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TWL mod for Rega RB600 arm---help needed

I just got finished reading the years-old discussion thread concerning the fishing weight modification for OL and Rega arms for use with low-compliance cartridges, and I really want to do this but I'm at a loss as to how to go about it. I recently mounted a Denon 103r on my Rega RB600/Rega P25, so I have the perfect set-up that would presumably benefit from doing this mod. Today I bought some 1/2 oz. lead bullet fishing weights to try out, hoping I'd be able to simply blu-tack them on to the ends of the bearing housing bolts. This didn't work because the blu-tack isn't strong enough to hold the weights straight out and they gradually just sag downward. I thought about super-gluing them on but there doesn't seem to be enough surface area making contact for that to work. I read in the old discussion thread about guys drilling and reaming these things out so they would pressure fit over the bolts, but I haven't a clue how to go about doing this and don't really have the tools. So, I'm asking for any and all guidance---or, if one of you is able to fashion some weights for me to use, all the better, and I will pay you handsomely for the trouble! Thanks, Will Herrera
will_herrera
8 responses Add your response
jphii
485 posts
 
If you look at my system you will see how I did it. Blu-tack worked for me, but I did Paul's adjustable VTF tweak too.
will_herrera OP
40 posts
 
Hi Joe---thanks for your response---great pic of your TWL mod; I think I may have purchased weights that are less than ideal for my situation, the ones you are using seem to be wider (and shorter) than the ones I got. Mine are 3/8" at the base (practically the same width as the bearing housing bolts themselves), weigh approx. 14 grams each and are more elongated than yours. Can you tell me what kind you got, i.e. how wide are they at the base and how much do they weigh? If I got ones like yours I'm sure the blu-tack would work! By the way, what is that arched wire thingy going from one weight to the other? Thanks, Will
narrod
1,064 posts
 
How do you equalize the weight? How exacting are the weight measurements of fishing weights?

Wendell
dougdeacon
3,338 posts
 
Will,

The weights need to be wider than the nuts, so you can drill them out to a snug-ish fit. The fit doesn't need to be exact. I super glued mine on and they worked great.

The wire thingy is what Joe referred to as "Paul's adjustable VTF tweak", invented by my partner. It's just a paper clip bent to fit into the holes at the end of the weights. Swivelling it forward or aft alters VTF over a range of a few hundredths of a gram. Quick and easy fine tuning of VTF without moving that blasted counteweight.

As to Wendell's question, equalizing the weights isn't critical. Rega doesn't even equalize lateral weight on its own its arms (look at the asymmetrical bearing housings on an RB-300 for example). That said, you could easily equalize the weights during the drilling out.

Highly worthwhile tweak, and TWL's thread gets the credit for re-launching my enthusiasm for vinyl playback. We outgrew (and outspent) our tweaked OL Silver years ago, but we never would have the rig we enjoy today without TWL's enthusiasm and help (though we'd have a lot more money in the bank!).
will_herrera OP
40 posts
 
Thanks for your reply Doug---so *that's* the paperclip VTF tweak, very cool---I guess I would have figured that out if I had read up some more on that tweak, which I have not so far, but apparently there's not much to it! I'll have do that tweak once I get this TWL mod implemented. peace, Will
jphii
485 posts
 
I matched the weights just because I was having fun in the shop that day. I bought one big weight, cut it in half, then drilled it so if fit tight on the bolts. As for not much to it, you're right. But it will shock you what each mod does.

Like Doug said, TWL is responsible for quite a few people getting back in to vinyl. I'm kinda back from a little absence again too. Just got my motor back from Chris a week ago and have been having a grand old time all over again.
will_herrera OP
40 posts
 
I have approx. 6,000 vinyl LPs and have been collecting for years, so having a high quality analog front end has become *very* important to me. I don't even have a digital front end source currently and frankly I don't miss having one, I have enough LPs to last me several lifetimes and I'm always acquiring more! good listening, Will
braab8
56 posts
 
thought I'd chime in here,I went thru the same problem when I implemented the TWL mod (btw where is Thom?) Doug (thanks Doug/Paul) helped me,reccomended I get some Super glue "gel" or the equivalent which should cinch that right up for you.

As regards the drilling if you have a variable speed drill just find a bit that's just smaller than the diameter of the fishing weight and with a pair of vise grips (and an EXTRA pair of hands) slowly drill-out a shallow hole ,be careful so that it's not too deep and then you should be done.

You will be pleasantly surprised with the results.

Jeff
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