Q&A # 277 - March 14th, 2002

Staff

Q How would you compare the Rotel RMB-1095 with the Sherbourn 5/1500?

A These two amplifiers are quite similar. I would choose based on the features you need. The Rotel has balanced inputs, while the Sherbourn has switchable limiters and can be bridged. The 1095 is one of the reference components in our home theater test lab. We use it with a Theta Casablanca II and the balanced inputs.

Q My system consists of Yamaha RX V3000 receiver, two JM LABS Cobalt 820 front towers, JM LABS Cobalt 820 Center Channel, four JM LABS Cobalt SR 800 rear (surround) speakers, Velodyne HGS 15 Sub. I am looking for a DVD player that compliments my system well in regards to quality/output etc. and would like a few suggestions.

A The Panasonic RP-91K at $699 MSRP has no chroma bug and will play DVD-A. Denon is about to introduce their new DV-1600 which will also play DVD-A. Both will output progressive component video.

Q I have a NAD T550 DVD player hooked up to an analog JVC 32 inch TV. I am considering purchasing a digital TV to replace the JVC. I have been told that the T550 is not a "progressive scan" player, and therefore I will not be able to take advantage of the resolution of a digital TV. Is there a TV with this feature onboard? Also, do I need to purchase a line doubler or scaler to get the best possible resolution? I would rather not replace the NAD as I am really pleased with its audio performance, it is the one DVD player I have auditioned which plays CDs extremely well.

A Digital TVs have their own deinterlacers built-in, so you can use the interlaced output from your NAD DVD player. An outboard scaler probably will give you an improvement over the one that is in the TV. Something like the iScan or the Videon Omega One would be fine for the system you outlined.

Q Thanks for the very informative and interesting site. It helped me to find the right DVD player, as well as new speakers me and my family enjoy very much.

My question is how to integrate existing stereo set up into multi-channel digital processing. Currently I use stereo preamp and two power amps (Parasound HCA 1000A ) in vertical bi-amping with Bohlender Radia X3 speakers (4ohms, 150watt).

I am planning to buy a Denon 3802 receiver both for DVD movies and to listen to music (stereo or DPL-II). Apparently it has pre-outs, but is it possible to incorporate a tube preamp (at least for the CD player signal) and still have DPL-II?

Also what would be the best way (if any) to use external power amps with the Denon. Should It be bi-amping for L and R front speakers or better to use one power amp for L and R speakers, and the other for the center speaker? (I am not sure in that case how to connect the mono pre-out to stereo amp for a bi-amping option.)

Finally, will my system benefit from external amplification at all,  considering the high efficiency (93dB) of the main speakers and comparable power ratings of Denon (110 watt/ 8ohms) versus Parasound amps (125 watts/ 8ohms)?

I intend to use a pair of B-G X3 as front, B-G X1 as center, and pairs of old KEF C75 (4 ohms) and Tannoy 6.5 (8 ohms) for surround. I also have a powered subwoofer.

A You can use the tube preamp by connecting the front left/right pre-outs of the Denon to a line in set of inputs on the tube preamp. Connect your CD player directly to the tube preamp also. The output of the tube preamp goes to your power amplifier. Connect your DVD player to the Denon. Then, when listening to music, you use just the CD player, tube preamp, and power amp connected to the front left/right speakers. When listening to movies, use the Denon, tube preamp, and power amp. You can bi-amplify with a mono output, but the two amplifiers will send the same signal to all the drivers. The best way to bi-amplify is to use an active crossover to split the signal into high frequencies that go to one amp driving the tweeter and midrange drivers, and low frequencies that go to the second amplifier driving the woofer. Using outboard power amplifiers will help your receiver quite a bit, with the center and rear channels, since the power supply will not have to deliver current to the front left/right channels.

1) When integrating a stereo preamp that does not have a unity gain or theater bypass input into an HT system, you must use a consistent and repeatable volume setting on the stereo preamp to be sure your calibrated values remain consistent. If you do this, the integration goes just fine. If you don't, well, let's just say the results are less than spectacular.

2) We should clarify the difference between passive bi-amplification (utilizing the speakers internal crossover network) and active bi-amplification (utilizing an external crossover). Much care needs to be exercised with the active option. You need to make sure the crossover type (Butterworth, Linkweitz-Reilly), slopes (12dB/octave, 24dB/octave) and frequencies align with the drivers (and speakers) design characteristics.

You are intending to use passive bi-amplification. Because the amplifiers in this case are identical, vertical vs. horizontal bi-amping is merely an issue of where the amplifiers are utilized.

3) For CD Player with DPL-2 and "regular stereo listening", I recommend taking the stereo output into the tube preamp as suggested and taking the digital output into the Denon Receiver. This will allow for both untouched stereo, and DPL-2 as desired.

This configuration is workable, but will be a pain to use if the tube preamp has no remote control. Not the end of the world, but we should at least mention these details.

Q I own a Toshiba 40H80 (2001) with a Toshiba SD9200 DVD player. Over the past few months I been noticing large vertical red streaks in certain saturated (red or fleshtones) scenes on any DVD movie. I thought this was the chroma bug, but after reviewing all the DVDs you mentioned on your site, I've concluded that this my be something else. I recently purchased "Desperado" Superbit, and in the opening scene where Steve Buscimi is talking to the bartender, I can see streaks down the left side of his face and neck. It's very obvious and virtually unwatchable. I've checked 25 DVDs and noticed these streaks on all of them though with some movies it's less visible.

I've tried different component cables, including XLO and Tributaries Silver Series. I even used a Pioneer DV-37 and still noticed this problem. I don't recall seeing this problem on other sets, but is it possible that the TV could magnify this problem? Is this the chroma bug, if not what is it and can it be removed?

A Chroma bug is made of horizontal streaks. What you are seeing could be YC delay, but it is more likely a convergence error. Projection TVs pretty much arrive in poor shape and need a proper convergence
session (aligning red on top of green and blue on top of red).

Q How will the proposed DVI interface between decoders and TV monitors affect existing TVs where the decoder is already built-in? Will I be able to watch 720p and 1080i with existing decoder/TV combinations?

A By built-in we assume you mean the few TVs that actually have the HD set top box built into the TV. We don't have an absolute answer to that question. In theory, the TV should know that the decoder is built into the TV and the signal is safe from copying. This is not an absolute, as the decoder may have the same logic as an external box, which would then down res (scale down to 480) the signal. Chances are the TV maker might not even know 100% what it will do.

Q With the wealth of new DVD players (many of which appeared to address your Shootout I and II concerns), when do you plan a new set of reviews? The new Denon 3800 and 1600 are very tempting, but I prefer to check them out with you guys first.

A We are testing one Denon right now and will be doing the others as soon as we get them. The shootout data from the last set were so complicated, we did not have room to publish them, and they were of interest primarily to design engineers, so we will be concentrating on more useful consumer data in upcoming reviews. This will include charts and graphs on such things as frequency response and noise, but not all the heavy duty stuff that was in the last shootouts. The engineering data will go directly to the companies for incorporation in new products. After all, Secrets is primarily a consumer magazine, not an electrical engineering journal. We got a little carried away.

Q I own a Sony 36 inch Australian HDTV ready set.

When I play a NON anamorphic DVD on my progressive scan player, the letterbox picture displayed is quite small. The TV has no (I think you call it) 'zoom' mode using progressive input.

But most of my DVDS (90%) are all anamorphic (enhanced for widescreen TVs). Those DVDS fill the whole screen, if the aspect ratio is 1:85, or fill up most of it with a 2:35 film - which is correct.

I am interested in purchasing the JVC D-VHS player and my question is  . . . if I play a D-VHS pre-recorded movie tape that will be in widescreen, will it fill up all/most of the screen like my anamorphic DVDs? I obviously hope it will!

A Studios are thinking of releasing High Definition movies in D-VHS (high definition tape recorders), since current DVD technology can't handle High Def, so this is a very pertinent question. The answer is yes, it will be displayed full screen because HD is a 16:9 format. 1080i and 720p are 16:9 only, which means they MUST be enhanced for widescreen TVs. The spec does NOT allow for non-anamorphic HD material. 480p can be either 4:3 or 16:9.

A word of warning: don't expect the HD tape format to have much more than a nitch market. Very few studios actually plan to support the D-VHS format, and the majority will hold out for HD-DVD. On that note, the technology for short wavelength lasers has been announced, so HD-DVD is on its way. The disc space is incredible at about 45 GB.

 

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