RB300, anti skate setup and left/right Bias

NeilP

A few paragraphs first explaining ..then i'll let you know what my actual question is......


This 'problem'  is an annoyance I have ALWAYS had with my one and only 'audiophile' turntable...and I have had it a couple of years...errrr.since 1987 when I bought it and my Claymore Inca Tech from Rayleigh HiFi in Chelmsford.

Planar 3 with RB300 .  a few months ago i gave it a new Rega Exact cartridge,   I have since had Col re vamp my Claymore.


Since new it always bugged me a bit that I thought that there was a left / right channel volume out of balance issue.  It always sounded to loud.....err RHS I think.


Have Sure stylus weight gauge, and it is set to 1.75g,  Standard RB300 counterweight...but set right up close to the pivot and the remaining weigh tdialed in correctly with the 'spring dial ' adjuster on the RB300.
TT levelled at the platter


Now the anti skate force...is the issue ..supposed to set it to the same weight as the tracking force..so 1.75 g as well..gice or take 'listening test'.



Now to the question.

Recently I read that if you put the stylus down on a blank piece of vinyl..or the glass platter, when it is correctly set up..it should track slightly towards the centre of the platter...maybe taken about one second to track from outer edge to the centre, on blank vinyl with no grooves

Is the correct??


If it is..then maybe I have had a faulty RB300 arm since new and this is the cause of the left right imbalance .


With my RB300, the arm always pulls to the outside, even with tracking force set to Zero.  I have religiously set it to 1.75 on the little slider and always had a channel imbalance.

This imbalance has only been annoying me again because I started ripping vinyl to the computer..and always have 2-3db imbalance in channel levels

cj66

Hi Neil,

First and foremost the bias calibration markings on most tonearms are rather inaccurate and this is particularly so on the Regas.
I've always set the bias to roughly half that of the tracking force and tweaked from there. The easiest test for checking if your bias is in the right ball park is to let the hydraulic lowering device handle cueing the cartridge at the outer, middle and inner portions of a not so treasured LP. If the arm "wanders" off course during lowering your bias is wrong, adjust until this is cured.
The most important factor is to make sure your cartridge alignment is spot on. A minimum of a two point protracter is essential for this.
Once done your channel imbalance should be rectified.(unless you really are unlucky enough to have a faulty arm)

NeilP

Well regarding cartridge alignment, it is a Rega cart, on Rega arm, and has the theee point mounting, so not a massive amount of adjustment available.

Also due the shape of the Rega Cartridges, alignment is near enough impossible, as they are thin narrow units at the bit you can see, 

interesting what you say about watching to see what the stylus does on lowering.  
There seems to be a lot of mid information about this.  One article I read, thought the bias should allow /cause it to run inwards slightly, some say it should not move, yet mine, even with bias set to zero, pulls the arm outwards.

still confused 

i even phoned up Rayleigh HiFi today, and they did not really know either

Docfoster

Didn’t Guantánamo Bay replace water boarding with cartridge setting-up as it’s primary method of breaking detainees...?
Horrific experience.

NeilP

Think you are correct with that

Docfoster

NeilP said:

Think you are correct with that

Yes.
Seriously, I do empathise.
Although my personality probably makes me especially vulnerable to the frustrations involved in setting up a cart’. And I did feel liberated when I removed the turn table from my main system.
But I don’t want to be unduly gloomy. Do keep things in perspective. All the best with it!

uglymusic

Neil. I think you're doing the right thing. Get those plastic fruit bowls digitised quick and forget about the black arts of cartridge and tonearm adjustment.

But, then, I'm biased   

cj66

NeilP said:

Well regarding cartridge alignment, it is a Rega cart, on Rega arm, and has the theee point mounting, so not a massive amount of adjustment available.

>Enough to get it very wrong (20 degrees or so of possible mistracking)

Also due the shape of the Rega Cartridges, alignment is near enough impossible, as they are thin narrow units at the bit you can see,

>Almost but still have to get it right, even rounded cartridges must be correctly aligned.

interesting what you say about watching to see what the stylus does on lowering.  
There seems to be a lot of mid information about this.  One article I read, thought the bias should allow /cause it to run inwards slightly, some say it should not move, yet mine, even with bias set to zero, pulls the arm outwards.

still confused

>The bias is only enough to compensate for the opposite force created by tracking the groove of the LP, it does not need to have pin ball flipper force

This is possibly a dying black art amongst dealers thst have "moved on".

Signed.

Ex chief Waterboarder at a secret Surrey location.

P.S. Cartridge alignment is less taxing than doing this quote/post on a phone!!!

Docfoster

cj66 said:
P.S. Cartridge alignment is less taxing than doing this quote/post on a phone!!!

Yes. You really shouldn’t be even attempting that.
It’s explicitly forbidden by the UN’s declaration on human rights.