Rega P25 Setup Question


Hi,

I feel kinda stupid asking this, but here goes:

I just got a rega p25. It has an expressimo counterweight on it. My old technics table had both a weight adjustment and an 'anti-skating' adjustment. The manual says there are adjustments for both of these on the rega as well, but I only see the one dial on the tonearm.

When I put the counter weight all the way forward, towards the tonearm base, and install my cartridge, the tonearm balances when I set the dial to 1. My cartridge recommends 1.8-2.2 grams of weight, so I put the dial at 3, just after where a big dot is on the dial.

My question is: Is this setup "correct" ... I'd expected an anti-skate control, but is this all built in to the one dial, or am I missing something? Is the dial for just the weight, or both ?

Any knowledge or suggestions much appreciated.
mrgoby
The dial is for anti-skate. You need an external tracking force gauge to set the VTF.
I'm pretty sure the dial on the side of the arm is for tracking force and the "slide" on the base of the arm is for anti-skate. That's the way mine is setup.

It is REALLY preferred that you don't use the spring loaded VTF dial at all. Leave it a ZERO and get a tracking force gauge to set the cartridge at the desired 2.2 grams by sliding the counterweight forward and/or back to achieve this. Your cartridge might be to light to accomplish this without using the VTF dial though. You could add an extra weight at the cartridge end.
Here is an excerpt from the manual:

Cartridge tracking force adjustment

1. Ensure that the tracking force adjustment knob is set to the zero position.

2. With the cartridge permanently fitted in the correct position adjust the main balance
weight so that the arm is “floating” with the stylus just 1mm clear of a record.
(This adjustment should be made with the anti-skating knob to zero. Note: Even
at zero there will be some small residual anti-skating force. Therefore it may also
be necessary to gently touch the arm bearing carrier to stop the arm moving outwards).

3. Rotate the tracking force adjustment knob to the required tracking force. If in
doubt it is usually advisable to use a tracking force that corresponds with the
upper limits of the cartridge manufacturer’s range.

Anti - Skating (bias) adjustment

Set the bias adjustment knob to the same number as the tracking force. Note:
This is not critical and a figure of 1-1.5g will normally be suitable for moving magnet
cartridges and 1.5-2g for most moving coil cartridges.
Okay, I'm getting confused now. My understanding was vertical tracking force was equal to weight... I thought anti-skating was a horizontal (or diagonal ?) force applied by a spring.

Section 3 in the manual mentions the "tracking force adjustment knob", then the Anti-Skating (bias) adjustment knob... and that I should set it to the same number as the "Tracking Force"... this leads me to believe there are two knobs that should be set to the same value... such as a "VTF" adjuster and a Bias, or antiskate adjuster... I see now that these are the same knob, or at least that there is only one, anti-skate knob on the turntable.

My problem I think, as far as getting even more confused, as Mofimadness points out, was that the heavy weight from expressimo is too heavy and putting it all the way forward was still not enough to balance my cartridge weight. I've put the stock rega weight on and it does in fact balance now and I have some room to move forward still... So, I'll get a scale and measure the 2.2g.

Does this sound reasonable ?

Thanks :)
Mrgoby, yes use the stock weight for now. The anti skate adjuster in NOT a knob, but a small silver "slider" that sits right under the arm on the black base. If the arm is in the arm rest, it's right underneath the arm just to the left of the cueing lift. It sildes from front to back and has markings 0, 1 ,2. Do you see it?
Okay, I'm starting to see clearly now. Thankyou Mofimadness, for I now see this anti-skating slider and all is made clear.

Just to get this straight, the knob/dial on the side of the tonearm is for VTF, though, correct ? So basically the way I had it setup wouldn't have damaged my cartridge, due to lots of anti-skate force being applied ?

Out of curiousity, why is it recommended not to use the spring loaded VTF, for better sound, or to prevent stylus damage, or both ?

I know the expressimo is supposed to cut down on gyroscopic resonance, or some such thing. Would it be worth it to add more weight to the stylus end and use the expressimo, or is there any disadvantage to doing such a thing ?

Thanks a lot for the help.
The whole idea with any tonearm and it's counterweight is to keep the weight as close to the pivot point as possible. With the way Rega uses their VTF dial, it adds a spring to the mix and makes you use the weight further back on the shaft, away from the pivot point. There are many people who actually take the spring out as a mod to the arm. They say it improves the sound. I have never done this, but trust the ears of several who have.

The way you initally had it would have worked, but it's kinda hard to tell how much VTF you had because you ran out of room on the VTF dial.

The aftermarket weights, like your Expressimo, not only add more mass, but drop the center of gravity below the shaft even more than the stock units. That's why it's shaped like a tear drop. These weights REALLY do work and sound better. I sure would try to find a headshell weight for your cartridge, (or change carts) to utilize the Expressimo.

You are correct in that the dial on the side of the arm is for VTF and slider is for anti skate.
You're welcome. My pleasure!

Here's a link for a 3 gram headshell weight:

http://www.lpgear.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=LG&Product_Code=STDHDSHWT&Category_Code=HEADSHELLS
I advise not using the VTF on the arm. Better to disengage the spring by having the setting close to 0 and setting VTF with an external gauge. I found, over the years, this reduces any ringing caused by the spring. I had actually forgotten the 300 came with VTF because I never used it.
But to reiterate an earlier point, please use a VTF gauge when setting the Vertical Tracking Force appropriate for your cartridge. DO NOT I REPEAT DO NOT RELY on the numbers on the REGA counterweight dial!

A good inexpensive gauge is made by Shure and can be purchased online.
To eliminate the effect of the spring you have to turn the dial up past 3 not down to 0. Crank it up past 3 and use the weight to set the VTF!!!