Audio system

[last updated: 29 October 2016]

hi-fi system diagram

The video side of the system is described here.

My multi-channel Rotel RSP-1572 A/V control pre-amp is a digital audio/video 7.1-capable surround-sound processor that I've set to output just stereo analogue audio to my minimalist power amplifier.1

Sound in the (sur)round:

I have spent years trying (and rejecting) a series of surround sound solutions going all the way back to initial Hafler systems in the Old Windsor flat in 1975. I enjoyed a brief dalliance with the quadrophonic systems of the mid-1970s (Sansui's QS matrix stereo was for a while my choice, as I didn't have the room or the budget for a full-on Ambisonic system). Later came Dolby Pro-Logic, followed by Dolby AC-3 (a 5.1 discrete digital channel solution initially available as an RF "track" on LaserDiscs in the mid-1990s).

AC-3 had good channel separation, but was compressed and certainly doesn't compare to the latest lossless 7.1 surround sound formats available on Blu-ray. Another step along the way was DTS, though that, too, had a restricted bit-rate when squeezed on to a DVD. And so it went on. The more channels, the more speakers, the more amplifiers, the less the chance of what you could call domestic harmony in the living room. It was getting crazy.

Amplifier: High-quality stereo music does more for me than any number of whizz-bang bullets, car crashes, explosions, and helicopters flying around overhead. And I live my life to a musical soundtrack. So in 2010 I reverted to simple stereo — hence the Rotel RB-1572. It's a 250 watts per channel Class D amp with an on/off switch and, erm, that's all. Unless you count the over-bright blue ring of light (not Cherenkov radiation) around that switch.

By feeding analogue audio into the pre-amp I can use its "Bypass" option. This avoids any conversion of the analogue audio into digital (for completely unwanted DSP "shaping" of any sort in the pre-amp) and just hands an unmangled signal across to the power amplifier:

The two front speakers receive pure analog stereo full-range signals with no
subwoofer crossover, no delay, no level adjustments, and no parametric eq.

Can't say fairer than that. Despite the spelling of "analogue".

Loudspeakers: Splendid PMC FB1i devices — they only ceased production in 2013 after a 10-year run; long may mine continue, I hope. I have removed both the centre (dialogue) speaker (a PMC TB2+MCi) and the rear surround speakers — a venerable pair of "Rock Solids" (now back upstairs in the reading room) that had last been my surround pair in 1998.

The rear surround pair from 1998 to 2009 were Sony SS-176Es that I originally bought, in some haste, and at a time of relative poverty (IBM salary, remember), to replace my even more venerable Celestion Ditton 66 studio monitors.2

Signal sources

CDs and MP3s: My several thousand CDs took up an unacceptable amount of space in the living room — well, unacceptable to Christa, certainly :-)

My first solution was to record them on to minidiscs. This (literally) burned through three recorders over many months. And posed a fiddly, typesetting nightmare when it came to labelling them. But the only way to fit a lot of CDs on to a lesser number of minidiscs is to record them in the lowest quality LP4 format.

I next ripped the CDs to MP3 files, storing the CDs up in the loft. Now I was wasting time shifting clusters of MP3 files around a variety of portable playback devices. None was entirely satisfactory. None was as high quality as the sound from my original CDs — largely because I'd initially ripped all the damn' things at 128Kbps fixed bitrate (an unwise decision). With retirement came the time to fix this, once and for all. I started re-ripping my way through the CDs, using highest-quality and variable bitrate. Much better.

But with retirement, sadly, came Christa's final illness, and an end to my motivation. I had no interest in hi-fi while our remaining time together was so precious, and so limited. It was eight months or so after Christa's death that a visit from Gill re-sparked my interest in finishing the job. The MP3 files are safely and variously stored on several drives and network devices. I play them with VLC from a Linux PC with high-res digital sound. (I can also use the Oppo to stream them from the NAS.)

I can hear no significant difference in quality between these VBR MP3 files and my original CDs. An argument could be made for re-ripping them all one final time, as lossless FLAC files, but Life's too short. The CDs live in CaseLogic folders in the dining room.

Radio: I have all the BBC national radio channels via the Humax digital satellite TV/radio PVR (used 99% of the time for radio). I use 'get_iplayer' to download BBC Radio 3's "Late Junction" and weekly jazz programmes as 320 Kbps MP3s within their window of availability. I sometimes use the BBC's "high-definition" audio streaming, but the 48KHz PCM live digital feed from satellite also sounds fine. My NPR satellite feed has gone walkabout, but I'm unbothered by its loss.

Minidiscs: My Sony MDS-JE780 minidisc recorder is obsolete, but works fine. Furthermore, having used my custom-made audio/video switchbox for a decade before 'upgrading' to my first full-blown A/V amplifier3 in 1998, I found Sony MD recorders can make very useful audio switchboxes.4 (Not that I need one!)

Cassette tapes: I have 250 or so high-quality classical music tapes and another 200 of all sorts of radio speech5 items. I was lucky to unearth a dusty old Denon DRM-555 tape deck in a forgotten corner of a large "Comet" store and pleased to liberate it at a bargain price. It's only two-head, but has Dolby C Hx Pro, and (since I only use it for playback, not recording) it does just fine. Its playback quality is on a par with the three delightful Aiwa ADF-770 machines I had in the 1980s.


1  Triggered by hearing that £150,000 Steinway system in May 2010. It was stunning to hear simple stereo music of a quality I hardly dared believe existed. Hence the Rotel, with which I can get the volume I want without overloading anything. (An advantage to solo occupation of a detached house.)
2  I had these from 1976 when moonlighting as a hi-fi freelance magazine record and kit reviewer. They were magnificent, but sadly I destroyed them two decades later while foolishly playing the LaserDisc of "Top Gun" at reasonably authentic SPL to niece #2 (who subsequently [consequently?] went on to become a helicopter pilot in the RNZAF). Go figure. I don't think I'll repeat this particular flight test as it's quite an expensive business.
3  I began with a £450 Korean "Dual" box but quickly replaced that by a relatively high-end (£1,600) Yamaha DSP-1 that offered Y-C video switching, and had eight digital audio inputs. Plus, it could decode the Dolby AC-3 RF signals carried on newer LaserDiscs. The Yamaha lasted for eleven years — money well spent.
4  Just as I used a JVC SVHS tape deck in a similar way for routing combined audio and video analogue signals around in the living room back in 2001.
5  I have a huge hill to climb in terms of properly documenting the wealth of spoken material I've captured over the last forty years or more. Death will very likely beat me to it :-) <Sigh.>