Perfectionist Optimizations

      As mentioned at the outset, the Arcam AVR300 is a sturdy, adaptable workhorse that will sound great in any system, whether simple or complex, whether high end or budget. No matter how you set it up and use it, the AVR300 will sonically outperform any other surround receiver and any other surround processor, regardless of price. Indeed, the AVR300 is intrinsically so superbly transparent and pure, that it can afford to give away a little sonic quality, if and when you invoke the more complex DSP processing modes or longer signal paths through the processor, and the AVR300 will still sound better than other competing processors regardless of price, even in their best sounding modes. For most of you, that's all you need to know, and you can skip reading this section.
      But a few of us are perfectionist purists, who try all kinds of tactics to get the last dollop of sonic realism out of our systems. I proudly confess to being one myself, and indeed it's precisely this passionate pursuit of perfectionism that has made my high resolution lab system so revealing, thereby making it a better analytical tool for bringing you better product evaluations. This section is dedicated to us passionate perfectionist purists. And it is also dedicated to the Arcam engineers who put equal passion into refining the sonics of the AVR300. Thanks to these Arcam engineers, the AVR300 is not just a sturdy, adaptable workhorse but is also a refined thoroughbred, which, when sensitively handled, can rise even above being the best sounding surround receiver and processor, and can yield true perfectionist sonic performance, taking a place in a perfectionist's system that had previously relied on expensive high end separates.
      We were so impressed by the AVR300's sonic performance that we were inspired to try to get the most we could out of its sonic performance. Just how good could this amazing product sound? This exploration was also part of our scientific responsibility, since you can't truly say you have correctly evaluated a product unless and until you have found and explored its limits. Just where were the limits of the AVR300's intrinsic performance?
      Also, our standard procedure for evaluating complex components such as surround processors is to first evaluate individual sections, and then to progressively add further sections into the signal path (this standard procedure is scientifically necessary, in order to control as many variables as possible). In the case of the AVR300, this standard procedure naturally led us to individually evaluate sections such as the analog Direct mode multichannel line section and the power amplifier section. When the sonic performance of these AVR300 sections proved to be so spectacular, so much better than competing surround processors, the only way to find and explore the AVR300's sonic limitations was to directly compare it to expensive high end separate components, such as separate analog multichannel line sections and power amplifiers. When we then found that the intrinsic performance of the AVR300 at its best was equivalent to (and in some ways surpassed) the sonic performance of the expensive separates, it naturally became part of our duty to tell the perfectionist purists among you how you could similarly optimize the sonic performance of the AVR300, so you too could get the maximum performance from this refined thoroughbred.
      First, set the tiny ground lift switch on the back panel to the ground lift position. Ostensibly, this switch should be set for minimum hum or noise, if present in one position or the other. But if you don't hear any hum or noise in either position, there's still a difference in sonic quality. The ground lift position probably breaks a ground loop for most systems, and ground loops degrade sonics in ways other than hum or noise, so with most systems the AVR300 sounds slightly better with these ground loops broken, as they are in the ground lift position.
      Second, if feasible, set the tiny speaker impedance switch on the rear panel to 8 ohms rather than 4 ohms. The 8 ohm setting supplies a higher rails voltage to the power amplifier output stage than the 4 ohm setting, and the AVR300 power amplifier sounds slightly better with this higher rails voltage. You need to use the 4 ohm setting only if you play the power amplifier very loud and your loudspeakers have an impedance of 4 ohms (or less) down at lower frequencies (say below 300 Hz) where a lot of power is required. You could try the 8 ohm switch setting for best possible sonic quality, even if you have 4 ohm loudspeakers, and then check to see if the unit is running hot rather than warm with your normal usage. If it is running hot (or thermally shuts off), then of course change to the 4 ohm switch setting. The 4 ohm switch setting reduces the rails voltage on the output stage, which lowers the amount of wasted heat generated, but still allows the rated power of 100 watts per channel to be generated into the lower impedance 4 ohm loudspeaker load. Remember that this advice is only for the perfectionist seeking the absolute ultimate sonic quality from the AVR300, and the rest of you should follow the manufacturer's instructions and simply set this switch to match your chosen loudspeaker's impedance.
      Third, after you have finished setting up the AVR300, with all level and delay settings optimized as discussed above, then disconnect all video inputs and outputs from the chassis. All of the most revealing audio products sound better when high frequency noise in the vicinity of their audio circuitry is reduced or eliminated. And all processors sound better when you keep video signals, which act as high frequency noise contamination, out of their chassis. Because the AVR300 is so stunningly transparent, it reveals even more than other processors the sonic improvement you get by removing video signals from the chassis. Indeed, Arcam themselves turn off the digital processing circuitry in the AVR300 when you select the Direct analog mode, precisely to slightly improve the AVR300's sonics by eliminating the noise that the digital circuitry generates in the vicinity of the analog audio circuitry. If Arcam can go to this trouble to get perfectionist sonics out of even a budget product like the AVR300, then surely you too can go to the slight trouble of disconnecting all video signals from the chassis, since video signals represent high frequency noise contamination just as digital signals do.
      Instead, run your main video signals from your disc player directly to your display (which will also improve your video quality). Try to use the video switching built into the display, or, if you must, get an external dedicated video switcher. If you want to work with the AVR300's menus in the future, you don't really need to hook up to your video display for an OSD, since the AVR300 provides an excellent menu tree on its own front panel display that makes it surprisingly easy to navigate through all menus. Again, please note that this advice is only for the sonic perfectionist, who wants to hear the AVR300 at its absolute best. Everyone else can freely use and enjoy the AVR300's excellent video switching, routing, and conversion facilities (it can convert composite or S-video input to component video output).
      Fourth, optimize the power cordset. The AVR300 sounds great with the factory supplied cordset. But, just like the finest, most expensive high end components, the AVR300 too can sound even better if you feed it with just the right power cordset. In fact, because the AVR300 is so transparently revealing, it reveals a lot of information about all the electrical signals input to it, including the electrical energy coming from the powerline via the power cordset. Note that the output electrical signal from any audio component actually comes from, and gets all its energy from, the powerline via the cordset, while the audio signals input to that audio component merely act as valves or gates to modulate the energy coming from the powerline via the cordset. Thus, if the powerline energy as transmitted via the cordset is imperfect, it will modulate the output signal of that audio component, as surely as if the input audio signal were imperfect. An audio component as superbly revealing as the AVR300 clearly reveals all information about the quality of the power cordset, as surely as it reveals all information about the audio input signal representing music.
      If you use the AVR300 just as a surround processor in a perfectionist high end system, the AVR300 can benefit from the fastest, purest high end power cordsets. The best sounding such cordset we found for the AVR300 is the Von Gaylord Chinchilla silver power cordset. On the other hand, if you also use the AVR300's built-in power amplifier, then the AVR300, with the slight added solid state crispness from the intrinsic sound of the power amplifier, can sonically benefit from a power cordset having a little more self inductance, to provide a euphonically helpful slight softening of upper frequencies. The best sounding such cordset we found is an ordinary looking, inexpensive generic cordset from Well Shin, a Taiwanese manufacturer. It is a 14 gauge SJT power cordset, the same type as the cordset supplied by Arcam with the AVR300. This Well Shin power cordset sounds much better, for the AVR300, than other generic cordsets. We tried many other generic cordsets, but they had too much self inductance, so they softened and defocused upper frequencies too much (thereby sacrificing some of the AVR300's superb articulation) - and/or they had dielectrics with distorting absorption properties, so they smeared and dirtied and veiled the sound (thereby sacrificing some of the AVR300's superb transparency and clean purity).
      Fifth, if you want to hear the AVR300 at its intrinsic best in Direct analog mode, it helps a bit to physically disconnect all incoming digital signal cables. This reduces the entry of contaminating digital noise into chassis, which will help the sound of any high end analog audio component, including here the AVR300. Again, this is also why Arcam themselves, as perfectionist purists at heart, even go to the trouble of shutting off power to all digital signal processing circuitry within the chassis, when you select the analog input, purist Direct mode.
      If you want to hear the AVR300 at its intrinsic best with a digital signal input, it helps a bit to physically disconnect just those incoming analog signal cables coming from the same source component that is feeding the digital signal. This reduces ground loop problems, which slightly degrade sonic quality in any high end component, including here the AVR300.
      Of course, if you employ a single disc player for playing both high resolution surround audio discs (SACD and DVD-A), whose signal can only be transferred in analog format, and also for playing discs that can be transferred in the recommended digital format that sounds so wonderful in the AVR300 (video discs and redbook CDs), then you'll have both a digital interconnect and multiple analog interconnects running from your disc player into the AVR300, and as a matter of practical convenience you won't want to constantly be unplugging and plugging cables. In this case, rest assured that the sound of the AVR300 still meets perfectionist high end standards, and sounds as good as high end separates. Only if you want that last teeny bit of sonic transparency, to hear what the AVR300 intrinsically is truly capable of, is it worthwhile to go to the trouble of unplugging and plugging cables when you switch between analog and digital signal transmission.
      As an intermediate tactic, we might suggest that you merely unplug the digital interconnect cable when listening to analog input from the disc player, since that is only a single cable to be bothered with. Another possible tactic for the dedicated perfectionist is the following. Think of the huge amount of money the AVR300 has saved you, compared to high end separates. Then allocate a small fraction of this money to buying a second disc player. Use the player that has the best sounding analog output (today the McCormack UDP-1) for playing all discs where you want to (or have to) bring the signal into the AVR300 in analog format (and use the AVR300's analog Direct mode). And use the player that has the best looking picture (today the Arcam DV29, which also produces excellent audio, especially via its digital output) for playing all video discs, as well as all audio discs you want to bring over in digital format (e.g. two channel CDs for surround enhancement processing in the AVR300). Note that, even with this two player tactic, it would still be sonically helpful to physically disconnect the digital input cable, or at least turn off power to the player that is the digital source, while listening to the player that is the analog source.
      Sixth, set the crossover frequency in the Subwoofer setup menu to 90 Hz. Fortunately, this 90 Hz frequency is so close to the most useful and commonly employed crossover frequencies, 80 Hz and 100 Hz, that you can probably leave the setting at 90 Hz regardless of your subwoofer setup. When you choose the 90 Hz setting, the sound of the AVR300 is optimally warm and airy, unusually so for a solid state product, and very natural and musical. At frequency settings to either side of 90 Hz, the sound gets slightly leaner and harder, and progressively more so the farther you go from 90 Hz (the crossover frequency is selectable in 10 Hz steps).
      What's going on here? The same DSP that does all the signal processing also operates the subwoofer crossover, and when you select different crossover frequencies the DSP must interrupt its main signal processing with different cycling times and periodicities. We suspect that, for some reason, the interruptions for 90 Hz dovetail perfectly with, and therefore cause minimum disruption to, the main signal processing, thereby providing maximum intrinsic sonic fidelity for the main signal processing - whereas the interruptions for other frequencies progressively deviate from this optimum dovetailing and minimum disruption, thereby causing slight sonic fidelity degradations for the main signal processing path, which get progressively slightly worse as you deviate farther from the 90 Hz optimum. Whatever the cause, this phenomenon is in the part of the DSP that is preprogrammed by the DSP manufacturer Crystal Semiconductor, so there is nothing that Arcam can do to change it. But, if you are a perfectionist who wants to hear the AVR300 at its intrinsic very best, you can do something about it, now that you know the AVR300 will give you its very best sound if you set this adjustment to 90 Hz.
      Seventh, also in the Subwoofer setup menu, under Stereo Mode, choose Large, not Large + Sub, nor Sat + Sub. The AVR300 sounds best, in all processing modes, when you select the Large choice in this menu item. And the sound subtly degrades, in all processing modes, if you select either of the other two choices. Ostensibly, this menu item selection should only affect behavior when Stereo mode is selected through the DSP. But in fact it subtly affects sonic quality for all processing modes. Why? Some DSP cycles are probably sidetracked for the choices that add the "+ Sub", even if you haven't actually put the AVR300 in Stereo mode through the DSP, and these sidetracked cycles somehow subtly disrupt the DSP's handling of the main signal path, enough to cause a subtle degradation of sonic quality. Again, this part of the DSP is preprogrammed by Crystal Semiconductor, so Arcam cannot change this effect.
      Incidentally, you'll recall that in our main review above we advised against ever actually using this Stereo mode through the DSP, since this path through the DSP sounds inferior, and since the far better sounding analog Direct mode is available for handling stereo sources with maximum sonic fidelity when you want to hear them straight (when you want to hear stereo sources enhanced by the AVR300's stunning surround enhancement modes through the DSP, such as Neo 6 Music, then of course you won't be using that Stereo mode either). Thus, in practice you'll never want to actually use this Stereo mode through the DSP. And therefore, in practice, it doesn't matter one whit which of the choices you select for this subwoofer Stereo Mode setup menu item, so you might as well select the one which gives the AVR300 the best possible sound for all its other modes (by some fluke of DSP programming), namely the Large choice. Note that the AVR300's subwoofer feed, for all its other modes (besides this Stereo mode through the DSP that you'll never actually use), is not affected by this menu item choice, so the AVR300 will still feed and control your subwoofer's input signal just fine, regardless of how you set this particular menu item.
      Eighth, in the EX settings menu, choose the Auto PLIIX Movie selection. When you select this choice, the AVR300 sounds the most naturally relaxed (again, remarkably so for a solid state circuit), and also has the richest ambience with the most spacious imaging. In contrast, if you select the Auto DD EX choice for this menu item, the AVR300 sound becomes slightly harder, ambience a little drier, and imaging a little more closed in. Or, if you select the Manual choice, then the AVR300 sound becomes even harder, with considerable loss of ambience and imaging spaciousness. Remarkably, all this is true regardless of what the AVR300 is doing, what processing mode (if any) you have put it into, and what type of program material or input signal it is handling. In other words, this menu item, which should only affect behavior when the AVR300 detects EX encoded program material, actually subtly affects its sonic quality in all modes, for all kinds of program material. The reason for this strange behavior is probably again related to sidetracked DSP cycles disrupting the main signal processing, worse when Auto DD EX is selected, yet worse when Manual is selected, and minimally when Auto PLIIX Movie is selected, thereby producing the best sound from the AVR300's main signal path, regardless of what further processing mode the DSP is actually engaged in. Again, this part of the DSP is pre-programmed by Crystal, so Arcam cannot change this phenomenon.
      Fortunately, this menu item is easy for you to just set optimally per our advice here, and then forget about. Additionally, this sonically optimum choice here also fits in perfectly with our previous sonic findings above. Since we found above that PLIIX is by far the best processing mode for video soundtracks, whether they are EX encoded or not, selecting what is here the sonically optimum Auto PLIIX choice, as being the automatic choice for soundtracks that are EX encoded, fits in perfectly with our other sonic findings above, for getting the best out of the AVR300.
      All these perfectionist optimizations are worthy of expensive high end separate components, which similarly respond with improved sonics to subtle optimizations. It is a tribute to the AVR300 that it so clearly reveals the sonic benefits of these subtle optimizations, and sonically rewards you for attending to them. This further proves that the Arcam AVR300 truly belongs in the company of the finest, most expensive high end separate audio components.

Conclusion

      The category of AV receiver is generally not taken seriously, and is looked down upon with disdain, as a product of convenience for everyman, but not for the serious audiophile or videophile. In fact, Hi-Fi News, in their just published year end awards for best products of the year in many varied categories, did not even deign to include a category for AV receivers. Most of the AV receivers on the market do indeed justify this disdain and dismissal.
      But the Arcam AVR300 shatters this preconception. The AVR300 is easily the world's best AV receiver, and far better than other AV receivers. And it is also far more than that. The Arcam

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