Audiophilleo 1 and 2 USB to S/PDIF transport
Jul 23, 2012 at 9:52 PM Post #887 of 1,214
That's my understanding as well; all modified AP devices require the PP battery supply. They're married at the barrel connector (hip).  
Quote:
Got some bad news.  Looks like once the AP1 has been modded, it's not designed to work without the PP.  Tried to unhook the AP1 from the PP and connect it directly to the Vaunix/laptop.  The bitrate display just flickers, and the error message "No Ext Power" appears on the bottom of the AP1 screen in red letters.

 
Jul 23, 2012 at 10:08 PM Post #890 of 1,214
Quote:
Check that the firmware is current via the menu. Should be v1.9. This is a know issue with previous versions of the firmware. 
 
EDIT: Mine did the same thing on an earlier version of the firmware. 

 
It's v1.9.  I just updated the AP1 this afternoon.
 
I'm going to uninstall all the drivers and try this from scratch.
 
Edit:  Close to three and a half hours of troubleshooting.  DiskCleanup, Microsoft Windows Resource Checker (SFC), Check Disk, and reinstalling literally every single USB driver and controller.  Did all that, and it's still showing up as "Unknown Device" in the "Universal Serial Bus Controllers" section.  But for whatever reason, it seems to be working.  Only question is, when will it stop working and start clicking away to hell again?  If/when it does, it's going back to Audiophilleo.  I'm so ******* done with this nonsense.
 
Jul 24, 2012 at 11:18 AM Post #891 of 1,214
So, both the PP and the AP are current? PP firmware should be v1.9, the AP firmware should be 1.2? If you are current with those, then there's something wrong. Call Phillip. 
 
I'm a Mac user, so no drivers necessary. 
 
Jul 24, 2012 at 11:36 AM Post #892 of 1,214
Quote:
So, both the PP and the AP are current? PP firmware should be v1.9, the AP firmware should be 1.2? If you are current with those, then there's something wrong. Call Phillip. 
 
I'm a Mac user, so no drivers necessary. 

 
AP1 firmware is v1.21.  PP firmware is 1.9.  Everything seems to be working okay... for now.  I'm going to just leave the damn thing alone and hope it doesn't start going haywire again.  If it wasn't such a neat toy, I probably wouldn't have expended so much effort to get it working again.  If it acts up again, I'll call Phillip.
 
Thanks.
 
Aug 7, 2012 at 10:02 AM Post #893 of 1,214
I had weird issues with the PP seeming to drop dead, which Philip instructed me how to reset. Since then it has been fine, but it might not have liked being plugged and un-plugged at some point. Just brought out some very nice recordings made by Kostas Metaxas in Melbourne and enjoying the greater sense of space and pinpoint imaging with my whole kit.
 
Aug 7, 2012 at 11:02 AM Post #894 of 1,214
I've experienced something similar a couple of times. I went through the PP interface to reset the device. Is that what you did? Are you still using the Vaunix? Any reflections/observations with or without? 
Quote:
I had weird issues with the PP seeming to drop dead, which Philip instructed me how to reset. Since then it has been fine, but it might not have liked being plugged and un-plugged at some point. Just brought out some very nice recordings made by Kostas Metaxas in Melbourne and enjoying the greater sense of space and pinpoint imaging with my whole kit.

 
Aug 13, 2012 at 10:54 AM Post #895 of 1,214
I hate to be a buzz-kill, but hooking things up that way doesn't make a lot of sense.
 
The Benchmark DAC1 (all versions) has a non-defeatable ASRC in it to reduce jitter.
This means that ALL INCOMING DATA is reclocked to the Benchmark's internal clock.
(You can read their tech briefs as to the details and why they were chosen....)
 
I believe the USB input on the Benchmark is NOT asynchronous.....
but the USB clocking doesn't matter because the ASRC will be reclocking the signal anyway.
Using an asynch USB adapter might avoid the occasional actual USB error,
and the ground-isolation of the AP + PP might reduce or eliminate some ground noise,
but overall it's really a bit of a waste.
(It WILL let you do 192/24 USB - which you couldn't before - but that's about it.)
The whole point of paying the price of the AP is outstanding jitter reduction and,
since the Benchmark will be discarding the nice low jitter clock produced by the
AP and replacing it with its own clock anyway, that benefit will be wasted.
 
The AP makes good sense with any DAC WITHOUT an ASRC (most don't have one),
or with one like the new Emotiva XDA-2 (where the ASRC can be bypassed),
but it's sort of wasted on a DAC with a non-bypassable ASRC.
 
(With the Benchmark, a much cheaper, higher jitter asynch USB adapter will give you the same USABLE benefits,
since the jitter at the input doesn't matter anyway.)
 
Sorry
Keith
 
 
Quote:
I know how much you guys like pictures, so here's a quick teaser:
 
 
 
 
 
 
 
Will be using AP1/PP -> Benchmark DAC1 USB -> Gilmore Lite w/ DPS -> Sony Qualia 010.

 
 
Quote:
I know how much you guys like pictures, so here's a quick teaser:
 
 
 
Will be using AP1/PP -> Benchmark DAC1 USB -> Gilmore Lite w/ DPS -> Sony Qualia 010.

 
Aug 14, 2012 at 10:42 AM Post #896 of 1,214
Harrumph.......
 
It's only the DATA lines that are (and should be) 90 Ohms impedance.
Since you aren't going to cut the data lines anyway, the cable project is trivial.
The original data lines stay right where they are.
Cut the power lines and run them to a separate connector and you're done.
(The only cost is the two cables you'll be sacrificing.... and the one that becomes the power
feed should be nice and heavy, but there's no point whatsoever in using an "audiophile" one for that.)
 
Another thing to consider is that some USB devices may not like running on a power source that
has no ground reference whatsoever to the data source.
With a normal USB connection, both devices are connected to the same ground and +.
This means that they (and the data) are REFERENCED to the same ground.
The data itself is a differential signal (a data + and a data -).
IN BASIC PRINCIPLE, differential signals don't need a ground but, in practice, that may not be true;
it depends on the actual circuitry in the sender and receiver.
 
When you cut that wire, and use a battery, you are totally floating the grounds between the sender and receiver.
Some senders and some receivers simply may not be willing to work that way.
(Devices INTENDED to provide galvanic isolation SPECIFICALLY incorporate circuits that work well that way.)
Also, by cutting the ground reference connection, you open the possibility of OTHER noise happening between them.
(One of the reasons common ground are normally used is to prevent noise voltages developing BETWEEN grounds.
By isolating the grounds we are eliminating this protection.)
 
The most sensible solution is to design the USB input of the DAC itself to incorporate galvanic isolation
if the DAC is sensitive to ground noise.
 
From the information provided, the Vaunix hub is designed using proper engineering principles...
The power and signal grounds are separate (probably connected at a single point somewhere).
This means that the Vaunix does a very good job of providing clean power to the receiver.
I believe it also incorporates filtering to remove out-of-band noise from the signal and power lines themselves.
It does NOT provide galvanic isolation between the source and receiver (and isn't intended to).
 
 
 
 
 
 
Quote:
I don't that Y-cable needs to be that expensive - I was going to DIY one (just need to calculate the impedance to be close to 90 Ohms).  One could also just butcher a wirewold etc by running a stanley knife down the middle and reterminating the ends - it wouldn't be pretty but it would be a cheap[er] Y-cable with sure 90 Ohm impedance.  Perhaps like the starlight that came with the AP2/purepower
very_evil_smiley.gif

 
personally though I plan to start from scratch and just aim for within USB spec tolerance of 90 Ohms - I just need to figure out how the shielding affects the impedance - or I could just copy the gauges used in any cheap to-spec USB cable.

 
Aug 14, 2012 at 10:49 AM Post #897 of 1,214
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It's temporary. Will move the AP1/PP back to the Cary Xciter once I get my Cary CAD300-SEI.  Xciter only takes 48/16 over USB, and I need 96/24 input, so I use BNC via AP1.
 
Aug 16, 2012 at 10:27 AM Post #899 of 1,214
According to Philip, the AP (with PP) will NOT work without the PP unit connected -
because the PP mod replaces the original isolated power supply that runs the output side of the AP with the input from the PP.
If the PP's battery is dead, then it passes the power from the computer through to the AP (probably with some filtering),
but you can't run the AP without the PP box connected.
 
It is my understanding that the reason they couldn't include the option to switch back and forth is that the mod involves
actually removing the original isolated power supply module that provides galvanically isolated power to the output
section of the original AP.
 
In principle, it should be possible to modify a USB cable to tap into the USB power from the computer,
and then route this power to the PP input connector on the AP to power the other half of the AP.
The end result would be similar to the AP with PP when the PP is discharged (and so running in charge mode).
(This would let you run a modified AP "portable" without the PP, but would eliminate your galvanic isolation,
so the result would NOT be equivalent to an unmodded AP, would almost certainly compromise the performance of the AP,
and might actually risk damaging it..... It hardly seems worth the risk)
 
As for the problem someone reported with power switching on and off.....
all USB ports have a set limit on the amount of current they can supply,
and there is a lot of variation between them (it's supposed to be a standard value).
This is why some USB hard drives just won't work right attached to some PCs.
There is also often a variation between individual ports on a single PC - or between front panel and rear panel ports.
I've especially noticed that it tends to happen with some ports on some laptops.
Also remember that EACH USB PORT has a set current limit.....
so, if you plug an unpowered hub into a port, the single power limit on that port applies to the SUM of everything you plug into the hub (plus the hub itself).
(So plugging an AP with or without a PP plus other stuff into a single unpowered hub would be a bad idea, and might even be bad with a wimpy powered hub.)
Depending on which ports you use in certain computers, you may have the same situation.
The solution there is to use a powered hub (ANY powered hub - preferably a decent one).
Another solution, if you're using ports on a PC, is a wire that taps power from TWO USB ports.
(It has two connectors that go to the computer, one full, and one that just uses the two power leads.
These wires often come with USB hard drives.)
 
Keith
 
 
 
 
 
Quote:
Got some bad news.  Looks like once the AP1 has been modded, it's not designed to work without the PP.  Tried to unhook the AP1 from the PP and connect it directly to the Vaunix/laptop.  The bitrate display just flickers, and the error message "No Ext Power" appears on the bottom of the AP1 screen in red letters.

 
Aug 28, 2012 at 1:38 PM Post #900 of 1,214
Does anyone know if Phil is on vacation or otherwise disposed? My LCD stopped working and I have been trying to contact him for the last day and half now.

It was working fine then all of sudden, no display (unit still functions though).
 

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