analog gurus, please help, cartridge too light?

dear gurus, i recently purchased a rega p25 tt with the rb600 arm. the tt was also purchased with a benz micro mc20e2 cartridge which i understand later is a very light cartridge with a weight of 4 grams total. my problem is that i cannot get the arm to balance even with the counterweight all the way forward and tracking force and the antiskate setting to zero. the arm still goes up quite a bit. should i change to a heavier cartridge? i am hoping not as i already paid for this one with the understanding that this cartridge is compatible with this arm. should i just set the tracking force and antiskate to zero and just use a stylus gauge and set the tracking to 2 grams as recommended? i read somewhere that the rega arm can be set to the max tracking to relieve some spring inside and then adjust the tracking force by the stylus gauge?with my setup right now, is the expressimo heavyweight out of the question? thanks for any comments. yes, i am a newbie. curtis.
While this sounds like a VERY funky situation, you can always add mass if necessary. The key to doing so is to try and keep it as balanced and evenly distributed as possible. I know that Music Direct carries some type of tonearm wrap and there is always "blu-tack" type stuff. Someone that has run into this situation may be able to help you out or pass on some first hand info as to what works best. You might also want to contact Rega and / or Benz and see what they have to say. If you are afraid to tinker with weighting the headshell or arm, you either need a different cartridge or a more versatile arm. Sean
I agree with Sean, this seems wierd, but first make sure the turntable is correctly leveled. Just increasing the tracking force to compensate is not the proper way to address the probem, since the static balance of the tonearm will not be correct. Now that I think about it, check to see if your counterweight is put on facing the right way. Most weights have a bevelled edge on them that faces front, and you could have it on backwards. Also, check that the cartridge is correctly mounted, using an alignment guage. The cartridge may be mounted too far back in the headshell, and if you can move it forward, it may balance. If you have to increase mass, try using tungsten cartridge mounting screws(sorry, don't know where to get them), as this is less likely to affect the sound than tonearm wraps(unless you need a tonearm wrap). Also, there are headshell weight shims that bolt between the cartridge and headshell, and will require a VTA adjustment. If all fails, contact the mfr.
Other than the above, it may have the "wrong" counter balance on the arm.
I'm affraid that Tungsten mounting screws will not help this situation. Even if you will rich the balance you less-likely will be able to set up the tracking force. As far as I konw Rega arms have extra room so you can mount your cartridge at the very edge and still have some holes left behind vacant. So all it takes for you is to mount the bolts and nuts(maybe only temporarily 'till you get something recommended by manufacturer)of an appropriate size and necessary weight before mounting the cartridge.
Why don't you just tape a penny on top of the cartridge?
dear gurus, thanks for the comments so far. i am hesistant to add weight on the tonearm just to get this thing balance. taping a penny to the headshell came to my mind but i was a little apprehensive about stability. i have to admit i bought the table and cartridge from a non-rega dealer and so far he has not been too helpful. the counterweight is in the right direction and it is the lightest counterweight tha rega makes to the best of my knowledge. i guess i need to contact rega-laureman audio to get further directions. i thank all those that replied. does anybody has the email address for: laurerman audio? thanks, curtis.
Technics has a flat weight specifically designed for headshell mounting...
Dear Curtis,
Your cartridge is a poor match for your tonearm. I do not recommend this cartridge as you have a very respectable tonearm and turntable that will not be able to realize its full potential. There is nothing wrong with your choice of cartridge manufacturer.

You already mentioned the problem you are experiencing with setting tracking force because of the weight of this cartridge. Even if you were to apply one of the previously mentioned band-aids it will not solve your problem.

You have a compliance mismatch problem. The compliance of a cartridge is a measure of its reactance or responsiveness to frequency changes. A low compliance cartridge is like a car with a loose suspension. It requires a tonearm with a higher effective mass to control it as it moves along its path.

What you have is a low effective mass tone arm mated to a very low compliance cartridge. This is not good because even if you get the tracking issue resolved with additional weight, the tonearm will not be able to handle resonances created from this cartridge/tonearm combination. If this occurs within the audible frequencies, you may experience problems with the overall sound quality. There is also the risk of groove jumps if the right frequency strikes. In additon, if your rega is a stock model then it will have even more difficulty dealing with resonances created from this combination because of the way the headshell and the counterweight is attached to the armtube.

Tonearms designed with medium to high effective mass are designed to better deal with lower compliance cartridges while low mass tonearms are better suited to high compliance cartridges.

The fact that your cartridge is very light only compounds this problem further. I would have thought that because this cartridge has such low compliance it would have been made heavier. I would suggest that you consider a different cartridge for this tonearm.