why convert from usb to spdif??
Something like Doede's 1543 mk II which converts usb to I2s to feed the dac chips works well. You can't use your existing SPDIF DAC, but the mk II is so inexpensive, it can be tried with out financial hardship. I implemented the Mark II with Jung Super Regulators for the power supplies. The effort was well worth the results.
Something like Doede's 1543 mk II which converts usb to I2s to feed the dac chips works well. You can't use your existing SPDIF DAC, but the mk II is so inexpensive, it can be tried with out financial hardship. I implemented the Mark II with Jung Super Regulators for the power supplies. The effort was well worth the results.
Alternative of the shelf solution
The efforts here to tease out the best quality from a 100 USD device are very interesting. The question I would ask is if one is trying to get spdif out to a dac, such as Brian's great sounding Satch, wouldn't it be far simpler, easier, less expensive and practical to just buy the new version of the Squeezebox, if you want the higher sampling rate, or the Duet if you do not? It seems to me that the spdif output of the stock Squeezebox is low in jitter, but there are of course lots of options to improve it. Plus, it can be wired to the server or use a wireless connection.
The efforts here to tease out the best quality from a 100 USD device are very interesting. The question I would ask is if one is trying to get spdif out to a dac, such as Brian's great sounding Satch, wouldn't it be far simpler, easier, less expensive and practical to just buy the new version of the Squeezebox, if you want the higher sampling rate, or the Duet if you do not? It seems to me that the spdif output of the stock Squeezebox is low in jitter, but there are of course lots of options to improve it. Plus, it can be wired to the server or use a wireless connection.
Question to you guys:
I have a QNAP 109 II NAS with Squeezecenter pre-installed, feeding a couple of Duet receivers. Works fine, but now there's a new version of Squeezecenter out and I'd like to upgrade. But I have no idea how to upgrade any software that is actually on the NAS. I can get to the NAS throught it's IP and the port number (9001 on my system) but that only gets me the Squeezecenter GUI.
Anybody know how to do that?
jd
I have a QNAP 109 II NAS with Squeezecenter pre-installed, feeding a couple of Duet receivers. Works fine, but now there's a new version of Squeezecenter out and I'd like to upgrade. But I have no idea how to upgrade any software that is actually on the NAS. I can get to the NAS throught it's IP and the port number (9001 on my system) but that only gets me the Squeezecenter GUI.
Anybody know how to do that?
jd
I agree with you GTHICM, to some extent & I'm looking at the SB Touch as a future purchase for me mainly because they have put some effort into the SPDIF & clocks (running 2 clocks on a low jitter mux to switch speeds) - only issue is that over here it's >$300 & not $60 - 80 as is the Musiland (god bless the Chinese
). The other advantages of the SB Touch, in my opinion:- runs off ethernet, wired or wireless so galvanic ground isolation probably covered
- no need for a PC in the listening room
- remote control via iPhone or iTouch (could probably do this with PC & Musiland too)
- possibly the user interface but don't know about this yet?
So I'll be looking at how the iTouch pans out
If u guys do so much tweaking, u might consider bypass the USB/spdif and PC and use a media server instead and use the spdif output - no USB conversion. Put in a 1TB hdd and you can have a huge library of music. My 500gB is almost full
eg.
various TVIX module
HOME > Products > Product Info > TVIX HD M-6500
or
http://www.dragontechcorp.com/downloads/iobox-100hd_panels.gif
There are many others.
I use the TVIX and I found spdif output are excellent.
Or do the ultimate and tap the I2S from the inside.
http://www.diyaudio.com/forums/digital-line-level/84056-music-server-tda1541-i2s-direct.html
eg.
various TVIX module
HOME > Products > Product Info > TVIX HD M-6500
or
http://www.dragontechcorp.com/downloads/iobox-100hd_panels.gif
There are many others.
I use the TVIX and I found spdif output are excellent.
Or do the ultimate and tap the I2S from the inside.
http://www.diyaudio.com/forums/digital-line-level/84056-music-server-tda1541-i2s-direct.html
Where We Are Now and Why
The replacement transformers have arrived. I'm just waiting for some SMD parts and then we will:
- leave the RCA output with our resistors and 75ohm cable untouched
- install the transformer on the second out and connect (with some SMD parts) that to a 2nd RCA output. This will allow us to switch between the current output (which is already significantly better than stock) and the output with the upgraded transformer.
Thanks for the comments; I'm very interested in the other ways mentioned and will get one of those devices to compare.
Some have asked why we are doing THIS instead of THAT.
This is a vendor's forum. The idea was to see how far we can go with what we have on the shelf using the commonly and cheaply available Musiland (which gives us 24/192) and a computer transport.
To recap:
The Musiland needed a good clock, power supply, and the right cable. These things removed much of the performance bottleneck.
In addition the chipset likes and is able to swing more voltage so we made the circuit changes for that, but the transformers (already marginal) were unable to keep up. So we used resistors and this has taken us to the current level of performance.
Now we have the upgraded transformers and will try the next phase described.
Regarding some of the other ways to get digital music playback I received this interesting email:
"Brian,
I had a look at several of these Media Streamers. Reviews of many can be found at the MPC Club website, they are worth reading for the comments on the music side of things.
I do not wish to comment on the SPDIF output implementations in these machines, but yes, they work and bitperfect if the volume control is left at full.
All these machines have a most basic software and interface section for the Music part.
Worse, none to the best of my knowledge handle music playback in "gapless" mode, absolutely essential if live or classical albums are ripped into seperate tracks (or indeed such items the recent "Love" Album made from The Beatles back catalog or something like DSOTM by Pink Floyd.
The only way around this would be to rip such albums as complete images, in that case these players lack the support for .cue files that allow individual track access in these whole CD Images.
This basically precludes their use for music playback if one listens to anything where gaps inserted between tracks are unacceptable."
The replacement transformers have arrived. I'm just waiting for some SMD parts and then we will:
- leave the RCA output with our resistors and 75ohm cable untouched
- install the transformer on the second out and connect (with some SMD parts) that to a 2nd RCA output. This will allow us to switch between the current output (which is already significantly better than stock) and the output with the upgraded transformer.
Thanks for the comments; I'm very interested in the other ways mentioned and will get one of those devices to compare.
Some have asked why we are doing THIS instead of THAT.
This is a vendor's forum. The idea was to see how far we can go with what we have on the shelf using the commonly and cheaply available Musiland (which gives us 24/192) and a computer transport.
To recap:
The Musiland needed a good clock, power supply, and the right cable. These things removed much of the performance bottleneck.
In addition the chipset likes and is able to swing more voltage so we made the circuit changes for that, but the transformers (already marginal) were unable to keep up. So we used resistors and this has taken us to the current level of performance.
Now we have the upgraded transformers and will try the next phase described.
Regarding some of the other ways to get digital music playback I received this interesting email:
"Brian,
I had a look at several of these Media Streamers. Reviews of many can be found at the MPC Club website, they are worth reading for the comments on the music side of things.
I do not wish to comment on the SPDIF output implementations in these machines, but yes, they work and bitperfect if the volume control is left at full.
All these machines have a most basic software and interface section for the Music part.
Worse, none to the best of my knowledge handle music playback in "gapless" mode, absolutely essential if live or classical albums are ripped into seperate tracks (or indeed such items the recent "Love" Album made from The Beatles back catalog or something like DSOTM by Pink Floyd.
The only way around this would be to rip such albums as complete images, in that case these players lack the support for .cue files that allow individual track access in these whole CD Images.
This basically precludes their use for music playback if one listens to anything where gaps inserted between tracks are unacceptable."
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Empirical Audio Off Ramp
Another ready made alternative that may offer increased options for interface to different dacs, including i2s, is the Empirical Audio Off Ramp converter. Although it would appear to be more expensive than the Musiland upgrade path, although it is not clear to me that it really is, given the cost of all the additional components and parts for the upgrade, it seems a ready made solution.
Here is the link for further information:
Off Ramp Converter > Products : Empirical Audio
Another ready made alternative that may offer increased options for interface to different dacs, including i2s, is the Empirical Audio Off Ramp converter. Although it would appear to be more expensive than the Musiland upgrade path, although it is not clear to me that it really is, given the cost of all the additional components and parts for the upgrade, it seems a ready made solution.
Here is the link for further information:
Off Ramp Converter > Products : Empirical Audio
You are right and we will. But at this point it would introduce another variable whereas we just want to spotlight the difference between Rout and TXout.
In fact today we installed the upgraded transformer into 75ohms and had a preliminary listening A/B between Rout and TXout. I'll write more later after we do something more extended but briefly:
There were 4 of us and 3 didn't know which was which, Rout or TXout. We listened to one track, about 8 passes. After the first pass 2 of 4 listeners choose Rout as better detail and bass, 2 listeners choose not to comment.
By the third pass the tide changed to favour the TXout and by the last pass it was unanimous the TXout was best. It took a few passes to identify that the extra detail was really a kind of aggressiveness and the bass was somewhat exaggerated.
All agreed the TXout had more real detail and more tuneful bass. Dynamics were about the same. The listeners liked the word 'natural' to describe the TXout. Next week I'll check out some bass heavy tracks to find out if the lows are rolling off at all. I'll then install a TX in second output with a little different loading. Once we get a winner there then I'll do the BNC connection.
Thanks but we're not done yet. That one starts at $700 for base unit + $800 for Ultraclock and + ??? for upgraded power supply. So we can still go a ways and be well within the budget of these uber enablers.
There's a new driver out 1.0.7.0
http://www.musiland.com.cn/downloads/drivers/MlCyMon_1.0.7.0.zip
http://www.musiland.com.cn/downloads/drivers/MlCyMon_1.0.7.0.zip
Music Server Computer transport - More!
Musiland USB to DAC:
We left off last time with the resistors in place of the pulse transformer to the SPDIF. Getting rid of the transformer and adjusting the output to 75ohms really opened up the sound.
The new transformer parts arrive and we install one in place of the resistors. The other output still has the resistors so we are able to A/B:
Nov 20
Today we installed the upgraded transformer into 75ohms and had a preliminary listening A/B between Rout and TXout. I'll write more later after we do something more extended but briefly:
There were 4 of us and 3 didn't know which was which, Rout or TXout. We listened to one track, about 8 passes. After the first pass 2 of 4 listeners choose Rout as better detail and bass, 2 listeners choose not to comment.
By the third pass the tide changed to favour the TXout and by the last pass it was unanimous the TXout was best. It took a few passes to identify that the extra detail was really a kind of aggressiveness and the bass was somewhat exaggerated.
All agreed the TXout had more real detail and more tuneful bass. Dynamics were about the same. The listeners liked the word 'natural' to describe the TXout. Next week I'll check out some bass heavy tracks to find out if the lows are rolling off at all. I'll then install a TX in second output with a little different loading. Once we get a winner there then I'll do the BNC connection.
Nov 23
We confirm all the bass is still there, just less overhang. More listening also supports the differences noted above.
Comparing CD transport to Computer transport -- Round 2:
Today we compare the current setup to the CD transport. Earlier we were unable to hear a difference which is a first for our listening panel. We have 5 persons in our panel of listeners today,-1 female, 4 males and ages 25 to 40 except for me, saying goodbye to my 5th decade. I do the switching between CD and Computer transports, the others don't know which is which.
Music is a track from a Stereophile disk: Rendezvous. The first track leads in with some very delicate cymbal sounds. The second round was Michel Buble Fever and then Robbie Williams Straighten Up and Fly Right.
Once our ears 'warm up' we do hear differences between transports:
3 listeners feel the Computer is more natural and retrieves more hall sound, ie ambience. One listener says the CD transport has a faster pace and is more lively. The #5 listener can hear no differences. 3 feel the Computer is better overall, one chooses the CD transport -- all by a small margin.
Both sound very good. It seems we are now at a level where differences are more a falling of the shadow rather than markedly better or worse.
Next we'll turn attention to the computer power supply. We want to get rid of that SMPS brick and power from a regulated linear supply. We need 19v/3.9A and I think we can do that with a substantially heat sinked filament supply.
Musiland USB to DAC:
We left off last time with the resistors in place of the pulse transformer to the SPDIF. Getting rid of the transformer and adjusting the output to 75ohms really opened up the sound.
The new transformer parts arrive and we install one in place of the resistors. The other output still has the resistors so we are able to A/B:
Nov 20
Today we installed the upgraded transformer into 75ohms and had a preliminary listening A/B between Rout and TXout. I'll write more later after we do something more extended but briefly:
There were 4 of us and 3 didn't know which was which, Rout or TXout. We listened to one track, about 8 passes. After the first pass 2 of 4 listeners choose Rout as better detail and bass, 2 listeners choose not to comment.
By the third pass the tide changed to favour the TXout and by the last pass it was unanimous the TXout was best. It took a few passes to identify that the extra detail was really a kind of aggressiveness and the bass was somewhat exaggerated.
All agreed the TXout had more real detail and more tuneful bass. Dynamics were about the same. The listeners liked the word 'natural' to describe the TXout. Next week I'll check out some bass heavy tracks to find out if the lows are rolling off at all. I'll then install a TX in second output with a little different loading. Once we get a winner there then I'll do the BNC connection.
Nov 23
We confirm all the bass is still there, just less overhang. More listening also supports the differences noted above.
Comparing CD transport to Computer transport -- Round 2:
Today we compare the current setup to the CD transport. Earlier we were unable to hear a difference which is a first for our listening panel. We have 5 persons in our panel of listeners today,-1 female, 4 males and ages 25 to 40 except for me, saying goodbye to my 5th decade. I do the switching between CD and Computer transports, the others don't know which is which.
Music is a track from a Stereophile disk: Rendezvous. The first track leads in with some very delicate cymbal sounds. The second round was Michel Buble Fever and then Robbie Williams Straighten Up and Fly Right.
Once our ears 'warm up' we do hear differences between transports:
3 listeners feel the Computer is more natural and retrieves more hall sound, ie ambience. One listener says the CD transport has a faster pace and is more lively. The #5 listener can hear no differences. 3 feel the Computer is better overall, one chooses the CD transport -- all by a small margin.
Both sound very good. It seems we are now at a level where differences are more a falling of the shadow rather than markedly better or worse.
Next we'll turn attention to the computer power supply. We want to get rid of that SMPS brick and power from a regulated linear supply. We need 19v/3.9A and I think we can do that with a substantially heat sinked filament supply.
I tried 3.3V battery (LiFePO4) substitution of regulators & noticed no improvement.
Looking at the datasheet for the regulator, AMS1117, it's noise output is 0.003% of the output voltage - so for 3.3V output, the noise is about 100nV (for 1.2V noise is 36nV). I thought batteries would have bettered this noise value but I'm only listening to this using the PCM1793 internal DAC?
Looking at the datasheet for the regulator, AMS1117, it's noise output is 0.003% of the output voltage - so for 3.3V output, the noise is about 100nV (for 1.2V noise is 36nV). I thought batteries would have bettered this noise value but I'm only listening to this using the PCM1793 internal DAC?
Mistake in units above - noise is 0.000099V which is 99uV which is nowhere near as agood as other regulators Power supplies and regulators | Peufeu's Electronic Stuff
So batteries should improve this significantly?
So batteries should improve this significantly?
Some Hard Data/Comments on the Musiland Before and After
OK an on-the-ground tech report:
"I had an unmodified Musiland for use as simple SPDIF generator and found my receiver had problems locking consistently (I was debugging the software control for this receiver). Putting a 'scope on the signal out of the musiland showed this, left picture.
The actual signal level is around 200mV peak-peak and there is a huge 100mV spike on each transition.
First, this is WAY below the IEC 60958 type II specification of 0.5 - 1V peak-peak (and low enough that some receivers designed to this standard will not trigger reliably). Secondly the waveshape is UGLY. And NOISY. Brrrr... No wonder the poor receiver was constantly complaining about unlocking.
Okay, out come the original transformers to be replaced by the "magic part" (sorry, cannot reveal which, it is pretty decent but most important it's parasitics are consistent and I know what they are).
Remove the original disastrous resistive divider. A corrected divider was applied AFTER the transformer, with an impedance that correctly terminates the transformer; drive is now from a very low source impedance (the buffer in the Musiland is < 10 Ohm Z-Out).
After that the trace was much more like it, correct levels at around 0.8V Peak-Peak, minimal rining on the edges, but the traces where still furry. So I added an SMD CLC filter (1uF/0.1mH/1uF) between USB input and main circuit (musiland has a place for a choke on the PCB but does not fit, shame, things would be much quieter with choke) and I added a 220uF/10V Os-Con as bulk filter capacitor. Now the traces are not furry anymore. As shown but with different scale to allow for the different output level:
A quick before/after listening test showed that most of the hard and mechanical sound quality has gone, now we do not only get all the bits, but most of the music as well.
Doing the full mod with clock and seperate supply is still quite a bit better, but the basic mod alss gives a major step up in sound quality. Oh yes, and I can go back to debugging my receiver control software, for now we have a lock absolutely rocksteady (and the clocks out of the receiver are SO MUCH less jittery, before you could see the jitter with the naked eye on the 'scope!)..."
OK an on-the-ground tech report:
"I had an unmodified Musiland for use as simple SPDIF generator and found my receiver had problems locking consistently (I was debugging the software control for this receiver). Putting a 'scope on the signal out of the musiland showed this, left picture.
The actual signal level is around 200mV peak-peak and there is a huge 100mV spike on each transition.
First, this is WAY below the IEC 60958 type II specification of 0.5 - 1V peak-peak (and low enough that some receivers designed to this standard will not trigger reliably). Secondly the waveshape is UGLY. And NOISY. Brrrr... No wonder the poor receiver was constantly complaining about unlocking.
Okay, out come the original transformers to be replaced by the "magic part" (sorry, cannot reveal which, it is pretty decent but most important it's parasitics are consistent and I know what they are).
Remove the original disastrous resistive divider. A corrected divider was applied AFTER the transformer, with an impedance that correctly terminates the transformer; drive is now from a very low source impedance (the buffer in the Musiland is < 10 Ohm Z-Out).
After that the trace was much more like it, correct levels at around 0.8V Peak-Peak, minimal rining on the edges, but the traces where still furry. So I added an SMD CLC filter (1uF/0.1mH/1uF) between USB input and main circuit (musiland has a place for a choke on the PCB but does not fit, shame, things would be much quieter with choke) and I added a 220uF/10V Os-Con as bulk filter capacitor. Now the traces are not furry anymore. As shown but with different scale to allow for the different output level:
A quick before/after listening test showed that most of the hard and mechanical sound quality has gone, now we do not only get all the bits, but most of the music as well.
Doing the full mod with clock and seperate supply is still quite a bit better, but the basic mod alss gives a major step up in sound quality. Oh yes, and I can go back to debugging my receiver control software, for now we have a lock absolutely rocksteady (and the clocks out of the receiver are SO MUCH less jittery, before you could see the jitter with the naked eye on the 'scope!)..."
Attachments
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Hi, I've been following this thread with a lot of interest. Thanks for the reports. I suppose the filter above is for the USB power lines?
I've modded a Musiland 01-MINI and extracted the spdif and i2s lines.
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