HiFi Subjectivist ¦ Audio Forum ¦ NVA User Group

Here is the micro-headphone rig in action.

After a couple of days of intensive listening and tweaking I am really pleased with the results soundwise - with a niggle or two. The Nuforce uDac3 is a remarkable device with crystal-clear delivery and the power to drive a difficult headphone like the AKG K601, but it has the tendency to make the top-end somewhat bright and hard. So most of my efforts have been into trying to inject some warmth into the proceedings without losing any of the uDac3's excellent detail. My guess is that it has been designed to run with the more mainstream, bass-heavy cans such as Beats (ugh!) and with Sony's it also works really well.

This has meant firstly switching from Grado's to the AKG cans and then I have replaced the Volumio 2 test version on the Pi with the current version 1.55 release. The SQ of Volumio 2 is as clear as vodka and just as intoxicating, however there are not, as yet, any inbuilt ways to adjust the EQ. Version 1.55 gives the user the possibility to select sample rate (most of my FLAC files are CD-rips so I prefer 24bit/44.1kHz) and a selection of kernel settings to adjust the manner in which the digital audio signal is converted and have a slight effect on character and colour - my favourite setting is 'Buschia' which adds warmth and some roundness to the bass.

There is no doubt that a different approach would give a better result - an NVA AP10H run from a Pi/Hifiberry DAC or Durio would definitely result in a major case of audio nirvana. The point of the exercise here, though, is to provide some acceptable sounds whilst herself is watching the soaps, etc. or having a quiet hour in the afternoon with a book / crossword / shut-eye; and as a budget solution the Nuforce DAC is exactiy what I need.

Still got to try mine, but will be doing so soon, will let you know my thoughts then.

The AP10P does have huge advantages over smaller chip-type headphone amps, as it has current output to go with the voltage swing. The output is slugged via inline resistors too, so if the 'phones are more difficult to drive, this resistor can be lowered in value to allow more signal drive through.

Sorry, I just thought the AP10P needed a plug as it was mentioned above.

_D_S_J_R_ wrote:The AP10P does have huge advantages over smaller chip-type headphone amps, as it has current output to go with the voltage swing. The output is slugged via inline resistors too, so if the 'phones are more difficult to drive, this resistor can be lowered in value to allow more signal drive through.

Sorry, I just thought the AP10P needed a plug as it was mentioned above.

So did I - that's why I mentioned it !

Another experiment in the cybernetic gloom.

Still curious about what the Audioquest Jitterbug can do - and trying to knock the manufacturer's claims down to size - I have tried another experiment.

Spotting that my modem/router also has a USB socket for attaching peripherals such as a HDD or printer, I stuck the Jitterbug in there and had a listen on the most transparent system I have which is a Pi/Digi+ running through the Hegel HD12 with the Grado SR225e plugged directly into the DAC.

Playing a very familiar album: Tangerine Dream 'Hyperborea', full of dynamic synth noises and subtle effects - and doing A/B listens with and without the filter. The effect was more pronounced than the NAS trial the other day. Again a slight increase in volume, clearer and cleaner space around instruments, deeper and tighter bass, wider soundstage, crisper dynamics. And the idea that there was more depth and stability.

The router is a standard article supplied by the telephone company and probably quite cheaply made. However it sits as a spider in the middle of the domestic network 'web' and all data is passed through it. Logical then that cleaning any EM disturbances here might improve matters throughout the whole system.

Further investigation will be necessary here, but those who do make use of network links as a primary music source might well notice a difference.

Thanks for a very interesting, and what could turn out to be expensive, thread. I'm picturing the bloody things plugged into everything with a spare USB socket.

Cheers, Slinger. I'm already making plans to get a second Jitterbug to experiment further.

Fret no disrespect, each to they're own and all that......but that pic tickles me pink (not triangle though)......
I just look n laugh.....Liliput & The Borrowers spring to mind.

Small is beautiful, Jammy !

It is quite remarkable sometimes how bits of kit that have been stashed away as being 'not quite good enough' can suddenly recapture the spotlights.

Several years ago I bought an AKG K420 headphone as I needed a lightweight set to go on holiday. It's okay soundwise. Polite, unexciting and very 'introspective' . Checking out a few cheapish headphones this afternoon with the Nuforce uDac3 running from my laptop the forgotten K420 came out on top with a full and lively performance. The dry and punchy delivery from the tiny USB DAC balanced nicely with the K420's shortcomings and the combination is really enjoyable.

Just thought I'd mention it.