Foam rot

I have a pair of OA-14 where the foam surround is damaged, is it old age? (or OA-12, OD-11, OA-116, OA-2212, OA-50/51/52)

Yes, it is most likely old age. The expected lifespan for a surround is in normal conditions 12 – 15 years. You should stop playing your speakers or you might damage your amplifier also. The woofer can be either repaired or replaced.

You have four alternatives:
1. Get new surrounds for the woofers. Either you do it your self or have someone perform the operation for you. Surrounds can be found if you search the internet.
2. Another possibility is to find a shop selling speaker units, the will probably know who can put new surrounds on your speakers.
3. Get in contact with CarlssonPlanet and see if we can help you
4. Get new woofers.
This is valid for the Scan-speak 18W/8542 and the earlier models of SC 165 (Peerless 6.5″). The Scan-Speak 18W/8545 and the SC 165 Mk III and Mk IV have rubber surrounds that are age proof. See Restoring and upgrading.

Changing the woofers

What units do you recommend when buying new woofers?

If it is the SC 165 (6.5″ Peerless woofer) we recommend that you buy the new SC 165 (6.5″ Peerless woofer) also known as B65-oa it has model no 831881.
If you need a replacement for your OA-51 or OA-52 You should consider buying the Scan-Speak 18W/8545 used in Mk II and Mk III instead of the Scan/Speak 18W/8542 and upgrade your speakers to a higher level. This is well worth the extra cost. The biggest cost is for the woofers anyway.
See Restoring and Upgrading where you find information on the various speaker units.

Full range units

The Full range unit of my OA-5 speaker is damaged (Or V-1, OA-4, OA-6 Pop-box or Coalscuttle) What should I do now?

Tread lightly, the Philips (Norelco) 9710 is no longer in production. At CarlssonPlanet we have not yet found an acceptable replacement.

1. First check if it is beyond repair (see restoring and upgrading)
2. Search e-bay and similar places, the 9710 was made in huge quantities in its time and was in production in the eight ohm version until 1980.
Look also for old speakers using the 9710, it was used in many commercial products and also a favourite in the DIY community for horns etc. The 800 ohms version, 9710AM (800 Ohms), is however more scarce.


I have a damaged tweeter on my Carlsson speaker, what do I do?

This is not a big problem. All tweeters are still available on the market except for the Peerless MT 20 HFC and MT 24 HFC that were used in OA-4, OA-5, OA-6, OD-11, OA-12, OA-14, OA-116, OA-2212, the Pop-box and the Coal scuttle.
Regarding these we recommend using the Peerless CT62 instead which is a recommended upgrade anyhow. In all other cases replacing the tweeters with new ones is possible but you should consider upgrading your speakers.
For replacement or upgrading, see restoring and upgrading.

Foam surrounds

Does CarlssonPlanet sell foam surrounds?

No we don’t. Foam surrounds can be found on the internet if you search for them. See to that you get the right type.
From time to time used speakers, thoroughly cleaned and with new original surrounds can be purchased through CarlssonPlanet. These are tested OK after the new surrounds have been installed. Check with CarlssonPlanet 

Buying Hifi equipment

Can you recommend a good CD, amp, or turntable etc in my price range that fits with my Carlsson speakers?

This question in different form is one of the most frequently asked. It is also almost impossible to answer due to the enormous number of products available on the market.
As a rule we only answer questions about Also look at user reviews at the internet, try the http://www.audioreview.com/reviewscrx.aspx for instance.

Special Tools

What tools do I need for restoring a pair of Carlsson speakers?

You need only normal tools as found in most people’s toolboxes, soldering iron, cutters, pliers, screwdrivers, knives etc.
For the boxes you need soap, white spirit, sandpaper and wood oil etc, nothing fancy.

Original units for Carlsson speakers

Does CarlssonPlanet sell original speaker units or where do I find new units?

Sometimes CarlssonPlanet can supply used but tested parts. These are mainly 6.5” mid woofers, Peerless tweeters and sometimes 7” Scan-Speak and 8” Philips (Norelco) 9710. Others are less frequent.

In Sweden we recommend the following sources:

Larsen HiFi
Tel. +46 370 70900
[email protected]

This is the producer of Carlsson speakers for models in the 50 series and the new coming models.

One of very few speaker units retailers in Sweden, does business abroad.

Outside Sweden
Check with Danish Sound Technology.
http://www.d-s-t.com/main/index.htm and see what distributors they have closest to you.

Carlsson Society

Is there a ”Carlsson society” or similar?

No, not at present. However we have a large quantity of people interested so we hope to be able to start one later on.
The Stig Carlsson Trust handles the designs, patents and recordings etc. They have the responsibility to spread knowledge about Stig Carlssons “ortho-acoustical principles”. This is, at present, done mainly by introducing new models based on Stig Carlssons designs and ideas.

Tubes (Vacuum tubes, Valves)

Where do I find new tubes for my Coalscuttle, OA-6 Mk I or “Pop box amplifier”?

In Sweden we recommend:
Tel: +46 8 718 00 16
Fax: +46 8 718 59 70

The tubes used are not very rare.
The most common types are EL86, ECC83 and PCC88. These are available as NOS and in new production. Search the internet for your best dealer.


Can CarlssonPlanet restore my Carlsson speakers?

Yes, if we get to decide when. We do this on a hobby basis so therefore we don’t have the possibility to do a lot of speakers. Mail us.

Restoration of other Sonab Equipment

Can CarlssonPlanet restore my old broken Sonab equipment?

In Sweden we from time to time restore the Sonab turntables. Sending these to Sweden is costly and risky but feel free to ask. Mail us.

Old Sonab Speakers

I have a pair of Carlsson speakers would you like to have them?

Yes, we do not like seeing old Sonab speakers thrown away. We have however very small possibilities to buy them from you because we don’t sell them again without a costly restoration and upgrading. The best opportunity is to put up an ad on E-bay or similar.
Don’t throw them away!

What’s the difference between OA-6 (Mk I) and OA-6 Typ 2 (Mk II)?

OA-6 Mk I
Is an active bi-amplified speaker with built in OTL tube amplifiers so all it takes is a signal source and a pre amplifier.
It was equipped with a 10” woofer, an 8” full range speaker as midrange and four tweeters. The 10” and 8” were high impedance units with 800 Ohms impedance, the tweeters were transformer coupled. Its design has a lot in common with the “Coalscuttle”. It was made with premium components and good care. Even today it is an extremely well sounding speaker if restored.

OA-6 Mk II

Is unfortunately not an equally good speaker. Even though it is an active speaker it needs a power amplifier. The active part is a “bass-energizer” helping the Philips 9710 Full range speaker to act like a woofer. It is a nice speaker that is easy to drive but it will not play music at loud levels.
Due to the “Bass-energizer” it is NOT suitable to use with tube amplifiers.

Martin Dellstig – Co-Editor


No comments yet.

Leave a Reply