This area of the site is being produced primarily to create an online record of KEF drive units from the period of interest. It is hoped that eventually it will contain a comprehensive list of the types of items produced and sold by KEF during that particular period and it will provide technical details and pictures of these items. A leaflet (10 74 UN3) which was issued by KEF in the 1970s and provides details of the B139, B200, B110 and T27 has been reproduced here for online viewing.

KEF Drive Units

Links

Illustration

Drive Units and ABRs (dimensions approx)

B300

B300B SP1071 (350mm diameter). Picture on right and information about drive unit supplied by Colin Royle on Sunday 22 February 2004.

Spec. sheet supplied by Bob Neidorff on 28 May 2006

Info in 'KEF selbst bauen' document

B139

Spec sheets on Dave Dlugos site including cutout dimensions and potential substitutes

B139 6171 (330 X 240) Manufactured late 60s or early 70s. Usually bare metal chassis. Image shown is of a 6171 with painted chassis. Rubber surround. Polystyrene cone.

B139 SP1044 (300 X 210) Narrower chassis than 6171. Chassis painted black. Rubber surround. Polystyrene cone.

B139 SP1044 Spec Sheet (German)

B139B SP1044

Info in 'KEF selbst bauen' document

Spec sheets on Dave Dlugos site for B139 and B139B

To come

BD139B SP1042 ABR Polystyrene cone.

BD139B SP1082 ABR Polystyrene cone. All pictures supplied by Colin Royle on Saturday 9 April 2005. Colin also points out that the pictures show "the SP1082's more compliant suspension deforming under the polystyrene cone's weight" "This explains the lower resonant frequency, etc cf SP1042." Apparently the gold items supporting the BD139s in the photographs are Mitchell bananas.

Info in'KEF selbst bauen' document

BD139 (330 X 240) SP1037 Manufactured late 60s or early 70s. Usually bare metal chassis. Originally foam surrounds. Later models replaced by rubber surrounds - probably all examples with foam surrounds will have disintegrated and if repaired will have been replaced with rubber surrounds. Polystyrene cone.

Info in 'KEF selbst bauen' document

To come

B139 SP1333

All pictures supplied by Barrie Brett on Wednesday 6 April 2005

B200

Spec sheets on Dave Dlugos site including cutout dimensions

B200 SP1014 (244mm diameter) - (used in Chorale and KEF KIT 1)

Info in 'KEF selbst bauen' document

Spec sheet on Dave Dlugos site

'Rabbits ears' B200 SP1014 drive unit from 1971 LNB Paralab 20s. Information and photographs supplied on 19 January 2006 by Colin Royle

B200 SP1022 - (used in Cadenza)

Spec sheet on Dave Dlugos site

To come

B200 SP1039 (244mm diameter) - (used in 104 and 104ab)

Info in 'KEF selbst bauen' document

Spec sheet on Dave Dlugos site

B200 SP1047 - (used in KEF KIT 1)

B200 SP1054 All pictures supplied by Colin Royle on Saturday 9 April 2005.

Spec sheet on Dave Dlugos site

B200 SP1063 (used in Corelli) All pictures supplied by Colin Royle on Saturday 9 April 2005. Colin also advises that the only visible difference between the SP1014 and SP1063 is the voice coil - one's Copper the other's Aluminium.

Spec sheet on Dave Dlugos site

B200 SP1070 (used in Celeste III)

B200G SP1075 Photographs and information supplied by Steve Bell 17 January 2004. - (used in 103.2 and; CS2)

Info in 'KEF selbst bauen' document. B200G SP1075 Spec sheet.

B110 - Some information about differences in drive units with same specification - supplied by Colin Royle on Sunday 29 February 2004..

Spec sheets on Dave Dlugos site including cutout dimensions

B110 A6340

B110 A6362

B110 SP1003 (140 diameter)

Info in 'KEF selbst bauen' document

Spec sheet on Dave Dlugos site

B110 SP1057 (used in 101) - All pictures and information supplied by Colin Royle on Sunday 29 February 2004.

Spec. sheet supplied by Bob Neidorff on 28 May 2006

Info in 'KEF selbst bauen' document

Spec sheet on Dave Dlugos site

B110 SP1228

B110C

T27

T27 A6340 Used in the earliest LS3/5

T27 6535 drive unit from 1971 LNB Paralab 20s. Information and photographs supplied on 19 January 2006 by Colin Royle

T27 SP1032 (108 diameter)

T27A SP1032

T27 Spec. sheet

Info in 'KEF selbst bauen' document

T15

T15 (110 diameter) - Pictures supplied by Andrew Goloskof on Sunday 5 September 2004.

T33

T33A SP1074 Photographs and information supplied by Steve Bell 17 January 2004.

Info in 'KEF selbst bauen' document

T52

T52 SP1049 Picture on right and information about drive unit supplied by Colin Royle on Sunday 22 February 2004.

T52B SP1072 Picture on right and information about drive unit supplied by Colin Royle on Friday 20 February 2004.

Info in 'KEF selbst bauen' document