Phil Leigh Wrote:
The Altmann boxes make a big difference for me - you should try them
(sb-JISCO-UPCI-Dac de Jour...)
I recall some recent thread discussing Altmann's devices and lack of
any meaningful technical information about them on his sites. I just
can't allow to myself to invest
325xi Wrote:
I recall some recent thread discussing Altmann's devices and lack of any
meaningful technical information about them on his sites. I just can't
allow to myself to invest another $1K into some back box not analysed
and not discussed from technical perspective.
I agree and
philodox Wrote:
I actually sent the Brochure and Manual for the Digital Lens to Dan
Lavry for his opinion... and lets just say he doesn't have a high
opinion of what they are trying to sell. I'll take a look at that
link, thanks. :)
It depends on how you look at the Digital Lens: As a
Cool, thanks for the explination. Dan also mentioned that my DA10 has
the RAM buffer as well... which I was unaware of. ;)
--
philodox
box clever, watch your system come together
crazy weather at the end of my tether
::#12427;::
heavily modded akg k340 xlr out lavry *black* da10 headphone
325xi Wrote:
Altmann's boxes are said to do wonders to both sound and jitter :) ,
although I have no idea how much hype in it... http://www.jitter.de/
The Altmann boxes make a big difference for me - you should try them
(sb-JISCO-UPCI-Dac de Jour...)
--
Phil Leigh
philodox Wrote:
That Genesis Digital Lens sounds like a really cool piece of kit. I
just read a few reviews on it... too bad it was discontinued in 2003.
Any ideas if there are other similar devices out there made by other
manufacturers?
Altmann's boxes are said to do wonders to both sound
I actually sent the Brochure and Manual for the Digital Lens to Dan
Lavry for his opinion... and lets just say he doesn't have a high
opinion of what they are trying to sell. I'll take a look at that
link, thanks. :)
--
philodox
box clever, watch your system come together
crazy weather at
reeve_mike Wrote:
Hi
I have close to 500 SACDs so I am keeping mine :-)
Mike
You could of course rip them as wellbut it would take a serious
amount of disk space.
I've been thinking of simply feeding the Purcell (via the FireWire) the
output from a SACD, then lifting that signal
Hi
CarlOtto Wrote:
What I wonder here is - how did you get the wordclock sorted (is
someone doing this as an add-on?) and since I assume you could not get
balanced (AES-EBU) output from the SB3 - don't you then get a slightly
better sound via the Verdi connected with XLR to the DAC?
That Genesis Digital Lens sounds like a really cool piece of kit. I
just read a few reviews on it... too bad it was discontinued in 2003.
Any ideas if there are other similar devices out there made by other
manufacturers?
--
philodox
box clever, watch your system come together
crazy weather
reeve_mike Wrote:
I have two sources: a SB a dcs Verdi.
For CD replay these feed a dcs Elgar+ via a dcs Purcell upsampler.
The whole replay chain is synch'ed via a dcs Verona clock
(the SB path is modified to include a word clock input).
If I have ripped a CD I play it via the
OK, in case anyone cares, here's a (hopefully correct) explanation of
how some components of jitter can be correlated with the frequency
components of the analogue audio signal.
Suppose you digitize a 1 kHz sine wave with 16 bit at 44000 Hz (I know
the CD standard is 44.1 kHz; more on that in a
opaqueice wrote:
OK, in case anyone cares, here's a (hopefully correct) explanation of
how some components of jitter can be correlated with the frequency
components of the analogue audio signal.
I for one would love a correct explaination about jitter and how it is a
problem. From what I can
opaqueice wrote:
OK, in case anyone cares, here's a (hopefully correct) explanation of
how some components of jitter can be correlated with the frequency
components of the analogue audio signal.
[snip]
I'm afraid you are wrong in so many ways.
A digital signal does not have periodicity - it
pfarrell Wrote:
This is flat not true. It is not like a square wave, it is a square
wave. And there is no tone to it, you don't listen to the digital
signal
you listen to the analog signal after it has been processed by the
DAC.
It is *not* a square wave, because not all the bits are
OK, I will take this point by point...
Robin Bowes Wrote:
I'm afraid you are wrong in so many ways.
If so, I'm happy to learn something.
A digital signal does not have periodicity - it is just a stream of
bits. It is sent over analogue transmission paths as a square wave.
In this
erm, guys...
a perfect square wave can by definition only have 2 DC values with an
instantaneous transition between them (of course this is not possible
in the real world but we can get pretty close to perfect) with a
(variable or fixed) mark/space ratio determining the
periodicity/instant of
Phil Leigh Wrote:
erm, guys...
a perfect square wave can by definition only have 2 DC values with an
instantaneous transition between them (of course this is not possible
in the real world but we can get pretty close to perfect) with a
(variable or fixed) mark/space ratio determining the
Phil Leigh Wrote:
These changes to the timing of the transitions may be random, periodic
(eg related to an AC frequency elsewhere in the circuit such as the
mains) or correlated to the music because of the DAC analogue stage
impacting something in the clocking/clock recovery chain via the
CardinalFang Wrote:
What is the process by which a modern DAC samples the input? Does it go
by voltage measurements at fixed intervals or is there an inbuilt
clocking mechanism that causes the buffering of bits? Of course I
shouldn't be so lazy and should go find out for myself!
Paul
As
The DAC chip itself is not the main cause of jitter. The main cause of
jitter is from the transport (or SB3 in this case) and the SPDIF
receiver. That is why there are quite a few folks who bypass the
receiver by using separate clock signals. There's a thread about this
over in the DIY section,
opaqueice wrote:
As I understand it, that rounding is the cause of jitter. A (basic)
DAC uses rising or falling edges as a clock, but since as you say those
edges aren't very well defined that introduces errors. If the DAC used
its own clock, since that will not be exactly in sync with the
I've been reading this thread with great interest because I don't own a
SB yet but I'm very interested by it.
Anyway, in my opinion, I think the most relevant piece of information
here is what Philodox posted. He has a real life experience where his
Eastsound CDP used as a transport into a DAC
pfarrell Wrote:
Most of the understandable discussions of jitter talk about the
timing of the signal being wrong, not the rounding of the edges
of the signal.
Yes, but I think the reason there are timing errors is that the edges
are not precisely well defined, due to rounding etc. So if
Phil Leigh wrote:
Robin - are you saying that you don't think jitter exists (in which
case, what does a jitter meter measure?) or that it does exist, but the
presence of jitter on the digital stream doesn't affect the performance
of the DAC?
Neither.
In fact, quite the opposite!
R.
opaqueice Wrote:
See above. About data rates, I totally agree - the problem is that
this digital audio standard sucks. There is a far better way to do
things - transmit all the data first, asynchronously with error
checking, to a big buffer sitting next to the DAC, and only then decode
I think we are in danger of violently agreeing!
the rounding does introduce uncertainty in the timing - so that's
jitter...
and yes what we need is an I2S feed from the SB into the DAC (or a
master clock approach like dCS).
I guess I'm in the minority in preferring the digital out of an SB2/3
a question about terminology - do you guys call all of these square
waves, or only the top one? I would say only the top one, but maybe
there's a different terminology in different fields:
http://en.wikipedia.org/wiki/Biphase_Mark_Code
By the way, that shows nicely how the clock and data are
ModelCitizen Wrote:
This is very interesting.
Can you confirm that my understanding of what you have said is correct?
You are saying that the SB analogue outs are less likely to be prone to
jitter than the digital outs coupled to an external DAC (even a
Benchmark Dac 1 for instance)?
MC
Loftprojection - Thanks for the support. :)
I do hope that I can get my Squeezebox up to the level of my Eastsound
with some of the mods that I have planned. [Considering thise - battery
PSU; disconnect analog stage; maybe BNC connection] Not so that it can
replace my Eastsound [I want a CD
Yep - they are all square waves - with different m/s ratios but
certainly all square waves...
--
Phil Leigh
Phil Leigh's Profile: http://forums.slimdevices.com/member.php?userid=85
View this thread:
I just wanted to point out that square waves, although they have a
nominal frequency, are really composed of an infinite number of
sinusoidal signals. The edge of a theoretical square wave is an
impulse with infinite frequency (i.e. vanishingly small period). I've
attached a pic I took with my
Phil Leigh Wrote:
Yep - they are all square waves - with different m/s ratios but
certainly all square waves...
OK, so that accounts for the confusion before. In any case the
particular square wave you would get from SPDIF encoding a pure sine
wave at 1 kHz will have a bump in its spectrum
Phil Leigh Wrote:
Philodox - what I am saying is that bass solidity (well defined, easy to
listen to) is easily damaged by jitter. One of the most commonly heard
improvements is better bass when jitter is significantly reduced.Oh, I see
what you are saying now. I thought you were implying
Phil Leigh Wrote:
Can I suggest that you/we read up on correlated vs. uncorrelated jitter
as they are different beasts...
From what I understand, the word correlated refers in this context to
any non-random effect on the jitter spectrum, for example an effect
which is correlated with the
OK, I had a chance to check on this a little more, and there apparently
_is_ an effect where the jitter spectrum can have a peak correlated to
the analogue signal frequency. Apparently this happens mostly when the
jitter is due to bandwidth limitations in the transmission line, and
will be in
I think you'll find that its the correlated jitter that is the problem -
in the same way that level-related noise pumping is really annoying with
DBX companding, whereas Dolby (B) is just dull...(sorry - best analogy
I could come up with).
The uncorrelated (to the music) jitter is less
Mike Anderson Wrote:
For sound quality, how would you compare the SB3 running into a high end
DAC with a high end CD player?
I'm having a debate with someone who thinks you simply can't beat a top
quality CD player, no matter how good your DAC is.
I'm not an engineer, but I can't
opaqueice Wrote:
If you were using the CD player as a digital transport (i.e. sending
its digital out into the same DAC as the SB) I think the SB will
probably win or tieThat's not my experience - good though the SB3 is, it just
isn't as good
as the best transports.
In theory, the SB
Until you try and turn them into sound, bits are indeed bits...and one
day someone will devise an experiment to prove this. There are many
reasons why an accurate rip to HD will give a reliably (ie repeatably)
accurate rendition of the right bits in the right order - and why even
the BEST CDP in
I tip my hat to Phil and his brave display of logic :)
--
radish
radish's Profile: http://forums.slimdevices.com/member.php?userid=77
View this thread: http://forums.slimdevices.com/showthread.php?t=24670
Phil Leigh Wrote:
The only people who don't accept that an accurate rip+HD will outperform
a high-end CDP as a digital transport are:
1) people who (currently) own high-end CDP's
2) hi-fi reviewers
3) buffoons who know nothing about how computers work.I use both my
Squeezebox 3 and my
Phil Leigh Wrote:
The only people who don't accept that an accurate rip+HD will
outperform a high-end CDP as a digital transport are:
1) people who (currently) own high-end CDP's
2) hi-fi reviewers
3) buffoons who know nothing about how computers work. (Pat, this isn't
a reference to
philodox Wrote:
I use both my Squeezebox 3 and my Eastsound CD-E5 as transports to my
Lavry Black DA10. The Eastsound is noticably better as a transport.
I'm afraid you fall into Phil's category 1, hence helping prove his
point ;-).
But seriously, and I ask this in a spirit of friendly
Phil Leigh Wrote:
Until you try and turn them into sound, bits are indeed bits... There
are many reasons why an accurate rip to HD will give a reliably (ie
repeatably) accurate rendition of the right bits in the right order -
and why even the BEST CDP in the world (whatever that is) will
flac jacket - very funny (ROTFLMHO)
I too can hear NO difference between coax (expensive Kimber Silver one)
and toslink (middling quality) in my particular system - but I'm happy
to believe that others will hear differences in their systems.
I'm wondering if Philodox is hearing jitter...bass
Phil Leigh Wrote:
I'm wondering if Philodox is hearing jitter...bass solidity is one of
the victims of jitter IMHO...
Can you eleborate on that? I've heard a few examples of
(intentionally) jittered sound files (with MUCH more jitter added than
the SB or any decent source should), and they
opaqueice wrote:
philodox Wrote:
I use both my Squeezebox 3 and my Eastsound CD-E5 as transports to my
Lavry Black DA10. The Eastsound is noticably better as a transport.
I'm afraid you fall into Phil's category 1, hence helping prove his
point ;-).
But seriously, and I ask this in
Robin Bowes Wrote:
No, it's not the same at all.
Network transmission has error correction. The data is wrapped up in
various layers of protocols.
With digital audio, the bits simply transmitted over an analogue
medium.
There are all sorts of ways the signal can degrade in
opaqueice wrote:
Robin Bowes Wrote:
It's the timing information that is the issue. This has been covered on
these formums many times.
There are (at least) two problems which could occur; one is timing
(jitter) and the other is simply bad bits. I think it's impossible for
bad bits to
All I was saying is that bass solidity (timing?) is affected by jitter
(IMHO).
I think we humans are quite sensitive to timing errors in lower
frequencies - it's just a theory, nothing more.
There is an audible difference in correlated vs. uncorrelated
jitter...
IME jitter is responsible for
Robin Bowes Wrote:
Please read up on what jitter is and how it can and does have a
spectrum
related to the music.
To follow Robin's advice, here is a much quoted good place to start:
http://www.stereophile.com/reference/1093jitter/index.html
And note the distinction between on the one
Robin Bowes Wrote:
Please read up on what jitter is and how it can and does have a
spectrum
related to the music.
I have read quite a lot, and I think I have a decent understanding of
jitter. Nothing I have read has indicated that the jitter spectrum
should be harmonically related to
opaqueice Wrote:
These sidebands around the signal being decoded aren't harmonically
related to the signal, making them particularly unpleasant.
The above statement refers specifically to the numbers in the example
given in the text.
If one chose the right numbers one could make them
opaqueice Wrote:
I'm afraid you fall into Phil's category 1, hence helping prove his
point ;-).I can turn that around pretty easily. People who can't accept that
high
end transports make a difference... don't own them. :popaqueice Wrote:
But seriously, and I ask this in a spirit of
Robin Bowes Wrote:
opaqueice wrote:
Robin Bowes Wrote:
Please read up on what jitter is and how it can and does have a
spectrum
related to the music.
I have read quite a lot, and I think I have a decent understanding
of
jitter. Nothing I have read has indicated that the
Can I suggest that you/we read up on correlated vs. uncorrelated jitter
as they are different beasts...
Philodox - what I am saying is that bass solidity (well defined, easy
to listen to) is easily damaged by jitter. One of the most commonly
heard improvements is better bass when jitter is
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