Q&A - #7 - April 8, 1997

Q I am quite grateful for your publication. I even enjoyed reading the "bios" of some of the staff. There would appear to be a predominance of considerably higher-than-room-temperature IQs on the staff. This, for me, is good because I've got a vintage 1969 Dynaco Stereo 70 and Pat 5 Preamp. This means my audio expertise is about 30 years out of date.

I've been obsessively shopping for new equipment since the beginning of the year. On the one hand, I have a bias for a tube sound. On the other hand, a Sunfire Cinema Grand is what I ideally need to drive a home theatre system that includes Dolby Digital. I've also looked at receiver/tuners that feature 5.1 inputs for outboard processors, i.e., Yamaha RX-V2090 and DDP-1 decoder or the RX-V990 that you have mentioned. There are also a couple Sony units as well as Pioneer and Pioneer Elite. On these lines I have enough information. I do have mixed feelings.... well, actually I have reservations about a receiver in the first place, but given the financial realities, a reciever which will allow for upgrading (or resale) is probably the only thing I can get away with and preserve some semblence of "domestic tranquility" at home...so these mixed feelings are about the Onkyo TX-DS838 or the 828. A dealer who represents Onkyo is pushing these at me. I would appreciate any input you might provide me addressing these products. I am similarly curious about the Marantz SR-770, 870, or possibly the SR-96. Of note is that these lines from both of these manufacturers have rear channels of 50 watts or more which is likely well advised for AC-3 application. I've not as yet even found the Marantz in town, so your input is welcome. I do see that its specs cite a three year parts and labor warranty which could be of some value.

All of this is taking me totally out the "tube" realm that I've been accustomed to for the past 29 years, (which is a credit to Dynaco, Hafler, et al.) So now, thanks to you e-zine, I have just become aware of Sound Valves and am quite encouraged. I'd be even more encouraged if I were just going to stay in two channel land, or if Dolby Pro Logic was all I wanted. The trouble is, now that I've done some shopping, I've heard DTS & AC-3. I understand in your review of the VTP-101i preamp by Sound Valves--which I am convinced I would love--that the EPL loop (external processor loop, just like on my 30 year old Dynaco Pat 5) can be used to encorporate a ProLogic processor, but I don't see any way that the 5.1 system required for AC-3 can be utilized by this preamp. I would like you to tell me I am wrong! If I were wrong, then I would dismiss my concerns about domestic tranquility, in other words--forget family budget, keep or trade up the Stereo 70, create three more channels of tube amplification, perhaps with mono blocs from Sound Valves, get an appropriate processor and be set for another 30 years, (though technology will likely require some supplemental expenditures.) Actually, what I want is a 5.1 system that's powered by tubes which drive a five speaker Mirage system in which the mains are a nominal 6 ohms and require a minimum 50 watts of power. Can this be done? Can this be done with, for instance, three Sound Valve Mono Blocs rated at 40 watts each, and the old Stereo 70 at 35 watts/ch? Lastly, much like Acurus has done with solid state amplification, is there a three channel tube amp on the market? (Or for that matter, using Mr. Carver, or Rotel, as an example, how 'bout tube amps w/ 5 channels???)

A There are a lot of people who love the sound of tubes, including us. Tube amps of considerable output (say, 200 watts/ch) can be had, but at considerable price. Your mention of the Sunfire Cinema Grand is noteworthy, because Bob Carver designed it, along with the original Sunfire Stereo Amplifier, with a tube-like sound, even though they are both solid state amplifiers. Take a look at the square wave response (10 kHz, ± 10V) for the Sunfire Cinema Grand [click here] and the Sunfire Stereo Amplifier [click here]. You can see that the Cinema Grand waveform is quite rounded, and the Sunfire Stereo Amplifier response is very much like a tube amp (check the square wave response graphs shown in the Q&A # 6 from last week for comparison). That is not to say these amplifiers sound just like tube amplifiers. They don't. But they do have some of the sonic characteristics. However, in your case, it is obvious that tube amplifiers would be most satisfactory. For surround sound, you will definitely need a decoder of some kind. Using "Y" connectors, along with the variety of pre-ins and pre-outs on select receivers, I don't see why you could not have your cake and eat it too. The EPL on the Sound Valves VTP-101i tube preamp is basically like a tape loop, but it is set aside for those who want to include the preamp in a surround sound system. Just make sure that whatever receiver you buy has pre-in jacks and pre-out jacks, and a set of 5.1 discrete inputs. The 2090 and 990 have all of these. The scenario might go something as follows: The analog outputs of the CD player and LD player are connected to the CD inputs and Aux inputs, respectively, on the VTP-101i. The regular outputs of the 101 are connected to one of the line-level inputs, such as VCR-1, on the receiver. The RF output on the LD player is connected to the RF input on the AC-3 decoder. The front left/right analog outputs of the AC-3 decoder are connected to the inputs of the EPL on the 101, and the outputs of the EPL are connected to the front left/right 5.1 discrete inputs on the receiver. The center and surround left/right analog outputs of the AC-3 decoder are connected to the center and rear/left right 5.1 discrete inputs on the receiver. The pre-outs of the receiver are connected to your tube power amplifiers. Use the one you have now for the rear surrounds, and get three 60 watt tube monoblocks to drive the front left/right and center (connect them to the pre-outs of the receiver). In this configuration, you can play CDs and LDs in Pro Logic, with all of the sound passing through the tube preamp, and the front left/right of the AC-3 will pass through the tube preamp.

Q I need your confirmation. I read every Q&A section on your website. I sold my existing Pro Logic system (receiver, subs, laser) to start fresh again. I was excited to find out that Dallas was one of the test markets for DVD on March 24. I would like to buy the Panasonic A-300 for two reasons: (1) internal DD decoder; (2) Karoake feature. Meanwhile, I have a 2 year old 56" Toshiba theaterwide 16:9 ratio (ironically, the new DVD showcase features new 40" TV w/video component inputs for use with Toshiba's DVD 3006) with modest Pro Logic built-in. I seriously doubt the TV has 5.1 inputs and component video inputs either. I opted for Pansonic instead of Toshiba 3006 w/component video since I don't plan to purchase any TV in the next 2 years that are HDTV ready with component video. Does this mean I can't take advantage of Dolby Digital sound from DVD movies like "Twister"? I plan to hook directly to the TV through S-Video and nondigital audio input.

A First I must say that the current crop of TVs like the Toshiba with component inputs are NOT "HDTV ready". The only display devices that are "HDTV ready" are the data and graphics grade projectors from companies like Runco, Vidikron, Sony, and Zenith, to name a few. These projectors start at over $10,000. The Toshiba TW40F80 and the TW56F80 (the successor to your TV) both contain component video inputs.

The Panasonic A300 has the Dolby Digital (AC-3) decoder built-in. The A300 provides you with 6 analog outputs that you must feed into a Dolby Digital ready receiver, like the Yamaha that was reviewed in Secrets some time ago, in order to take advantage of Dolby Digital. The other way to take advantage of Dolby Digital is to use the Digital output and feed into a Dolby Digital processor. So, yes you can take advantage of Dolby Digital. If you already own a Dolby Digital processor then you would be better off getting the Panasonic A100, since it is the same as the A300 minus the built-in Dolby Digital decoder.

Q In the past I have purchased equipment based on your reviews. Most recently a Sunfire sub. My last purchase (Toshiba 2006 DVD player) just missed your review. I thought I would add some comments to your review. Here are some observations you might pass on to your readers:

I had the impression from reading the ads that movies that are formatted only in 'Widescreen' could be viewed full screen on my standard 35" Mitsubishi TV by using the pan and scan feature. After setting the mode to 'pan and scan', the two movies I purchased in widescreen only ("The Color Purple" and "A time To Kill") still only play in letterbox. Apparently there is some information that must be present on the disc that allows 'pan and scan' to function. When I purchased the movies I wasn't aware that the format was printed on the box, either Standard or Widescreen or both. Of the seven movies I purchased, five have both formats, while the above two are Widescreen only. So from now on I will only purchase movies that are formatted for Standard.

I found by accident that when playing music CDs that the digital out and analog out are both simultaneously active. This allowed me to switch between the digital and analog modes on my AV receiver (Denon AVR3600) while playing a CD. I could not hear any difference in the sound between the two modes. The reason I know it was working is that I could unplug the analog cables, first the right and then the left, and it would correspondingly follow. But when the receiver was in the digital mode I had full stereo sound even with the analog cables unplugged. I also compared the sound to my CD player and still could not detect any difference in the sound, and I think I have a good ear for sound. In your review the person doing this test said that the sound from the CD player was better. So I've tested it with 3 different configurations and could not tell any difference. My speaker system, mains, center and surround are very evenly matched and are very clean with a frequency response essentially flat from 18Hz to over 20kHz according to a laboratory sound pressure meter which I borrowed from work and tested outdoors. The sub is the Sunfire, the fronts are Linaeums, and the surrounds are Cambridge Soundworks "The Surround" , but which I think are not very good for Dolby Digital. I plan to change them out soon with Linaeum dipoles. I made my own speaker cables from 50 conductor flat ribbon cable split 25 and 25. They have very low inductance and capacitance. I wonder if many of your readers or staff have ever tried this. Cheap and works well.

Oh, one more thing. The Toshiba did come with an S-Video cable, albeit a very cheap one, so I replaced it with an AudioQuest cable. The literature I've read said that an S-Video was not included with the 2006.

A Thanks for your additional input. The Pan and Scan, and/or Widescreen versions are on separate sides of DVDs. I think many of us had the previous impression that the DVD players would be able to take the widescreen image and convert it to a Pan and Scan image. Depending on the setup, you may or may not hear any differences between a regular CD player and the DVD player with CDs. There are many variables operating. Apparently, the Sony DVD player uses two different lasers, one for DVD (red), and another one for CDs (infra-red). Other DVD players have just the one infra-red laser. We will know more as the next few months pass.

Q I'm looking to upgrade my home theater system, and I purchased the Denon AVP-8000. Now I recently ordered the Adcom GFA 5503 & the Adcom GFA 5500. Later I hope to get my speakers, but want to get financially free of my current investment. The reason I write is because I am reconsidering the amps. I spoke with my dealer & he said that I could ship them back if I don't open them & get the Parasound HCA-2003 & the HCA 1200II for another 500 bucks. I know you reviewed the Parasound system & Mr. Moretti reviewed the Adcom amps. Can you give me some advice? I plan to use my system for both music and movies & have heard NHT speakers, B&Ws, PSBs, & Energy. Thus far, I'm partial to the NHT VT-2. But I'm not absolute on this. Again, the speakers will be purchased next year so I can do some better research. I'm just a working class Joe, with a middle income, so that is why I'm looking at "B" level equipment. Please try to understand my financial limitations. I'll probably spend about $3,500 on the speakers next year, but no more. Your response will be greatly appreciated!

A The Adcom 5500 and 5503 use MOSFET output devices, while the Parasounds use bipolars. Other than that, they are reasonably equivalent. MOSFETs are a little more musical, while bipolars tend to have more punch. It all depends on your tastes. Since all of the models you mentioned have sufficient power, I would suggest that you get the ones that sound the most pleasing to your ears.

Q I understand that the Yamaha 3090 has a bass management flexibility for the rear speakers when used in 5.1 mode which is a plus. I like this particular model for its integrated amp and the price (in addition to purchasing a DDP-2 later). I know Yahama is favored widely for reference in comparison tests, but I also enjoy the decorrelation provided through home THX cinema since it rolls off the brightness associated with AC-3 sound bitstreams, hence Denon AVR 5600. Do you suppose Yamaha can compete to tone the AC-3 brightess found in DVD software? Cost wise, I would like to opt for an AC-3 system without spending the money for a THX system including speakers.

A The Yamaha 3090 already has AC-3 built-in, so you would not need the DDP-2 AC-3 decoder. However, if you want to add DTS later, you should consider a receiver that has a discrete set of 5.1 inputs, like the 2090. You could add AC-3 and DTS decoders (see our review of the Millennium DTS decoder next week) and come out with about the same price as the 3090. Not all DVD discs are bright. Some are, but not all. It's the same with any movie sound track sources. If the brightness really bothers you, you can trim it with the tone controls built into the receiver, or use a multi-channel equalizer like the AudioControl Rialto or Bijou.

Q I would like to know if you can tell me anything about the Krell Video Standard. What do you think of using the Wadia 27 directly to the Krell 600 without preamp?

A The Krell has very fine audio quality, but if you want more power, you will need to look at other products. We have connected CD players directly to power amps, and the result is less than satisfactory, in my opinion. Often, there is not enough voltage to drive the power amp to full output, and the tonality seems a bit odd (not very natural). However, it does bypass circuitry, and to many, this is the purist approach.

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