Historic TT Project

[Dr Bunsen Honeydew]

"In the standard die casting process the final casting will have a small amount of porosity. This prevents any heat treating or welding, because the heat causes the gas in the pores to expand, which causes micro-cracks inside the part and exfoliation of the surface. Thus a related disadvantage of die casting is that it is only for parts in which softness is acceptable. Parts needing hardening (through hardening or case hardening) and tempering are not cast in dies."

[Classicrock]

Sorry Doc I'm with DSJR on Rega. Horses for courses but they work well on NAS and Mitchell and so does SME on the later. Of course they aren't perfect but at it's original price point the Rega 350/300 was a bargain for the sound produced (on the right deck - but probably not Rega's own which i never have liked much). Whatever your views on the cast tube and possible variations if even significant at this price point the main cause of the sterile /grey sound is the counterweight. Origin live founded a whole business on this but it worked though pretty crudely finished and overpriced.

The latest Rega cast arms are different I believe probably due to original casting wearing out necessitating a revised design (but it lasted 25 years). Since the casting is new I would expect current arms to be more consistent. Also the pricier versions of Rega arms are priced too close or above better designs. The decks you favour don't appear to like the more rigid arm designs. Would agree the PL71 arm and similar are likely at least as good as RB300 so no point in changing - different for SL1200 and current crop of chinese sourced clones - really crap arms on those Hanpin things made for major Jap brands.

[Dr Bunsen Honeydew]

You miss the point I think. The arm is worse than the original Japanese one, and it was bullshitted onto the market per usual. I can assure you die cast tooling does not last that long and the die would have been replaced many times in that time. AND if you took an example from the early life of the die to later life the differences would be obvious.

OK a little reality. The metal after it has been injection molded or die cast is in a partial foam state, so there are little holes unpredictably placed throughout the casting, they interfere with the transmission of mechanical energy up the arm tube and are a major other cause of the inconsistency. It is bad engineering for a tonearm, but per usual marketing has made assets out of deficiencies.

The other thing I can assure you of is that if it had been a good idea back then the Japanese and now the Chinese would have done the same thing a bloody sight cheaper. Tone arms need to be *machined* from solid.

[Classicrock]

That's interesting but is the interference caused by 'bubbles' significantly different sound wise between concurrent samples. Has anyone investigated this? If the differences are inaudible Rega can easily get away with it. Also in theory the new designs were a better match for MC than the R200 (Acos Lustre). So a fairly cheap arm that suited MC was attractive (though Rega only made MM cartridges until recently and before them the rather nice Supex? derived model.) Now would the Acos lustre derived model sound better than an RB300 on Michell or NA decks? (Anyone made this comparison?). Which one works best could be deck dependent whatever the design flaws.

[Dr Bunsen Honeydew]

"Also in theory the new designs were a better match for MC than the R200 (Acos Lustre)"

Firstly it was not an Acos Lustre, that is a hi-fi myth that has built up for some reason. The arm was made with small variants for Pioneer (and others) in Japan and Rega ordered them OEM with the basic unselected bearing (but still very good) (Pioneer had selected ones in the PL71) and a notched rubber drive belt for the bias as opposed to a spring as in other variants. My version on the PL71 tracks a Ortofon SPU Gold perfectly and copes with the energy transmission perfectly. The RB300 with a SPU in it would be a bloody mess. I have also received a PL71 from the USA so damaged in transit that I put the Rega R200 on as replacement and it also had no trouble with the SPU.

You are just repeating marketing nonsense put out by Rega to justify the change - it is bullshit!!

ACOS LUSTRE



REGA R200



The differences should be obvious, but they do share parts as all Jap arms do.

This is PL71 and as can be clearly seen is virtually identical to the Rega R200

[alfafan123]

As an ex "Rega Dude" and having owned many Rega decks I never warmed to the RB series arms finding them as described by others in previous posts. I also found the bearings to be variable in quality. However to my surprise the RB101 (which is not a die cast) arm on my RP1 sounded much better IMHO and happily tracked a Dynavector 10x5... not my favourite cartridge but arguably a step up/above from the 'umble RP1.I am told the RB101 uses an extruded arm tube. If so it would seem to support the Doc's analysis about die cast arms although of course there are many other variables.

[Sandman]

"Also in theory the new designs were a better match for MC than the R200 (Acos Lustre)"

Firstly it was not an Acos Lustre, that is a hi-fi myth that has built up for some reason.

Can't see why that myth exists, Acos certainly had a hand in the Rega arm as an OEM, but the Lustre is way more engineered and thought out product, but apart from being S shaped and similar OEM headshell / bias dial etc there's not much in common as far as I can see, and having had an original Planar 3, and later Planar 2 they are chalk and cheese. The Acos on my Lenco produces a great result and I'm afraid Jammy for me the 1210 is now in a box under the stairs, as a reserve, if we are talking idler vs DD...but what suits one man not suit another....

[Dr Bunsen Honeydew]

Well I hope you are right when my G99 gets back on the road. I would be happy if it is better than the PL71. Though I have to say the 401 was a bit of a disappointment, a curates egg, being very good in parts.

[Alfi]

Well I reckon it'll be better than the 401 Doc, those Goldring's/Lenco's are very underrated TT's especially when plinthed properly.

Alfi

[Dr Bunsen Honeydew]

Did you try my idea about increasing sub chassis weight.