I obtained an Aro arm-top with some bits missing, at the Audio Jumble, earlier this year. One of the missing bits was the bias weight.
So now, I have:
An Aro/heavy counterweight/Troika/with Bias.
An Aro/standard counterweight/XX2MkII/without bias.
I weighed the Naim bias weight, and it comes in at around 1.7gm , with a 50mm 0.08 monofilament thread.
If I have time, I'll do some listening later and in the meantime, I've made some enquiries to J7 @Origami about getting a new one made and he says he can make an exact copy of the original for me.
There was a topic one here back in 2008 about the same subject, where I referred to a reference in a HiFi Critic cartridge review, in which Martin Colloms said that some cartridges seem not to require bias when mounted in the Aro. I further found (back in 2008), that some Naim staff, were also using the Aro without bias. TBH, I can't honestly say I've done comprehensive comparisons between with and without bias. The view at the time seemed to be pro-bias.
Aro Bias Weight
Posted by: Deeply on 29 July 2018
I’ve had my Aro for eleven years and my LP 12 has been looked after by Derek Jenkins of Tangerine Audio. In that time have used 3 MC cartridges Dynavector 20 LX, Micro Benz Wood SL and now Kiseki Blue NS he has always used the bias weight.
Regards,
Martin
It’s easy enough to swap the weight when you swap arm tops, you should be able to hear what the optimum bias is, try some solo piano for this. With a both a 17D3 and a T proteus it was second from the outside but I did adjust the hanger so that might not hold.
Yes, but I have the two Aro's on two different turntables (because I already had a spare arm-base), so I don't really want the hassle of swapping the threads over TBH. I'll get the new one made & at some point I'll do the comparison; I was hoping that it would be today, but not looking likely now with the wife having her feet up watching telly!