Post by MartinT on May 1, 2018 11:39:10 GMT
Prodded by this page and scratching an itch to see whether it makes an improvement, I decided to modify my Allo DigiOne board for direct 5V power, rather than taking the dirty 5V feed from the Pi. allo say that this should make no difference as the DigiOne has a DC-DC converter and plenty of filtering on-board. Challenge accepted!
The first step was to remove the on-board DC-DC converter to separate the power feeds. It's the black block on the right of the board in the photo below. This was the hardest task as there is a ground plane sucking away heat from the soldering iron. My solder sucker just could not clear the holes of all solder. In the end I used the technique of repeatedly applying heat to each of the four pins and slowly leveraging the module out. It wasn't pretty, and for this alone I do not recommend that you try this unless you are very confident of being able to finish what you started.
With the module removed, pads prepared to accept wires on the top side.
It's far easier to buy a USB to DC-plug power cable and snip the latter off, preparing the ends, than to contemplate wiring up your own USB plug. I filed out a hole in one of the case cooling slots to take the cable in, using some heat-shrink sleeving on the inside to act as strain relief. Do not get the polarity wrong as you will destroy the DigiOne board! Test and triple-check everything before powering up.
Showing the working Pi with both cables connected to my Chinese DC-DC converter supplying 5V from the 12V battery (itself modified with two Tokin supercaps, one per USB socket). Two snap-chokes on either end of the short cable and job done. Now the 'computer' and 'transport' power are fully separated back to the DC-DC converter. I could even upgrade this setup by using a second DC-DC converter but that would probably bring near-undetectable improvements.
So, what does the new setup sound like? In all honesty, it's a very small improvement so in a way Allo were right. However, I do detect a change in the presentation of depth perception and clean top end, something the DigiOne is already good at.
A couple of examples: in Estimated Prophet by Grateful Dead, the feeling of an ensemble performance is enhanced with greater depth. In Words by Low, there is a very strong sense of stage and the acoustic of the venue. In both recordings, but especially the latter, treble is very detailed, sweet and not at all harsh.
So, was it worth it? As I said, I fancied having a go even if there was no change. It's a small improvement, nowhere near the level of, say, running the Caiman SEG DAC from Stan's supercap power supply. However, I'm glad I did it for the fun of knowing that my power arrangement is fully optimised. Do I recommend doing it? For most people, no, and remember that your warranty on the DigiOne will be invalidated.
The first step was to remove the on-board DC-DC converter to separate the power feeds. It's the black block on the right of the board in the photo below. This was the hardest task as there is a ground plane sucking away heat from the soldering iron. My solder sucker just could not clear the holes of all solder. In the end I used the technique of repeatedly applying heat to each of the four pins and slowly leveraging the module out. It wasn't pretty, and for this alone I do not recommend that you try this unless you are very confident of being able to finish what you started.
With the module removed, pads prepared to accept wires on the top side.
It's far easier to buy a USB to DC-plug power cable and snip the latter off, preparing the ends, than to contemplate wiring up your own USB plug. I filed out a hole in one of the case cooling slots to take the cable in, using some heat-shrink sleeving on the inside to act as strain relief. Do not get the polarity wrong as you will destroy the DigiOne board! Test and triple-check everything before powering up.
Showing the working Pi with both cables connected to my Chinese DC-DC converter supplying 5V from the 12V battery (itself modified with two Tokin supercaps, one per USB socket). Two snap-chokes on either end of the short cable and job done. Now the 'computer' and 'transport' power are fully separated back to the DC-DC converter. I could even upgrade this setup by using a second DC-DC converter but that would probably bring near-undetectable improvements.
So, what does the new setup sound like? In all honesty, it's a very small improvement so in a way Allo were right. However, I do detect a change in the presentation of depth perception and clean top end, something the DigiOne is already good at.
A couple of examples: in Estimated Prophet by Grateful Dead, the feeling of an ensemble performance is enhanced with greater depth. In Words by Low, there is a very strong sense of stage and the acoustic of the venue. In both recordings, but especially the latter, treble is very detailed, sweet and not at all harsh.
So, was it worth it? As I said, I fancied having a go even if there was no change. It's a small improvement, nowhere near the level of, say, running the Caiman SEG DAC from Stan's supercap power supply. However, I'm glad I did it for the fun of knowing that my power arrangement is fully optimised. Do I recommend doing it? For most people, no, and remember that your warranty on the DigiOne will be invalidated.
