Why the vinyl revival is working
Record players that
sound just as good as CDs
Records don't disintegrate
after 20 years!
Do you
realise how much music is locked up in your records?
The record groove
Why bother with records?
A DIY cartridge alignment tool that
works
Visitors secondhand
vinyl gear, wanted or for sale
contact me by e-mail
Why
the vinyl revival is working
You can pick up a good vinyl LP in superb condition for about 5 quid! I
bought three the other week for £1.50! On every second hand market there are hundreds of
LPs going for a song (pun intended).
OK, the chances are that a market stall won't have exactly what you're looking for just at
this moment (but if you ask the stall holder you may be pleasantly surprised), so try one
of the many specialist vinyl shops that are springing up in every town. Just like the
record shops of old, they have everything sorted into categories, making whatever you're
looking for, easy to find.
With vinyl your money buys much more music!
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Record players that sound just
as good as CD
How much is a good CD player? I'd say around £300. So how much is a record
player that sounds just as good? Again I'd say around £300. But what if your amp doesn't
cater for a record player input? Easy, go for a gram pack (follow this link - click here). You get everything
you need - pick-up cartridge, turntable and interface box - and still for around £300!
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Records don't disintegrate after
20 years!
Regardless of the present age of the records in your collection, the blanket
statement predicted that each one of them would disintegrate in 20 years time! I can't
remember exactly when this statement was made, but I think I heard it on the BBC news (so
it must be true?).
Of course, we're not that gullible, and realise it was just another scare tactic from
those digital marketing men who can't stand the fact that vinyl isn't going to go away!
(what a pity that the newsmen were so easily drawn-in by this one, and I suppose if they
were, Joe Public was too).
You see, you and I, who still love listening to vinyl, are a thorn in the digital
salesman's side - let's remain so!
If you need reassuring - I have records that are 50 years old (older than me!), and
they're made of less stable stuff than vinyl. They are showing no signs whatever of
disintegrating, so another 20 years aren't going to make that much difference! And as for
my vinyl collection, even the most abused of them will still be around long after I'm
gone.
Nice try chaps!
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Do you realise how much music is locked up in your records?
Question? Do you have any
records? (I mean Long Players not CDs). You have?
Well do you realise how much music is locked up in them that you've probably never heard?
Believe me there's as much as you'd get from a CD! If not more!
How many records do you have? That many? And do you ever play them? Do you realise what
you're missing out on?
You spent all that money over the years buying your favourite music and you're probably
spending it all over again on CDs when you don't need to!
You can release that buried treasure - all that music you never knew was there until now,
and start enjoying your investment at last - simply by understanding more about it - then
refurbishing or replacing that old turntable and buying a cheap accessory.
You wouldn't believe how well made some of
those records are. The record companies really didn't know how much effort they were
putting in because they hadn't got the equipment to play them properly. So very often they
resorted to "overkill" just to be on the safe side. But then it didn't really
matter because you and I were playing them on equipment that just garbled it all up.
Then, in the late seventies/early eighties a handful of companies started making really
good turntables and pick-up cartridges which could at least track grooves properly and put
out a better sound.
Companies like Thorens, SME, Dual, Rega, Roksan, Lyn (Sondek), Ortofon, Audio Technica,
etc... (e-mail me if you think your company should be in this list).
At last we'd got to the point where the mechanical old record groove could be turned into
a super electrical signal. But that was about that!
The trouble was the amplifiers couldn't do much with it and even though the sound was
better (due to the source), it still sounded a bit garbled, twitchy, clicky and distorted
(especially on brass and orchestral crescendos).
This is where the cheap accessory comes in! For quite some time people have been making
exotic (expensive!) little "black boxes" to go between your turntable and amp,
specifically to sort out the "garble". But they only appealed to Hi-Fi fanatics
with stashes of money. Up until now that is. We've just started making a low cost (£60)
"phono stage" (not to be confused with other low cost "phono stages")
which really digs out the music (you'd be amazed - even I was) and not being satisfied
with that we made a better one - still less than £100 ($150).
So now you can delight in the joys of your record collection at long last! (follow this link to learn more about our
phono stages)
If anybody from Decca is reading this I'd like to ask "did you really know how good
some of your pressings really were"?
There now follows some info for the technically minded.
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The Record Groove
A narrow helical (spiralling) "v" groove 500
metres in length is pressed into a thin disc of smooth plastics material. Undulations in
the groove walls store the equivalent of 300Mb of music at frequencies up to 40kHz! (twice
that of CD). The other side carries the same. The medium is known as the long playing
gramophone record. LP technology is about 60 years old and was developed from the hard
learned lessons of 78s (a total of about 80 years of development). Hi-Fi sound
reproduction started life on 78 with FFRR (full frequency range recording).
The music is reproduced from the groove using an
electro-mechanical pick-up fitted with a stylus. The record is rotated at a given speed
and the stylus is lowered into the groove. The undulations vibrate the stylus causing a
small electrical current to flow in the coils of the pick-up. The current is amplified
sufficiently to drive a loudspeaker and we hear the music. Simple?
No! Lets look at two frequencies within the audio
spectrum, 50Hz (bass) and 10kHz (treble) for example. Because wavelength is inversely
proportional to frequency, the size of the groove undulations required to produce a fixed
amount of electrical energy at 50Hz will have to be 200 times greater than required at
10kHz! You would only get 6 seconds of music on the average LP!
So how's it done? When cutting the master the bass
has to be severely attenuated compared with the treble to make the groove undulations a
uniform size, narrow enough to get 20 or 30 minutes to each side. Or to put it
technically: You must make its output (amplitude) non-linear plotted against
frequency. This allows the size of the undulations to be the same at all frequencies, so
that the stylus velocity in the groove is constant.
Engineers have been developing constant velocity
recording since the very first 78 rpm electro-mechanical records. At first it was a
mixture of constant velocity at low frequencies with constant amplitude at
high frequencies, and then the nearly universal adoption of constant velocity at
both high and low frequencies. The particular turnover frequencies from which constant
velocity was applied varied from manufacturer to manufacturer and from year to year.
The groove width of these old records was quite coarse.
Because of constant velocity all records need a
very special preamplifier to make them sound right when played, this is called the phono
preamplifier. Today's phono input caters for modern records only. In the past there were
numerous "standards". All require equalisation to give the correct tonal
balance.
The professional would use a variable EQ phono preamp where
the particular frequencies can be selected by switches or potentiometers. Alternatively
there are fixed EQ preamps
available for the more popular equalisation curves. You can use a modern RIAA/IEC phono
preamplifier along with a graphic equaliser for the older "standards" but it's
hard work and you're never sure when it's right.
Constant velocity recording was standardised in
the mid 1950’s with the introduction of the RIAA (Record Industry Association of
America) characteristic curve by RCA. Up until then large numbers of long playing records
and singles had been pressed to a number of standards including AES, NAB (NARTB), British
Standard, 629, etc. The RIAA replay curve was further modified with the introduction of
the IEC amendment, requiring low frequency cut at sub-sonic frequencies.
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Why bother with records,
when CD is much better?
The answer is (while CD doesn't have scratches, clicks and pops and is much more
convenient to use) vinyl reproduces much higher frequency harmonics which CD simply
cannot! With CDs you have to cut frequencies above 20kHz with a "brick wall"
filter to stop the nasty 44.1kHz sampling frequency breaking through. Also CD high
frequency reproduction is the result of a circuit "guessing" what shape it
should be when presented with insufficient sampling points (hardly Hi-Fi - but thanks to
the marketing guys we all believe it's the best?). Many of the harmonics which bring
"life" to the music extend beyond 20kHz. Good vinyl records extend well above
20kHz and even at twice that there can still be a useful output (and a faithful one at
that). Good phono preamps like the Gram
Amp 1 and Gram Amp 2 extend up to 90kHz (-3dB) and, with the right sort of turntable
can bring more musical enjoyment than CD could ever achieve.
If you wish to challenge the above, please answer the
following question. Can you draw the shape of a graph given just two points on its line?
This demonstrates the inability of CD to reproduce the shape of high frequency waveforms
accurately. Musical waveforms may not be sine waves, or square waves, so you cannot answer
by making assumptions.
I will welcome a healthy discussion on the pros and cons
of vinyl (and CD) on this page - just e-mail
your comments.
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A DIY
cartridge alignment tool that works
How do you align a cartridge properly? Don't you need specialist equipment?
Well, answering these questions in reverse: No you don't need specialist equipment and,
you may laugh, but to align a cartridge properly requires a piece of A4 or similar size
paper, and a pair of scissors.
Fold the paper in half - lengthways (like a tall menu card - yes?). Make it a sharp
crease. About half way along the crease cut a "V", with the snips about 1cm
apart, the bottom of the "V" having a 90 degree angle. Unfold the paper and fold
it back the other way - to make it lay flat. The "V" will be a diamond shape
hole in the middle of your paper. You've now got a precision cartridge alignment
protractor. All you need now is to know how to use it.
Place a LP on the turntable then slip the protractor over the spindle, on top of the
record. Rotate the turntable (by hand), until you can drop the stylus into the crease,
just about the position of the start of the record.
Now, the crease intersects the centre of the record, so it is exactly at right angles with
the groove. And the correct alignment is when the cartridge centre line (front to back
that is), is at right angles to the crease!
That's an easy thing to gauge by eye if your cartridge has a flat front, which most do -
just gaze down from above and if the cartridge front looks parallel with the crease,
congratulations, you're aligned, at least at the outside.
But just in case it hasn't a flat front, make a soft pencil mark to indicate where the
stylus was sat - take off the paper and fold it width ways at the mark, so you get another
crease at right angles to the original. Then by line of sight you can see if the cartridge
centre line (looking just below the cartridge from the front), looks parallel with the
(second) crease.
In either case, if it's not parallel, you'll have to slacken off the cartridge and slide
it back or forth in the headshell/arm, to get it right. Then tighten up and check again.
Now for the inner groove. Again set the stylus down into the crease near the runout of the
last track. Check again by the same methods (making another crease at this point if you
have to). Don't be surprised if it's out! Cartridge alignment is an iterative process -
tweaking back and forth 'till it's just right.
But what if you can't get perfect alignment whatever position you slide the cartridge to?
That is due to the effective arm length being longer or shorter than that of the cartridge
(in other words the holes are in the wrong place). It happens, don't worry, even with
£400 worth of cartridge and arm! So you twist the cartridge - you're not after getting
the cartridge parallel with the arm, but parallel with the groove (no it won't unbalance
it!)
After faffing about like this for half an hour or so, you'll have the cartridge perfectly
aligned to the groove, horizontally that is!
The next article in this series will deal with vertical alignment, stylus pressure and
bias (anti-skate).
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Visitors
secondhand vinyl gear, wanted or for sale
A free service to our non-commercial visitors for vinyl related gear only.
Include a brief description and your e-mail address, or phone number.
It's a free service, however, if you have a web-site I'd be grateful for a link - please
paste the following HTML code into your page...
<strong>support the vinyl record - <a
href="http://web.ukonline.co.uk/sleeprojects/phono_preamplifiers.htm">click
here...</a></strong>
I have a Decca Deram Transcription Pick-up, unused, in original box,
which I
would like to dispose of.
Contact: Keith Hewlett keith@island-eng.co.uk
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e-mail: sleeprojects@ukonline.co.uk
tel/fax: 01226 244908
write: Graham Slee Projects, 1 Monks Way, Monk Bretton, Barnsley, S71 2JD |
