Arcam AV8 FAQ
April 15, 2003

Performance

On Screen Display

Set Up & Installation

 

Q. What is the video bandwidth and is it sufficient for HDTV?

A. Most good AV processors have sufficient bandwidth to handle HDTV. Arcam feels that a bandwidth of 100 to 150 mHz is required to properly pass a 720P or 1080i HD signal. But, realizing that some video enthusiasts may use outboard processors delivering more demanding signals, the bandwidth of the AV8 is 300 MHz, making it suitable for even 1080P.

Q. What makes the AV8's "direct" analog path better than other similar features on other processors?

A. There's "direct" and then there's "direct." In the AV8 a direct stereo signal (or multi-channel signal via the DVD-A/SACD input) travels across one circuit board only, a board that contains no digital signals. In addition, the direct mode also shuts down the DSPs further decreasing noise levels. Arcam engineers tell us that the AV8 is actually the best stereo preamp they've ever made.

Q. Should I use a digital or analog input for my CD player?

A. The assumption is usually made that, while the digital circuitry in AV processors may be good enough for movies, it is rarely good enough for music. Thus most people would automatically use an analog input for their CD player.

With the AV8 that could be mistake. The DACs in the AV8 are outstanding. And, the AV8 is one of the few processors in this price range that incorporate a separate quartz crystal Phase Lock Loop circuit (most others rely on the rather ordinary PLL provided in the SPDIF input receiver chipset).  This separate PLL provides a very high Q (narrow bandwidth) filter.  This reduces jitter by an order of magnitude when compared to most AV processors.

So, the short answer is, "It depends on the CD player." Most CD players should be connected to the digital input. The rare exception would be something like the Arcam FMJ CD23 or CD33 in which the digital performance is being pushed to the theoretical limits.

Q. How does the AV8 handle on screen graphics with component video or progressive scan signals?

A. Due to the expense and complexity most manufacturers do not overlay graphics on progressive video. In fact, many do not provide graphics on any component output, progressive or interlaced. This then requires the user to switch the TV to another input, composite or S-video, any time they need to see a menu. This is, to say the least, cumbersome.

The AV8 delivers full on screen graphics on interlaced component video. In addition Arcam provides a very innovative solution on progressive scan. When a menu is required, the AV8 automatically switches from progressive mode to interlaced. The picture disappears and is replaced with the menu displayed over a gray background. Upon exiting the menu, the picture reappears. No user intervention is required.

Of course this does require a video display that can handle the switch from progressive to interlaced, as is the case with most plasmas, projectors, and other high quality displays.

Q. What is an Elantec Pixel Switch?

A. With most AV processors the display of on-screen graphics (volume bars, selected input, etc.) results in degraded picture quality. That degradation can either be permanent - as in a cheap receiver where the video always passes through the OSD (On Screen Display) chip - or temporary where the video only passes through the chip when on screen graphics are displayed.

In the AV8, rather than settle for either permanent or temporary, Arcam opted for never. The AV8 uses professional Elantec Pixel Switches to overlay the graphics on the video. This super fast chip switches off the video and superimposes the graphic element - pixel by pixel. You have the benefit of full on screen graphics AND the precious video signal NEVER passes through the OSD chip. This innovative approach was the direct result of including professional broadcast engineers on the AV8 design team.

Q. Can I change the names displayed for the inputs?

A. The AV8 did not originally include this feature. However updating to Version 3.0 adds this capability. Hint: Since it is a bit awkward to physically change the front panel inscriptions over the input buttons, we suggest using customized names that incorporate the original input name. For example if the SAT input is connected to a HDTV receiver, a convenient customized name might be HDTV-SAT.

Q. How do I know what software version I have?

A. The software version is displayed briefly on your video monitor at start up. To take a longer look, simultaneously press DVD, CD, and OK to enter the engineering menu. Here you will find the version number of the AV8 software, as well as version numbers for the various surround decoding software.

Q. Are there discrete Power On and Power Off IR codes? How about discrete codes for mode selection?

A. Yes, there are a wide variety of special IR codes that can be useful in building Macros to automate the systems. These include ON, OFF, as well as a large number of discrete codes for mode selection. The use of these codes requires a programmable remote, like some Philips Pronto models, that allows direct entry of RC5 codes based on the device number and code number.

Q. The remote control signals for the AV8 also control some of my other components. Is there anything I can do about this?

A. Arcam has anticipated this problem. It is particularly common in multi-room systems where IR repeaters may be picking up remote control signals from rooms in which other amplifiers using RC5 remote control codes are in use (or even AV8 Zone 2 commands).

Enter the engineering menu by simultaneously pressing the CD, DVD, and OK front panel buttons. Then press THX to display an additional engineering menu. You will now be able to change the Main Zone and/or Zone 2 to an alternate code set. (Default is device number 16, the alternate is 19.)

The "Aux" section of the Arcam remote control can be set to this alternate device. See the remote control's manual for details. For maximum convenience you may want to do a number of other tweaks to the remote control, like changing the "punch thru" volume settings. Alternatively, you may also use a remote capable of accepting direct RC5 code entries, such as some of the Philips Pronto models.

Note that your current IR remote (set to device number 16) will stop working the instant the AV8 is changed to device 19. So it is best to use the front panel buttons to navigate the engineering menu.

Q. I've seen some processors where the crossover frequency can be set independently for the Front, Center, Side, Rear, and Sub. Why can't I do that on the AV8?

A. In practice we've found that it is usually sufficient to specify each speaker grouping (Front, Center, Side, Rear) as either "Large" or "Small" and then have control over the global crossover frequency for all the speakers set to "Small". Providing more flexibility actually causes problems when the bass is summed for the sub. Given that bass is usually very similar in all the channels, you have now summed the same low frequency signal with different phase delays caused by the different crossover frequencies. This will cause cancellation through a comb filter effect as the signal goes in and out of phase at different frequencies. This creates bass nodes in the subwoofer. The other alternative is to create the sub signal by filtering all the channels using the same filter (at the lowest crossover frequency used), but still use different filters for each of the speakers. This creates a good sub signal but now you have holes in the bass response due to the frequencies that are not redirected to the subwoofer, but have been filtered from the speakers.

A less problematic approach to addressing speakers with different characteristics or radically different room placement is to provide individual bass and treble controls for each speaker, not just pairs of speakers. This provides additional flexibility by allowing independent adjustment of, say, the Front Left and Front Right speaker, when the living situation forces one to be pushed back into a corner while the other is well out from the side wall. This, coupled with the crossover adjustments already provided in the AV8, can help sort out problems at all frequencies, not just bass problems. (And, since the bass and treble adjustments applied to the individual speakers have no effect on the signal summed for the sub, the aforementioned phase problems are avoided.)

Q. Can I prevent people from changing my settings?

A. Yes. Simultaneously press Tuner, DVD-A, and OK. This locks the menus. Press the same buttons again to unlock.

Q. Can I block Zone 2 access to some source components?

A. Yes. This setting is found in Advanced Set Up Menu #4.

Q. If one of my source components outputs digital audio and component video, do I still have to connect analog audio cables and S-Video and/or composite video cables?

A. Strictly speaking, no. However it is highly recommended. These alternate signals will be required to feed the tape record outputs (either to an audio recorder or VCR). In addition, Zone 2 receives its signal only from the analog and composite feeds.

Q. Why am I not getting any S-Video (or composite) on some sources?

The AV8 looks for the highest quality video available from any source.  It then mutes the video on all lower quality video outputs.  For example if your DVD player is providing a component or progressive scan output, the AV8 will pass the component signal but mute the S and composite signal.  This is done for two reasons.  1) Allowing the other (usually unused) signals to pass through only serves to increase the electronic noise levels inside the AV8.  2) Muting the poorer quality signals insures that the user will be forced to select the proper input on their TV.  Otherwise they might accidentally leave the TV tuned to a lower quality input.

Hint:  If you need to view an AV8 set up menu through composite or S, (for example through a secondary monitor on a service bench) but the DVD player's component signal is causing the S and composite to mute, simply select another input (say, Tuner) or momentarily turn off the DVD player.  The set-up menu will then be available through all video outputs.

Q. The 12-volt trigger outputs are not behaving as I would have expected.

A. Two things to look at. First, make sure that, in the AV8 set-up menu, you have set the Trigger Output to "Screen Control," as opposed to "SCART". (SCART is for use with European TV's and allows the trigger outputs to force the display device to the proper input. It is not applicable in the U.S.)

Secondly, do note that each trigger output jack is stereo and contains two different 12-volt trigger signals. For example, the main trigger carries "Main Zone On" on one channel and "Zone 2 On" on the other. Thus a mono mini-plug will not work. Our favorite solution is to use a Radio Shack 274-375 adaptor with a stereo plug on one end and 2 mono jacks on the other. With that fitted to the trigger jack you may now use an ordinary mono mini-plug cable, selecting the appropriate trigger (main or zone 2) by using the correct mono output jack of the adaptor.

When in "Screen Control" mode, both the primary trigger and the #1 Video trigger provide on/off control for power amps, etc. The #2 Video trigger is only live when a video source is selected and can be used to lower a screen, or for other video related tasks.

Q. I'm not getting any component video, or the component video is scrambled.

A. Make sure you've set the High Quality Video in the set-up menu to "Component," as opposed to "RGB." Also, you must assign the component inputs to a specific video source component. See the manual for details. (We recommend that you first select a component other than the one for which you are changing settings; that is, one that has no High Quality outputs, like a VCR. This way you will avoid any interruption in the on-screen menu as your new settings take effect.)

Q. I don't have any Zone 2 Audio when playing DTS films.

A. This is not a problem with the AV8. Zone 2 gets its audio from the analog inputs. Most DVD players cannot output analog stereo when decoding DTS. Select the disc's Dolby Digital soundtrack it you require audio to Zone 2.

Q. I can't adjust the tone and/or balance controls.

A. THX standards do not allow for the adjustment of tone and/or balance. If you'd like to adjust these parameters, be sure to select a mode that does not involve THX post processing.