Cantanko

The next step in the home cinema build is getting a decent Freeview antenna. I already have Freesat gear, but the kitchen really needs a freeview set, plus there’s still content on Freeview that has yet to make it onto DVB-S.

In looking around for a decent antenna, I found a rather good site run by someone who obviously knows their stuff and confirmed my suspicions that there’s no such thing as a digital aerial. I’m well within the Sutton Coldfield transmitter footprint and as such a decent Log40 antenna should do me fine. From the roof, I even have line-of-sight to the transmitter, which is somewhat of a bonus

I’ve also chucked £15 at a dedicated DAB dipole. If my experiments with in-car DAB were anything to go by, a decent antenna will pay dividends. I’m a complete DAB laggard, however if I’m going to be on the roof I may as well stick an antenna up there for it.

ATV seem to sell all the right bits at the requisite quality for an install that isn’t going to fail within a couple of years, so it’s probably worth checking them out.

Just found out how to get a little more sonic entertainment from the iMac that’s hooked up to the amp via a digital interconnect. In thumbing through the manual it turns out the DSP-AX620 can handle a PCM stereo source up to 32-bits per sample at 96KHz, which is nice, but initially I couldn’t find out how on earth to furnish it with such a signal. Despite playing some 96KHz, 24-bit FLAC files I have, the iMac was still churning out a rather ordinary 16-bit, 48KHz bitstream.

It turns out there’s a not-often-publicised little app squirrelled away in the /Applications/Utilities folder.

Open this up and a veritable smörgåsbord of audio options are presented. Why this isn’t in the usual “Sound” control panel section, or at least why there’s not a link to it from there, is beyond me.

Either way, you can use this gadget to set the optical audio output to be a 24-bit, 96KHz bitstream. It actually normalises the resolution and rate of anything Core Audio is asked to play to what’s set here, hence the reason the FLAC files were popping out at 16/48. A quick modification:

…and the Amp happily picks up the new bitstream:

And you know what? I’m not sure my ears are good enough to perceive the difference… I have Dire Straits’ “Brothers In Arms” in both formats and perhaps I can hear a more accurate rendition of the very top end, but to be honest my ears’ frequency response rolls off quite steeply after 18KHz nowadays Such is life: by the time you can afford a system capable of reproducing high definition audio, your body no longer has the bandwidth to acquire it accurately.

Still, I have a new set of words on the front of the amp and that makes me happy

I am rather chuffed – my misbehaving Yamaha DSP-AX620 that I bought for a pittance from eBay has had it’s digital side resurrected! continue reading…

A couple of years back, I bought a semi-knackered Yamaha DSP-AX620 from eBay for a tenner: all of the analogue stages were working correctly, however the DSP board was misbehaving. As I was using a discrete decoder and the ’620 had a 6-channel analogue in, this was fine and dandy, but as I now have a new shiny iMac with an optical audio out I need to get the DSP board working again or buy another amp. continue reading…