Triode's USB 24/192 plug in - sound quality impressions

[adamdea]

mods,

is it about time to close this thread, comments about sound quality are not appreciated and it has turned into a triode appreciation thread.

OMG. And the winning entry in this years unintentional irony competition is..... The only reason to close down the thread would be your presence on it.

Triode is trying to establish the question of whether improvements can be made to the S/PDIF; and he is trying to answer it without resorting to claptrap. He has been kind enough to solicit reports of people's findings, but that does not mean he has to accept and act on every such finding. Why can't you just accept that and leave it there. If it disinclines you to report your findings again, then I imagine that is a consequence which everyone else can live with.

[cfraser]

Due to the title of this thread, anything that is NOT subjective doesn't really belong here, if you want to get "technical"...

I'm sure Triode is tired of hearing the same praise over and over... So what do you want people to talk about here? I got the distinct impression Triode *wanted* us to talk this crap exactly right here.

[garym]

Due to the title of this thread, anything that is NOT subjective doesn't really belong here, if you want to get "technical"...

I'm sure Triode is tired of hearing the same praise over and over... So what do you want people to talk about here? I got the distinct impression Triode *wanted* us to talk this crap exactly right here.

Triode does discuss sound quality issues here and based on my reading tries to learn from comments made by users in order to improve EDO. He doesn't want to hear only praise. You may be confusing him with Soundcheck, who could not handle any constructive feedback, often threatening to take his toys away and play elsewhere, which he eventually did evidently).

It is actually an entirely different issue with SBGK. He has repeatedly demonstrated in numerous threads that he either doesn't understand the simple basics of how LMS, servers, TCP/IP, networks, and SB players work or he chooses to ignore this in order to tinker in his own fantasy world. Nothing wrong with living in one's own fantasy world. And I'm sure the makers of duct tape and plastic sandwich boxes are happy to see folks like SBGK tinker as much as possible. But he wants to ignore any requests for even basic rigor in comparisons and instead decides that none of us in the "chorus" (as he refers to any naysayers) have equipment that is "revealing" enough.

[pandasharka]

Triode does discuss sound quality issues here and based on my reading tries to learn from comments made by users in order to improve EDO. He doesn't want to hear only praise. You may be confusing him with Soundcheck, who could not handle any constructive feedback, often threatening to take his toys away and play elsewhere, which he eventually did evidently).

It is actually an entirely different issue with SBGK. He has repeatedly demonstrated in numerous threads that he either doesn't understand the simple basics of how LMS, servers, TCP/IP, networks, and SB players work or he chooses to ignore this in order to tinker in his own fantasy world. Nothing wrong with living in one's own fantasy world. And I'm sure the makers of duct tape and plastic sandwich boxes are happy to see folks like SBGK tinker as much as possible. But he wants to ignore any requests for even basic rigor in comparisons and instead decides that none of us in the "chorus" (as he refers to any naysayers) have equipment that is "revealing" enough.

Back from the land of Linn for a catch-up.

Garym, as a LOT of people have realised already, SBGK lives in fantasy land and could start an argument in an empty room. He tweaks, tweaks, puts the SBT innards in a sandwich box, returns, tweaks, tweaks, gets banned, returns, tweaks some more...

Nothing there.

Other than the Peoples Front of Judea who is converted - I cant remember his id - a complete T**T - it had something to do with carpet, from memory. Logitech mods should do the right thing and ban them for good as a job lot.

[cfraser]

^ Speaking from the Judea People's Front: I missed the sandwich box and duct tape episode. Are there re-runs anywhere? Seriously, I'd like to see it.

I don't mind trying weird $#!+ if it's not a lot of trouble/messy and is free. Most of the time I undo it anyways.

[garym]

^ Speaking from the Judea People's Front: I missed the sandwich box and duct tape episode. Are there re-runs anywhere? Seriously, I'd like to see it.

I don't mind trying weird $#!+ if it's not a lot of trouble/messy and is free. Most of the time I undo it anyways.

I'll have to try and find it. It was actually a posted picture on another thread a while back. Great stuff!

[Alenakiu]

There has been some discussion on the Touch forum about the EDO app and the potential benfits to audio quality from the spdif output at 96k and below. This is not the primary purpose of the enhanced digital ouput app but people have debated whether any possible change in audio quality exists. I thought it would be useful to spell out what the changes are that are in EDO. As I may speculate about any impact on sound quality, I thought I'd do it here as its definately a discussion for the audiophile forum...

EDO essentially comprises three parts:

1) A custom linux kernel which is the standard Logitech kernel with the following changes:
- spdif - additional clock divider values to allow 176.4/192k playback
- usb scheduler - minor changes including change of default compilation options to allow most dacs to connect to usb
- usb audio - major changes to include most of the more recent linux kernel changes that support uac2
- experimental alternative kernel idle routine [disabled by default]

2) A squeezeplay applet which allows the kernel to be installed and provides menus to select the output device. It also starts up the audio output of squeezeplay and does a couple of things differently from standard squeezeplay:
- it does not start an effects jive_alsa process (it is assumed users don't want to hear the effects processing)
- it bypasses the alsa plug layer and uses the spdif output "TXRX" directly, simplifying the amout of processing required between jive_alsa and the spdif output driver
- increases the priority of the irq task associated with the spdif driver (primarily to improve performance for 192k playback)

3) A new jive_alsa binary which adds support for additional alsa formats for packing samples into alsa frames - this is necessary for the usb dac support, but there are no changes which I believe would impact spdif.

Now I don't claim sound quality improvements from any of these for spdif playback and I have not done any critical listening for this. I would also not want to make any claims without being able to measure the circuit in more detail. However you could speculate about the following:
- not sending output to the analog will avoid there being any data sent to the internal dac and avoid any audio related load on this part of the circuit/psu
- bypassing the alsa plug layer will reduce cpu load
- not having a second jive_alsa process running reduces cpu load slightly

However all these could be achieved with TT3 (I don't run it, but reading the code it looks like it will do this and much more) So its probably best to see EDO as doing the more obvious bits of TT3 to me.

There is one other component of the app which is dissabled by default and is a complete experiement - this is the kernel idle option. This can be turned on from Settings > Advanced > Digital Output. What it does is subsitute the default kernel idle task (which allows the cpu to enter low power mode) for an alternative one (which does not enter low power mode). I speculate that if cpu load has an impact on sound quality then this should have an impact as less than 100% cpu means the idle task is being run for a portion of the time. One could speculate that things like buffer and priority tuning change the frequency and duration at which tasks run and so also impact the frequency and duration the cpu spends in the idle task and hence the low power waiting for irq state. I would be very interested if people can tell the difference with it enabled or not....

Sorry if this has been asked, but any chance of EDO for Transporter?

[AlexM]

Hi,

I originally created this thread at Triode's suggestion to a) prevent contamination of the technical thread in the SBT sub-forum and b) to allow others to post their impressions of the SBT primarily as a USB source.

As usual it has degenerated into the usual derrogation of others subjective perceptions, making others wrong and the SBSK sideshow.

Accepting that any subjective impression is just that, no more and no less, can we not park the invective and slanting matches, and provocative trolling?. There is no need to convince anyone of anything, just report your own 'truth'.

I am still enjoying a wonderful sound from my SBT and Music Streamer II+, and the plug-in works faultlessly. I am looking forward to getting.my CA840C back from the shop to allow me to try 24/192 via Spdif.

Regards to all,
Alex

[lake_eleven]

Have anyone tried setting RWin value to 1073741823

This changed the sound from SBT for good in my system.

courtesy: http://touchsgotrythm.blogspot.co.uk/

[AlexM]

Hi,

I originally created this thread at Triode's suggestion to a) prevent contamination of the technical thread in the SBT sub-forum and b) to allow others to post their impressions of the SBT primarily as a USB source.

As usual it has degenerated into the usual derrogation of others subjective perceptions, making others wrong and the SBSK sideshow.

Accepting that any subjective impression is just that, no more and no less, can we not park the invective and slanting matches, and provocative trolling?. There is no need to convince anyone of anything, just report your own 'truth'.

I am still enjoying a wonderful sound from my SBT and Music Streamer II+, and the plug-in works faultlessly. I am looking forward to getting.my CA840C back from the shop to allow me to try 24/192 via Spdif.

Regards to all,
Alex