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New FIFO buffer for RPI/SBCs

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C

chris14

Member
Joined 2018
cdsgames said:
Behind the scenes we are working on the PSUs.


Nirvana SMPS. I think everyone here knows about it. 1 output

2. LPS with dual output (3A and 1A) Ultra low noise.


We are facing significant difficulties to solve all bugs and every day we are testing and measuring. We are confident to bring both to the market.
Click to expand...

When would you expect to have the dual linear power supply ready, and what price point are you aiming for? Have you considered dual bank battery or super capacitor supplies for the clean side, not too much of a challenge technically but can you get the price to be competitive.
 
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andreallo

Member
Joined 2015
gtv4 said:
I think I got sent one of the rogue Katana power connectors and now have a toasted Katana. In any case I have no Katana LED on 3 way power, blinking controller status LED on 2 way power and Alsa not recognising the Katana in both cases. I've raised a help desk and hope Allo acts responsibly :eek:
Click to expand...


Sorry to hear that.. on the bright side,we've sent a notice to all customers notifying them of this possibility and removed the few rogue cables from our stock, so this shouldn't happen anymore.


Please PM me your order number and we will send you a replacement KATANA board ASAP.


regards
 
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atca

Member
Joined 2018
John Luckins said:
A small but perhaps important correction to what I reported earlier. I did not find continuity between the red (+ve) power input on the Katana board and pins 2 and 4 on the GPIO to the RPi. What I detected was the same voltage on pins 2 and 4 of the GPIO as was being fed to the red input power lead (the one connected nearest to the GPIO header). I think the difference might be very significant and I'm sorry to have reported it incorrectly as continuity. It was late here and I should have checked directly for continuity as well.

To spice things up further though I have just noticed this...

https://www.diyaudio.com/forums/att...1543167376-fifo-buffer-rpi-sbcs-sany0679a-jpg

Apart from the labels can you spot the difference. Note that both connector males are properly orientated in their sockets and both of the flying leads are as supplied by Allo. Ooops!

The upper lead was supplied most recently. The lower lead came with my original Katana. I'm upset again.

John
Click to expand...


Which is the right orientation negative black at top nearest Katana logo?
 
M

Markw4

Member
Joined 2016
Question for cdsgames:
When Katana first came out you said that each dac was getting its harmonic distortion compensation adjusted. Is that still the case?

If so, if someone has both output stage boards, which one is used for HD comp. adjustment?

Since the policy is now that people can have two output stage boards to use as they wish, if HD compensation is still being used, and if output stage boards differ from one to another, then it would be good for there to be some way for both boards to be calibrated, at least if the customer wants it. If so, maybe there could be a cal file stored on RPi that the MCU can read in depending on which output stage board is being used?

I got to thinking about it because the review Katana you sent me came with the 'sound quality' board installed. I am probably more of a 'thd' board kind of guy, and I might have a better impression of sound quality if the output stage board I am using has optimal distortion compensation settings being used. Don't know if it does or not?

Also, if using Volumio, where are the software reconstruction filter settings hidden? Or, do they have to be dip switch selected?

Thanks!
Mark
 
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cdsgames

Member
Joined 2015
Hi Mark


Katana 1.2 has compensation for THD+N board ony not for SQ. In fact with SQ board , even if we use compensation , THD does not change much.


As for the filters , you have the sequence to change manually using dip sw in the manual , but you can change filters by going to your software (Moode , Volumio etc) and use the settings.
 
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Markw4

Member
Joined 2016
Hi cdsgames,
Sorry, I'm still not clear if compensation is adjusted with the the exact output stage that will be shipped with the dac, or with one standard output stage used for all Katana boards and that is never shipped to anyone?

In other words, is the distortion compensation process more to compensate for the output stage board, or to compensate more for the Katana board?

Or, to try another way, if someone blows up a Katana board due to a power cable with the wire colors switched, and you ship them a new replacement Katana, will the new Katana have the right distortion compensation for the output stage board that the customer already has?
 
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cdsgames

Member
Joined 2015
Katana compensation is done for average THD+N opamp output board.


We measured 10 boards and chose the value that was average. (not much variation )



Then we tested the THD+N of next 50 boards and found that it was around +1db max (I guess it depends on variation of components)


Whiteout THD+N compensation the results were at least +2db worst
 
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marudo

Member
Joined 2018
andreallo said:
Sorry to hear that.. on the bright side,we've sent a notice to all customers notifying them of this possibility and removed the few rogue cables from our stock, so this shouldn't happen anymore.


Please PM me your order number and we will send you a replacement KATANA board ASAP.


regards
Click to expand...

Andre/cdsgames,

This is surprising; I thought we were 3 who had quality issues on our delivered product, being sent with wrong pin on the THD optimized opamp.
But it turns that Allo's toll manufacturer is rushing in all orders. Hopefully you can improve proper segregation in the shop floor to avoid mix up of "supposed obsolete part" with new version. I believe, the assembly plant is not properly segregating parts that are reject or for rework. Hopefully Allo can work more on their quality management to bolster quality check points.

Right now the Katana pictures in the allo website has a disconnect in the actual v2 unit; it advertises the katana v1.1 internals - very misleading. Should the v2 contain wire in the Katana? I don't have mine delivered.
 
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S

soundcheck

Member
Joined 2005
soundcheck-audio.blogspot.com
You know...

...I'm really wondering how long a company can cope with such a catastrophic
product launch (and related cost).

Meanwhile I'm getting worried that Allo might be grounding this (rather complex) project altogether. It wouldn't surprise me.

Anyhow. I keep the fingers crossed that they'll manage. :xfingers:

Those of you having a Katana just enjoy it. And don't fry it! :D
 
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cdsgames

Member
Joined 2015
Hi Soundcheck




we shipped to date over 150 Katanas to customers .Still we have a number of mistakes that is unacceptable I am not happy with our shipping dept and , we had a discussion .. sorry to say but we had people fired over the multiple mistakes .



I am fully confident on our Katana , because of the sound quality. I am also fully confident that we will improve and will ship with minimum errors


Meanwhile, as always , we will support any customer that received wrong cables etc.


We are here , we are listening.
 
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