What tonearm will better mine?

I have been running a 12" Jelco SA750L with an upgraded Decca Super Gold on a Garrard 401 for a few years. I'm happy with the sound and happy with my pre, power and speakers. (Croft 25R, EICO HF35s, -good tubes, Quad 57).
I keep hearing that my tonearm is a weak link even though it sounds pretty awesome to me. What would it take to replace the Jelco and make a significant improvement? What should I expect to hear better? Would I have to drill the massive plinth? Thanks.
EMT 997
Dear @noromance: As you said and confirm the Jelco you own is very good tonearm and IMHO the 997 is no better, maybe different but not better.

What you can do is try your cartridge or cartridges with different headshells: different build material, different overall shape, different weigth, etc. Trying the one that could matchs in better way the cartridge needs and you will know which one because with it the cartridge quality performance been improved.

Other important subject are the headshell wires where you can make an up-grade with better headshell wires and obviously a better tonearm/phono IC cable.

Other subject not less important is that your cartridge/tonearm set up been as accurate as you can. The MINT LP protractor ( inexpensive. ) makes a " difference " for the better if you don't own it. This protractor is made it in specific for the: TT/tonearm/cartridge of each one customer. Unbeatable at any price.

That's what I will do in your place before to think in a tonearm change.

Regards and enjoy the music,
Thanks both. So I can spend $4000 on an EMT or tweak what I have!
Would there be no decernable difference between the Jelco and say a Schick or a Phanthom2? 
No real comments on the Jelco vs. other arms. I’m happy with my 750D and have read a few reports from users who went upmarket and, in the end, still felt the Jelco was great value so I stick with it.

Raul’s suggestion is a good one though if you don’t want to spend big money. One tweak that I have found to be very worthwhile with my 750D has been the Ammonite Acoustics mounting collar, which eliminates the slight slop in the OEM collar and ensures correct positioning of the arm as it relates to azimuth. Very important with more exotic stylus profiles.

I also recently changed out the stock Jelco headshell to a Yamamoto HS4 Carbon Fiber headshell. This was a real eye (or ear) opener: pretty substantial improvements across the board in information retreival, overall presentation and dynamics. A no brainer for about $100 U.S. on ebay.

I've had the Mint LP protractor for a number of years and it is indeed very good, and important with respect to getting the best out of one's arm and cartridge. 
Another option is the Ortofon RS 309D. I have heard the Jelco, Ortofon and EMT all on the same table with the same cartridge. I would rank the Ortofon better than the Jelco and the EMT better than the Ortofon
Thanks again. What improvements did you experience?
I imagine improved tonal color and bass definition with an increase in dimensionality...
@noromance not sure which cartridge do you have, but the Schick "12 tonearm was made especially for Ortoron SPU! For your Garrard 401 it would be a perfect match with low compliance cartridges, but for normal cartridges (5-10g) you need lighter counterweight. The Schick is the most ellegant tonearm on the market today imho. Here is a picture of mine.

The only problem with Schick is that you have to wait 4-5 month in line for tonearm when you buy new from Schick. 
Chakster, nice set-up. Thanks for tge info. What improvements would there be over the Jelco with my Decca SG-P?

If you feel like going hard-core Decca/London, the two arms known as great matches with the cartridge is the Fidelity Research 66 and the Zeta. There are not a lot of them around for sale, so you'll need to be patient.

One new arm popular with the cartridge is the Helius Omega. Kind of expensive at around $3200 for the Standard (copper wire, tungsten bearings) and $5200 for the Silver Ruby (silver wire, ruby bearings). A very sophisticated arm designed and made in England by a genuine rocket scientist!

Dear NoRomance,

If the Garrard truly is as "rough in upper-mids & treble" and "lacking in detail" as many experienced users suggest....then it seems to me that putting a "Super Arm" on the table, which puts a T/T’s failings under a very severe microscope, would be casting pearls before swine?

As I may have mentioned before, the Jelco is every manufacturer’s favourite "starter" arm. Doesn’t mean that it is a bad tonearm - in fact it is extremely competent - but it is just that.

So the answer is yes, improvement is possible.

You should also have shortlisted the VPI 3D which is well within your budget. I don’t use VPI at all and I’m not on commission. ;^)

Come to think of it...does $4K not buy you a complete Prime turntable? If so I’d seriously give that some thought. :)

If the Garrard truly is as "rough in upper-mids & treble" and "lacking in detail" as many experienced users suggest
I don't think you need to worry about that. 

Chakster, nice set-up. Thanks for tge info. What improvements would there be over the Jelco with my Decca SG-P?

I’ve never tried Japanese Jelco, but German build quality of Schick is superb, i like oldschool style of design and simplicity. The Garrard 301 Hammertone is even more attractive to my eyes when it comes with Schick tonearm. I could only dream about Garrard Hammertone, but i have Schick on my SP-10mk2 with UltraCraft shell and low compliance Argent MC500HS cartridge since i’ve sold Ortofon SPU Spirit and Classic GM mk2. Anyway, it’s hard to ignore some other tonearms i wish to try, but Jelco is not in my list. The good thing about Schick is the low price and high quality, you don’t have to pay much to have your own experience with Schick "12 on your Garrard. I have several tonearms at the moment, for the Schick (with two different counterweights) i would ask $1800 including shipping worldwide and pp fee (just to give you the raw idea how the Schick compete with other suggested arms in terms of price).  
Meaning no disrespect, and acknowledging that other posters may in all likelihood have more experience with various arms than do I, may I humbly suggest that the extreme nature of the Decca/London cartridges is what needs to be taken into consideration when looking at arms for use with them. They put out a massive amount of physical energy, revealing any resonances in the arm's tube and rattles in it's bearings. The freedom from rattling bearings is one reason unipivots have traditionally been recommended for them, the other being that unipivots often feature damping, which the cartridge can use. The cartridge has vertical and horizontal compliances differing from one another, making getting the resonant frequency in the optimum 10Hz range in both planes more difficult than do "normal" cartridges. 
I heard a Decca in a VPI 3D....outstanding.
Thanks all. No one has actually explained what sort of specific improvements one should expect from a new (expensive) arm. I think I'll order the low-slung counterweight and carbon fiber headshell for the Jelco for the moment and spend the difference on more records. 
Expressimo Audio makes a copper end stub and counter weight for your Jelco I purchased mine last year it made a major improvement. The arm is much more stable.
Thanks cjaronica. It looks like it means dismantling the arm off the table. Interesting though.
Why not first get a very good tonearm cable? the internal wire is decent stuff (silver I think) but a nordost tonearm cable will be a big jump forward, as would a furutech for instance
Which of the arms mentioned have on-the-fly or at least easily repeatable VTA? I am surprised to see many tonearms that are raved about don't have easily repeatable VTA and I wonder if their owners don't adjust VTA for each LP or what? I know Pete Riggle sells adapters for Regas and a few others, but do you guys not adjust VTA with some of these arms? Thanks.
Hi Noromance

You should try a "WOODY" From Pete Riggle. I have had a system very similar to yours and my 401/Woody/SPU  really made music in that combination.
A tone arm can be a weak link.   Your's is not!   The Decca is an excellent, but very finicky cartridge!   If its working well?  That means your arm has to be excellent.  Leave it alone.   I have destroyed Deccas not using a tonearm that will work with a Decca. 

Deccas I love.   They eliminate the obscuring of the signal that using rubber for the regular cantilever's bushing. The tonearm has to be exceptional to work well with a Decca. If you are looking for a way to improve  it may be a different tonearm cable.  But, if the Decca works fine?  It means the arm is excellent! 

 I used Mayware V with my Decca super gold and was very pleased

Then I have changed to Graham 2 supreme and could not believe how much better it is in every parameter. As I understand decca work best with unipivots.By the way TT is Nottingham Spacedeck 

I recently bought two Jelcos (SA-750D and SA-750E) for my modded Empire and Lenco tables.  The one on the Lenco replaced a JMW 10.5i arm and spare armtubes and sounds better to me in ALL respects.  I came out of that deal with more than $1K in cash, so hard to complain :-)

And yes, I'm running a Decca Super Gold too (among 9 mounted carts) and the Jelco loves it.

PS  The SA-750D is a direct drop-in replacement for the original Empire arm (Model 298) and an amazing improvement.
I’ve had many Deccas over the years in various arms. I think "boazro1" has it right with the Graham arm. I’m sure they have an an arm wand that will have the correct weight for the cartridge. The arm, as I recall, has variable damping that can be a boon for Deccas. The SME V has this feature too and I have heard such a set up with a Decca that was magical. ( The dealer should make sure the cartridge - any cartridge -has the correct azimuth before selling it to you.) Also, I understand that the Deccas need to be loaded differently (Ohms) than conventional 47KOhms so you may want to get that correct before trying new tonearm cables. I always find I like to do upgrades incrementally it increases enjoyment over the long term.
I have used several series 9 Ikeda (of Fidelity Research fame) cartridges that are a "moving coil Decca" with wonderful results. Unfortunately, the new Ikeda company will no longer be offering them. However, their new tonearms are supposed to be an update of the (rare) FR -64 and I have no reason to doubt that.
Yes, the Super Gold needs to be loaded at around 22k ohms resistance with 220pF capacitance, which creates the optimal electronically damped circuit with the cartridge. Another arm worth looking into is the Well Tempered. And if your Super Gold doesn't have the Decapod installed on it noromance, it may be the best thing you can do for it. 
Thanks bdp24. I tried loading the Decca with 33k many years ago in an Ittok and liked it better at 47k. The Croft preamps seem to play well either way. Tempted to do the DeccaPod. What improvements have you experienced? 
@binkt Please tell us more about your experience with the Pete Riggle Woody. I just read up on that arm which I have not heard, and it has many amazing features that I haven't seen before like on the fly azimuth adjustment. (Not sure if I am brave enough to do that). 
I also believe there is a version of that arm made specifically for use with SPU carts. 
Anybody else hear or own these? At $1900 including multiple headshells and weights for low/med/high compliance carts, it looks like a good value proposition, at least on paper. Cheers,
One tweak that I have found to be very worthwhile with my 750D has been the Ammonite Acoustics mounting collar, which eliminates the slight slop in the OEM collar and ensures correct positioning of the arm as it relates to azimuth. Very important with more exotic stylus profiles. 

I also recently changed out the stock Jelco headshell to a Yamamoto HS4 Carbon Fiber headshell. This was a real eye (or ear) opener: pretty substantial improvements across the board in information retreival, overall presentation and dynamics. A no brainer for about $100 U.S. on ebay.
I have to second the Ammonite Accoustics mounting collar.  The brilliant thing about these is that he makes them from ebony!  Expensive? maybe, but not in "Hi-Fi" terms.  The great thing about ebony is that it is used to make musical instruments, oboes, clarinets for example.  All materials have a resonance, but the resonance of ebony is benign.  Match that with a Yamamoto Ebony (or Mpingo) headshell and you will get a real benefit.  Also there is the 'Shuggie Collar' as a tweak to the Jelco.  They are sold by ammonite accoustics.  The only downside to the Jelco is that the grub screw on the mounting collar is not centered.  A bit like rolling a log but pushing it with your foot at one end instead of the centre - it might go off course.  So great care is required in set up.  The aftermarket collar is is essential in mounting the arm to a Technics and I guess the same can be said for a Garrard.  The last tweak is silver rewiring.  I am not really a 'cable guy' but I do believe the smaller the signal the more important it is to have good a good cable.

As you may have guessed I am a Jelco owner.  If I was building another TT I would not go for a VPI or 'modern' tonearm.  I might even plonk another Jelco on it.  My other thought would be an SME M2-12.

The old Decca's were extremely variable, each one needing to be loaded to match it's particular performance. The current London's are much more consistent, and can be loaded according to builder John Wright's recommendations.

Noromance, the Decapod (why it is spelled with only one c I don't know) offers a couple of improvements. The "Pod" makes the cartridge less microphonic, being a thick slab of aluminum that replaces the much less non-resonant thin piece of tin that is the stock top plate of the cartridge. The Pod makes unnecessary the stock cheesy red plastic mounting bracket, a major source of weakness in the mating of arm and cartridge. The Pod is threaded, allowing for a tight direct fitting to the arm's headshell. The discarded plastic mount also contains the cartridge's output pins, which connect to thin strips of brass or copper (like the blades on the battery connections inside a flashlight) on the back of the cartridge body, necessitating an extra break and connection in the signal path. With the substitution of the Decapod for the stock mount, the output pins are on the cartridge itself, a huge improvement with a signal as low in voltage as that of a cartridge's, even the Decca's 5mV!

I believe the Decapod is available as a DIY part, or you may return the cartridge to have it installed by John. He will at the same time adjust and test the cartridge, returning it with a performance test report if I'm not mistaken. I wouldn't have a Decca without the Decapod!

Thanks everyone.
bdp24, The name may be a play in decapods - animals like crabs - I guess the tight grip...
Wasn't the red plastic part of the damping? I like the idea of a solid base for the Decca. Have you heard the Decapod upgrade? My Mk.Vll has already been to JW for a Paratrace tip which was a major upgrade. I'll shoot him an email when it's due a retip. Thanks.

The red plastic mount wasn’t designed for damping, but merely for mounting the cartridge, and perhaps for easy switching between models---elliptical, spherical, the version for 78’s. The cartridge originated in the 1950’s, long before people were as concerned with damping resonances as are we now. That mounting design exhibits a fair amount of flex, allowing relative motion between cartridge and headshell, obviously not a good thing. People have tried all sorts of DIY remedies, the most common being Plasticene, Mortite, Blutack, modeling clay, and other putty-like materials wedged into the space between the top of the cartridge and the bottom of the mount, to prevent that motion. The Decapod is a far better solution, making the cartridge as tightly secured to a headshell as any "normal" one. I ordered my London Super Gold Mk.VII with the Decapod already installed, but my earlier Decca SG originally had the stock mount. I sent it back to John for him to install. Yes, definitely worth the money!

The Paratracer tip is universally lauded by Decca/London owners, and when I need a retip I’m definitely going to have John install it on my London.