AUDIO over IP - REDNET 3 & 16 Review. AES67 Sets A New Standard for Computer Audio

[astrostar59]

  I have ordered a PowerVolt triple output LPS.
They stated a 4-6 week build time.
Here is a link to more of the specifics.
http://www.head-fi.org/t/806827/audio-over-ip-rednet-3-16-review-aes67-sets-a-new-standard-for-computer-audio/2355#post_12965064
I'll probably post my results in the DIY'rs Cookbook thread (see below).
 
 
No, not for this.
But previously I did ask them about what fuse they use and was told "There are no seviceable parts inside".
Which translated means there is no reason to open up the unit and fuss with anything inside.
 
Performing this bit of surgery will void any warranty and anyone who attempts this MUST take that into account.
 
This is the beginning of a series of posts about this whole process…
http://www.head-fi.org/t/781268/the-diyrs-cookbook/690#post_12898661
 
JJ

John
I PM'd the guy who sold a RedNet 3 with an external LPS attached to it. He told me today it sounded better than stock but his LPS was DIY and cost more to build than the RedNet 3. I have asked some more questions too describe the sound change, and also to confirm how many hookups it needs i.e. 15v and 5V DC.
 
I have a HDPlex LPS with 5V and 15V outputs, so maybe I can use that? Getting very interested in this. If I do do it, I would drill out the IEC socket area on the back of the Rednet case, and add a plate with the 2 voltage plug inputs. Keep it all neat.Would be nice to go via the on/off switch, though not sure it that is too fiddly. I have an on/off on the HDPlex mind.

 

[johnjen]

  John
I PM'd the guy who sold a RedNet 3 with an external LPS attached to it. He told me today it sounded better than stock but his LPS was DIY and cost more to build than the RedNet 3. I have asked some more questions too describe the sound change, and also to confirm how many hookups it needs i.e. 15v and 5V DC.
 
I have a HDPlex LPS with 5V and 15V outputs, so maybe I can use that? Getting very interested in this. If I do do it, I would drill out the IEC socket area on the back of the Rednet case, and add a plate with the 2 voltage plug inputs. Keep it all neat.Would be nice to go via the on/off switch, though not sure it that is too fiddly. I have an on/off on the HDPlex mind.

That sounds doable, but be sure that you have both +15 and -15 volts with a common ground between them, which would also be the same ground as the +5 volt source.
IOW make sure that the LPS that is supplying these 3 voltages can share a common ground.
AND that they can supply 'enough' current, but since there really isn't much power needed to run the RN3, shouldn't be a concern.
 
And the 2mv rated triple output LPS that I'm starting with should be under $150.
This makes for a relatively inexpensive experiment.
 
Another thing I've noticed is, digital circuits are noisy, REALLY noisy, as in they tend to 'pollute' the ground plane and voltage rails with this noise.
 
And further, that LPS's also tend to absorb/reduce this and all noise better than SMPS's do.
The thing is, it's hard to know how much of a SQ improvement there will be by absorbing more of this noise via using a LPS, than not.
 
That is what this experiment is aimed at, to start by using a 'simple' LPS to see if further sophistication and refinement in this area is warranted.
 
In one sense this is a repeat of the experiment I performed previously on my FMC setup that I use to optically isolate my computer from my RN3.
 
So I'm hoping I'll hear roughly the same (or perhaps even better) results.
 
And if it were me in possession of that HDPlex, I'd use 3-pin XLR connectors to connect them because they are rated at well beyond the current you'll need, and because both male and female panel mount versions are available (to make it impossible to connect it up incorrectly).
 
JJ

 

[astrostar59]

  That sounds doable, but be sure that you have both +15 and -15 volts with a common ground between them, which would also be the same ground as the +5 volt source.
IOW make sure that the LPS that is supplying these 3 voltages can share a common ground.
AND that they can supply 'enough' current, but since there really isn't much power needed to run the RN3, shouldn't be a concern.
 
And the 2mv rated triple output LPS that I'm starting with should be under $150.
This makes for a relatively inexpensive experiment.
 
Another thing I've noticed is, digital circuits are noisy, REALLY noisy, as in they tend to 'pollute' the ground plane and voltage rails with this noise.
 
And further, that LPS's also tend to absorb/reduce this and all noise better than SMPS's do.
The thing is, it's hard to know how much of a SQ improvement there will be by absorbing more of this noise via using a LPS, than not.
 
That is what this experiment is aimed at, to start by using a 'simple' LPS to see if further sophistication and refinement in this area is warranted.
 
In one sense this is a repeat of the experiment I performed previously on my FMC setup that I use to optically isolate my computer from my RN3.
 
So I'm hoping I'll hear roughly the same (or perhaps even better) results.
 
And if it were me in possession of that HDPlex, I'd use 3-pin XLR connectors to connect them because they are rated at well beyond the current you'll need, and because both male and female panel mount versions are available (to make it impossible to connect it up incorrectly).
 
JJ

Interesting. This is the reply today from the guy who did the external LPS ohm a Rednet 3:
 

If I remember correctly it needs positive and negative 15V, positive and negative 5V, and something like 75V. So the hdplex wouldn't work. It needs balanced power for the negative rails.

The hdplex may not have the wattage either.

There's several places to connect inside and it needed an umbilical cord.

I think the 75V is the 52V which isn't needed I believe. I am unsure if my HDPlex has balanced rails? I will email them and ask.

 

[mourip]

 
Interesting. This is the reply today from the guy who did the external LPS ohm a Rednet 3:
 
I think the 75V is the 52V which isn't needed I believe. I am unsure if my HDPlex has balanced rails? I will email them and ask.

 
Have you tried opening it up and probing all of the connections from the PS?

 

[astrostar59]

   
Have you tried opening it up and probing all of the connections from the PS?

No not yet. I was hoping someone else would beat me to it.

 

[johnjen]

I have already opened up the box and measured the voltages, and they are marked on the motherboard as well.
You need +5, +15, -15 and a center tap ground for the ±15vdc and a ground for the +5vdc.
 
And as I noted these grounds are common to chassis ground.
 
In my post about the SMPS noise I listed the pin numbers and their voltages.
 
JJ

 

[astrostar59]

  I have already opened up the box and measured the voltages, and they are marked on the motherboard as well.
You need +5, +15, -15 and a center tap ground for the ±15vdc and a ground for the +5vdc.
 
And as I noted these grounds are common to chassis ground.
 
In my post about the SMPS noise I listed the pin numbers and their voltages.
 
JJ

Hi JJ
Do you think my HDPlex 150W would work? It has 5V DC and 15V DC. Here is the page for it:
http://www.hd-plex.com/HDPLEX-Fanless-Linear-Power-Supply-for-PC-Audio-and-CE-device.html

 

[johnjen]

In a word, no.
Because it doesn't provide -15vdc, along with +15vdc that is center tapped to ground.
This particular configuration is needed for the balanced portion of the RN3 design.
 
The +5 and its ground is easy enough to find, but having the ±15vdc AND the +5vdc (triple output) is rare.
 
JJ

 

[Clemmaster]

Would it work without the +-15 in a digital only application?

 

[johnjen]

My guess is probably not because there is much of the circuit that is running balanced, and if both legs of that portion of the circuit were effectively 'dead', I figure the rest of the circuit would suffer.
Not to mention that if you use the AES output, which is a balanced transmission line configuration of the digital information flow, that ±15vdc is mandatory.
 
Also it needs to be mentioned again, that the +15 and -15 legs need to be center tapped with a single (common) ground.
Put another way, you need one ground smack dab in the middle between +15 and -15 for this to work, so 2 different power supplies (a + and a - LPS) that don't or can't share a common ground won't work either.
 
IOW, I'd not advise it.
 
JJ

 

[Golfnutz]

Rednet 3 / D16 power supply specs:
 
Brand: FEREX
Model: FP07M063
Applicable Products: DVB digital TV set - top box
Input voltage range: 100V-240V
The output voltage: + 5, + 15V, -15V, + 51V
Output Power: 10W

Input characteristics
      Input voltage range: 100V-240V AC
      Input voltage frequency: 47Hz-63Hz
 Output characteristics
     Output combinations: + 5V, 2A; + 15V, 0.7A; -15V, 0.7A; +51 V, 80mA
      Ripple: 50mV
      Efficiency: 70% Min. (220V AC / Max Output Current)
 Dielectric strength: AC 3000V, 10mA, 60Sec
 Insulation resistance: 30M Min DC 500V
 Mean time between failures: working time 50000H

Protective function:
 Output Overvoltage Protection (OVP)
 Output Short Circuit Protection (SCP)
 Output Overcurrent Protection (OCP)

 

[wushuliu]

  Rednet 3 / D16 power supply specs:
 
Brand: FEREX
Model: FP07M063
Applicable Products: DVB digital TV set - top box
Input voltage range: 100V-240V
The output voltage: + 5, + 15V, -15V, + 51V
Output Power: 10W

Input characteristics
      Input voltage range: 100V-240V AC
      Input voltage frequency: 47Hz-63Hz
 Output characteristics
     Output combinations: + 5V, 2A; + 15V, 0.7A; -15V, 0.7A; +51 V, 80mA
      Ripple: 50mV
      Efficiency: 70% Min. (220V AC / Max Output Current)
 Dielectric strength: AC 3000V, 10mA, 60Sec
 Insulation resistance: 30M Min DC 500V
 Mean time between failures: working time 50000H

Protective function:
 Output Overvoltage Protection (OVP)
 Output Short Circuit Protection (SCP)
 Output Overcurrent Protection (OCP)

 
Oh that's not too bad at all. I thought there'd be higher current draw. Could probably roll your own with any number of small power supplies on ebay. And that 51v barely pulls anything. Would be great if it could be eliminated though. 

 

[mourip]

   
... And that 51v barely pulls anything. Would be great if it could be eliminated though. 

 
I wonder if it is used at all. Perhaps it just comes with that OEM PS which is described as used for other devices also.
 
I cannot imagine what would use 51v in a device like the RN3.

 

[Clemmaster]

Isn't the 51V used for mic phantom power?

 

[mourip]

Isn't the 51V used for mic phantom power?

 
I think that phantom power is 48v but I see no function of the RN3 that could use it. It is all digital in and out. No microphone inputs.