Onkyo is on a roll. I first realized this some time ago when visiting their HQ in Japan, and discovered for myself the scale, breadth and imagination of the company.

Historically, the brand has struggled to find suitable distribution in the UK, and its products - while often innovative - have missed the commercial mark. But that's changed quite dramatically in 2007. Today, the brand's range of receivers are almost indecently well-endowed and come with price points that have sent their rivals scurrying back to their spreadsheets.

The latest model certain to send a wave of excitement around the AVR community is the TX-SR805. As with its stablemates, it has an enormous range of features, yet typically sells for an unprincely £800.

Indeed, I challenge you not to do a double-take when you digest its specification: the SR805 is a 7.1-channel THX Ultra2 receiver - not the lower-specified THX Select - and is generously rated at 130W per channel (our own Tech Labs measured it as 146W with five channels driven - a very good performance.)

THX is above all a post-processing standard, but the branding has important quality-related connotations, and with suitably-designed THX Ultra2-certified speakers, it has the capability of an unusually well-controlled overall character, even deep into bass territory.

Of course, there is nothing to preclude good behaviour with conventional (ie non-THX compliant) speakers, which is just as well given the paucity of THX speaker options on the market. Certainly this was the case during the test period, during which I used both a multichannel MartinLogan Fresco/Dynamo system, (see page 58), and Mordaunt-Short Performance main and centre speakers in combination with foreign rear surround speakers and subwoofer, all matched, using Audyssey MultEQ XT room correction, which brought unity and purpose to a system that could - perhaps should - have sounded a mess. It did so with the ambitious, wide-ranging recreation of an urban nightmare that is the 5.1-channel Dolby Digital soundtrack to Once Upon a Time in America.

Visceral

I think potential buyers might expect an exciting visceral performance from an AVR of this ilk. But I must admit that this is one of the few moderately-priced home cinema receivers that I have ever willingly tolerated with well-recorded music; the power and the subtlety of Anton Bruckner's symphonies on Super Audio CD, for example, played in stereo. Receivers like this won't normally stand the pressure.

This, in short, is an accomplished performer, one that goes loud and soft, that is detailed and subtle, and that can bring a touch of panache and power to proceedings when required without sounding brash or synthetic. Even when driven hard, the sound never sags, or shies away from what the recording demands.

Connectivity includes a bank of three HDMI inputs, and one output, conforming to the latest HDMI version 1.3a spec. This was introduced late 2006, and is capable of 1080p at 48bit colour depth (DeepColour).

This is the highest performance HDMI version in use, but its benefits over other versions are limited mainly to the interaction of Dolby True HD and DTS-HD Master Audio from Blu-ray and HD DVD players. It is currently standard practice to fit Dolby True HD inside your HD player and output it as Linear PCM. However, there are theoretical advantages to doing the decoding job externally, a situation that may be exacerbated by the rapidly falling price of HD players.

When it come to DTS Master Audio, the trend now is to only offer a bitstream output from compatible players. In virtually all cases outboard decoding will be done by AVRs like this Onkyo.

To drive the 805's decoders, I hooked up the AVR via HDMI to Toshiba's new HD EP35, which can deliver a bitstream output to the receiver. 300 on HD DVD, funneling Dolby TrueHD, is a thrilling sonic experience. The lossless audio is supernaturally crisp and well-delineated, with the 805 capable of astonishing dynamics. If you think Dolby Digital Plus is good, you ain't heard anything yet.

The HDMI inputs are assignable to whatever inputs you wish (except phono!), and you can then programme the display to allocate a new name to the newly assigned input should you so wish. The menu system that drives all this flexibility is comparatively straightforward and far from flashy, but at least understandable and easy to use.

Three component video inputs are also available, plus six composite and S-video inputs; a similar number of audio inputs; a mix of digital optical and electrical inputs; a multichannel analogue input and the aforementioned phono.

Unlike its bigger brother, the SR875, there's no Silicon Optix Picture Processing, but there is a Faroudja deinterlacer, which smooths jaggies from analogue sources but keeps the resolution unchanged. It should be noted you can't input 1080i into the component inputs without the receiver downscaling it to 720p.

It's possible to configure video processing so that all signals either come via the component or HDMI output. The system is limited, however, in that an HDMI input cannot be routed out via component. This may impact on some system configurations when more than one display is being driven. All inputs via HDMI travel through the receiver without any alteration or upscaling. What goes in comes out.

Surround options available include all the usual suspects, up to and including THX Surround EX and DTS 96/24, extending also to the very recently introduced THX-Neural Surround, which is broadly comparable to DTS Neo:6 or Dolby Pro Logic IIx - but don't let anyone from these two estimable organisations hear you say this.

This far from exhausts the TX-SR805's capabilities, which extend to some second and third zone capabilities (one at preamp level only, so a local power amp will be required in that zone). Multizone is limited to two-channel sound in both cases.

The main room can continue in 5.1 or 7.1 channel form, though not if one of the extra zones is being driven at speaker level. The front speakers in the main zone can be biamped if required, which offers real benefits when listening to music in stereo.

Zone 2 is supported by an external remote control receiver, and a 12V trigger can be added, for example to switch a local power amplifier.

Onkyo has also licensed the Audyssey microphone driven MultEQ XT room correction system, which includes simple speaker equalization facilities. I would argue that Audyssey MultEQ XT remains one of the few proprietary algorithms that doesa worthwhile job, and that makes musical (or rather soundfield) sense over a significant area of the listening room.

This is defined by up to eight sets of data points determined by moving the microphone around between test runs, though it can take many minutes to calculate the necessary correction data after it has been sampled.

Parameters handled by Audyssey MultEQ XT include checking the number of speakers, their sizes, crossover settings (which can be varied for each speaker pair), and distances, as well as applying graphic equalizer settings on a per speaker or subwoofer basis. Speaker impedance must be set to 4 or 8Ω, to optimise power delivery.

The remote control is well designed. As is the way of these things, though, it's got more buttons than, er, Button Moon; there's an extensive onboard library of commands for other system components. It will even command your iPod connected via the (optional) Onkyo dock.

In terms of features, few rivals offer as much bang for your buck. No other brand has THX Ultra2 at this price point. Unlike the bigger SR875, there's no internal scaling, but this shouldn't be much of an issue, asI suspect most users will scale their footage elsewhere.

G'wan, buy one

There's no doubting that this is a superior product, and that it will perform equally in a mixed audiophile/home cinema context. If you don't need the extra processing thrills of the SR875, buy one!