Q&A # 149 - November 23, 1999

Staff

Q I've searched your previous answers on eliminating hum, but not come across a scenario like mine. I have a Sony STR-DE825 receiver, Sony DVD, VCR, TV, and Boston speakers. Until recently, everything was fine. However, now when I first switch the receiver on after a significant time off (e.g., overnight) I get a loud hum through all the speakers. All the other pieces are off. If I turn the volume up, the hum diminishes to virtually nothing. Turn the volume down, and the hum returns. To get rid of the hum, I turn the receiver off, then on again. Sometimes I have to do it more than once. I have made no changes to the system in the last 9 months or in any electrical equipment in the room, but the hum started about 2 weeks ago. The hum did start at about the time I had a new refrigerator and dishwasher installed. These are in the next room, 30+ feet away. When checking the electrical connections, I noticed that the light on the surge protector had gone out. I replaced the surge protector. All the equipment goes through the same protector. It is hard to find out by a process of elimination what is causing this because once it clears up, I have to wait a day before it reoccurs. Trial and error could take forever. Do you have any ideas?

A It sounds like a faulty solenoid in the receiver to me, but first, unplug the refrigerator and see if you still get the hum. Receivers usually have solenoids that click in a few seconds after you turn them on. If one is not going on, it could cause the hum.

Q Is there anything "different" about component video cable from regular video cable? I'm perfectly happy to go the Monster cable route, as you've suggested, but I've seen some ads suggesting that "component video" cable is different than others.

A The only difference between monster standard video and component video cables are color coding and bundling. I use three M1000V for my component cables. Their component pack has 3 cables tied together and they are color coded on the ends. The color coding helps ensure you plug the right cable into the correct connector, but that is about it.

Q I am interested in upgrading my video, with the future (at least as far as I can see) in mind. I am considering the DreamVision DLP projector. A DreamVision sales rep told me that they will have a new HDTV-ready model in early 2000, the Movie Star Plus. Specs are 1024 x 768 XGA resolution, single chip DLP, 16.7 million colors, 4:3 and 16:9, Horizontal Frequency 15 kHz - 80 kHz, and brightness of 1100 ANSI lumens. Also I am considering a progressive scan DVD player Pioneer Elite DV-08 (plays DVD  audio as well) and HDCD. I also have heard and seen great things from the DVDO iscan. My questions are these: If I get the DVDO, do I not need the progressive scan DVD player, are they both doing the same thing? Also, is the Dream Vision with those specs truly HDTV-ready, does it suffer from the same issues that CRTs with smaller than 9" guns suffers from, and finally does HDCD really make a difference?

A HDTV has two standards that most will be supporting: 1080i (1920 x 1080) and 720p (1280 x 720). Both of those formats will be scaled by a DLP projector to 1024 x 768, so you will lose a lot of resolution. Notice that 1024 x 768 is a 4:3 size, while 1080i and 720p are 16:9 aspect ratios. DLP currently does not have 16:9 panels. Future models will, but I do not know when those will be available, and boy will they be expensive. In theory, progressive DVD will be better than the DVDO. Remember that the DVDO can scale other sources besides DVD, where progressive DVD is only good on DVD. HDCD does sound better than non-HDCD, but the HDCD signal is also a few dB louder, so that has something to do with it.

Q Is PAL/NTSC a factor in DVDs themselves? I know that one must have a PAL player to work with a PAL TV, and NTSC likewise. But I wish to know if the DVDs themselves are produced to work only on one system or another.

A Yes, there are PAL and NTSC encoded DVDs. Some DVD players can convert on the fly, but I am not sure how good the quality is. Anyone out there with such a player please let us know your experiences. I have seen some NTSC/PAL VCRs, but not the interconverting DVD players yet.

Q I was wondering if you knew where I could get an external comb filter to connect my CLD-95 to my Pioneer RPTV which has a decent but not outstanding comb filter.

A Faroudja, Camelot (Crystal Vision), and Monster all make external comb filters. I believe the Monster version is the cheapest. It actually uses the same algorithms as the Crystal, minus the edge enhancement features. (I think it is made by the same people who make the Crystal.) One side note is that the CLD-95 actually does Y/C separation internally then re-combines them on the composite output. So it is not a totally clean composite output. They do this so that they can perform some digital noise reduction. We have also started to see inexpensive gadgets that convert composite to S-Video so that you can connect all your components to the S-Video jacks on your receiver and switch in the one you want to use, so that the final signal comes out of one S-Video jack to your TV. On most receivers, you can't route an incoming composite video signal (VHS VCR) to the S-Video output from the receiver that goes to the TV. But, keep in mind this is strictly for convenience in switching your sources. It will not improve the signal.

Q I am moving into a new house and need a new TV. The sitting room is 13' x 15', and I'll be watching TV across the 13' part. Can you tell me what is the minimum and the optimal size of TV I should get? I am looking at a Sony FD 36" Trinitron or a rear projection (no idea which one is good). Since I have a surround system, I don't really need all the fancy features and would like to either save some $$$ or get a better/bigger picture for my money.

A Somewhere between a 40" and 50" should fit nicely. Toshiba has a new 40" 16:9 set that is DTV-ready and will accept progressive DVD. We should have a review of it done in a few weeks. Just as a reminder, there are only two HDTV formats, 1080i and 720p. All the other formats, such as 480p, are part of the DTV (Digital TV) series of formats. There are lots of them, but only the 1080i and 720p are HDTV. Remember also that the majority of DTVs out there that are HDTV-compatible, actually up-convert most signals to one format or the other, and only those with 9" guns are truly capable of displaying 1080i. The others handle the signal but fall short in actually displaying that much resolution. And, none of them will display 720p right now. If a 720p signal comes in, they down-convert it to some other resolution. However, they all look pretty nice, and we can't wait to get our hands on some of them.

Q I'm considering purchasing a Dwin HDP700 projector (with transcanner) and it has a scanning rate up to 64 kHz. Does this mean that it'll handle all HDTV formats? Or will it only handle up to 720p and 1080i? Also, is there any news about the status of the lawsuit that Faroudja has against Dwin? I'd hate to buy a projector and have the company go under.

A The Dwin can handle all HDTV formats, but because it only has 7" CRTs, it cannot fully resolve all of the detail in 1080i. It will display it and it will look good though. No word on the Faroudja/Dwin lawsuit. Many companies are now doing 3:2 pull down, and I am not sure where Faroudja stands on this.

Q There were a few 'false' starts of progressive DVD in last two years due to un-resolved copyright issue with Hollywood. But lately a number of new announcements seem that progressive DVD players might be real. But do these new players really output progressive a signal originating from the disc or just up-convert the 480i signals (which Hollywood will have no say to this, right?)

A The progressive players are indeed now hitting the street. Toshiba has two models, and Panasonic has one. I will be taking a closer look at the Toshiba SD-5109 in the coming weeks. I am not 100% sure if an internal MPEG decoder is outputting the true progressive signal or if they are line-doubling. I hope to have a better answer soon.

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