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Post by MartinT on Mar 14, 2019 19:47:39 GMT
OK, I tried upsampling everything to 32/192 at Very High quality. The Pi handles it easily with CPU at 20-25% even with my underclocking.
No difference, still pops when unlocked.
I've put it back to native as I think the DAC sounds slightly better with the original data.
I'm not going to dwell on this because the reality is it's not bothering me much. I2S is that much better that I'm never going back.
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Post by nrg on Mar 18, 2019 18:23:28 GMT
Speaking of upsampling, I’ve been using the command line parameters in squeezelite to 4x upsample all my 44.1 files for some time now. Max rate 176400 with hIX or high quality, intermediate filter and everything upsampled to 176400. I’ve just been reading this archimago.blogspot.com/2017/12/howto-musings-playing-with-digital_23.html and decided to play around with the settings...hmmm, I’ve been missing out and now realise that my previous setting has been clipping the upsampled data and was definitely not optimum....changing to vX::4:20 or 28 has made a heck of a difference, Ive tried the other settings for passband etc but eliminating them seems to give the best result with my TDA1541a DAC. May be worth a try?
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Post by MartinT on Mar 18, 2019 19:20:52 GMT
Thanks, I'll give it a go.
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Post by nrg on Mar 19, 2019 22:33:22 GMT
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Post by MartinT on Mar 20, 2019 0:07:36 GMT
After a lot of testing of the I2S system and the Pi config.txt underclock/undervolt settings, I'm completely happy with the results. I can't do anything about the pops with the LKS DAC but can workaround them. More importantly, the sound quality is excellent and an important step up from S/PDIF.
The Pi 3 / Allo Kali / HDMI output board make a superb setup for an I2S over HDMI streamer.
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Post by MartinT on Mar 24, 2019 21:43:03 GMT
Further to this, and after some more system tweaking, I can say that I2S pulls away from S/PDIF in every respect: timing, dynamics, musical flow. By eliminating clock/data combination to create the S/PDIF signal and then separating them out again at the DAC, you are eliminating two conversion steps from the chain. It shows in the audible results. I'm completely won over by this methodology.
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Post by nrg on Mar 24, 2019 22:44:21 GMT
100% with you there Martin. I’m also surprised how much I can alter the sound just by playing around with the squeezelite (SoX) settings...
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Post by Stratmangler on Mar 25, 2019 0:15:05 GMT
There's fuck all information moving from 24 to 32 bit word depth. The additional bits are recovery bits, put there for mastring purposes only.
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Post by MartinT on Mar 25, 2019 7:10:21 GMT
There's fuck all information moving from 24 to 32 bit word depth. The additional bits are recovery bits, put there for mastring purposes only.
I think you're commenting on the supposed fix for the Allo Kali, as recommended by Allo? If so, it's a fix to aid the Kali's decoding and nothing to do with sound quality. I don't understand it anyway as my Kali works with 24-bit files just fine, so I'm not doing any kind of upsampling. Steve I think uses 32-bit in his setup.
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Post by speedysteve on Mar 25, 2019 7:50:15 GMT
There's fuck all information moving from 24 to 32 bit word depth. The additional bits are recovery bits, put there for mastring purposes only.
I think you're commenting on the supposed fix for the Allo Kali, as recommended by Allo? If so, it's a fix to aid the Kali's decoding and nothing to do with sound quality. I don't understand it anyway as my Kali works with 24-bit files just fine, so I'm not doing any kind of upsampling. Steve I think uses 32-bit in his setup. I have it set to 32, for the only reason that Allo specifically said it should be set to that. I does seem to work fine on 24 though?!
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Post by speedysteve on Mar 25, 2019 22:55:13 GMT
I found this on the Kali 32bit advice..
---------------------------------------------- Note that the first batch of Kalis (the ones that were sent to reviewers and a small number of units that were actually sold) had a bug that caused 16bit audio to have its channels reversed (and some more weird stuff happening with their I2S output resulting in somewhat degraded sound quality), but according to allo.com all effected units have been exchanged with fixed ones plus the ones that are shipping now to customers come with a fixed version of the firmware.
Even if for some reason you come by an affected unit, all you have to do is tell your RPi to output 32bit audio. That will fix everything. -------------------------------------------------
So that clears that up.
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Post by MartinT on Mar 26, 2019 6:25:07 GMT
Good to know, Steve. I'm leaving things set to no upsampling and letting the DAC do its thing.
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Post by speedysteve on Mar 26, 2019 8:08:13 GMT
Yes, I don't think there's any chance we have the duff boards at this point in time.. Odd advice to me from Allo really! They should have qualified it!
I've been setting it as 24K / native to see what the lights do.
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Post by speedysteve on Mar 27, 2019 19:50:55 GMT
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Post by MartinT on Mar 27, 2019 22:03:12 GMT
Thanks. I don't think we have to worry with the relatively new Kali boards we have.
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Post by petea on Apr 2, 2019 20:21:08 GMT
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Post by MartinT on Apr 2, 2019 20:25:47 GMT
Almost all DACs use I2S internally from inputs to the DAC chip. For instance, my DAC converts S/PDIF and USB to I2S. It's externally connecting directly into I2S via HDMI or Ethernet that is starting to gain traction.
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Post by petea on Apr 2, 2019 20:36:31 GMT
Aha, got it. Thanks, Martin.
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alp
Rank: Trio
Posts: 161
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Post by alp on Jun 15, 2020 17:55:35 GMT
My Topping D90 has an I2S over HDMI input. After looking at the somewhat eye watering prices for USB cables like the AQ Carbon I have been mulling over trying I2S. You can get an Allo Kali and an I2S HAT with an HDMI connector for less than £100 or instead of the Kali an Ian Canada reclocker HAT for about £70 extra (which you can also spend more to upgrade the oscillators). It surely get rid of several metres of stiff and unruly USB cable and may even sound better . Has anyone tried these recently with the RPI or Asus Tinkerboard?
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Post by John on Jun 15, 2020 19:42:44 GMT
Check that you are getting the right hat for the D90 as they have different models. Audiophonics can advise. I think it uses the Gustard connector type. You supposed to be able to change the arrangement but I could not find anything on the D70 that can do this
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