superior high bias. The heat problem is not the Odeon package. The heat problem is you. You see, Plinius rightfully had to take into account the practical fact that many stereo system owners, and even more home theatre system owners, stuff their power amplifiers into closets, or into cabinets, to get them out of view. This forced Plinius to set the bias conservatively low on the four secondary channels, thereby lowering the total heat output so that the Odeon could be installed in such enclosed spaces. If you stuff the Odeon away like some users would, then the extra heat, generated if all six channels instead of just two were set to high bias, would have nowhere to go, so this extra heat would turn that enclosed space into an oven, eventually tripping the Odeon's safety high temperature sensors and shutting the amplifier off. But the great news is that, if you leave the Odeon out in the open, then this extra heat can safely dissipate into the open air volume of your room. Thus, if you take the simple step of leaving the Odeon out in the open, the chassis itself can adequately dissipate the extra heat from setting all six channels to high bias. Hopefully you'll see that the Odeon's package, with its seductively sculpted curves of brushed aluminum, is so attractive you'll want to proudly display it out in the open. And now you know there is a much more important reason to place the Odeon out in the open. Better sound. Much better sound. The musically beautiful Plinius sound, rather than the glare of conventional solid state sound, from all six channels instead of just two primo channels.
      We strongly suggested to Plinius that they make a high bias version of the Odeon, with all six channels instead of just two channels set to the better sounding high bias, and that they make it available upon request to buyers who promised to not hide their Odeon in heat-trapping small enclosed spaces. We argued that this would be critically important to the many customers who would want to use the Odeon for surround music, for triamping, for concert videos, and for all those films where music instead of zap and crash sound effects are mixed to the surround and center channels. Indeed, without this, the Odeon would be virtually relegated to the same action flick role for which common, less musically natural solid state amplifiers suffice, where only sound effects come from the surround channels. Plinius agreed to make this high bias version of the Odeon - and indeed, they were so persuaded by our arguments that they decided to make this high bias version standard for all of you. Thanks to our investigative analysis above, and our persuasive instigation, Plinius have changed their product, and have improved it. They agreed with us that the Odeon should offer the best possible sound, the true Plinius musically natural sound, from all six channels, not just two channels. And they have decided to give everybody the sonic benefits of the better sounding high bias for all six channels, as standard in all Odeons (so you don't need to make a special request).
      Before giving the green light to the high bias version, the Plinius engineers conducted further tests, measuring the Odeon's temperature rise when all six channels are set to the better sounding high bias, under various likely user installation scenarios, and they determined that it is acceptable for all normal user situations. From these new tests, they report that a serious heat problem would only occur in the unusual and abusive situation of the Odeon being totally enclosed in a small cabinet (which of course would not constitute adequate ventilation for any other power amplifier either). In any event, the Odeon's temperature sensing protection would shut the amplifier down if any abusive ventilation situation were to make the amplifier too hot. Thus, open racks and open shelving units should be adequate for the Odeon (if you provide at least four inches of clearance above the Odeon, just as with other power amplifiers). Naturally, as with every power amplifier, the more open ventilation you can give it, the better, since the lower resulting internal temperatures will help prolong the life of the parts inside (such as the critical electrolytic capacitors).
      This Plinius change to uniform high bias for all channels means that every new Odeon should be fully capable of giving everyone that magic Plinius sound from all six channels, so everybody can confidently use the Odeon for full fledged surround music, or for music triamping, as well as for natural sounding cinema. It's rewarding for us reviewers to see a manufacturer so caring and responsive to outside input about improving the sound of his product to meet your needs better. And it's one of the highest services a reviewer can provide to you the reader and consumer, when, instead of merely passively reporting on a product's sound, he can proactively help to make the product better for you, by publishing constructive critical suggestions that persuade manufacturers to give you better sound from their product than even they thought possible.


Energy Source

      The third key to optimizing the Odeon's sound concerns the energy you feed it from your powerline. We found that the Odeon is very sensitive to the quality of the powerline energy source (especially source impedance), and is very responsive to improvements you make to the energy source, rewarding you with even better sound. This sensitivity actually reflects a virtue of the Odeon; it is a testament to the revealing transparency of the Odeon circuitry, and also to the low impedance of the Odeon power supply. Some other amplifiers are less sensitive to energy source quality, perhaps because their circuitry is not as revealing of anything (be it input audio signal or input energy signal), or perhaps because their power supply has an undesirably higher source impedance in itself (which would tend to mask high source impedance problems occurring in the powerline energy source prior to the power supply). Therefore, it is worth your while to optimize the sound of the Odeon by putting some time and effort into optimizing your powerline energy source.
      People often assume that the audio circuitry supplies the output signal of any and every audio component, and that the power supply merely has an ancillary role, passively supplying the audio circuitry with the background voltages it needs to work. That's true in a small way: the audio circuitry does indeed need juice from the power supply to do its work, and it does rely on that juice being stable, quiet, and low in source impedance throughout the audio spectrum (so the power supply can supply juice quickly and in the amounts needed, to keep the audio circuitry in a desirable constant state). But it's also wrong in a major way. For in truth, the output signal of every audio component comes directly from the power supply, not the audio circuitry, and in point of fact it is the audio circuitry which plays a merely ancillary role, acting as a mere valve or gate to let out proportional fractions of the output energy that must come directly from the power supply. This is true for all electronic components, so it's important to pay attention to your energy sources for all audio and video components (for example, in our research we've found that even CD transports, which output only digital 1's and 0's, are still sensitive to choice of power cord). It is particularly important to be cognizant of this true situation when we are dealing with power amplifiers, where the output signal comes directly from the power supply in terms of current, power, and phase angle, not just in terms of voltage (as is the case with audio components outputting merely low level voltage signals). Furthermore, a power amplifier has a much lower output impedance than other audio components, which means that the low impedance desiderata for power supplies in general are even more stringent for power supplies in power amplifiers.
      In the case of power amplifiers, a power supply must be able to supply, instant by instant, a lot more energy than all the energy that the audio circuitry (acting as a valve or gate) can let through, even under the dictates of the loudest and fastest audio signals driving the most difficult loudspeaker load. We say "a lot more" because, if the power supply can't make available a huge overabundance of energy at every instant, beyond that which the audio circuitry gate can let out even under worst case conditions, then this limitation of the power supply starts modulating the output signal, and that means distortion, since only the audio circuitry acting as a gate is supposed to be modulating the output signal of the power amplifier. We say "every instant" because the power supply must be very fast, even faster than the audio circuitry is, again to avoid modulation distortion (especially on high frequency transients).
      Consider a simple hydraulic analogy. You have a fast acting water faucet valve (say operated by fast audio circuitry), but the fluid (energy) coming down the pipe (say from the power supply) is as thick and slow as molasses. Obviously it does no good to have expensive audio circuitry capable of opening and closing the valve fast, and in accurate and distortion free obedience to a music signal, when the fluid coming down the pipe from the power supply is slow as molasses. The power supply sluggishness in supplying enough energy fluid molasses will dominate and distort the output capability of your system, regardless of how fast and distortion free your opening and closing of the valve (via the audio circuitry) is, in its tracking of an input music signal.
      Thus, a power supply can be a very real source of distortion, especially in a power amplifier, where the demands upon a power supply are so severe and multifaceted. In order to avoid adding to an amplifier's distortion, a power supply must meet the requirement of being able to supply far more energy than the audio circuitry valve can let out under worst case circumstances, and to supply this energy faster than the audio circuitry can open and close the valve. This means, among other things, that a power supply must have high current capability and very low source impedance, and must maintain these virtues for the full audio spectrum, in particular the difficult high frequencies.
      The power supply in turn gets its energy from your powerline. Thus, your powerline, and all the links between your powerline and the amplifier's power supply, are part of the energy source feeding your amplifier's output, so all must have similar virtues. Because the Odeon's power supply is so well done, with high current capability and low source impedance, which is maintained out to high frequencies, it has the desired virtues, which means that you will be rewarded with better sound if you see to it that the energy source from which you feed the Odeon has these virtues as well. That's true for other high quality power amplifiers as well, especially those which, like the Odeon, have the virtue of low internal power supply impedance.
      Incidentally, our comments here pertain chiefly to unregulated power supplies, which are the rule for power amplifier output stages, and are sometimes employed for the lower level stages as well. Regulated power supplies can be more immune to the source impedance of the energy source feeding them. But regulated power supplies have their own kinds of problems, especially with their own internal source impedance, which can vary based on the behavior of the regulating device (e.g. rising source impedance at higher frequencies, transient misbehavior, etc.).
      How can you improve the energy source for your Odeon? The first area you can easily address concerns two culprits who can easily spoil your energy source: the power cord feeding your amplifier, and any series powerline conditioners you might have been seduced into using.
      Virtually all series powerline conditioners raise the source impedance of the powerline significantly, thereby impeding the flow of energy, especially at higher frequencies. Yes, they do change the sound you hear. But often not because they are eliminating powerline hash problems, as they claim. Rather, they usually merely soften the sound because they add undesirably high source impedance to your amplifier's energy source, especially at higher frequencies, thereby starving your amplifier at higher frequencies, and causing a softening modulation distortion at higher frequencies. You are free to subjectively like this softening change, but it is distortion, and it usually veils true sonic transparency. The Plinius does not need the softening distortion of powerline conditioners to make it sound more musically natural, and the higher powerline source impedance imposed by these conditioners will degrade the sonic transparency and dynamic muscle of the Plinius. So, if you have a series powerline conditioner (one that adds circuit elements in series with the powerline), don't use it to feed any Plinius amplifier.
      Power cord designs differ significantly from each other in impedance characteristics, especially at higher frequencies, where the different inductances of different esoteric audio power cord designs cause them to sound very different, especially with revealing and sensitive amplifiers such as the Odeon. The high inductance of most power cord designs causes significant softening and veiling distortion of amplifiers as revealing as the Odeon, since this high inductance causes an undesirable rise in source impedance for the higher frequencies of the audio spectrum. We used a custom designed research lab power cord design to probe the Odeon's outer limits, and the sonic improvement over most power cords was dramatic. This is not the place for a review of the esoteric power cords commercially available, but we can tell you that there are pros and cons to all the best ones, with many clear turkeys but no clear winner among all those tested so far. So, in terms of commercially available power cords, your best bet is to compare a bunch for yourself specifically on the Odeon, and discover which particular set of sonic pros and cons best suits your listening preferences.
      The high frequency performance of power cords is a sorely misunderstood and overlooked, yet sonically crucial parameter. You might think that a power cord only has to carry frequencies no higher than the 60 Hz of the powerline, or perhaps the 120 Hz refresh cycling rate of a full wave rectifier that refills the energy storage reservoir caps of the amplifier's power supply. But in fact the energy refill time for an amplifier's energy storage caps is much shorter than 1/120 of a second, since refilling only occurs as a quick transient burst, in that brief moment when the full wave rectifier's cyclically varying voltage waveform exceeds the voltage left in the caps (after the last cycle's worth of energy drain by the amplifier). And, during this brief moment, your energy source (including the power cord) must be able to flood the amplifier's power supply with an overabundance of energy at an overabundant rate of speed. If the power cord inductance significantly raises its source impedance at high frequencies, then it will choke off some of this needed energy refill speed, in effect modulating the output signal of your amplifier, and this modulation distortion in turn will adversely affect the sonics of an amplifier with a low impedance power supply like the Odeon. It is helpful to think of the power cord as you would think of an interconnect or speaker cable, actually carrying the full audio spectrum, and therefore needing to have full spectrum capabilities if it is to allow your audio components to perform at their full potential. It is also helpful to think of the transient energy refill burst being like a signal traveling down the power cord, governed by the same rules of electromagnetic wave propagation that govern the traveling of regular audio signals along wires or cables.
      The Odeon is so revealing, and has such a low impedance power supply, that it is even sensitive to the quality of your energy source in exotic aspects that you might overlook. Staying with power cords for the moment, the Odeon can reveal whether your power cord contains inferior dielectrics in its jacket, and even if a power cord is touching external dielectrics such as wood, plastic, or ceramic tile, since these foreign dielectrics adversely affect the transient refill burst of energy that is propagating down the power cord to the amplifier's power supply. This means that, for optimum sonic performance, you should keep your power cord off the floor, and also keep it from touching supporting gizmos made of wood or plastic that are promoted as providing a sonic advantage by lifting the cord off the floor. If you do want to support your power cord off the floor, we recommend that you get small cardboard boxes (say 7 x 7 x 4), tape the bottom flaps shut, stand the top flaps straight up, and then support the cord just by running it orthogonally across the top edges of two vertical standing top flaps. An even better solution is to employ a short power cord, short enough to reach directly from the Odeon to your wall socket by traveling only through the air, without touching anything enroute (not even the edge of the platform on which the Odeon might be resting). If you are installing a new powerline socket in the wall to feed the Odeon (see below), you might want to install it high enough on the wall so that the power cord, feeding the Odeon down on the floor, won't itself touch the floor. Conversely, if you're using a powerline socket that is already low on the wall or in the baseboard, you might want to raise the Odeon a couple of feet off the floor on a platform, again so that the power cord does not touch anything as it travels from wall socket to the Odeon.
      We found that the Odeon is also revealing of the quality of the plug used on the power cord. The Odeon confirmed our previous research findings, from experiments using other audio components, that the heavy duty macho plugs (e.g. the Hubbell hospital grade plugs) favored by esoteric power cords (because that's what they've trained you customers to expect and demand), are actually among the worst sounding, being very sluggish and dull in the high frequencies. Our custom research lab plug, which we tried just to see how good we could get the Odeon to sound, yielded far better sonics. We tell you this here so that, in your search for the best sounding power cord, you don't make the mistake of believing the advertising hype and assuming that those macho plugs will give you and your Odeon better sound. You won't be hearing your Odeon at its best.
      A more difficult area for you to address concerns the portion of the powerline feed that's in the walls of your house. The Odeon can draw up to about 20 amps at maximum output on all channels. Thus, it is helpful to have a dedicated 20-amp line and circuit breaker, devoted to the Odeon. This insures that the Odeon will not be starved for current when showing you its muscle. Also, by not plugging other audio and video components into the same powerline run from your building's breaker box, you help insure that large transient current draws by the Odeon will not adversely modulate the performance of these other a/v components in your chain, which might degrade their performance.
      If you do have to run a new line from the breaker box for your Odeon, you might ask your electrician if he is willing to run the Romex pigtail out of the wall hole near your Odeon, and install an IEC female plug directly onto the Romex, which will plug directly into the Odeon. This removes a plug and socket from the powerline chain, avoiding their imperfections. It also means that the Odeon will be fed directly by sonically superior solid core Romex, instead of sonically inferior stranded power cord wiring. Unfortunately, this setup would technically be against code, since code requires inferior sounding flexible stranded power cable out in the open, where someone might step on it (which would bend the solid core wire inside Romex). However, we've advised you to keep the power cord run from the wall to the Odeon in the air and off the floor anyway, so this code concern is moot, since no one could step on a cord that's up in the air. Incidentally, 12 gauge Romex seems

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