Cartridge "shoot-out" : Koetsu Jade v SPU v FR7 v London Reference.

Two nights ago I discovered a box set gathering dust on my record shelf entitled "Beethoven, the Late Five Quartets",performed by the Guarneri Quartet. I hate string quartets and am not especially fond of Beethoven and had never played any of the 4 LPs within the box. I vaguely recall buying the thing online a couple of years ago in a moment of attempted cultural self-improvement. All in all things did not augur well when I plonked what was marked "side 1" onto my turntable. The cartridge in play at that moment was a Fidelity Research FR 7 fz not long returned from the Expert Stylus Company with a new cantilever and Paratrace stylus.
Fast forward 24 hours and I had reached side 3 opus 131. According to Wikipedia Beethoven regarded this as his most perfect  single work, Wagner said its first movement revealed the most melancholy sentiment in all of music and Schubert died 5 days after hearing it, proclaiming that there was nothing left to write musically.
For my part I really liked it. I have no idea of the musical nuances at play, it was just very enjoyable. Was I having a more profound time than listening to Santana or Brian Eno ? No comment and now on to the fun bit.
What I did was play the same side 3 over and over, simply swapping headshell/cartridge in my FR 66s tonearm. Beyond adjusting VTF  for each cartridge (as detailed below) and the volume knob on the preamp to adjust for different volumes produced by the different cartridges, all other parameters were identical.
A quick run through the system: Brinkmann La Grange turntable with said FR66s, using a Stillpoint record clamp; Allnic H3000 phono stage, Allnic L3000 linestage, Allnic A6000 monoblocks, Avalon Compas diamond speakers and a pair of Audiophysic Rhea subwoofers. All the cabling  (mains and interconnect) is Vertex AQ Hi Rez and everything is powered via a Vertex PSU.
Where the Beethoven came in handy was that the music was so engrossing that I didn't tire of listening to the same side over and over. I suppose the danger of repeat listening is that you are so sick of hearing something for the umpteenth time that you end up not enjoying the experience and the attempt to be impartial and objective goes out the window. What prompted me to try the different cartridges was that I was enjoying the piece of music enough to want to keep playing it over, so why not try different cartridges for added fun and adventure ?
So here, in a nutshell, are the results. These are of course entirely subjective and particular to this record in my system in a specific listening room. The same system in a different room might well sound totally different and maybe the "shoot out" would have ended differently to my ears. Oh and of course I'm a middle aged semi knackered specimen still suffering the hearing issues I believe were caused by the Who at Wembley Empire in 1975. So with that series of get out clauses these are my personal findings which I might as well describe in the order I played things.

FR7fz : lots of detail, nice extended treble, natural midrange , good bass , dynamic, but for some reason not fully engaging on this piece of music. There was nothing I could find fault on, no tracking issues , surface noise or anything that might offend. It was just that while listening to this particular piece of music my mind wandered and alighted on the idea of trying some other cartridges. Maybe that's more a reflection of me than the cartidge but I'm just reporting my findings. VTF was 2.2 GMT as recommended by ESCO.

Koetsu Jade diamond cantilever (in Arche headshell): Immediately following the FR7 this gave a more ordered, realistic sense of a quartet being in the room. String tone was a bit sweeter and more organic than with the FR7 - overall there was more of a sense of purpose to the music as a whole - a bit more "soul" to it. Again, nothing to find fault on in any respect, definitely more engaging on this piece of music than the FR7. VTF was 1.99 gm. Per curium I have experienced some tracking issues with this cartridge on certain  "difficult " musical passages. It doesn't take too kindly to worn vinyl. However after a lot of experimenting I found that a significant improvement in tracking was achieved by reducing the bias to the absolute minimum setting on the FR 66 -even no bias worked really well. I'd say that transformed the Koetsu for the better.

SPU Synergy: in a nutshell, very nice job made of the music. Everything was there - it was a slightly mellower sounding version of the FR7 in some respects. Not as engaging as the Koetsu. When listening to the Koetsu I wasn't thinking about what the next cartridge would be, but when the Synergy was being played I was. Nothing sonically to criticise - certainly no loss of detail or frequency extension. Very pleasant but, as with the FR7 (and unlike the Koetsu) I felt the cartidge maybe got in the way of the music and was processing it rather than letting it flow naturally.

SPU Classic: I bought this a year ago and it's the g type with the basic stylus (the round one ?) 
it's probably the Who concert(s) or maybe inverted snobbery, but my most enjoyable listen to this piece of music so far was with this (the cheapest and oldest (in design) in play. I should say at the outset that the sound with the SPU Classic had a kind of antique quality that might have especially suited this recording of old instruments . But putting aside tone or resolution, it was the way that the music just hung together properly that stood out. Again , as with the Koetsu, I wasn't thinking about next cartridge. At one point I noted to myself that the three dimensional image was the best I'd heard - as in it had a wow factor with the SPU Classic I hadn't noticed on anything before it. I would have happily stayed with the SPU Classic for the duration. VTF was 4.0 

London reference (in Yamamoto ebony headshell):I have owned this for several months and have been really impressed. Subject to having clean and not worn -out vinyl it tracks superbly and is very direct and dynamic and musical. It gets out the way and you just hear what's on the record (including dust and tired grooves - hence the above proviso). That intro was to soften up the rest of this section of the shoot out : String tone - spot on ; sense of music and flow - absolute ; soundstage - in the room: I kept waiting for something not to be near -perfect, but it didn't happen. From beginning to end the LR was faultless. All I heard was music, no traces of something going on somewhere in the system or in the vinyl. The winner ! VTF 1.99 gm. There's loads of debates going on about what arm to use with the LR. I've only used it with the FR66s and I've had no issues with it. I understand that its designer uses an FR64 so maybe high mass s the way to go.  Like with the Koetsu I found it was an altogether happier cartidge with minimal bias on the FR 66 - I also found that it sounded sweeter with the Yamamoto than an Orsonic.

So there you have it - in order of preference London Reference, SPU Classic, Koetsu Jade, FR7 fz and SPU Synergy. The SPU Classic and Koetsu get a special mention for being involving and emotional, but the LR gave you that with an added something, which on account of it being late and I'm not a professional reviewer I can't put into words anymore than why I actually really liked a string quartet...!

I hope this was informative - best regards to all.

Finally the London and Decca cartridges are getting their due respect in the U.S.A.! By Art Dudley in his Dec ’15 Stereophile column, and now by Howard here. Not for the faint of heart, the London Reference is the most dynamic, immediate, and exciting LP transcriber priced at less than $10,000 on the market. And the cut-from-the-same-cloth London Super Gold is available for only $1200!
Interesting read 👀
I get to regularly listen to many cartridges with the same FR66s arm and I have the FR7f (modified with line-contact stylus), SPU Silver Meister, SPU AE-Gold, Decca London Reference and Lyra Atlas.
The London Reference I agree is a great cartridge and sounds just as good on the FR-64s, FR-66s and Dynavector DV507/II. However I slightly prefer the AE-Gold for its luscious tonal colouring  and natural presentation.
The Atlas unfortunately trails this field...☹️
Thanks for the write-up....

Glad that you discovered the merits of the music.  Now you might look into finding the Guarneri versions of the Early and Middle SQs.  Probably my favorite interpretations.