Vinyl Newbie - Sound quality deteriorates as you get closer to the center

[admin_exported]

Hi Folks,

I've always liked vinyl and recently got my first record player and really know nothing about it. I'm fairly technical minded though.

Anyway it is a soundlab DJ deck and i have hocked it up to my stereo amp.

What i have found is that on the first couple of tracks on a 12" the sound quality is excelent and prefer it to any CD however as it closer to the centre of my 12s or on any 7 the sound quality seems to be poor.

Can anyone advise what this could be. I don't know much about carts or needles and no idea what is on it or the condition.

Thanks

Colin

 

[pwiles1968]

I'm a newbie myself to TT's so I may be barking up the wrong tree but a thought that springs to mind is head alinement's have you checked this.

 

[gpi]

Basically, the cartridge (or more specifically the cantilever) isn't lined up with the records' grooves accurately. Go to the following url and download the 'Stupid Protractors'. Print off the Baerwald protractor, place it over the spindle and use the grids to align the cartridge in the headshell. Simply keeping it square with the headshell and moving it backwards and forwards until it's aligned is sufficient, It's not usual to have to introduce a twist to the cart but this may be necessary is you can't achive accurate alignment when it's square.

http://www.vinylengine.com/cartridge-alignment-protractors.shtml

You also need to set the anti-skate to just below or the same as the tracking weight of the arm.

 

[fatboyslimfast]

I hate to say this, but the Soundlab decks have short DJ arms - these are useful for DJs as they offer more stability, but for hifi...sorry. Tracking errors all over the place.

Also, the tracking weight at which these arms and DJ cartridges track at will damage your records a lot faster than an equivalent hifi deck.

If you are serious about listening to your vinyl, pick up an old Pioneer PL-12 or a Dual 505 - £20 should do it. Either of these will be far better suited to the job...

 

[Henley]

It's due to the stylus not being at the correct angle to the record groove.

Records are cut using a linear tone arm where the cutter head is always at 90 degrees to the record wall. Unfortunately making a good linear tracking turntable is extreemly expensive so, many manufacturers choose to produce turntables with arms that pivot at an offset point. Thus, at the outside of the record the stylus to record angle is near perfect (the longer the arm the better the angle) but at the center of the record it is impossible to get this angle correct so you will experience more distortion (lower quality. Using a protractor will help to get the angle as close to perfect as possible but you may always notice this deterioration in sound. Unfortunately (as stated previously) your turntable has a very short arm so this issue will be exaggerated.I once saw a design of an arm where the headshell was on a pivot and the angle changed in relation to the position of the record. A genius idea but very impractical to produce for the mass-mid market.

 

[fatboyslimfast]

That would be the Garrard Zero-100. Great idea, but flawed implementation.

 

[Anonymous]

knew i should have bought that sl10 when i had the chance

 

[Anonymous]

THANK YOU GUYS, i will try what you've suggested.

I got the soundlab free from an old DJ friend and as i had no vinyl
wasn't sure how much i'd use it. I've not bought quite a bit now and
was thinking of a new deck anyway so your info has convinced me to go
ahead and get one.

Was thinking of a Project Genie Mk2 or 3 - what's your thoughs on this for me?

Also i have no idea what Anti-Skate is, can someone explain, i looked it up on google but just got a whole load of skateboard stuff. I know how to adjust it, just not why lol

 

[fatboyslimfast]

Anti-skate: Basically, when the stylus is in the groove, the rotational movement of the record exerts a force, which drags the stylus towards the centre of the record.

Anti-skate balances this force, meaning that the stylus exerts equal pressure on the left and right walls of the groove.

 

[Anonymous]

Although this is a video review of the Audio Technica AT440mla cartridge he does provide a good explanation of inner groove distortion etc here

 

[pwiles1968]

Colin_S:
Was thinking of a Project Genie Mk2 or 3 - what's your thoughs on this for me?

I have a Genie Mk3 a Nice intro in to TT's, and they look cool.

 

[Anonymous]

No-one's mentioned that on a 33RPM 12 inch record, the stylus is covering 20 inches of groove per second at the outside of the record and 7 inches per second at the centre. There is therefore going to be less resolution available towards the centre. I'd expect alignment issues to make matters worse, but would this reduction in data rate (albeit analogue) possibly cause problems to fidelity?

 

[Henley]

fatboyslimfast:That would be the Garrard Zero-100. Great idea, but flawed implementation.

Nope; far more ingenious but definitely not from Garrard. This one had 2 carbon fibre tone arm sections that were pivoted at each end. Can't say too much as we are still hoping that we can get it into production, one day 🙂

 

[gpi]

Will Harris:No-one's mentioned that on a 33RPM 12 inch record, the stylus is covering 20 inches of groove per second at the outside of the record and 7 inches per second at the centre. There is therefore going to be less resolution available towards the centre. I'd expect alignment issues to make matters worse, but would this reduction in data rate (albeit analogue) possibly cause problems to fidelity?

Don't confuse the poor lad even more, he's a vinyl virgin. ;o)