But all is not lost. It's easy to wrap a simple ground wire around the FM antenna coax jack on the back panel of the AVR600. And from there, run this ground wire over to the same wall outlet that you have the Von Gaylord Chinchilla power cordset plugged into (assuming your house has a grounded 3 wire electrical system; if it's only 2 wire, you should connect to a ground pipe buried in the earth outside). Before you attempt to make the ground connection to this wall electrical outlet, be sure you know what you're doing electrically, hire a qualified technical person if you don't know, and in any case turn off the power to this outlet at the breaker box before making any connection here. You can connect the ground wire to the central screw of the wall plate, or to the green screw inside, or to the ground socket of the power outlet right next to the one that the AVR600's Chinchilla power cord is plugged into (if it's available).
      Incidentally, the AVR600 has such high transparency and resolution that you can even hear the directionality of this ground wire, so you should try it both ways. It turns out that the correct, best sounding direction correlates with a model of this ground wire being an intimate part of the power EM energy wave propagating forward out of the socket toward the AVR600, rather than a model of this ground wire being a return path for power current, so the ground wire should be installed in a forward direction, i.e. with the same directionality that would yield the best sound for this particular wire carrying the plus leg of an audio signal propagating from the power outlet to the AVR600.
      Also, the AVR600 sounds dramatically better when you plug all three male prongs of the Chinchilla power cordset into the wall outlet, and don't use a cheater plug on it. Why should this be so? After all, the ground wire of the Chinchilla power cord goes nowhere, since the AVR600's IEC receptacle has only 2 prongs, and makes no connection at all to the Chinchilla's ground wire.
      Remember we discussed how the AVR600 is so superbly neutral and accurate that it benefits from having the power cordset be maximally accurate. One parameter of a power cordset's accuracy is its self inductance, with lower self inductance being more accurate. When you connect the Chinchilla power cordset directly into the wall outlet, without a cheater plug, then the ground wire within the length of the Chinchilla cord itself is connected to a real external reference ground, and also now to the system ground (thanks to your external ground wire connection). No ground current flows through this ground wire within the Chinchilla power cord, since one end is not connected to anything at all. But this wire is still electrically connected to ground, and this means that it can act electrostatically, like a ground plane (or wire), physically very near the active hot and neutral wires of the Chinchilla cord throughout the length of the power cord (and these hot and neutral wires do carry powerline current).
      An electrostatic ground plane that is very close to wires like this, and is close throughout the length of these wires, dramatically reduces the self inductance of these wires, in effect canceling out much of the detrimental effects of the inductance that would otherwise arise from the length of these wires. With the lower inductance in the Chinchilla, brought about by simply connecting its ground wire as an electrostatic agent, the AVR600 sounds much better in focused coherence, attack articulation, transparent revelation of inner detail, spatial imaging, tactile 3D body for portrayed voices and instruments and sounds, etc.

Menu Setups

      Every Dolby licensee is obliged to have certain parameters preset to specific default values, which Dolby deems to be sonically best. And, generally, Dolby's judgement is wise. However, the AVR600's breakthrough superiority in spatial imaging reveals that one Dolby default preset is not wise. There are three Dolby parameters, leftover from the legacy Pro Logic applications, which manipulate surround filed characteristics, called Dimension, Center Width, and Panorama. These parameters, and their settings, are no longer needed with more recent decoding systems such as PLIIx, but they are still engaged and still affect the sound (and Dolby licensees are not free to disengage them where they are no longer needed nor appropriate).
      The default settings for two of these parameters, Dimension and Panorama, are fine (at 0 and off, respectively). But the default setting of 3 for Center Width is no good, and it severely degrades two sonic aspects, both spatial imaging and also the sense of natural open airiness. Why does the default setting of 3 degrade the sound? It seems to electrically directly postmix plural distinct channels. It is always bad to directly electrically postmix two or more channels that have been sourced from different microphones, or that have been derived in different ways. That's because signals from two microphones differ from each other in phase, and do so in a constantly changing way.
      Likewise, plural channels derived by a phase dividing matrix or algorithm, such as the 7 channels derived by Dolby PLIIx from just 2 channels, obviously differ from one another in phase, and also do so in a constantly changing way. If these phase divergent signals are played from different loudspeakers, then the human ear/brain accepts their phase differences as being natural, and seamlessly integrates them into a soundfield, and indeed is able to hear and re-create a very rich soundfield based in part on precisely these phase divergences. But, if and when these phase divergent signals are directly electrically postmixed, then their divergent phases will cause immediate interference and partial cancellations of main portions of the original signals. This leaves the resulting, partially cancelled mish-mosh sounding like a mere hollow shadow of the original signals (before the postmixing), with some of the information cancelled and missing entirely, and the remainder sounding phasey, indirect, veiled, and ghostlike in a dynamically varying way (much like the famous flanging distortion effect). This also ruins spatial cues, which are very subtle to begin with and also depend on phase for their full effect.
      That's what the Dolby default preset of 3 for Center Width does, by directly electrically postmixing at least the front 3 phase divergent channels, and that's just how it ruins the sound. Because the AVR600 is so much better than the prior state of the art at correct phase coherent focus, and at spatial imaging, the AVR600 reveals as never before how much sonic damage is done by this Dolby default preset of 3 for Center Width.
      Clearly, then, when you set up your AVR600, you should change the Center Width parameter to 0 (in the general setup menu). Incidentally, these Dolby parameters are sometimes greyed out, so you cannot access them to change them, and this greying out happens sporadically and unpredictably (we once saw these parameters suddenly, spontaneously switch from black [adjustable] to greyed out [inaccessible] right before our eyes). Evidently, the AVR600 software gets confused. It sometimes thinks these general setup menu parameter adjustments (affecting all inputs) should be permanently inaccessible (for all inputs), if the input you temporarily are on happens to be auto-detected as having an analog input signal.
      Or perhaps the confused AVR600 software thinks that these 3 Dolby parameter settings only affect the sound if you have a system with 5 loudspeakers, and would not affect the sound if you have a system with 7 loudspeakers (but in fact they still do affect the sound with 7 loudspeakers, and with Dolby PLIIx). So, when this software confusion greyed out these 3 Dolby parameters, we did a workaround to outfox it. Using the main setup menu, we lied and told the AVR600 that our back surround loudspeakers were None, i.e. that we had only a 5 loudspeaker array, and then the AVR600 ungreyed these Dolby parameters, allowing us to then set the Center Width to 0. After that, we went back to the main setup menu, and now told the AVR600 that our back surround loudspeakers were Large, i.e. that we had a 7 loudspeaker array. Presto, mission accomplished! We have informed Arcam about this curious inconsistency.

Level and Delay Distance Trim

      As we extensively discussed in our reviews of earlier Arcam surround processors, we can get a much richer, more believable surround soundfield by setting the volume level of the back surrounds much louder than the front loudspeakers, with the side surrounds somewhere in between, and simultaneously setting a large time delay on these back and side surround loudspeakers that are set higher in level, in order to take advantage of the Hass effect. This unorthodox inequality of levels is amazingly effective in creating a very believable surround soundfield from one's huge library of mere 2 channel recordings (indeed so effective that I often prefer the surround soundfield imaging achievable from the 2 channel CD layer, then thusly enhanced to 7 channels by PLIIx, to that from the surround SACD multichannel recording heard directly). And, surprisingly, this unorthodox inequality of levels is very effective at improving the surround soundfield of most film soundtracks, making them much richer and more believably convincing than the orthodoxy of setting all 5 or 7 channels at the same volume level and same delay distance.
      To achieve all this, we found that a single setup of unequal delay distances sufficed for most program material, but that the settings for unequal volume levels have to be trimmed to be optimal for each recording (depending on how it was miked and mixed), in order to achieve the best surround space imaging.
      In the AVR600, Arcam has answered one of our prayers by making it easy to dial in a far more precise adjustment of delay distance and volume level than was achievable in their earlier surround processors. These improvements in adjustment resolution came just in the nick of time, and at the best opportunity, since the AVR600 can reveal subtleties so much better than all other units including Arcam's earlier processors, so with the AVR600 you can fully appreciate the amazing sonic magic that happens when you get these adjustments spot on for each recording.
      In previous Arcam processors, as in most competing processors, these adjustments had a resolution of 1 dB for level, and 1 foot or 1 millisecond for distance or delay. In the AVR600, the adjustment resolution for level is 4 times finer, at .25 dB, and the adjustment resolution for distance is 12 times finer, at 1 inch (!!).
      In our testing, we found that the new 1 inch resolution for distance delay is perfect, coinciding with what's known as a JND (just noticeable difference). As we adjusted the AVR600's delay (distance) up and down, we found that we could just barely discern the sonic effect of each step, and that 3 adjacent steps provided acceptable results, with the center one just seemingly subtly more right in some almost ephemeral way (this is exactly as it should be, for achieving optimal adjustments, as optimal as human perception can appreciate).
      The AVR600's new .25 dB resolution for level adjustment is not quite as perfect. In our testing, we found that one level setting was clearly much more right, but the 2 adjacent steps were clearly wrong, which means that the .25 dB step is still larger than the ideal JND (and this makes sense, since our previous research has shown that humans can hear .1 dB differences in amplitude level and .01 dB differences in amplitude frequency response). Nevertheless, we are grateful to Arcam for giving us all this new finer .25 dB level adjustment resolution, since now at least one setting does now sound right, and this is the important adjustment we constantly change, to optimize each recording's spatial imaging (it was frustrating to hear, with the coarser 1 dB level adjustment on Arcam's earlier processors and other competing processors, how one setting was too little but the very next step was clearly already too much, and that frustration is thankfully now a thing of the past).
      In Arcam's earlier processors and receivers, this frequent and important level adjustment could be conveniently done via the trim button on the remote, and the trim levels, once entered into the unit, would stay there forever until you change them, even if the unit were turned completely off or unplugged (these trim level settings were stored in a non-volatile medium). This made it very convenient if you wanted to listen to the 17 hour ring cycle over several days, or if you found that one set of level trim adjustments sufficed for a whole bunch of say your chamber jazz recordings (since they were all miked similarly). You could set up the level trim adjustments for the Ring or for chamber jazz, and then come back day after day to the same level trim settings, putting the surround processor in standby or even turning it off when not listening.
      Alas, in the AVR600 the level trim adjustment for your 7 channels is volatile. Highly volatile. Your settings disappear completely if you turn the unit's power off, or even if you merely place it into standby (the owner's manual is wrong on this point). Thus, if the phone rings, or if you want to continue listening tomorrow to the same recording of same type of recording as today, your only option is to put the unit into mute, but keep it fully powered up. Alternatively, you can learn to do as we do. Use the convenient level trim adjustment to discover by ear what the exact level settings are for each recording, to optimize its spatial imaging, then write this down on a card that you slip in with the disc.
      If you want to listen later to more of the same or similar recordings, you can also load these 7 level settings, that you have just written down, into the AVR600's nonvolatile, permanent memory by using the main setup menu and loading them in under speaker level. If you do this, you might want to engage mute first, to avoid being blasted by the pink noise that automatically comes on when you try to set each speaker's level in this setup menu. Note too that, because the setup menu offers you a choice only between silence or pink noise while setting speaker level, you cannot use the setup menu to optimize levels in real time while listening live to the program you are trying to optimize the levels for. When you want to arrive at the best level trim adjustments for a given program, obviously by listening live to that program, you have to use the level trim button and menu. But if and when you want any non-volatility for the same settings, then you have to manually write them down on paper and then later manually re-enter them in the setup menu, after hitting mute. I've worked with computers for 50 years, and the same question has kept arising for 50 years: are they more help or hindrance, and who is the servant and who is the master?
      All this level trim adjusting and note taking is actually very easy, once you get the hang of it. The first thing to keep in mind is that you are making only one really important adjustment, not 7 adjustments. This one important adjustment is the balance of the front surround hemisphere to the back surround hemisphere, and this is crucially different for different recordings because of the simple but important fact that different recordings are miked at different distances from the performers, hence they contain a different mixture ratio of up front direct sounds to indirect hall ambience and reverb sound, and therefore to reproduce their recording space best you need to play them back with a different mixture ratio of front hemisphere sound level to back hemisphere sound level (generally speaking, closer miked recordings require a higher back hemisphere trim level in playback, to bring out the hall ambience that was short changed in the recording, and vice versa).
      This single adjustment, of front to back ratio, is conceptually just like the Dolby Dimension adjustment, except that this Dolby adjustment got it wrong by lumping the side surrounds in with the back hemisphere, whereas the side surrounds actually belong in the front hemisphere, since they psychoacoustically control the width and depth of the front stage (we're assuming the ideal 7 loudspeaker array setup, with the side surrounds directly at the listener's side, and the back surrounds each located 30 degrees off the back centerline). Since only the back surrounds are in the back hemisphere, this means that you could simply keep all 5 front and side loudspeakers at a constant trim level all the time, and merely adjust the trim level of the back surrounds up and down. Thus, you'd only have to make one adjustment and write down one number for each recording, surely not a hard task. As you get into the magic of using the AVR600, you'll find that you can hear and appreciate subtle trim level adjustments beyond this, such as for example taking the side surrounds up by just .25 dB in order to enrich the stage width, depth, and ambience on a particular recording, and you can hen add these further trim adjustments to your notes as you wish, to enjoy your AVR600 experience even further.
      However, there's a small fly in the ointment of this rosy scenario. The back surround loudspeakers are always much higher in trim level than the main front loudspeakers, putting the trim level of the front main loudspeakers way down in negative territory (the total trim level range is -10 to +10). Now, the front main loudspeakers are of course the principal perceived source of the direct sound, so their fidelity is of paramount importance (the back surrounds are louder in level, but they are delayed in time, so your ear/brain does not perceive them as direct sound sources, thanks to the Hass effect). It just so happens that, as you adjust the trim level of the front main loudspeakers farther down into negative territory, in Dolby PLIIx, their sound gets softer and more defocused, probably as a result of the PLIIx algorithm and matrix subtractions.
      So, for best sonic fidelity, it's important to have the front main loudspeakers set as high as possible in level, consistent with the ratio between front and back that you have found to be optimum for spatial imaging on a particular given recording. Let's look at a typical example to make this clearer. A typical ratio for achieving optimum surround space, when enhancing a 2 channel stereo recording into 7 channel via PLIIx, is a 15 dB difference between back surrounds and front main, with the back surrounds being louder. Now, you could obtain this 15 dB difference ratio by adjusting the front main trim level  down to -10 dB and the back surrounds to +5 dB, or alternatively by setting the back surrounds as high as they can possibly go (+10 dB), which then allows you to then set the front mains as high as they can possibly go (-5 dB) consistent with maintaining that 15 dB ratio. The latter alternative will sound better than the former, because the front mains are higher at -5 dB instead of down lower at -10 dB.
      But this means that, for best sound, you want to always keep the back surrounds up at +10 dB, so that the front mains can then be as high as possible, consistent with whatever ratio sounds best for a given recording. And this in turn means that, rather than simply adjusting the rear hemisphere by adjusting one trim level value (for both back surrounds), you instead have to adjust the front hemisphere, and this requires the adjusting of 3 trim level values (one value for both front mains, one value for the center front, and one value for the side surrounds). So that's what we do, willingly and happily, in order to get the best possible sound quality from the AVR600. We adjust 3 values on 5 loudspeakers, instead of 1 value on 2 loudspeakers, and we write down these 3 values on a little card

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