Top of the line surround receiver
Here we have the top of the line Harman Kardon receiver, the AVR760. It is a very heavy amp that despite its heft manages to look very sophisticated. It is brave to bring to market a surround amp that has only one knob! But indeed why would you want more on the front. After all, you’re probably ending up using the remote exclusively anyway. But if you want you can operate the entire menu structure from the hidden buttons behind the flap.
It operates like a charm: all the menus are where you expect them and you can control each and every little aspect of the amp’s performance. For example, you can choose to have it setup itself completely automatically, by means of a measurement microphone. It then calibrates the speaker size and distance up to 10cm accurately. It did this so well that there was simply need to further tweak the settings. But if you choose so, you can also do it all manually, again via the frontpanel controls and display or for better convenience, on the TV using the excellent on screen GUI. Setting it up is easy and elaborate at the same time. For example, for any given virtual source you can assign analog and digital video and audio inputs completely freely and all separately. This means that before you can use it, you’ll first have to tell the amp for example that you want to use HDMI 1 for video, SPDIF coax 1 for audio and that yoy want to call this input Digital Video Player. You can also assign the output to physical analog or digital outputs. All in all, you could say that it is one large matrix of physical inputs and outputs that can all be freely interconnected via the software exactly as you please. It is incredibly flexible this way, much like what I am used to from broadcast equipment. Well done!
I could spend pages and pages describing the many functions that it has but suffice to say it-has-it-all. Really. There is no function that it doesn’t have or surround format that it cannot handle. It works with usb audio and video and you can even make it part of a home network so you can share files. Oh yeah, it also has an iPod cradle thrown in! In short: this is a very, very complete amplifier.
There’s one function that I do want to write some more about and that’s Dolby Volume. This is a kind of intelligent dynamics compressor and acoustics processor. Unlike popular belief, this doesn’t only work with dolby signals but it works on every format and every source. Even analog inputs or 2-channel wav coming from CD. Dolby volume is very effective in eliminating the often annoying large differences between soft spoken word and loud explosions, or between TV programs and commercials. It works in real time and is nothing like a regular compressor in work. In fact, you can hardly hear it work, besides it just doing its job of keeping levels steady. There is an aspect of Dolby Volume that I like less though. It is called Dolby Modeler. This endeavors to maintain the frequency balance, even when playing at soft levels. In practice this results in boomy bass and a less than clear midrange. But alas, amongst the options that are there on the AVR for choosing Dolby Volume modes, you cannot defeat the Dolby Modeler. So I resorted to using the built in eq to adjust the overly fat bass and retain some of the natural openness.
Above: all connections that you could possibly wish for, and more. All connections feel solid and are well-executed. But what is that big hole in the middle? In use, an internal fan blows out all the heat that develops in the output stages, nicely warming up the cables behind it. This fan is always on at a low rotational speed but speeds up rapidly as things heat up inside. In practice, the fan soon comes up to maximum speed (and considerable noise) in normal listening situations, even when the amp is placed completely freely.
This is what it is all about of course. How does the amp sound? Well, having listened to it using a mix of cd’s dvd’s and High Definition files I do have to say that I have mixed feelings with this amp. On the one hand is sounds very much self assured and there is no denying that it has plenty reserve to drive my B&W N804’s without breaking a sweat while having absolutely no digital signature. It is fluid and refined and never aggressive. It also has very powerful bass which in many setups will be a bonus. On the other hand it is so very refined and restrained that I find it lacking enthusiasm and liveliness. This amp seems to do its best in trying to avoid the typical 80’s and 90’s harsh and grainy sound and it succeeds amdmirably. This amp has the most fluid and strain-free treble that I have ever heard in a surround amp. It als sounds warm and mellow, like the stereotypical older English amplifiers, such as Quad. In fact, it sounds a lot like a Quad 405MKII but with more powerful bass anb more drive. But is this what you want from a home cinema receiver?
Me, I have double standards, I admit it. As regular readers know, for music I prefer refinement over drama, fluidity over attack and colour over sharpness. But even for my tastes, the HK goes a few steps too far. It sounds so very full, laidback and smooth that it simply fails to stir the soul, let alone impress with movies. It clearly doesn’t lack power or control, for sure it has plenty power as is obvious from the way that it handles my Nautili but it just doesn’t sound powerful. Is reminds me of the time when I compared an old Yamaha DSP-A1000 surround amp’s poweramp section to a pair of Bryston 7B ST’s. Mind you, the Yamaha is plenty powerful but the Brystons can supply 1000 watts. Each. Still, the Yamaha impressed me more despite its grain and its more aggressive nature. For movies it just sounded more dramatic. Well, the Yamaha was too much of a good thing of course but it just goes to show how a powerful amp doesn’t neccesarily sounds powerful.
Things that make you go mmmm
Thus far we have an amp that is a dream to operate, looks fantastic and sounds good but maybe just isn’t my taste. Okay, that’s fine. If you use more dynamic/aggressive speakers than the B&W Nautilus 804’s the results may be different. But what really surprised me was the regularity with which the internal fan would turn on. And when it turned on, it wasn’t just on, it was like there was a mini-hoover inside! The only way that you would not hear it humming was if you cranked up the volume to uncomfortable levels. At first I figured that it must be that I have it setup in a tiny space with too little air around it. So I placed it in a different location, completely free with air all around it. Imagine my surprise when I had the movie on pause while I was doing something else and all of a sudden the fan came on at full power! This is just ridiculous. The amp was completely free-standing, idling (not playing any sounds), my room was not hot at all and still the fan came on. I have to tell you, this just sealed the deal. Well, it un-sealed it in fact. This was the reason that I returned the amp, along with the sound that I wasn’t entirely happy with.
On closer inspection you could see that the heatsinks were made in a wind-tunnel kind of way. This is effective as long as the fan is on but without it there is hardly any passive cooling. This means that the fan is always on at a low rotational speed. And even then is it just audible, but low enough to not be a distraction.
On a last note, there was also a faint hum coming from the speakers at any volume level. This was audible from the couch at night, when there was no mucic playing. As soon as you played anything it drowned the hum. But still it is strange as no other amp I had ever had a hum this loud. Sure, most amps have some hiss when you put your ear against the tweeter but hum is rare. It may only be my unit but still I wanted to make note of it.
The AVR760 is a highly sophisticated surround receiver that caters for each and every popular surround format and function around. It also has unburstable power and big bass and is never aggressive. For me though it lacked some attack and bite. Not neccesarily sharpness, but a more forward sound with more drive would have been welcome. But this was in combination with B&W Nautilus 804 speakers which are admittedly a touch on the warm side. Things may be entirely different when using more forward, more accute sounding speakers. But besides the sound quality per se, there was another thing that Harman Kardon should really take not of and this is concerns the built in fan. The fan is always on at a low rotaional speed. But when the amp gets hotter, the fan speeds up. It turns out that it does this even when not playing music, when the amp has just been idling for a period of time and when it speeds up, it really speeds up! The fan is so loud that you couldn’t possibly mask it except when playing music at uncomfortably high levels. So, all in all: great software and looks, let down by a thing so simple as a fan.