Allo Digione Signature

[smethley]

What's the output impedance of the Digione?  From a quick look at the components on mine it's probably 50R.  That would be a bit of a shame as my DAC i/p impedance is 75R.

 

Sounds great tho', with either 50R or 75R cable!  Can the Signature really be better?  

[smethley]

24 minutes ago, allo.com said:

BNC is 75R and RCA cannot be at 75R by definition (geometry of connectors) so we chose 50R

Sensible choice!.  Thanks.

[smethley]

So, based on recommendations, I've ordered the Signature and battery pack to compare to my original Digione.

 

If I understand the power sequencing needs from earlier in this thread, I will not be able to simply turn off the battery pack and leave the Pi running (via the mains adapter), since when I next turn on the battery, the system my not lock onto the correct clock ('50% chance').

 

2 questions:

1.  How would I know if the correct clock has been locked onto?  (Why waste time rebooting the Pi if not necessary).

2.  Is there not an elegant way round this?  (I tend to never turn off my Pis).

 

[smethley]

On 10/26/2018 at 10:04 AM, nbpf said:

With respect to question 2, I would reboot the RPi after switching on the power on the clean side. If you do not want to reboot via remote login from a laptop or from a desktop, you can setup a ssh client on you mobile phone (ConnectBot, for instance) to reboot the RPi by just tapping the app's icon. I am not sure this is an elegant solution but it should work fine if you are not switching off/on the power supply of the clean side every few minutes.

Thanks, yes that's exactly what I do.

 

I'm still curious abut my first question tho' - how do we know the Signature has locked onto the correct clock?  Maybe Allo can tell us the answer?

Thinking about it, which two clocks are we talking about - the two xtals on the board?  If so, then if the wrong one was selected it should be noticeable via wrong audio speed/pitch I guess?  By way of example, as I play CD quality I guess I might be locking onto either 44 or 48 kHz, when of course I would always require 44 kHz?

[smethley]

11 hours ago, allo.com said:

Its all in the driver, RPI knows what file sample is playing and initializes the correct clock

Makes sense, but then surely then each new audio file will have its bit-rate read upon loading by RPI and this info passed onto the Digione board.  Therefore no need to worry about power up order.  Just complete boot/power up in any order, but before playing music.  After all, it must adapt to the bit rate of each new file on the fly - otherwise we'd have to reboot each time a new file arrives, which clearly we don't. Or have I completely misunderstood?

[smethley]

51 minutes ago, pjmcos said:

 

with the Katana v1 experience You have to follow the correct boot sequence, otherwise you will have a smurf. This is a case of the master DAC. I dont know in the transport (no issue on my Doubly powered USBRIDGE though)

A smurf?

[smethley]

8 minutes ago, pjmcos said:

 A smurf garble sound.. 

Thanks, so you always get a 'smurf', even if you send a new audio file?

 

To recap, I'm really just trying to find out whether I really need to reboot the RPI each time I reconnect batteries to the Signature.  I'm hoping Allo will make it clearer why this is / is not.

[smethley]

Thanks that's really helpful.

 

Allo, what's the explanation for the Signature?

[smethley]

12 hours ago, nbpf said:

Sure, I understand that the only thing that matters is that the interface is powered when the RPi boots.

Thanks for asking, and for answering.  That's my working assumption too.  I'm a bit baffled that Allo don't quite seem to know though, or if they do they can't explain it here in anything but woolly terms.