RAV229 and RAV17 Remote Control

Back by popular demand is the classic keypad universal remote control with LCD window indicator (RAV229) Yamaha debuted in the day when RX-V1 held the Flagship title. I do like this remote, but couldn't help missing the touch screen RAV-2000. Its graphical display and ease of programming were uncommon as far as touch screen remotes go. However, this remote was moderately easy to program, and contained many of the manufacturers codes. It was also a nice treat to be able to have certain buttons control different devices even when the remote was set for operating a particular device. For example, toggling the RX-Z9 to "CD" input allowed me to control my CD Changer with the buttons on the top half of the remote, while I could still channel surf via the buttons on the bottom half of the remote. You can also use the "learn" feature to customize any button to suite your needs.

While these remotes look basic enough, their feature set and control over all things Yamaha and all things not was most impressive. The RAV17 was absolutely captivated me with its simplistic one button joystick style navigation of the RX-Z9 GUI interface. While most A/V receiver advances in technology lead them to become more complicated to operate, the RX-Z9 just became much simpler. So much so, that I suspect even the Spouse would welcome the mini remote GUI approach. The RAV17 came in really handy for quick navigation through the RX-Z9 GUI, and, in my opinion, was actually more comfortable and palatable to use than the RAV229 for this task. The RAV229 remote did prove to be essential if you wish to operate all of your accessory equipment, however, and the backlight was both useful and essential during late night operation. I found most of the codes for it to operate my equipment, but had to manually program button by button for certain devices such as my satellite box, DVR and VCR.

Inside the Yamaha RX-Z9

Vrail = SQRT(2*P*R) where P = 170 watts and
R = 8 ohms, we get: Vrail = 52.2V + 10% overhead (good rule of thumb)
= 52.2V + 5.2V = +-57V. Yamaha has +-8V of margin on top of a normally
conservative design practice!

Given the size of the power supply, and the large storage banks, the RX-Z9 has potentially added headroom to better drive difficult speaker loads without missing a beat. However, be cautioned that this receiver is not specified to deliver its rated power with all channels driven - which is usually not a realistic operational condition in any real world listening environment anyway. The all channels driven test represents a worst case test condition with a best case test load but it does serve as a uniform way of determining a receiver's actual true power capabilities. Considering the power supply rating and 80V caps, the RX-Z9 would easily deliver 170wpc X 2 as specified and mandated by FTC regulations for manufacturers' power claims, and about 140wpc X 7 all channels driven (assuming line voltage held constant, 8 ohm loads), perhaps a tad less at full bandwidth and unclipped.

I do have reservations about how Yamaha chose to arrange the heatsinks of the power amp sections on the RX-Z9. The issue of comparing heatsinks vertically mounted on the sides of a unit vs. heatsinks mounted horizontally on the top of a unit is a little complicated, but I will do my best to assess the differences here. First, a few formulas. In general, for an object being cooled by natural convection:

Delta T = Q/(h-sub-c * A) [1]

where delta T is the temperature rise, Q is power dissipated, h-sub-c is the heat transfer coefficient and A is the surface area of the object.

Not depicted here, there are dual fans on the bottom side of the chassis that help force convection during high power demands. In my listening tests these fans only came on after pounding the RX-Z9 amps in extremely loud multi-channel DVD-A listening sessions for extended periods of time.

When you have a plate oriented vertically (like a heat sink),

h-sub-c = 0.29 * [(delta T)/L]^0.25 [2];

where L is the length of the item in the vertical direction. So according to the first formula, the higher your heat transfer coefficient, the less your temperature rise will be. According to the second formula, the less the length of your object in the vertical direction, the higher its heat transfer coefficient will be.

But, wait! The fins on top of the RX-Z9 have a shorter length in the vertical direction than the fins of alternatively vertically side mounted heatsinks of other receivers and should therefore, be more efficient. According to the math, it is true. But you have to think about the airflow. Heat rises. So when the air rises past heat sink fins of the vertically side mounted heatsinks, the air below the fins rises to fill the void and the process continues. This is why it is called natural convection; you will get a flow of air without any mechanical effort. Now think about the horizontally top mounted heatsinks of the RX-Z9. When the warm air tries to rise off these fins, cool air can't replace it nearly as easily. Air can't rise from below to fill the voids between the fins like it can in the vertically side mounted heatsinks. It can only trickle in from the perimeter of the unit. Actually, if you ran a computer model, you would find that towards the center of the top of the RX-Z9, the fins will be contributing almost nothing. It is almost like they aren't even there because they are so starved for air. It a nutshell, that is the difference between the two. This does explain why the Yamaha RX-Z9 runs significantly hotter than any receiver I have ever had the pleasure of reviewing, even during idle. Unfortunately the heatsinking topology employed by Yamaha is externally starved for naturally-convected cooling air and I highly recommend the user and/or customer installer be cognizant of this to allow plenty of air flow and perhaps forced air cooling if necessary.

Video Processing

Yamaha offers some very unique video processing features in their latest flagship receiver as evident by the digital video upconversion and DCDi processing powered by Faroudja. The integrated digital processing in the RX-Z9 allows you to tailor picture adjustments (brightness and contrast, sharpness, saturation, 3D NR and cross color suppression to reduce picture noise from the brightest of display images). It also does video scaling and upconversion of interlaced 480i signals to 480p/576p, 720p and 1080i as well as aspect ratio control or pass-through for both PAL and NTSC Display types. Be advised however that copyrighted signals such as DVD, will not be processed above 480p via the RX-Z9 even if you select higher resolution settings. If you have a DVD player such as the Denon DVD-5900 which does video upconversion to 1080i via DVI, you may be better off going that route to your Display. In fact, I found that when the Yamaha Video Processor was enabled, the Avia resolution test was now displaying resolution limits of about 475 lines, as compared to over 500 lines of resolution when the DVD-5900 did the de-interlacing. The 6.75MHz test window was displaying no discernible vertical lines like it did when the DVD-5900 was used as the de-interlacer. What was likely happening here was roll off within the RX-Z9 processing at the resolution limits of the DVD format. Again, my advice here is to use the RX-Z9 processing features only for composite video / S-video sources, or when you utilize a non progressive scan DVD player, or a player/display with a low quality de-interlacer, that would benefit from the RX-Z9 processor/scalar over that of your Display and/or DVD player.

The RX-Z9 also upconverts all composite and S-video sources to component video, but only if you enable the digital processing engine. For non interlaced video sources such as those from progressive scan DVD players, the digital processing of the RX-Z9 is bypassed, as it should be, even if you have it set to the “On” position. This is ideal for those who want to rely on the video scaling and processing of their DVD players, while also using the RX-Z9 video processing on their composite or S-video sources. I have had mixed results with the digital processing feature of the RX-Z9, including picture flickering via my VCR with certain video software.

However, I did note a more dynamic and smoother, almost film-like picture with the Processor engaged on many of my composite video sources such as my Dish Network DVR recorder, and some video tapes. “Mars Attacks” was a great demo tape to really show off the RX-Z9's ability to transform an old VHS classic into a modern day pseudo 7.1 surround sound spectacle at near DVD picture quality style. In contrast, my daughter's tapes such as Cinderella caused the picture flickering I previously discussed. Perhaps this is why on page 78 of the RX-Z9 manual, THX recommends turning off all video processing to achieve optimal video performance. My advice here is to experiment with the Yamaha video processing engine to see how it improves composite video sources. I suspect on large displays, or even front projector systems with poor de-interlacing circuitry, the advantages of this feature set would become paramount.