'Analog Dinosaur' succumbs to the joys of FBA : enter Raspberry Pi 2/IQ-Audio DAC+!!

[Gazjam]

+1 (with bells on, although the Sony DAC, featuring the use of TDA1541s, still has a very entertaining and musically valid sound of its own).

Anyway, a couple of observations, based on recent experimenting and further listening to the Pi/IQ-Audio DAC combo:

First of all, the ethernet cables that Gazjam recommended further back in this thread, shown here: http://www.ebay.co.uk/itm/1717289032...%3AMEBIDX%3AIT

...unquestionably sound significantly better than the much thinner Maplins Cat5e cable I had been using before. Technically, why that is, I don't know. I suspect it's got something to do with the shielding used in the former.

However, there is a marked difference in the sonic presentation of both ethernet cables (bearing in mind that the Duronic ones are actually £5 less than the Maplins cables I bought, so definitely not 'overpriced foo'). The Duronic cables tighten bass and open up the midrange and top-end, allowing markedly more detail through. The effect is so obvious, one can hear it instantly.

As such, I now use these cables from my NAS box to the router, and from the router to the Pi. Highly recommended, and at a bargain price! Nice one, Gary

The other thing is that I must retract my earlier statements about the IQ-Audio DAC+ sounding better with no active preamp in line. It turned out that the reason why I wasn't getting the proper results with my Croft was because I hadn't set the 'gain' high enough in Volumio, when adjusting it, before disabling the Hardware.

Once I had set it to 96 (the sweet spot in my system), and had successfully applied that setting, the sound is stunningly good now through the Croft, and significantly better than using the Volumio web interface alone to adjust listening levels, which I guess is as it should be.

I feel, however, that the process in Volumio should be explained more clearly for newbies, in terms of how to optimally partner the Pi/IQ-Audio DAC with an active preamp, as it is far from obvious, and thus mistakes are easily made! That said, things have now never sounded better

Marco.

Sweet
Glad you liked them.
As with other electrical and signal cables, connector quality and construction can have an impact on how good they work.
These Cat6A cables are inexpensive, robust, on paper do the electrical/networky stuff extremely well and the connectors and construction are bulletproof.

[Marco]

Yup, quality recco, dude!

Marco.

[Darren]

stunningly good[/B] now through the Croft, and significantly better than using the Volumio digital interface alone to adjust listening levels.....Marco.

Aww... now you've gone and spoiled it.... don't want a pre amp......

[montesquieu]

Don't be daft?! I suggest you get down of that high horse as the rarified air up there seems to be affecting your thinking!

DAC chip technology moves on at a rapid rate you need to reset your thinking from the old TDA151A days. Modern DAC chips give outstanding performance when correctly implemented and offer some great features. An integrated DAC close to the data stream utilizing the I2S bus with its separate serial line and clock has got to be better than encoding the PCM stream for SPDIF and worse USB. Why on earth wouldn't it be? Just because Audio Note have used an isolation transformer on the SPDIF interface does not make it perfect, its laughable to think that as you still need to recover the clock and you have issues dealing with ground plane noise. Utilising SPDIF / USB adds complexity and is unnecessary if you can use I2S with a well implemented DAC, it needn't cost Audio Note prices....the only issue as I mentioned before is the dependency on the power supply...

Totally ignores my main point which is that difference between the digital elements of DACs are relatively unimportant, what matters is the output stage.

[Marco]

What about what I wrote?

Marco.

[r100]

Marco, glad you found a way to bypass the digital vol control and use your hardware pre .. re the spotify problem, there are some fixes on volumio.org. basically it seems the password is not updated in one of the conf files.. maybe just wait for an upgrade [emoji41]

[Marco]

Cheers, mate. The Croft just wasn't sounding right before without being fed with a strong enough input signal... However, once fixed, it certainly unleashes the beast!

In terms of Spotify, I've got Duncan on the case, so we'll see what happens. Even if there are fixes on the Volumio site, I wouldn't know how to apply them.

Now I'm just looking forward to seeing what kind of linear PSU Paul Hynes comes up with for the Pi, as that should really elevate its performance into the upper echelons of high-end audio (but without the price tag)... Exciting times!

Marco.

[r100]

for sure !!

[montesquieu]

What about what I wrote?

Marco.

Unsurprised at the improvement with an active pre and glad you found a way to get there

I suspect an isolation transformer between the DAC output and preamp input (as was often used in the previous wave of DAC board projects) might improve things further thanks to better impedance matching, or better still an active buffer - perhaps have a go with an EE BBA or MF X10?

Unconvinced by improvements from ethernet cables though. Having spent 20 years in IT and knowing a little bit about these things ... the way data packets work over ethernet is not the same as with a co-ax cable (with checksum being required in all transmissions and no possibility of missing or altered bits that didn't also cut the music completely) I can't conceive of any possible mechanism that would make a difference to the sound (unless you are hiding a DSP chip somewhere on the cable).

I'm far from a cable ludditie - I have two silver cables (AN Vx) left in my system, a tonearm cable and a digital cable between Audio Note DAC and transport. But the technologies are different. Ethernet is not SPDIF.

[Marco]

Yup, I'm in no position to argue with that, but I also know what I heard (am hearing) - and what the two other people present did too, when the change was made! It certainly wouldn't be the first time in hi-fi that cable effects have flied in the face of 'accepted wisdom', and it probably won't be the last...

In any case, for a tenner, who cares? No puppies have died

Marco.

P.S Underestimate the IQ-Audio DAC at your peril. This little thing is unquestionably a veritable 'giant-killer'!