2. analog
  3. 1143476561

What cartridge to use....Rega RB25 Structural Mod

I have a Rega RB250 with the JA Michell structural mod and Incognito rewire mounted on an Acoustic Signature Final Tool. I am currently using a Koetsu Red with very good results. I am looking for something better. Aren't we all?? As you may or may not know, the Michell mod allows use of just about any cartridge made. There are 2 different counterweights. One for cartridges with a weight of 3 to 6 grams and another for cartridges with weights from 6-13 grams. The RB250 has an effective mass of 11 grams. So, with this in mind, what do you think. I am trying to stay within the $1,000.00 range, new or used. I have some cartridges in mind. The Dynavector DRT XV-1, XX-1, XX-2, ZYX Fuji R100 FS, Benz Micro LO.4, Lyra Helikon and the Ortofon Jubilee are some of the choices thus far. I have not listened to any of the above cartridges. I am going on reviews from this site and some of the professional reviews I have read. Please let me know if you've had any experience with similar setups or if you have any recommendations/suggestions regarding other cartridges I haven't mentioned. Also, I need to purchase a cartridge alignment tool. Any suggestions on tools under $50.00 would be great!!

Thank You
Jeff
128x128jfrizzell49
pauly
1,012 posts
 
“All unipivot arms are pushed to their limits of stability with low compliance cartridges”

Rubbish. That sweeping statement is simply not true. I have never ever had any stability issues with any properly set up unipivot in more than a decade that I have used unipvots.

“I wouln't recommend the use of something like a Koetsu, DL103R, or Shelter in most unipivot arms(although there are a few exceptions), especially any light weight unipivot arms.”

Since the carts you mention are low compliance carts, it would be rather dumb to use them on a lightweight arm, unipivot or not.

I have used all the carts you mention (Koetsu Rosewood, Shelter 501 and DL103) on a Morch UP4 (blue dot arm wand – 14 grams) and 12 inch Scheu Classic II (also 14 grams) with great results. I tried the same carts (on same table) on a modified R250 and it compared badly to the Morch and Scheu.

“Matching is critical, and proper matching goes beyond simple mass/resonance calcs.”

It goes way beyond that and includes the choice of turntable and the stand/isolation employed..

And again I feel the need to emphasize that I have no motive to prefer one arm over another other than for purposes of sound quality. I do not sell arms (or promote tweaks) for any audio equipment.

Regards
Paul
stefanl
296 posts
 
I am not suprised that you preferred the Moerch and Scheu over just a rewired RB 250 because you have to do more than just a rewire.The smearing is there very noticeably until you also add a metal stub and then use TWL's amazing Tracking Weight Tweak.The control in the RB 250 then becomes feather-touch.A form of VTA adjustment is also required and then all your attention must be given to adjusting the base-nut to EXACTLY the right tension(Usually Finger-Tight with just a Nip).This is critical and quite labourious at first but the Rega literally "sings" when it comes together.Anything from cartridges as different as the old Linn Asak(MC)(Supex 1000) to the Ortofon VMS 20E Mk11(M.Iron)for example,sound great.The smeared darkness and murkiness that people notice with a Rega disappears,it is an extremely sensitive and balanced arm in reality.I guess as I don't have the urge to change now,it's doing something o.k.
pauly
1,012 posts
 
“I am not su[r]prised that you preferred the Moerch and Scheu over just a rewired RB 250 because you have to do more than just a rewire”

Sigh ...

I used a number of stubs different stubs – brass stub & weight (from Brit Audio) a Michell stub & weight and a custom-made brass counter weight. They did improve the sound (especially on the 250’s) but did not bring it even close to the sound of a top-flight arm. In fact I would say the structural mod seems to be a bigger improvement that the rewire itself

I also tried it with spacers, Easy Rizer VTA, Pete Riggle VTA on the fly and the VPI VTA adjuster. The best sounding to my ear was with using the VPI adjuster, but again it was very disappointing compared to Morch.

The modified RB250/300 was on par with the RB600 I tried. Your posting indicating the level of quality (or should I say lack there of) pertaining to the bearings, fall in with my observations.

“A form of VTA adjustment is also required and then all your attention must be given to adjusting the base-nut to EXACTLY the right tension(Usually Finger-Tight with just a Nip).This is critical and quite labourious at first but the Rega literally "sings" when it comes together”

If you are eluding the poor performance is due to bad setup you are sorely mistaken. And no, the Rega only sings when you are not used to anything better – and there are many better arms out there.

Don't get me wrong, I think and RB250 is good value for money. If you happen like it, that is cool. Hifi is about enjoying what you listen to, no?

Ultimately though, you get what you pay for. Running a Koetsu on a RB is casting pearls to the swine.

Regards
Paul
stefanl
296 posts
 
"....I auditioned a Rega RB-300 vs SME V on a special Michell Gyrodec table that could accomadate two arms. Both had Koetsu Blacks mounted. We heard very little if any difference between the two arms/cartridges. The owner of this system then decided to sell the SME V and keep the Rega. Rest of system was ARC SP-9, Quad amp and Magnapan MG-III speakers." This is a post from Vinyl Asylum that seems to contradict the proposition that Rega's perform poorly with Koetsu cartridge's.Also did you actually try adjusting the Base-Nut of the Rega Arms you listened to,to the required tension?I know what an audible difference it does make,so as to eluding to what I hear as just being sorely mistaken,leads me to think that you did not explore the adjustments at this level.I think you have misconstrued what I intimated about the importance of the Rega bearings.This is my last post on this.We agree to disagree.
twl
3,251 posts
 
I seem to have become a bit sensitive to Pauly's condescending attitude towards the other members here, when clearly we are not the only ones with something to learn.

As such, I'll bow out of the conversation also, in deference to the "undisputed master" of tonearm design and cartridge matching.
More to discover