive and looking forward to the change that it will make.
Attachments
@Bryce, I had same issue here. For the top not fitting properly, in my case it was due to the opening around the metal plate close to the 3 filter DIP switch not being long enough. All I did was to cut a little piece in the corner to allow the metal plate to fit. Just be careful while cutting, the plastic is fragile and could could risk to break it all into little pieces.
That's great to hear. 
Hi Guys,
In Katana documentation I read that the Rpi gpio pin that are used are pins 3,5,35,12 and 40. Is that all for signal?
What pin is used by isolator for power? 2? 4? or both?
What pin is used by isolator for ground?
I would like to connect pi to isolator using short wires to fit my casing model.
Thank you for your help.
Terry
In Katana documentation I read that the Rpi gpio pin that are used are pins 3,5,35,12 and 40. Is that all for signal?
What pin is used by isolator for power? 2? 4? or both?
What pin is used by isolator for ground?
I would like to connect pi to isolator using short wires to fit my casing model.
Thank you for your help.
Terry
@cdsgames
I have been following this thread for some time. Being a happy owner of the Boss 1.2, I am looking for further advancement in SQ from Allo, but without the complexity of several PSU’s, or of having to become a constucter again.
So your post that Allo is working on a simpler solution has me very interested.
Keep up the good work and I await further news in this area.
Rob
My Katana 1.2 (SQ Board and Isolator) is sound so musical. It pulls me into the music like playing LP on a great TT.
I have about 200 hours in the unit with 5 listening sessions. Most of the break in is with powered speakers and some time i run an Internet station without the amp on.
For those of you who want to get the Best SQ, use Linear powers supplies, good ones!
At this time I have two great Military Regulated LPS in use, a 5V 4 and a +/-15 Volt 1,o amp. The +-15v is used for the SQ board and i have it connected to pin headers on the Micro controller boar, jumpers removed.
The 5v LPS is connected to the MC board, below on the Super cap. Son I will have to install a DIY LT3042 board with dual halves and a dual winding toroidal transformer. That will power the MC board and the katana dac.
The IFI Ipower 5v is connected to the bottom of the RPI board. I plan and moving the 5v 4 amp LPS to that positions once I am ready to install it.
What is hear is such great resolution, esp, it the midrange. The detail is recordings, esp, good ones bring out the music like i have not hear it before. The separation is reminded me of analog.
The background is dead silent, a great treat. I do have my whole system plugged int to isolation transformer which helps yet compared to the Boss 1.2, the Katana 1.2 with isolator board and the setup i described earlier, gives the ultra quiet, black velvet background..
I have about 200 hours in the unit with 5 listening sessions. Most of the break in is with powered speakers and some time i run an Internet station without the amp on.
For those of you who want to get the Best SQ, use Linear powers supplies, good ones!
At this time I have two great Military Regulated LPS in use, a 5V 4 and a +/-15 Volt 1,o amp. The +-15v is used for the SQ board and i have it connected to pin headers on the Micro controller boar, jumpers removed.
The 5v LPS is connected to the MC board, below on the Super cap. Son I will have to install a DIY LT3042 board with dual halves and a dual winding toroidal transformer. That will power the MC board and the katana dac.
The IFI Ipower 5v is connected to the bottom of the RPI board. I plan and moving the 5v 4 amp LPS to that positions once I am ready to install it.
What is hear is such great resolution, esp, it the midrange. The detail is recordings, esp, good ones bring out the music like i have not hear it before. The separation is reminded me of analog.
The background is dead silent, a great treat. I do have my whole system plugged int to isolation transformer which helps yet compared to the Boss 1.2, the Katana 1.2 with isolator board and the setup i described earlier, gives the ultra quiet, black velvet background..
Making a DAC with one PSU is a great challenge . As you can see from Katana "saga" the DC/DC convertor will always introduce some audible noise in the output. Our main efforts will be on how to bring great sound from it . Decoupling of the opamps will be studied but most important , tested .
@cdsgames,
Do you know what gpio pins are used by isolator and katana?
Power and GND?
thanx
Do you know what gpio pins are used by isolator and katana?
Power and GND?
thanx
@terry22,
Depending on your casing dimensions and component location, you might be able to use IQAudio's GPIO Expander:
Accessories - IQaudIO Limited
I've seen other commercial products that provide remote access to all of the GPIO pins. Just do a search for RPi GPIO Extender or Expander.
Just a thought!
Greg in Mississippi
Depending on your casing dimensions and component location, you might be able to use IQAudio's GPIO Expander:
Accessories - IQaudIO Limited
I've seen other commercial products that provide remote access to all of the GPIO pins. Just do a search for RPi GPIO Extender or Expander.
Just a thought!
Greg in Mississippi
@cdsgames.
Thank you if you can give me the info.
I didn't understand why pin 2 and pin 4 were higlited(needed) in the docs. And there was no mention of ground pin.
Thank you for the link Greg. I'll have a look if it may fit.
the stack with rpi+ isolator + 3 katana board is really too high for my case.
I would like to have rpi+ isolator and the 3 katana boards side by side.
Thank you if you can give me the info.
I didn't understand why pin 2 and pin 4 were higlited(needed) in the docs. And there was no mention of ground pin.
Thank you for the link Greg. I'll have a look if it may fit.
the stack with rpi+ isolator + 3 katana board is really too high for my case.
I would like to have rpi+ isolator and the 3 katana boards side by side.
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First test on new LPS at 2A. Spike at 20Khz is observed in all testing of PSUs , its just earthing. Most noise (audioband) is under -135dbv = 200nV
Output (last reservoir ) are supercaps .
Whole next week we will test.
Output (last reservoir ) are supercaps .
Whole next week we will test.
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Cdsgames,
Will the Audiophile Rpi be compatible with the other streamers and digone transports? Will it be a snug fit for the Rpi-Katana-Isolator housing? Hopefully, allo will consider this upgrade with their existing products.
Actually my USBRIDGE right now is so left behind(my decision not to leave volumio in the Sparky). I feel usbridge is so isolated now from allo's
development. MoOde though, is my preferred Rpi OS for my allo rigs.
With compatibility of the new Audiophile Rpi. We can only expect a vertical upgrade of the katana.
I still prefer the Rpi because of the immense availability of distro for now.
@cdsgames
Why don't you open a proper "Allo" vendor forum?
Each product gets a thread.
Announcements get a thread.
New projects get a thread.
asf.
Quite some interesting info gets simply buried in e.g. a "New Fifo.." thread or other threads which just a few people are reading.
I'm sure that'd make live for you and us much easier.
And most serious vendors are actually doing it.
Please consider it - at least if you guys plan to stick around for a while. 😉
Thx.
Why don't you open a proper "Allo" vendor forum?
Each product gets a thread.
Announcements get a thread.
New projects get a thread.
asf.
Quite some interesting info gets simply buried in e.g. a "New Fifo.." thread or other threads which just a few people are reading.
I'm sure that'd make live for you and us much easier.
And most serious vendors are actually doing it.
Please consider it - at least if you guys plan to stick around for a while. 😉
Thx.
Hi Soundcheck
I will contact the moderators and ask for the forum. One year back , I have tried tand was told there is no space.
Meanwhile Nirvana PCB will arrive after Chinese new year (so around the 15 of Feb). LPS testing is going one ..we tuned the filters and arrived under -140dbV (0-30Khz) and 4uV or less 0-5Mhz
-140 is 100nV..
I have reserched LPS and published data , the low noise ones are advertised around 1uV. I see nothing like our LPS
I will contact the moderators and ask for the forum. One year back , I have tried tand was told there is no space.
Meanwhile Nirvana PCB will arrive after Chinese new year (so around the 15 of Feb). LPS testing is going one ..we tuned the filters and arrived under -140dbV (0-30Khz) and 4uV or less 0-5Mhz
-140 is 100nV..
I have reserched LPS and published data , the low noise ones are advertised around 1uV. I see nothing like our LPS
Audiophile RPI is primarily a USBbridge with a Compute module RPI 90deg Sodimm . Yes it has a RPI connector and you will be able to use Digione , Boss and even Sig and Katana (but box might not be very pretty on the last 2 ones)
Still we have a while to finalize the design etc and then testing..so it wont be out for a while
Every rail has an ldo , but we concentrated efforts on the ethernet IC and USB hub. We are using a better solution (ICs) then stock RPI 3B+ and of course filtering is substantial
Did RPi foundation allow you to modify the pi and make it Audiophile Grade and market it as raspberry pi?