|
|
|
Q When do you think the new TVs and DVD players, which support a progressive scan connection, will begin to hit the market? Do you know which equipment manufacturers will offer them? Will the progressive scan connection be standardized (e.g., will Sony's progressive DVD work with Hitachi's progressive TV)? Finally, do you know if the upcoming Sony DVP-S7700 will have progressive capabilities?
A The
first Progressive DVD player is currently on the market. It is
a DVD-ROM and progressive decoder card available from
http://www.digitalconnection.com The decoder card will work with
almost any DVD-ROM drive and is priced at $159 for a PCI or $179
for an AGP version. The card will run under Win95 or Win98. The
quality is pretty impressive with no motion artifacts on film.
You will still see scan lines if you have a projector that has
an optimum scanning rate greater than 31.5 kHz.
Toshiba will have one out in September.
The new Sony is NOT progressive. As far as the connection on the
end, I am waiting myself to see what everyone offers. The computer
one I mentioned above uses the standard VGA connection out of
your PC. Let's hope they all standardize on something.
Q Will
I have any problem using longer single-ended interconnect cables
of up to 15 feet? I plan to move my equipment rack next to me.
This way, I can have an instant access to my preamp (active) volume
control. In addition, if I want to buy a new preamp, my option
will no longer be restricted to preamps with remote volume controls,
thus giving me the flexibilty and choices of brands.
A Interconnects
of 15 feet length will pose no problem as long as you select shielded
cables and keep them away from AC power cords.
Q Previously
you mentioned that a tube preamp and solid state power amp combination
is good. Will the converse be true (solid state preamp and tube
power amp)? My Onkyo 434 receiver has pre-outs. I'm toying on
the idea of getting either a tube power amp, or a tube integrated
after I get your opinion. My audio/ video gear consists of NHT
SuperZero, Infinity center, Velodyne VA1012XII sub (which you
helped me decide over two brands - thank you very much), and JPW
as rears.
A In
my opinion, tube gear somewhere in the chain always gives a system
a nice warm sound. There are several CD players with tube output
stages that are great (keeping in mind that the rest of such CD
player's electronics are solid state). The reason I like to use
tube preamplifiers, is that tube power amplifiers are very expensive
if you want high power. You can easily spend $5,000 - $10,000
for 250 watts per channel (two channel amplifier) for tubes, while
$1,500 will buy a good solid state amplifier of the same power.
In your case, you obviously want to have tubes in your home theater
system. I would suggest getting a tube preamplifier with a processor
loop to drive a solid state power amplifier for the front left/right
channels. Something like the Sound Valves VTP-101i tube preamplifier
($800) and Adcom GFA-5802 ($1,800) two channel solid state (MOSFET)
power amplifier (300 watts rms into 8 Ohms) would work very well
together.
Q I
currently have the Atlantic Technology 350 system with the two
12 inch Atlantic Technology subwoofers and wanted to ask your
advice about having two subs versus one. I read about the Sunfire
Mark II subwoofer and was very impressed. My question is would
a single Sunfire Mark II subwoofer perform better than my two
Atlantic 12 inch Technology subwoofers, or is it better to stay
with my setup (dual 12 inch subs)?
A The
Atlantic Technology subs for the 350 system are the 352pbms. Although
they will play loud enough (100 dB is plenty), they are only rated
down to 35 Hz (- 3 dB), while the Sunfire will go all the way
to 20 Hz. Stereo subwoofers can give an enhanced experience over
one subwoofer, and most movie sound tracks don't really have very
much below 30 Hz. However, if you want the full range of human
audibility, the Sunfire will deliver it in that lowest, very difficult
to reproduce, octave (20 Hz - 40 Hz). I don't see why you could
not incorporate a Sunfire into your system and still use the Atlantic
Technology subwoofers too by spreading them around the room. We
use four subwoofers in our reference home theater system (two
for front left/right, one for the center, and one for the LFE
channel in DD and DTS).
Q Do
you guys know whether the Pioneer DV-505 DVD player has a 7.5
IRE or 0 IRE black level? Their brochure, spec sheet, manual doesn't
say what it is.
A I
am not sure about the 505. I know the 909 has the IRE set at 7.5
and the DV-09 has the IRE set at 0. However, to find out what
the IRE is set at, you can put on the PLUGE pattern (DVD or LD
Video Standard Test Disc) and turn up the brightness. If you see
the black bar on the left of the gray bar (in other words, if
you can distinguish the two as separate bars), then the IRE is
most likely at 7.5. If you can never see the black bar as black,
then the IRE is at 0.
Q I
recently bought the movie "Sphere" and tried to play
it on my Sony S-7000 DVD player. My unit would try to play it
but returned the message of "Insert Disc" after a few
seconds. I tried this twice by returning the merchandise to Fry's
Electronics and replacing it with a new copy of the movie. The
result was the same as the first try. Finally one of Fry's staff
decided that we should check another copy of the same movie on
different models. The same result occured when we used their S7000,
but the movie played on the S500D. This is frustrating, and I
told Sony so. Do you have any other known problems (as well as
solutions) for this "high-end" model?
A I
played "Sphere" from beginning to end and encountered
no problems with my Sony S-7000. However, I have one of the first
batch of Sony players that still had the internal switches to
defeat Macro Vision and region ID.
I have experienced the insert disc problem
once, but after I took the disc out and re-inserted it, the problem
disappeared. I suspect that your problem occurs because you have
one of the later S-7000s, where the macro vision defeat capability
has been eliminated. DVD is extremely high tech, and I think that
we will be having such problems for several years, while all the
copyright protection schemes are smoothed out.
Q When
I was in the store I noticed that one company has a processor
dedicated to THX built into their high end receivers. When I got
home, I noticed that most of the movies I own use THX. Is there
a unit that I can add that will support this technology as well
Dolby Digital and DTS?
A THX
is a standard, rather than a technology in itself. The standard
applies to processors, amplifiers, speakers, cables, and movies.
In the case of movies, it means that the sound and video meet
that high standard, but you don't need a THX processor to enjoy
that high quality. With Pro Logic, THX processing means that the
left and right rear speakers are still mono, but they are slightly
out of phase with one another, giving more ambience. There are
a few other manipulations of the signal too, but many high end
receiver/processors, in particular the new ones that have DD built-in,
can do much of this with their own DSP, although they can't call
it THX for trademark/copyright reasons. Essentially, if you have
the THX certified movies on LD and DVD, and a good processor for
DD and DTS, you are already enjoying the benefits of THX.
Q My first good amp/preamp was from kits put out by Southwest Technical Products Corp around 1975, a preamp, and two Tiger B mono amps. They were awesome, and I don't know why I abandoned them. After that, I bought a Sansui Z5000X receiver in 1984 for about $320 US. It doesn't have a ton of features, but the specs seems to be quite lofty and expensive to replace (70w/ch rms at .007%THD or better, 20-20K Hz, if I'm to believe the manual), especially in a receiver these days. I'm dedicated simply to stereo for music listening, and I'm hoping it lasts and can be repaired.
1) Am I right in assuming that if it's rated
at 70W at .007%THD, then it probably puts out at least 25% more
at 0.1% THD? Or is
this widely variable based on design?
2) Assuming kits are a possibility for me,
what price will I pay to get comparable performance in today's
market? I'm almost resigned to
the fact that finished amps with this low distortion cost at least
several thousand, even at this wattage.
A 
Harmonic distortion is one of those things that
looks great on specification sheets, but the number by itself
can be misleading. Mass market receivers have low distortion figures,
but that is usually because a large amount of negative feedback
has been used in the design. If you look at the harmonic distortion
specs for a high performance amplifier, it can be on the order
of 0.5%, or even 10% for some tube amplifiers. Negative feedback
reduces the second order distortion, but increases odd ordered
distortion, such as fifth. So, although the number may be low,
the presence of odd ordered distortion makes the sound much more
harsh and irritating that the amplifier with more distortion,
but where the distortion is primarily second order. Designers
can take the distortion measurement anywhere they want on the
graph. Clipping is usually defined at where the distortion takes
a sudden upward swing on the power output vs. distortion graph,
or at about 1%. However, that is just a definition. The presence
of 10% harmonic distortion in class A, single ended tube designs
can actually be pleasing, because it is second order distortion.
Your amplifier probably puts out about 72 - 75 watts at 0.1% THD.
But that 0.1% could very well be quite irritating to the ears,
because it contains odd ordered distortion.
There are a number of tube and solid state
kits out there, and probably most of them will give you a better
sound than your receiver's amplifier. Many of them are in the
< $1,000 price range. Try Sound Valves for a start on your
trek to high performance audio.