soundcheck;541158 Wrote:
Thx for clarifying that. I didn't have a chance too look inside.
I just took my conclusion from looking at Alsa, where you see three
different sound devices. Usually PC-speaker is not a device under Alsa
on a normal PC. That's obviously different in the embedded
I am wondering if it is a good idea to take the headphone output as
reference.
As far as I have seen (within Alsa) the headphone out seems to be fired
by a Wolfson WM 8974.
The AKM DAC for the analog out has much better specs. Still I'd guess
that the SPDIF performs best, since also the AKM
soundcheck;540814 Wrote:
I am wondering if it is a good idea to take the headphone output as
reference.
As far as I have seen (within Alsa) the headphone out seems to be fired
by a Wolfson WM 8974.
The AKM DAC for the analog out has much better specs. Still I'd guess
that the SPDIF
Great stuff
JohnSwenson;541039 Wrote:
The headphone out can also be shared by the IR blaster circuit. There
is an enable signal to each (headphone amp and IR blaster). I haven't
looked carefully at that circuit to see exactly what it does.
I've been digging around for this info since I've
JohnSwenson;541039 Wrote:
Thats not correct, the Wolfson DAC is only used for the internal speaker
used for the bleeps and blurps etc. The AKM chip goes to both the
headphone amp and the analog outs.
The analog outs have a resistor and one cap in the path between the DAC
and RCA Jacks.
pounce;540272 Wrote:
What do you want specifically from the community?
1. First of all I am just reporting a finding.
2. People that might consider to use the Touch as a server and a
transport at the same time should be aware of this finding.
3. If others don't experience my finding, I
soundcheck;540405 Wrote:
Folks.
FYI.
I just stepped over a comment of John Svensson at the USB driver/plugin
thread, where he pretty much confirms what I am saying about streaming
vs. local operation.
Cheers
No he doesn't...
soundcheck;540426 Wrote:
1. How about that one:
http://forums.slimdevices.com/showpost.php?p=481447postcount=6
John is doing wild guessing too. As I said. Nobody has ever shown
what's going on.
2. On headphones something happens. If you don't listen to headphones
there is
Phil Leigh;540434 Wrote:
... and that isn't an opinion?
NO. It is a result of a real life test in an adequate test
environment.
Phil Leigh;540434 Wrote:
The Touch is a completely different design to the Duet. In my opinion
(!) no amount of Duet mods will improve it over a
Well, I know you are going to disagree, but here is a TEST anyway:
Source: 30-second WAV clip of Limehouse Blues from Jazz at the
Pawnshop
Replayed via SBS and via TinySC (using a self powered USB drive),
analogue (RCA) out captured into M-Audio 24/96 @24/44.1
ADM comparison (at highest
Well - very interesting.
I plugged in some Sennheiser PMX60's into the Touch and repeated the
test above, comparing TinySC with phones in vs. TinySC with no phones.
The overall correlation null drops by 6dB to -80dB, meaning that with
Phones connected the analogue signal via RCA out is changed.
Phil Leigh;540401 Wrote:
...
Don't knock it until you've tried it.
There is no difference at all in the s/pdif stream (which is captured
perfectly, using the soundcard locked to the Touch clock) using
internal or external streaming. They are identical.
Ok. I'll give it a go.
When you
pounce;540472 Wrote:
Ok. I'll give it a go.
When you see a difference how do you know it's actually audible and not
something that's masked by the content?
The test approach would be to baseline with whatever AD you have
regardless of quality? I struggle with this a bit since you
Well... the presence/absence of connected headphones has a much smaller
(measured) effect on SBS replay than it does on TinySC replay. Also the
impact is still greater on the right channel with both SBS and TinySC.
I'd need to study the circuit diagram and physical board layout to even
hazard a
Well... the presence/absence of connected headphones has a much smaller
(measured) effect on SBS replay than it does on TinySC replay. Also the
impact is still greater on the right channel with both SBS and TinySC.
I'd need to study the circuit diagram and physical board layout to even
hazard a
Phil Leigh;540489 Wrote:
Well... the presence/absence of connected headphones has a much smaller
(measured) effect on SBS replay than it does on TinySC replay. Also the
impact is still greater on the right channel with both SBS and TinySC.
I'd need to study the circuit diagram and physical
pounce;540495 Wrote:
Do you have an SD card to test TinySC with USB and SD to see if it's a
power issue?
I'll see if I can borrow one from my daughter...
--
Phil Leigh
You want to see the signal path BEFORE it gets onto a CD/vinyl...it
ain't what you'd call minimal...
Touch(wired/XP) -
pounce;540495 Wrote:
Do you have an SD card to test TinySC with USB and SD to see if it's a
power issue?
He better answers your question with YES. ;) Otherwise I'd be wondering
what we're discussing over here all day long. :D
--
soundcheck
Oh. I was too slow. As a matter of fact he said NO. He needs to borrow
one.
It's been a pleasure talking to you guys. ;)
--
soundcheck
soundcheck's Profile: http://forums.slimdevices.com/member.php?userid=34383
View this
soundcheck;540503 Wrote:
He better answers your question with YES. ;) Otherwise I'd be wondering
what we're discussing over here all day long. :D
I'll have one in 3 hours. I have no idea what you are talking about...
--
Phil Leigh
You want to see the signal path BEFORE it gets onto a
All tests are recorded from the analogue outs using the same 30 second
clip (see earlier post):
Left/Right Channel correlation: higher number = closer match (fewer
differences)
(USB disk not connected)
1) SD Card + Headphones in vs. SD Card + Headphones out: L:100/R:103
2) USB Disk +
Cool. Interesting. Looks like power may have an impact.
Have a powered usb hub to try the diff? ;)
--
pounce
pounce's Profile: http://forums.slimdevices.com/member.php?userid=12645
View this thread:
pounce;540616 Wrote:
Cool. Interesting. Looks like power may have an impact.
Have a powered usb hub to try the diff? ;)
The usb disk I was using has its own PSU - I don't have any that will
run from Touch power alone... :-(
--
Phil Leigh
You want to see the signal path BEFORE it gets
You don't need a powered hub if your drive is powered externally. That's
interesting.
You are running ethernet, yes?
I need to try this now. I'm curious to see just how much I can
influence a difference by doing bad things.
--
pounce
Hi folks.
FYI.
I did run a test to either stream the tracks or to play them locally
from
a SD-card.
On the SD-card test scenario I even disconnected the ethernet cable, to
avoid catching any distortions through the ethernet.
I was running 44.1/16 .wav files.
First experience:
On local
Test methodology?
--
pippin
---
see iPeng, the Squeezebox iPhone remote, at penguinlovesmusic.com
pippin's Profile: http://forums.slimdevices.com/member.php?userid=13777
View this thread:
You have many many variables above what you have stated to deal with.
First, you haven't mentioned what connection you are using. You do
mention Jitter. Is this the only item you are considering to impact the
quality?
If so perhaps if you are in the business you might send your device to
some
It can be +jitter, +EMI/RFI, +power fluctuations, +timing variances, it
can be Alsa, rt-kernel settings, scheduling and priorities, asf. It can
even be a problem within the applications.
Higher load usually causes trouble, especially if your audio chain sits
very close to your processor. I'd be
soundcheck;540271 Wrote:
Since you read about my Linux background, you might guess that I
applied your mentioned tweaks already. ;) THX anyhow.
Really, because you were so vague in your posts about what you have
done and what you are trying to focus on (thus the comment about
testing
As a starting point I'd suggest capturing the analogue output, and then
comparing with audio diff maker to establish that there is a measurable
difference.
See elsewhere on this forum for the use of audio diff maker.
--
Grahame
soundcheck;540265 Wrote:
Play and listen - AB comparisons - it was pretty obvious to me.. ;)
Do you have two touches?
I mean... This switching involves switching between player connections
and then starting the playback again. It's not like you can switch back
and forth between the signals.
Grahame;540275 Wrote:
As a starting point I'd suggest capturing the analogue output, and then
comparing with audio diff maker to establish that there is a measurable
difference.
See elsewhere on this forum for the use of audio diff maker.
I don't think this is going to work. You will
Grahame;540275 Wrote:
As a starting point I'd suggest capturing the analogue output, and then
comparing with audio diff maker to establish that there is a measurable
difference.
See elsewhere on this forum for the use of audio diff maker.
I don't think this is going to work. You will
33 matches
Mail list logo
