Use a heavier headshell.
What issue are you having?
Some people claim the Decca/London design doesn't like the knife-edge style bearings of SME arms. If you can get your hands on a Zeta at a reasonable price (under a grand), snap it up! Johnnie at Audio Origami knows all about the arm, and has restored and/or rewired many of them. A real good arm for the D/L's.
The Decca is a quirky design. It has different horizontal and vertical compliances. So neither a low mass or a high mass arm will work optimally with it. The best arm for it might be the Sony Biotracer (on the Sony DD TT). This advanced-design arm has the ability needed to compensate for the Decca's wayward-tracking in both horizontal and vertical planes!
I have a maroon in a Naim Aro unipivot, I had to drop the back of the arm by a mm or two to get the sound to fill out and there is a definite sweet spot for VTF and I have to make a new arm board to get the overhang right. Even with overhang 2mm too much I’m enjoying the result immensely, bar a little coarseness at the start of a side because of that overhang error but the sound has a lot of presence notwithstanding that, I have the red plastic bracket and the cartridge just slides up onto it, I had to reseat this as it moved a bit when I took the cap off and I didn’t get any sound at first. I remember it sounded thin before dropping the rear of the arm.
There are several tonearms that work well with the London Decca series cartridges, the Fidelity Research FR-64 and FR-66 being the most notable (and among the most expensive). I have used Ortofon, Jelco and the Thomas Schick tonearms with good but not great results. I found that the Pear Audio Cornet 2 tonearm unipivot works very well with the Decca Gold. This is an updated version of the Nottingham tonearm designs, so you might start there.
Some have reported that the Dynavector DV-507 works well but I have not tried this combination myself. A friend of mine runs his Decca cartridge on a Pete Riggle Woody tonearm and claims that it's the best pairing for the Decca series. I'm skeptical but I have not yet had a chance to hear it so I'll pass it along as an unendorsed recommendation.
I've tested the London Decca Reference on the FR-64S, FR-66S and DV-507/II and the FR-66S is undeniably the best match.
With both FR-64S and DV-507/II.....the Decca mistracked at the same point on every disc.
And I agree with previous posters.....the Deccas like their arms with the pivot slightly down.
A unipivot is what is recommended in the instructions that come in the cartridge box. Then again Art Dudley claimed to get good results with a maroon in a Rega arm. This with the addition of a Townshend outrigger and trough (the deck is a Rock mk2) was going to be my fallback if the Aro didn't work but what I'm hearing is tracking error at the start of the album not mistracking on transients. Getting the alignment to cross two null points rather than just failing to reach even one will deal with that but with an Aro that means boring a new arm board, fortunately I have a blank ready to go but the system is 800 miles away at the moment.
Unipivots are not right for the Decca. Lots of resonance reflects back into the arm....you need solid bearings.Sorry stringreen, I gotta disagree with you on this one. Not all unipivots work well with the Decca cartridges but those that do work better than gimbaled or tonearms w/ captured bearings - IMO.
dhcod, I haven't tried a Moerch tonearm with the Decca (never even occured to me to try it) but having owned a DP-6 in the past I would guess that this is not a good match. YMMV
It should work pretty well with that arm. Try the SME headshell. Maybe add a little mass.Thanks bpoletti. I did this and the Decca came alive! Quite a bit of surface noise but wow. So immediate sounding!
Now trying to deal with a little thin sounding bass. Setup is definitely finicky.
I added 4.4 grams using an SME headshell weight and that was the difference maker. That and finally getting the VTA correct! The surface noise is really interesting because it's almost like there's a threshold that if it hits, there's noise. Otherwise it's quiet. I don't seem to have many records with just a little noise with this cartridge.
The Decca/London is tricky because its’ lateral and vertical compliances are very different, the lateral being about 50% higher than the vertical. Schizophrenic! Of course, the effective (moving) mass of all arms is partially determined by the distance of the rear counterweight from the arms’ bearings. To increase an arms’ em, move the counterweight further away from the bearings. To keep the tracking force the same, additional mass is then added to the headshell, thereby further increasing the arms’ em. Serendipity! An arm with medium lateral mass and high vertical would be optimum for the Decca/London. Is there such a beast?
A good way to add mass to the "classically"-styled Decca/Londons (the Maroon/Gold/Super Gold, etc.) is to order it with the optional Decapod top plate/mount. A second benefit to the welcome added mass of the pod is the far superior mounting of the cartridge to the arm it affords. The stock cartridge holder/mount is a flimsy joke, completely unacceptable. Owners of stock cartridges can have the Decapod installed at the factory at the same time retipping is done. Well worth its’ modest price.
@noromance, you make a good point. A heavier counterweight closer to the bearings can produce the same effective mass as a lighter one further away, plus create less moment-of-inertia, a good thing say engineers (I take their word for it ;-). The Zeta arm has a counterweight that has it’s rear plate bolted on, with two internal steel washers which can be added or subtracted as needed or desired. Mine was missing one of the washers, so I substituted lead weights bought at a hobby store.
I needed the extra mass to compensate for 1- the missing Zeta counterweight washer, 2- the extra mass of the Decapod on my London Super Gold Mk.7 (it doesn’t weight much more than the standard mount), and 3- the outrigger that is integral to the Townshend Audio Rock Elite table I have the arm mounted on; it gets bolted on to the cartridge end of the arm. The Rock/Zeta/Decca-London combination, a true classic!
The horizontal and vertical compliance differences presented by the London Decca cartridges necessitate the use of a "stiff" tonearm. Adding weight to the headshell and increasing the counterbalance weight of a tonearm will not compensate for a resonance compliance mismatch and, in fact, can make it worse. Not all stiff tonearms are heavy and not all heavy tonearms are stiff (although most are).
Think of it this way: a PVC pipe is lighter and "less stiff" than an aluminum pipe of equal size, and an aluminum pipe is less stiff than a steel pipe of equal size. A carbon fibre pipe of equal size would likely to be stiffer and lighter than the PVC pipe; especially if the carbon fibres were aligned down the length of the pipe and not wrapped circumferentially.
Adding weight to each end of the PVC pipe won't make it any more stiff. But the added weight, outboard of the fulcrum (pivot point) will almost always increase the resonance amplitude as they swing around the axis.
As stiff an armtube as possible benefits ALL cartridges, but the Decca/Londons, having no rubber damping suspension (and no traditional cantilever; the stylus is attached to a V-shaped metal plate, which goes straight up into the cartridge) benefit most of all. The D/L’s transmit a LOT of mechanical energy into the arm, exacerbating any armtube flex and/or bearing "rattle" present in any given arm. The Zeta is known specifically for its’ strengths in those two criteria.
The front-end damping provided by the Townshend Rock is exactly what makes that table so appropriate for use with Decca/Londons. A damped arm has long been recommended for use with the cartridge, and I have had a few; the Decca International, the Mayware Formula 4, and a modified (with damped bearings) SME 3009 Improved. The Rock makes a damped arm unnecessary (and in fact the front-end damping afforded by that table is a better way to damp than applying it at the back end of the arm), allowing armtube stiffness and superior bearing design & build to be prioritized. The Rock comes with a metal arm mounting plate drilled for the Linn/Zeta arms, which share the same pivot-to-stylus distance. The plate even has the six holes required by the Zeta’s arm mounting collar---very handy. I added a layer of thick acrylic under the metal plate, as that plate is a little too ’lively" for my liking. Yes, I believe in damping resonances!