Q&A # 260 - October 26, 2001

Staff

Q A Hi-Fi dealer suggested to a friend of mine to test the quality of the amplifying section of his Marantz integrated amplifier by directly connecting his CD analogue outputs to the amplifier pre-ins. He seems to have noticed increased detail in sounds, loss of soundstage, and more SPL when listening to music. I can buy the increased detail bit but why would the soundstage disappear
and why would the volume be louder without the preamp section? How valid a test do you think this is?

A It is a reasonably valid test, assuming that there is not some sort of buffer chip between the pre-in and the power amplifier section that is not between the preamp and power amplifier. The change in soundstage is due to differences in the way the CD output interfaces with the power amplifier and the way the preamplifier interfaces with it. Such things as the output impedance of the CD player and the impedance of the preamp output stage can affect the sound quite a bit, especially when you take the cables into account. Remember, there are no cables between the receiver's preamp stage and the power amp stage. The volume changes because the CD player output voltage is different than the output voltage of the preamplifier stage.

Q Are Superbit DVDs a real improvement or merely a marketing device to get consumers to buy a DVD twice?

A Superbit DVDs [http://www.technofile.com/articles/superbit_dvds.html] use twice the bit rate of regular DVDs for the video, but regular bit rates for the audio. So, instead of 3.5 Mbits per second, it would be 7 MBits per second. The max for current DVD is 10 MBits per second. The result, from what I can tell, is somewhat more detail in the picture, but not a huge difference. They eliminate some of the special features, like director's commentaries, to make room for the high bit rate movie itself. All new things like this are marketing oriented to get you to buy them. What amuses me is that I think it is cheaper to make the Superbit disc because all they do is turn up the knob that assigns how much bits there will be allocated to the video tracks. It is like telling your graphics program to use less compression in creating the JPG picture. So, they save money and time that it would take to create the special features, and charge a higher price for the disc. More profit per disc. Isn't Capitalism great?

Q I recently ordered a Pioneer DV-444 based on some other reviews I read. Now I really feel bad about that after reading your DVD Player shootout # 2, rating the DV-434 as the player to avoid. Is the DV-444 just as bad?

A We have not seen the Pioneer DV-444. Early reports suggest it is similar to the DV-434, but it has not been confirmed by us. If you are not happy, hopefully your dealer has a good return policy. The Panasonic RP56 is in the same price range if you are looking for a low cost player with good performance.

Q In the review of your Panasonic RP56 you said it has slight roll-off which is not that noticeable. What is roll-off? What does it look like?

A Roll-off means a decline in the frequency response that is gradual. It can occur with audio or video. In this case, the video roll-off means that the fine detail, which is handled by the highest video frequencies, will not be as visible as it would with a player that does not have the roll-off.

Q I bought a Sony KP-57Xbr10w wide screen HDTV ready set. It only has one input capable of displaying either 480p or 1080i. Through the testing you guys have done, do you think the digital reality creation feature (line doubler) displays a picture as good as a progressive scan DVD player? Any help you can give me would be greatly appreciated, as I would like to save this slot for a HDTV converter.

A Most of the scalers in TVs are not very good. Perhaps they will be at some point, but not right now. However, the question is moot in your case, because you need an RGB input (three jacks) to input the progressive scan signal from the DVD player. Your TV takes a composite signal (or S-Video) which is 480i, and scales it to 480p or 1080i using its internal scaler.

Q I would like to make my own power cords. Do you have a source for good quality materials?

A Here is one: http://www.okonite.com/Product_Catalog/section2/sheet18A.html. You might want to also consider nickel plated AC sockets such as those supplied by PS Audio, called the Power Port [http://www.psaudio.com/products/powerport.asp].

Q I just read your DVD Player Shootout #2 and had a question in regards to the Panasonic DVD-RP56. You mentioned that "If you have a TV that locks into Full Mode with 480p signals, this may not be the player for you." Can explain what "Full Mode" is and how you determine if your TV locks into "Full mode?" Thanks!!

A Widescreen TVs can display an image with different aspect ratios. When you feed an image to the display, you must tell the display how to display it. For all anamorphic widescreen films, you put your TV in Full Mode. This mode stretches out the image sideways to fill up the screen. If you have a non-anamorphic widescreen film, you set your display to Zoom Mode. If you have a Pan&Scan film, you set your display to 4:3.

Several TVs made by Panasonic, Pioneer, and Mitsubishi have TVs that will lock you into Full Mode when it detects a 480p signal. This makes it difficult to enjoy all Pan&Scan and non-anamorphic widescreen DVDs. It is a bad design in the display device.

Q I have one of the new Sony WEGA TVs with the 3D comb filter. I also have a Marantz receiver with S-Video switching. For convenience reasons, I've plugged all of my video sources via S-Video into the receiver (the composite feeds go through a passive $15 converter first) and out via S-Video to the TV.

The problem is that with my present setup, a composite picture (e.g., cable) going straight into my TV is much better quality than getting converted to S-Video, sent into the receiver, and then to the TV. How can I take advantage of the 3D comb filter on the WEGA but still have the convenience of S-Video switching? I heard that when you go S-Video, the comb filter on the TV is bypassed. If so, do the composite to S-Video adapters have comb filters in them? If so, what kind are they and of what quality? I want to take advantage of both picture quality and S-Video switching convenience.

A The $15 passive device is a basic YC separator. These are for convenience only. The YC separator in your TV, which is a 3D adaptive comb filter, will do a much better job. I recommend you feed cable, LD, and VHS into your TV using the composite input. Save the YC input for DVD and DSS. You have to choose between convenience and quality in this case.

� Copyright 2001 Secrets of Home Theater & High Fidelity
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