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Plans for Tannoy GRF or Autograph

M

messengerman

pfm Member
Having gotten the Tannoy bug with a lovely pair of Dorsets I had the opportunity a year or so ago to add a pair of Mansfields. These used the bigger HPD385 15" drivers and this pair had been freshly reconed by Lockwoods.

Initially the sound was disappointing - boomy bass and missing the midrange delicacy of the smaller Dorsets. Moving them around didn't make any great difference so I decided to let them be and see if they improved after a bit of running in.

A year later I have decided to try new cabinets. I'm going to make them myself and will probably do Autographs though I may opt for the simpler corner GRF. I'll use baltic birch ply and original plans if I can find them. (anyone got any current links?)

The idea is to stick closely to those original plans perhaps strengthening some of the larger panels but making no fundamental changes to the working shapes. The outside though is a different matter and I'd like to try and create a more up to date external appearance.

If anyone's interested I could post pictures of the build as it goes along.
 
Hi Messengerman

Yes please, would love to see the DIY pictures as you proceed.

It's one segment of the hifi fora I like the best! :)
 
messengerman said:
The idea is to stick closely to those original plans perhaps strengthening some of the larger panels but making no fundamental changes to the working shapes. The outside though is a different matter and I'd like to try and create a more up to date external appearance.
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I would not make the corner GRFs unless I had a particular reason for so doing. The rectangular GRF is almost sonically identical, smaller and much easier to make and accommodate in your living area.

I have a pair of Autographs and I have never heard anything to touch them. They are quite wonderful. The HPD was not intended for horn loading in the same way as the earlier models but I'm sure it will perform very well in either model cabinet. Later Autograph production examples included a rectangular version and this has a more modern appearance although the bottom end performance is a little compromised relative to the corner variant due to the inability of the side walls to provide rear horn extension. However, it is much easier to construct. So is the GRF Professional.

The corner version Autograph, particularly the initial horn development and the Tractrix front horn are a nightmare to fabricate but well worth the effort. See Australian, Richard Norrish's site for interesting construction photos and comments.
 
Thanks everyone for the links and info. I'll be sure to post updates as i go.

There does seem to be loads of variations out there on these two designs. Varied opinions too. I had read a few adverse comments on the rectangular GRF (vs the corner) which was the main reason I was looking at the corner one. Though I must say corner speakers would also fit rather well in my living room.

As you say Richards C the rectangular GRF does look easy to build and is also by far the easiest to restyle. Might a good starting point and allow me to try out finishes before I attempt an Autograph.

The Autograph does seem to get universal praise for its sound and so is definitely my long term preference.

I expect what I do first will depend on the availability (or otherwise) of good plans. I think I could manage the build but I don't fancy attempting to recontruct such a complex design from partial plans a la Richard Norrish.
 
messengerman said:
I expect what I do first will depend on the availability (or otherwise) of good plans. I think I could manage the build but I don't fancy attempting to recontruct such a complex design from partial plans a la Richard Norrish.
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There is no complete and accurate set of plans for the Autograph beyond those prepared by various people for commercial purposes and therefore not generally available. The revised Tannoy company used to release this information but have been reluctant to do so in recent years - presumably they would prefer to assist someone to purchase one of their new creations rather than lose the business to a fifty year old competitor, albeit of the same name.

Ronald Rackham's brilliant concept for housing his other brilliant achievement (the development of the Dual Concentric) is complex and difficult to visualise in three dimensions from two-dimensional drawings. The Carlo Guidetti dimensions are sufficiently accurate for all practical purposes but his drawings are far from being complete and you will not be able to construct a cabinet from them alone. However, if you combine these with those provided by Alain Kobsch and to be found on Steve Spicer's Kiewa Valley site - Tannoy Section - which are more pictorially comprehensive as well as with Richard Norrish's photos, you will at least have a starting point!

Have no illusions, making a pair of these monsters will require woodworking skills, will be expensive and will be no easy task. It won't be made any easier by your choice of birch wood. Unless you employ the umpteen-ply panels (which are more glue than wood), it will be like working with blotting paper with a tear-out guranteed with every cut.

The idea of starting with the R-GRF is a very good one. Despite what you may have heard to the contrary, (and be wary of opinions given on this subject - the opportunities to hear any sort of GRF are not common so the opinion probably is inaccurate hearsay), the R-GRF is an excellent cabinet and who knows? - it may prove to be all you want. Hope that it is for you will age prematurely in constructing the Autograph. That's a promise!

Richard.

PS Sorry I am unable to put in the link thingy - the technology is beyond me.
 
You obviously know your subject Richard. Many thanks for taking the time to post. I'll have a pop at the R-GRFs first. A smooth open baffle job I think, in Piano black. But first I have to finish building my workshop!

How did you come by your Autographs? Are they original?
 
messengerman said:
You obviously know your subject Richard. Many thanks for taking the time to post. I'll have a pop at the R-GRFs first. A smooth open baffle job I think, in Piano black. But first I have to finish building my workshop!

How did you come by your Autographs? Are they original?
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Whilst the R-GRF may seem like a bookshelf job compared with the Autograph, at 43" X 24" X 20" it is still a large box and might look rather brooding and sepulchral in unrelieved black - just a thought.

My Autographs came from West Norwood many years ago but I have intentions of building another pair myself as I think I can improve on the quality of construction and appearance. Don't know when this will be but I shall have to start soon if only to justify the expense of already having bought the Golds to put in them. Tannoy's core business was manufacturing speakers, amplifiers and other electronic stuff; the woodworking side of things was of marginal interest to GRF and generally speaking, the cabinets were an adjunct to sell the drivers and consequently not up to the highest standards of cabinetmaking.

I have built several R-GRFs - it's not what I do but people having heard mine insisted that I made them a pair too! - and there are a few improvements you can incorporate into the construction. Stiffening the back panel is one and I can help you with advice should you need it as you progress.

Good luck,

Richard.
 
I'll be sure to take you up on that offer and I'd love to hear to how you get along with the Autograph build.

Not sure where you're based. Oddly enough I actually live in West Norwood. Not 100 yards from one of the old Tannoy sites ( I think they had a few here). I might just put a Made in West Norwood sticker on the back of the R-GRFs :)
 
Richard C. said:
.... it is still a large box and might look rather brooding and sepulchral in unrelieved black - just a thought.


Richard.
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They could look like that. I think it might be a question of having the finish in mind at the design stage. After all pianos are quite big but look much better in black than in bare wood.
 
messengerman said:
Oddly enough I actually live in West Norwood. Not 100 yards from one of the old Tannoy sites ( I think they had a few here). I might just put a Made in West Norwood sticker on the back of the R-GRFs :)
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They certainly did have "a few".

Tannoy started as the Tulsemere Manufacturing Company in 1926 with their first premises in Tulsemere Road. Later they expanded to a second building in Dalton Street. Eventually, the company operated in what seemed like a rabbit warren for they had premises in Canterbury Grove, Bloom Grove, Cox's Yard and several sites in Norwood Road, one of which Guy Fountain took over from the wartime Norwegian Navy. 344-348 Norwood Road was where the bulk of the cabinets were made but there was a small woodworking shop in West Dulwich in which many of the prototypes were produced. I imagine you must know these venues well.

After acquisition of Tannoy by Mr Harmon (Harmon Kardon) in 1974 and the introduction of his wholly inappropriate American approach to the operating of the company, things started to go downhill fairly rapidly. Because of political restraints in the US (Harmon became part of Jimmy Carter's administration), he sold the company to a yogurt manufacturer. A subsequent management buy-out wrested Tannoy from foreign ownership but only for a while - I believe the company now effectively is Dutch owned. I have no knowledge of current products.

To those of us old enough to remember the "real" Tannoy company and its pre-1974 products, (and I am old enough to remember the Parmekos in the Abbey Road Studios before Tannoy were installed) it is a fascinating history involving some very bright and clever people who produced speakers which, arguably, might have been equalled but never surpassed.

There is a fellow in Norfolk who produces facsimile decals of the original. But I like the idea of a "Made in Norwood" label; the romantic whimsy appeals to me but then I suspect I see these things from a perspective different from that of most others.

Richard.
 
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