This is a piece of news not yet discovered by the Hifi press. There is an upgrade kit for modifying the Carlsson OA-51 to OA-51.3 status. Until recently the model could be upgraded to .2 status but now the .3 upgrade kit elevates the speaker to a new level that was not possible before.
The biggest improvement is the absence of the slight hissing from the metal dome tweeter used in OA-51.2. The OA-51.3 is however not sold as a complete speaker. It is only available as an upgrade kit for owners of earlier models.
The upgrade transforms the speaker to a desirable high-end speaker.
The OA-51.3 is the favourite amongst most of the members of the Stig Carlsson Trust and also amongst most Carlsson fanatics
Restoration
Most things according to Restoring and upgrading.
There are however a few things that might need addressing:
The plastic front cover
Is most likely ruined from old age by now, get the new wire grill instead.
Inside the box
Some people like to tamper with the bass reflex tube and the internal wiring. This can be tricky as it is very difficult to do anything inside the box due to the battens and the stay wall.
Upgrading
There are three different upgrade kits plus a new grill and damping material for the damping panels available.
De Luxe upgrade to OA.51.3
• New tweeters, Carlsson T11oa. The new silk dome tweeter developed by the Stig Carlsson Trust and manufactured by Vifa. A unit with very low distortion.
• New Woofers, Scan-Speak 18W8545 carbon fibre reinforced woofers replacing the old 18W8542.
• A new filter with premium components, teflon insulated one strand wire and a modification instruction.
Standard upgrade to OA.51.3
• Same speaker units as the De Luxe kit
• A new filter with good standard components, air wound inductors and SCR/MKP polypropylene capacitors and with standard internal wiring.
Standard upgrade to OA.51.3 from 51.2
This contains the same parts as the standard kit but the woofers are not included.
New grill
The original foam front is most likely ruined by now. Therefore a new protective wire grill has been developed for the speaker instead.
New damping material for the absorbent panels
The panels have also by now most likely deteriorated. New damping material is available.
All kits etc are available from
John Larsen at Carlssonfabriken i Skillingaryd.
Phone: + 46 370 70 900
E-mail: larsen.hifi@telia.com
TECHNICAL DATA Carlsson OA-51.3
Principle: 2-way omni-directional bass reflex tuned to 38Hz, with absorbent panels.Impedance: 8 Ohm
Sensitivity: 87 dB / W / M
Mid/bass: 7”, Scan Speak 18W/8545
Tweeter: 25 mm silk dome (Carlsson T11oa)
Weight: 14.4 kg
Measures: 43 x 30 x 25 cm W x H x D. W including absorbent panel 72 cm
Inner volume: 16 litres
Finish: Walnut, rosewood, black ash or white lacquer. Other types to order.
Positioning: Close to a wall / Wall hanging
Cross over freq: 2500 Hz (OA-51)
Frequency range: 32-20.000 Hz (OA-51)
Frequency response: 40-17.000 Hz ± 2 dB (OA-51)
Prices
New speakers
Not available.
Upgrade kits etc
De Luxe upgrade: 7,900 SEK
Standard upgrade: 5,400 SEK
OA-51.2 to 51.3: 2,500 SEK
Design grill: 1000 SEK per pair
Damping material for absorbent panels: 50 SEK per piece
Second hand
OA-51.3: Ranging from 2,500 to 10,000 SEK depending on finish and if it is standard or DeLux.
Martin Dellstig - Co-Editor
This page was last edited 2007-10-02 21:50:42 by Per
