I've no problem with anyone running objective tests/measurements on the PCBs and would love to see some results but I'm not sure of your thinking with respect to the data delivery mechanism here?
The PCB simply takes DSD data and applies a low pass filter. What relevance is whether the DSD data is delivered via USB or Ethernet (in the shape of a BBB or RPi); we know from numerous DAC implementations that both USB and Ethernet are able to deliver good quality DSD data to the DACs.
Yes I have used DSD downloads as well as upsampled PCM files and, regarding noise, the results are the same in any given context.
I have tried to use BBB/Botic/Acko SO3 but currently Botic/HQPlayer NAA don't coexist for DSD, just PCM.
The only times I've experienced audible noise (other than the occasional pops) are
(a) when I tried to use digital volume control with upsampling, which was eliminated as soon as digital volume control was turned-off
(b) when I tried to use the Silk TVCs as both volume control and LP filter. By re-introducing a discrete component (RC) LP filter the noise has been eliminated. It was an experiment that didn't come off.
The PCBs may well be introducing noise but fundamentally the possibility of encountering noise is a facet of this approach to deriving an analogue signal from the DSD data and the lower the DSD data rate the more likely seems to be the possibility of noise, hence the desire to use DSD256 0r higher.
Felipe, the FlipFlop board offers double the output of your SE board.
I'm using a FlipFLop board with one of these;
BCF PCB and Kit
though there are other balanced to SE buffers available.
Just a thought
Ray
You're welcome. I reread my post and hope I didn't come across as defensive.
Interesting enough for you to experiment with?
Ray
Chaps, I may be doing this guy a disservice but I am suspicious of this link. The forum say's he's been a member since 2012 but he has only posted twice, both today and within a couple of minutes. Maybe a moderator can advise?
Ray
The original 6SN7 lampizator is also balanced input
Attachments
Thanks again, I'm just trying to follow you as better as I can, to have a somehow comparable situation. BTW, you think the SE output is so low? I'm putting a Salas Dcb1 in front of it.
I'm ordering parts next week. The LP parts are off board, I remember, right?
Inviato dal mio D5803 utilizzando Tapatalk
Give it a try. I would be interested in the results as, I'm sure, will others.
Ray
I can spare one of my own FlipFlop boards if you want? PM me if you want to arrange something?
Ray
I see you've started a thread on this buffer;
http://www.diyaudio.com/forums/tubes-valves/289075-output-tube-1578-no-dac.html#post4663012
One thing to remember is that there will be about 1.65V of DC offset on the output of the single-ended board that you'll be passing to the grid of the tube.
Ray