Well Tempered/CROFT/Harbeth...London SG or NAGAOKA

This system has performed very nicely with my Charisma Denon 103.... However, I don't want to keep borrowing my Step Up and 0.5 meter Interconnect from my main system. So I'm leaning toward a HO/MM to simplify and get this setup up and running on it's own. The synergy between the London and CROFT phono is well documented... And as many know, they like damped arms, so the SG should perform well with the Amadeus. The London SG retails at around $1,200 US. Enter Nagaoka... I believe the NEW Well Tempered MM is actually a modified Nagaoka, but based on it's price, it may haven begun life as a 150 or 200.  I'd likely go a bit higher up the line to a 300 or 500 series. The London seems like the way to go, but I do have concerns about the whole no Cantilever thing. I guess these are not for the faint of heart, as they say. Then of course, I don't want to sell the Nagaoka short. I like what I've heard about these, and they seem to fall in to the more full bodied, and not Hi-Fi or exaggerated camp. The London, I'm not so sure as they say these are so alive and open sounding. That may not be a bad thing, as long as they are not crude or etched in any way. Thanks in advance!
You may want to check out Raul's very long thread about MM cartridges. He started it 1-15-2008 and it's still pretty active. Raul liked the Nagaoka 50 super. Not sure how the 500 compares to that. 
Nagaoka is one of the biggest cartridge manufacturer, the WT cart is Nagaoka OEM work. Retail is $800, not sure what is special about it, but if the cantilever is not boron and the stylus is not line contact type then it's a rip off. 

For the same money you can find state of the art MM cartridge like Audio-Technica AT-ML170 or some nice Grace (depends on the model). You will find many info about those carts in the recommended thread. Simply ignore the fact that the author of that nice MM thread prefers digital and lomc now (who cares?). 

In my opinion AT-ML170 and for example Grace Level II BR/MR are the best MM ever made. What is important for your arm is the compliance of the cartridge. AT is mid compliance, Grace is high compliance. 

Your Denon is very low compliance, but make sure to convert 100hz (japan standard) compliance to 10hz compliance. 

@fnj04 "When she was good, she was very, very good, but when she was bad, she was horrid." The Decca SG can be utterly superb as long as the vinyl is in good condition. Surface noise is more obvious but dynamics are startlingly real and present. On the rare occasion the vinyl is rough, I switch to an older Ortofon HOMC. If I replay the same disk with the Decca, I ask why I bothered with the other cartridge. Yes, the Decca is noisier but it captures the music in a more palpable way. Think of it as a small price to pay for a clearer insight into the emotion of the music. Female voice is to die for. If you like the Decca, you can send it to John Wright to change the tip to a paratrace diamond for more refinement and detail. Or you can play it safe and get the Nagaoka MP500.

+1 for @noromance`s input on the Decca, but with one caveat:  

The Deccas are first-class cartridges, but it is not advisable to own one  without having a second cartridge as a go-to for those records which are simply too damaged and warped to be played on the Decca.
"Or you can play it safe and get the Nagaoka MP500".  no romance- I assume with the Nagaoka MP (500) I would give up the London's insight in to the emotion of music. I guess it's just a matter of how much. Might the MP500 do anything better than the SG? I also can't help but wonder how my Charisma Denon (wood body) 103 would compare to either. I find it very relaxed sounding... perhaps a tad on the polite side as I hear it through Homage T2 high Impedance SUT > Croft phono. If I stay with the Charisma, which I'm leaning against, I would probably try a Bob's Device SUT.  I consider the Charisma a very good cartridge for music with drive, like Led Zeppelin. But with the Harbeth P3's, hard rock isn't generally the choice anyway. So, I want to play to the strengths of Blood on the Tracks, Chris Isaak, Clapton: Unplugged.... I mention those because that was last nights playlist. This is great...Cheers -Don

Charisma DL-103 with Ruby Cantilever / Line Contact stylus has Dynamic Compliance: 7 um/mN and you're using it with oil damped tonearm which retalively light mass ? What is the effective mass of WTL tonearm ? 

If you already have WTL Nagaoka all you need is just to buy stylus of the higher model and mount it on it. 
I assume with the Nagaoka MP (500) I would give up the London's insight in to the emotion of music. 
Well, as you've noted, it's to what degree. The quasi-cantileverless design gives very fast risetimes such that there is an immediacy to everything with percussion benefiting very noticeably. Once you have used a Decca, it is not easy to switch back. That said, if you like your reproduction unoffensive and laid back, a Mullard man so to speak, then the Decca sound may be too edgy.  

I think I'm an Amperex Bugle Boy man (-: I'm just looking to play to the strength of the P3's.  Flesh out the midrange, plenty of  body, yet not lacking detail. The Charisma is really very nice... I just want to avoid having to purchase an SUT, and another interconnect. 
Chakster- I want to say the WT arm effective mass is 10 grams. Low mass, yet with the damping seems to work with a fairly wide range of cartridges. I don't own the WT cartridge. I've heard it was quite good though. 
Well, this is indeed a low mass, the reason why your upgraded Denon is not performing at 100% is that you need a superheavy tonearm for it, at least double mass compared to your WT arm or even higher. You have already upgraded the aluminum cantilever/spherical tip, so all you need is a mid or high mass tonearm as a compliment to extremely low compliance of your Charisma Denon. Think about it, maybe you’re missing something.

It’s good that you don’t have WT Nagaoka cartridge, maybe you have to try Garrott Brothers p77i cartridge if you want to stick to the new carts only.

But i think you’re missing alot when it comes to MM if you’re ignoring the very best Moving Magnets from the 70s/80s era. With 10g effective mass arm you can use mid or medium-high compliance cartridges. I think you can use Garrott p77i, AT-ML170, or that Glanz MFG-610LX - they are all medium compliance.

Cheaper alternative is Ortofon M20FL Super (Fine Line stylus) - this is an old favorite of many audiogoners, today it's under $300 in top condition. Also medium compliance. 
Boxer, Just a note to say that the Nagaoka MP50 is a long gone item.  The MP500 is said to be the modern equivalent, but as I recall, Raul et al, did not think it was quite as good as the old MP50.  I am relying on memory to say this.  Yet the MP500 is the best of the current Nagaoka MP line-up, for sure.
Thanks lewm, bummer it's not as good, since that is what's available new. I bought a jico for my empire 4000 d/lll & am breaking it in. It sounds great on most albums & fairly bad on other albums that really sounded good with my clearaudio MC. Hoping that issue goes away. 
chakster- good point, but I don't know that I'm missing something. The Charisma, to my ear, is a real overachiever at $750 US. Charisma Audio in Canada, is the distributor for WTL's.  I had his 100% backing on this combination. So again, maybe the damping allows some cartridges that wouldn't normally do well on the (low mass) Amadeus arm to work. 

"  It’s good that you don’t have WT Nagaoka cartridge, maybe you have to try Garrott Brothers p77i cartridge if you want to stick to the new carts only." 

Is there a reason you feel the WT (Nagaoka) or for that matter, an MP300 or 500  would be less than ideal? I'm sorry... I admit the technical side of this is something I rely on dealers, forum members, and others for. Cheers -Don
Well, in my opinion the majority of people just read the reviews and looking for widely available cartridges, dealers pushing what they got, but what if the review is not available and your dealer does not have a certain cartridge? Does it makes this "unknown" cartridge inferior to something that comes from the very big manufacturers like Nagaoka? I guess when famous MM thread was created 90% of those forgotten cartridges were unknown, but people were shocked how good they are compared to some very expensive new carts.  

Garrott Brothers reputation is second to none, people who taking care of the brand today are very good too. The price of P77i Dynamic Coil is AUD600 (equal to $460) it’s cheaper than Nagaoka, but it’s an amazing cartridge with Garrott MicroScanner II stylus. There is a higher model in Garrott line too: the Optim with Ruby Cantilever and Fritz Geiger Signature stylus. I think this is a good alternative to Nagaoka.

An old Garrott p77 (not p77i) is one of my favorites, i remember when i bought it from fellow audiogon member i was thinking about Nagaoka MP-50 and he had it too, but explained me that Garrott is much more interesting cartridge. I’ve been using mine on Reed 3P "12 tonearm and was happy about the sound compared to many top quality MM cartridges i have in my arsenal.

However, i think the AT-ML170 is a better cartridge and the higher price for AT-ML170 is reasonable compared to Garrott p77. The construction of the cantilever of the AT-ML170 has no analogs in today’s world. It’s hollow tapered Gold-Plated Boron pipe. The stylus tip mass is extremely low. The AT-ML180 is even better.

Anyway specs on paper is not always telling you how good is the cartridge, but you can check the specs for AT-ML170 for example:

Frequency Response (Hz): 5 - 40,000
Vertical Tracking Force: 1.25 +/- 0.3
Tracking Ability (microns) at center value VTF: 90
Tracking Ability (microns) at upper value VTF: 100
Channel Separation (dB at 1kHz/10kHz): 31/21
Channel Balance (dB): 0.5
Output (mV at 1kHz), 5 cm/sec): 4
Vertical Tracking Angle: 20 degree
Stylus Shape: 0.1mm MicroLine
Stylus Construction: Nude Square Shank
Cantilever: Gold-plated BORON
Wire Uses For Coil: PCOFC
Recommended Load Impedance (ohms): 47,000
Recommended Load Capacitance (pF): 100 - 200
Dynamic Compliance @ 100Hz: 10.0
(* please note that Dynamic Compliance @10Hz will be around 18-20cu)
Static Compliance: 40.0
Cartridge Weight (grams) 7.0
Replacement Stylus: ATN170ML

This article will help you to find more interesting things about top qulity MM cartridges: http://www.regonaudio.com/Stanton881AudioTechnicaATML70.html