Mar 9, 2018 19:16:56 GMT 12 nakmad said:

One of the few cartridges of any ilk that raised the hairs on the back of my neck.... .... in a good way... and still does from time to time as it's on rationed usage .

nakmad - which Decca model?

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Owen,

A Garrott Decca London Gold currently.

Prior experience/journey  with Decca's was firstly an ffss in London arm.. which brought home to me the descriptive term 'attack' ....simply amazing compared to my then diet of Ortofon's and Audio Technica's then a Maroon.. dynamic.. but not a great tracker.. then onto the Garrott Decca  . It gets used for special listening sessions, not casual listening.. don't want to wear it out too soon!.

Never play Leapfrog with a Unicorn.

A place for discussing these legendary & arguably quirky pickup cartridges.

The unique Decca pickup cartridge concept, designed by Decca engineers, dates back to the early 1950s I believe, originally a mono cartridge, later redesigned for stereo reproduction.

The Decca cartridge (together with the Decca fluid-damped unipivot tonearm) ceased production in 1989 when Decca Special Products division was closed down.

However, former Decca engineer John Wright was granted a licence to manufacture the cartridges under his London brand name & this continues to this day.

The London Decca product range ( www.london-cartridges.co.uk ):

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Mar 10, 2018 19:36:35 GMT 12 nakmad said:

Owen,

A Garrott Decca London Gold currently.

Prior experience/journey  with Decca's was firstly an ffss in London arm.. which brought home to me the descriptive term 'attack' ....simply amazing compared to my then diet of Ortofon's and Audio Technica's then a Maroon.. dynamic.. but not a great tracker.. then onto the Garrott Decca  . It gets used for special listening sessions, not casual listening.. don't want to wear it out too soon!.

nakmad that's quite a journey, starting with a FFSS 'head' no less.

Are you saying that you now still have the Garrott Decca, as well as a London Gold?
And do you have a 'GB Clamp' mount on your Garrott Decca by chance?

Sidebar:
The original Deccas had poor QC & the cartridges were (I believe) unpredictable & variable.
The Garrotts of course fitted one of their diamond stylii, but also checked over & re-aligned, tweaked & tuned the Decca.
Garrott Deccas were regarded as the best & are still prized - although London in 1992 & 2003 released new Jubilee & Reference models respectively, both with solid alloy bodies.

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Diagrams of the Decca cartridge construction:

The first thing that you can see is that there is no 'cantilever' in the usual sense.

1) The diamond stylus sits vertically down the centre of a fixed coil & horiz magnet poles - this picks up lateral stylus movement.
2) The stylus-carrying 'armature' also has the necessary vertical movement for stereo - which is picked up by 2 additional 'vertical' coils & magnet poles above.

The current London Deccas put out around 5mV (MM level) & cartridge mass is only ~6.7g (not sure about the London Reference).

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This the London Super Gold that I have recently acquired:

You can see the stylus 'tie back cord', the circular lateral coil & the lateral/horiz magnet poles either side.

The stylus on this model is an 'extended line contact'.

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Mine is a Garrott London Decca Gold too.

Sadly put away as my phono stage is His Master's Noise... a low noise phono stage.

www.diyaudio.com/forums/diyaudio-com-articles/163570-masters-noise-thoroughly-modern-tube-phono-preamp.html

Mine is a Garrott tickled Decca London Gold, where they fitted their microscanner stylus and did other internal tweaks.. the details of which escape me for now.
Mine is still using the Decca Plastic 'T' bar mount for want of a better description, all I've done is upgrade to the 4 pin mount  ., ( so no GB clamp or deccapod), and the obligatory blob of blutack between the can and the mounting plate.

I'd heard from a few sources that buying a Decca was a lottery, due to bad QC, and the Maroon that passed my way way clearly one of those. Brilliant 80% of the time, but used to distort badly on anything really exciting, so I passed.

Never play Leapfrog with a Unicorn.

fascinating transducers.

do these respond to the regular alignment regimes or require something bespoke ?

London Decca cartridge setup - despite all of the unusual tweaks that I've read about Decca owners resorting to, this is what I've learnt so far:

Maybe the London Deccas are more 'normal' than Deccas of the past, I dunno....

Alignment:
- Cartridge top level with record seems to work OK (VTA) - jury still out however, as I have only put in a few hours listening & use on it. (Note that the stylus is installed with quite a few degrees forward rake (SRA is +ve rake, ie. stylus points forward!).

- Cartridge is VERY difficult to align, due to absence of projecting cantilever & the closeness of the cartridge to the record surface (see pics) - otherwise regular alignment procedure (2-point or in my case, tangential/radial).

- Tracking Force 1.8g as recommended.







(I haven't yet experimented with the 'plasticene' tweak, between cartridge top & mounting bracket - that nakmad mentioned.)

The Blutak is on the headshell because I couldn't be bothered changing to a lighter c'weight.

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Hmm. yours is a Presence Audio built cartridge Owen?, so a "London"?, not a Decca lottery unit?

Never play Leapfrog with a Unicorn.

Was going to say I had the blutak between the cartridge and headshell,but then saw your remarks.Does make a difference.
Sold my Garrott Gold Microscanner-hardly used-after droppimg my old one onto the record.Still haven't found the diamond!
Haven't missed the stress of using it!
My Garrott P77 SAS and Technics 205/3 SAS are very close in sound and speed.

Oh that was tragic neilsan

nakmad - yes a London manufactured Decca, distributed by Presence.

A question, nakmad & jon:
The Garrotts died in early 1991 & John Wright started manufacturing London Deccas in around 1989 (all AFAIK), so you are saying that your Deccas are early Londons that were sent to the Garrotts?
Or, did the present Garrott owners continued to do Deccas?

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Some light reading..

Never play Leapfrog with a Unicorn.

I'm a little rusty on my Decca cartridge history..but as I understand it.. Mine definitely ( and probably Jon's), is a Decca manufactured body, re-engineered and retipped by the Garrott brothers. When Decca gave up on their cartridges,  John Wright acquired the rights to keep manufacturing them, under the London Brand name.( very late 80's?)  Yours is a John Wright/Presence Audio manufactured unit, a London, not a Decca ,  and suffering none of the QC issues of a Decca made unit.

Never play Leapfrog with a Unicorn.

The sound - the most important bit...

Yes, most people hear the speed, the attack.
The energy & power is exhilarating.

What's most striking to me however is the 'focus' of images, the 'solidness', presence & density' to sounds, voices especially, enunciation is effortlessly clear.
There is 3D acoustic energy around instruments.
Soundstaging is not a strong trait of my speakers, a full horn system.
I didn't expect this.

Bass is extraordinary, strong & solid. (I think the high horiz Effective Mass of the linear tracker matches well here.)
Treble is a work in progress as things run in... a touch 'etched' & 'brittle' initially, now better balanced with some loading adjustment (36k/220pF).

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Careful Owen, you are starting to be converted....

Never play Leapfrog with a Unicorn.

Mar 12, 2018 19:54:38 GMT 12 nakmad said:

I'm a little rusty on my Decca cartridge history..but as I understand it.. Mine definitely ( and probably Jon's), is a Decca manufactured body, re-engineered and retipped by the Garrott brothers. When Decca gave up on their cartridges,  John Wright acquired the rights to keep manufacturing them, under the London Brand name.( very late 80's?)  Yours is a John Wright/Presence Audio manufactured unit, a London, not a Decca ,  and suffering none of the QC issues of a Decca made unit.

Quite correct. Mine's a Decca, not a London. The previous owner sent it to the Garrott Bro's and never used it after that!!!

Something else...

Looking at your photos, your VTA is correct. The Tomahawk is parallel to the record which is the best setup as recommended by Decca. I'd be very careful playing around with the VTA as it is ridiculously easy to rip the stylus off! Slow and steady in that regard.

The Blue-tak trick, whilst useful, may not yield good results, whereas a Deccapod most certainly will.

nakmad - thks I hadn't read that one of KK's.
jon - yes, have been thinking about a version of the Deccapod.

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Mar 12, 2018 20:36:19 GMT 12 jon said:

Something else...

Looking at your photos, your VTA is correct. The Tomahawk is parallel to the record which is the best setup as recommended by Decca. I'd be very careful playing around with the VTA as it is ridiculously easy to rip the stylus off! Slow and steady in that regard.

The Blue-tak trick, whilst useful, may not yield good results, whereas a Deccapod most certainly will.

I thought the blutack mod was standard on the Garrott Decca, but I can't find  the review to confirm. A deccapod would be nice to try  but kind of hard to get I thought they could only be purchased with a new London cartridge?. But I dare say some of the clever clogs around here could knock something up 

Never play Leapfrog with a Unicorn.

Not standard for Garrotts. In fact they advised against using blu tack or plasticine.

Check out presenceaudio.com for a deccapod

Decca cartridge quirkiness:

1) The Decca red plastic mounting bracket is tapped for 6BA screws (provided) - does not use M2.5 as in most (all?) other cartridges.

2) The mounting bracket is a separate, slide-on piece, with metal contacts.




(internet pics)

3) The Decca stylus SRA has quite a few degrees +ve (forward) SRA rake - compared with conventional cartridges which usually have a couple of degrees -ve (backward) SRA rake.


(internet pic)

For reference (SRA):

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Mono records - I think I'm beginning to find that the London Decca is v good at playing Mono records.

No surprise I suppose, as:
- the design has separate coils for lateral & vertical stylus movement
- the Decca was originally designed for mono record playing (with only a lateral pickup coil).

However, I have no idea why record surface noise when playing stereo (as in mono), seems to be less obvious with the Decca.

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My signature on Lencoheaven...

Please let me build a system that is a bit forgiving on what I find in thrift shops for a handful of pennies and still is able to deliver the goods on good pressings.

Sounds like you've acheived my aim...

I get suspicious when people say that "the noise floor is much lower". It sometimes means that the transducer is missing or losing some information overall.
With the Decca, miscell surface debris noises, seem to be proportionately less prominent & the musical signal proportionately more 'present'.

How so? I don't really know but it may be something to do with the unique way that the Decca coils are wired with 2 vertical coils out of phase + 1 lateral coil, in a sum & difference arrangement (below)....

Or maybe just the stylus profile - 'extended line contact' in the case of the Super Gold.

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haha

i said that when i first got the lyra delos.

Lyra actually did it right when they designed their Mono cartridges, re-orientating the coils horizontally, to respond more accurately to monophonic (horiz) groove cuts.

Citroen, you've got a Lyra Mono as I recall?

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Yes, and it sounds very good even when playing stereo lps!

I unfortunately don't recall ever having heard a Decca cart

My London Decca Super Gold cartridge recently returned from a trip to John Wright Audio Services, Shropshire, UK to have a 'Decapod' mounting block fitted, a repair & recalibration. John, a former Decca engineer, is the officially licensed manufacturer & servicing person for Decca & London Decca cartridges.

Before mounting the cartridge to the TT, I though I'd take a look at it using the borrowed USB mircroscope recently mentioned & capture a few images.

As can be seen, the Decca differs from most other cartridges:








(This model has an 'extended line contact' stylus.)

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