Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Posting-Version: notesfiles - hp 1.2 08/01/83; site hp-pcd.UUCP
Path: utzoo!watmath!clyde!cbosgd!ihnp4!houxm!vax135!petsd!pesnta!hplabs!hp-pcd!raan
From: raan@hp-pcd.UUCP (raan)
Newsgroups: net.video
Subject: Re: problems with HiFi VCR's
Message-ID: <20600020@hpcvry.UUCP>
Date: Wed, 25-Sep-85 20:13:00 EDT
Article-I.D.: hpcvry.20600020
Posted: Wed Sep 25 20:13:00 1985
Date-Received: Mon, 30-Sep-85 01:30:58 EDT
References: <38@utecfc.UUCP>
Organization: Hewlett-Packard - Corvallis, OR
Lines: 84
Nf-ID: #R:utecfc:-3800:hpcvry:20600020:000:4180
Nf-From: hpcvry!raan    Sep 25 16:13:00 1985

I am not familiar with your particular unit, but I own a Sony SL-2700 Beta
HI-FI.

>> 1) Levels of hum and hiss seem inordinately high, and I find this rather
>> obstrusive in quiet passages.

My unit has the ability to play either the HI-FI or the linear sound tracks,
or both.  Are you sure you do not have the linear track on.  This is much 
noisier than the HI-FI sound and if both were on would show up as noise with
out affecting the frequency response (which is the other major difference
between the two).

>> 2) A whining noise is heard at the beginning of each Beta HiFi recording, but
>> this gradually decays.

I have not experienced anything like this.  Does your unit have indexing (if
it does, it may be out of adjustment and affecting the sound, since it records
a mark on the tape at the beginning of the record session).  To test this,
try positioning the tape in the middle of a section of already recorded tape
and then go from play to record without pressing stop.  (Press Play, Pause,
Rec, and then Pause to start recording -- assuming yours works like mine.)
This will start the recording without putting an index mark on the tape.  See
if this still generates the noise.

>> 3) Sometimes the Beta HiFi light drops out for a second or so, with a 
>> corresponding loss of hi-fi, but then comes back on again.

This is normal behaviour for the system when there are dropouts on the tape.
If this happens with several different new tapes, then the dropout sensor
in the unit may be out of adjustment.  A dropout will also manifest itself
as a horizantal glitch in the picture, usually moving from top to bottom
of the screen.  If all the tapes you try were from the same lot, then you
may still have a batch of bad tapes.

>> 4) There are random, short duration, low level, buzzing sounds (could these 
>> be tape dropouts?) which are especially apparent (and annoying) during quiet 
>> passages.

Try playing with the tracking control.  The HI-FI sound is very sensitive to
tracking errors, especially at Beta III.  The problem will show up as clicks
and pops or low frequency (30Hz to be exact) sharp toned buzzing.  This is
also related to the next item.

>> 5) Worst of all, a distortion problem which seems level and frequency 
>> dependent.  This is really apparent with solo recordings (for example, a 
>> female opera singer or a trumpet) where there is no other music to mask
>> the problem. I would describe the distortion as a harsh, jagged kind of 
>> sound which accompanies the music. This occurs at levels below the red 
>> LED (0dB). I recorded some sine wave test tones at different levels and 
>> frequencies. The performance seems OK at low frequencies, but at high 
>> frequencies the same harsh, jagged sound emerges, somehow superimposed 
>> over the test tone.

Because of the way the signal is recorded on the tape (in 1/30 second
slices) the playback signal contains a 30 Hz switching transient.  The
system has circuitry to remove this noise and normally does very good 
job of it.  However, (for reasons I don't understand) it fails miserably
on high tones without much background.  The worst case of this being test
tones.  This happens on both Beta and VHS HI-FI and has been reported
in Video Review.  I have confirmed it on all of my machines.  There
does not seem to be anything that can be done about it.  

>> 	The Sony Service Centre tells me (after numerous visits) that there is 
>> nothing wrong with my machine and that all SL5200's behave the same way. The 
>> special "HiFi" tapes improve the performance, but I really can't believe the 
>> unit is meeting the excellent specifications Sony touts so highly.

Other than the last problem mentioned, I have been reasonably happy with my
machines.  However, I am somewhat upset about the claims made for HI-FI sound
(on all machines, not just Sony) in light of this problem.  I feel that the
advertising is misleading.


---  Raan Young (hp-pcd!raan)

     ~~~~~~~~~~~~~~~
     uoregon   ---->\
     orstcs    ----> \
     hplabs    ---->  \
               ---->   >--!hp-pcd!raan
     harpo     ---->  /
     microsoft ----> /
     tektronix ---->/
     ~~~~~~~~~~~~~~~


Brought to you by Super Global Mega Corp .com