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
Hi Jeff

Just remember to tighten your arm by a single "NIP" - no less no more ok? ;-)

Regards
Paul

Ps. If you are interested in the zyx, have a look at http://www.high-endaudio.com/RC-Cartridges.html. Arthur S makes some interesting comments which you may find of interest
Well. I seemed to have started WW3 with this topic. Thanks for the fight!! I went out and bought the bullet weights to try TWL's mod. It works just as he said it would. Truly amazing!! I don't think the Rega bearings are so bad. Never did. Then again, like previously stated, I would have to compare it to other arms. The reason I have not is 1) budget and 2) because with the Acoustic Signature Final Tool, the arm mount needs to be changed(around $100.00-$150.00 per arm mount if it's not a Rega style mount) which again is budget related. The Koetsu mates well with the Rega in my system so it stays. I was thinking of trying a ZYX Fuji. Any thoughts?? TWL, what is your counterweight mod all about?
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.
"....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.
“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
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.
“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
I really think that all this discussion about arms needs to be related to the cartridge/cartridges that are to be used with these arms.

Not every tonearm is correct for every cartridge.
To discuss arms without cartridges in mind is quite "out of context" in my opinion.

Regarding the cartridge originally mentioned in the thread topic, 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.

All unipivot arms are pushed to their limits of stability with low compliance cartridges, and even the actions of the tonearm designers themselves, such as Graham, and Weisfield, and others, have incorporated "outriggers" or other types of stabilizers to help their unipivot arms deal with the lower compliance cartridges.

Matching is critical, and proper matching goes beyond simple mass/resonance calcs.
Yes,Poaul Ladegaard in his paper on mechanical resonances in turntables established that lightweight arms are really the best performers overall.I think he used a Danish Moerch arm as one of the arms in the experiment actually.This was cognizant also on the best arm /cartridge match in terms of cartridge resonance and system matching.If you can find a good used UP-4 I would probably try it myself.I don't think Garth is misleading though and I am aware there are better arms out there.Take Mark Baker's development of the basic Rega into the Encounter arm for example.You can see what could be done to it.
Whoh! Are you folks getting a little out of control? An Origin Live modified RB300 with Cardas wiring is hard to beat for the price. It beats performance on a lot of arms costing up to 3 times more if one has the correct set up with matching cart. I beg to differ with some of the negative comments above from the experience I have had.

I now use an Origin Live Incognito, Shelter 90x cart, SOTA vacuum table. But the Modified RB300 with 901 cart performed quite good for me on my system. It had new Cardas internal wiring with 5 pin DIN termination. I have read where the modified RB250 actually outperforms the modified RB300 (Thorsten Loesch/TNT-Audio, 1999 @ www.tnt-audio.com ).

I do believe the Benz would be too warm for the arm Jeff now owns.
Stefan

I know who Garth is. Garth sells Rega/OEM arms. He has a lot of experience but nobody lies more than a salesman. I believe that in the industry, lying to the public is known as marketing, no?

My setup is very good and more than adequate to come to an objective conclusion as to which arm is better. (I can send a photos and description off line if you want – email me) Also, I have no reason to like or dislike Rega arms. I am only interested in having good sound – I do not have to sell anything to anybody.

My RB's (I had 3) were all modified with Incognito(2) and Discovery. I loved them till I mounted my Morch – the difference was nothing other than dramatic. Even some arms that are less expensive than a modified RB (Scheu Classic/Bel Canto Unipivot and Graham Robin) are significantly better. Yes, I tried them both and now own a Scheu also. At one time I had two Morch's mounted on my table.

A good friend who is a Rega fan lent me his RB600 to compare against my Morch. It was a joke – the RB was blown out of the water. He now is running a Morch UP4 also.

I think Jeff would be well advised to consider upgrading to an arm like a Morch UP or Hadcock and keeping his Koetsu Red.

Regards
Paul
I am not the owner of all those arms,they probably belonged to a whole lot of people.I was actually quoting from Garth's experience with Rega arms who makes the Incognito Rewire Modification,which no doubt you are familiar with.He also states "I doubt a Rega arm would barely move with an ABEC 7P bearing which has a radial play of .0001 to .00015. I rebuilt a RB250 with ABEC 5P bearings and it was tight, very tight....I would say that the quality of tonearm assembly is of even more key importance than the type or tolerance of the bearings used."That is from someone with a lot of experience adjusting and tweaking Rega Arms and their bearings.I might suggest that you heard the Rega arm in less than ideal conditions and I would say that they are much better if tweaked from the "stock" form they are set-up on a Rega table.You would hear "smearing" in spades I am sure.I have seen the official Rega Fixture for the bearing nut and it is totally wrong.Roy Gandy probably has no right to sell his tables set-up in this way.That being said something like the Origin Live silver shows how good this arm can be,very close to a Triplanar 7 as Doug Deacon has stated on this forum.
"no less a critic than Art Dudley in Stereophile has stated that they [RB 250/300] are extremely good value for the money"

Yes, I agree. That is what I said in my post no? In fact, they are probably the best value for money arms out there. They are however, not very good. (In the same way $200 is a lot less than $3000)

"they all fell into the range of 1P-3P"

Agreed. 1P is the very worst ABEC grade and 3P is the second worst grade. 1P and 3P are not sufficient to reproduce music with any level of accuracy. All you will get is a blunted and smeared mess; which is what the RB250/300 deliver in spades.

BTW - I have not heard the RB1000, but have heard the 600 and 700. I heard the same bluntness and smearing from both. So I have no problem with your statement that 250/300 bearing spec the same as the so called ‘better’ models in the RB range.

"is a tolerance you cannot feel"

Agreed, you cannot feel it but you can most certainly hear it. Personally I listen to music – touching my tone arm does very little for me.

"I have had literally hundreds of Rega arms (of all models) in my hands and have never had a single one with excessive play."

That is a lot of arms to have owned (you must be very wealthy), but since they spec at 1P to 3P they all have excessive play. Your inability to discern that is hardly contrary to the fact.

Regards
Paul
"Clearly idler wheels suffer from so much noise contamination that the subtleties in the music are lost, and quality cartridges and arms are a waste of time (and money)." I believe that Mr.Sugano first developed the Koetsu on a Garrard Idler Wheel Drive Turntable so he must have thought they were o.k.As regards the Rega bearings,no less a critic than Art Dudley in Stereophile has stated that they are extremely good value for the money.Here is further experience with Rega "I removed the common bearing types from a RB250, 300 and RB1000, the vertical shaft bearing are all the same size. I sent them to a precision bearing distributor and they reported they could not measure or by inspection tell any difference in grade, they all fell into the range of 1P-3P(ABEC Grade), there is some overlap." They are quite adequate and further "Two to four ten thousandths(of an inch)(ABEC Grades Referred to) is a tolerance you cannot feel. Not only that due to the arrangement of the bearings they actually reduce the radial play.
I have had literally hundreds of Rega arms (of all models) in my hands and have never had a single one with excessive play.
Oh bother …

The DL103 is a fine cart for the price – I use one to listen to my old (read very worn) jazz LP’s. However, compared to a Koetsu Red, it can only be described as vulgar, edgy with an exaggerated top end. I have not heard the Shelter 901, but the having lived with both a 501 and DL103 for a while, you would have to be quite deaf not to recognize the 501 as being the more musical of the two.

I am not going to make a comment about your choice of tables other than to say if you used a half decent turntable for your comparisons, you would recognize the shortcoming of the DL103 and RB250/300 in a heartbeat.

Clearly idler wheels suffer from so much noise contamination that the subtleties in the music are lost, and quality cartridges and arms are a waste of time (and money).

Regards
Paul

Ps. As a DIYer myself, I applaud other folks who take the time and effort in this hobby to roll their own. That includes people who resurrect old tables. However, one should avoid the trap of evaluating your own handiwork with those rose tinted glasses.
I have owned the Origion Live Silver arm, and sold it a month ago. I replaced it with a rewired RB300 with the Michell technoweight. With my Denon DL103r, after my OL Silver, the RB300 was horribly microphonic and a great disappointment. Then I did Twl's hifi mod for $3 using bluetack, and suddenly I had my OL Silver's sound back. If you dont do Twl's mod and prefer to spend another $1000 on an arm, that's your choice... Also, do as I will shortly, and change the technoweight for Twl's counterweight mod. I shall almost certainly be selling my techoweight on Epay soon...

On the subject of cartidges, for $160 try the Denon DL103. Some here have prefered it to the Shelter 901. None of this will trully come alive without idler-wheel technology on your deck, or tens of thousands of dollars on belt drive, I think. My God I've become another one of those "I have superior knowledge" Audioholics!!! Still at least "my way" is cheap!
Look into one of the OriginLive arms and then later a Shelter 901 cart. This would be fabulous combo. You'll at least find interesting and informative reading if you do nothing else.
I agree (sort of) with TWL – keep the cart and upgrade the arm. If you do have some money to invest, get a better arm and you will be shocked to see how much the Red can deliver.

IMHO you are already running into diminishing marginal returns by trying to upgrade from Koetsu Red on your RB250. The RB250 bearings are not up to scratch to extract the most out of said cart, even less so from a better cart.

(I am being kind by saying the RB250 bearings not being up to scratch – the bearings are total shyte)

Regards
Paul
I have the Gyrodeck with the modified RB 250 Technoarm. I have had excellent results using a Van Den Hul Frog with this set up. You can find this cartridge used with in your budget. I use Wally alignment tools for set up.
I'd recommend adding a "TWL mod" to your 250, at the expense of sounding like I'm beating my own drum.

Please check out the "Strange Tonearm Tweak" thread, here in the Analog forum.
Many have found this to be a very solid improvement, particularly with the lower compliance cartridges, such as your Koetsu. In fact, it would be perfect for matching your Koetsu to that arm.

Note that I no longer sell this mod, and it is easy to DIY for about a couple of dollars.

You can make it removable if you want(by using Blu-Tack as the adhesive), so you can do a "before and after" comparison, and remove it if you don't like it.

If you don't think it is a dramatic improvement, I would be quite surprised, as many others have called it "the best mod for the money, ever".
It wouldn't surprise me to find that it makes more improvement than all your previous mods.
It has found many happy users, all over the world, and on this site, and on AA.

Maybe when you start hearing more of what your Koetsu can do, you might not want to change it. And that could save you bags of money.