Linn Kan 1 speaker restoration

[Al.M]

I restored these 1980s speakers recently and replaced the old cheap electrolytic capacitors with new and better quality ones in the critical circuit path with Aeon polypropylene and tin foil capacitors, got professional original new rubber surrounds for the Kef B110 woofers, and replaced the tweeters with new matching Scanspeak D2008/8511 ferrofluidless tweeters from Australian supplier.

 

I looked on the net for example restorations and despite the extensive talk there wasn’t much to go with so I had to nut this out myself.

 

Firstly, the net discussions vary between using the similar Hiquhon tweeter, Scanspeak D2008/8511 ferrofluidless vs 8512 ferrofluid units. The back of original tweeter units say a Scanspeak D2008 but not which exact model. One net discussion indicated the ferrofluidless version so I went with that, but many people seem to use the other. When I got them and measured the impedance between old and new they matched perfectly at 9.1 ohm and sound perfect.

 

The crossover circuit in below picture is quite simple parallel third order on tweeter and maybe a second order on the midbass woofer with an RC shunt and a mysterious 4.5uf capacitor connected from -ve to -ve, see original crossover pic darker blue cap. Does anyone have the full crossover schematic showing all values?

 

The inside construction of the cabinet is solid with 10mm thick fibrous resonance damping stuck to walls, wooly insulation, rear woofer basket and tweeter coated with a tan and black coloured gluey material possibly to keep resonances down. The drivers are a pain to get out as they are sealed in with that tan resin so one has to place a large screw in the holes prize out with a claw hammer. The woofer was near impossible to get out as it was difficult to find a large screw to fit so the only way wasto jimmy it out via the damaged roll surround gripped onto the rear basket.

 

The whole restoration took several weeks for parts to arrive, woofer surround replacement and with some dead end decisions like ordering Kef B110 surrounds from a EU supplier that turned out be too thick vs the original ones. Speaker Doctor in Perth was able to find  originals that match and did a fine job. The crossover soldering and scraping the gluey stuff out from the drivers and holes took about 6 hours.

 

Some pictures below, excuse my hand drawn xo picture.

 

The sound result is amazing, highly detailed I’d have to say that $100 Scanspeak D2008/8511 ferrofluidless tweeter is as detailed as any high end Scanspeak further up the ladder (D2904/9300, 9500, 9900), particularly on my tin foil caps over the original electrolytic caps, the humble and venerable Kef B110 midbass woofer does a good job and the whole sound is extreme detail, fantastic imaging and very coherent voice. I prefer this sound to the softer Ls3/5a speakers and they compete well with more modern monitors I have heard like Dynaudios and Sonus Faber. The best sounding amps for them are tubes (using 60w KT88) and none of my other large solid state amps (up to 200w) sound any where as good, lacking the detail, sweetness, coherence and imaging. 

Edited May 14, 2018 by Al.M

[Addicted to music]

I had a pair of Kans, I think they were the 2nd revision.  With the right amplification and even certain high powered spot welder (not Naim). These were astonishing!   Laid down the law on a pair  Spendor that was close to LS3/5a  to say who’s boss!   They actually come alive with live recordings....   I can just imagine what they be liked with the tweeter having a MKP in place of the original electrolytic.   Sadly I sold them when i got onto SNA..

Edited May 14, 2018 by Addicted to music

[Al.M]

Live music, acoustic, jazz, guitars, female vocals, trumpets simply amazing. I will add a sub with them later and it will be another match made in heaven. As a mini monitor with small 5 inch woofer with pronounced character there is less of the midrange hole that many good two way speakers seem to suffer from urging one to look towards three way speakers.

 

The Speakers will not suit neutralists as they do have a strong character to the sound.

 

I had these about 10 years ago and teamed them up with a DIY transmission line sub using the old Kef B139 oval 10inch woofer equivalent and always thought that was one of the best sound in my room and wanted to revisit that, very happy now

Edited May 14, 2018 by Al.M

[Misternavi]

to Kan or not to Kan, that has always be my response when one comes up for sale.

 

 

what are they like with heavy bass music?

[Al.M]

1 hour ago, misternavi said:

to Kan or not to Kan, that has always be my response when one comes up for sale.

 

 

what are they like with heavy bass music?

They do need a sub as bass is quite thin. With their sealed box design they match well with subs and there no integration issues.

 

Used Kans can be found for around $600-700 whereas 10 years ago they were around $400 so used value increased.

 

If you have fond memories of the Kan, believe me the new tweeters with upgraded capacitors is astonishingly detailed. In my previous Kans that was one of the negatives that the tweeter was a little brash, but it’s likely by upgrading capacitors on the old ones performance will improve without buying new tweeters. At the very minimum even retaining the old capacitors and piggy backing low value 0.1uf tin foil caps x $10 each (2) would make a difference.

 

Given the simple crossover circuit a DIY clone of the Kan is very doable provided the Kef woofer often seen used separately from vintage parts and projects is the same as the Kan (label says Kef B110 8 ohm), slap some resin on back of frame, assemble crossover, obtain set of new tweeters, make cabinet, perhaps $300-400 total.

 

BTW, I have Kef Ls50 the Kans seem to be keeping up except for bass. I will need to mod the Ls50 caps to be fare. The tweeter response alone on the modded Kans is definately sounding better than the unmodded Ls50.

Edited May 14, 2018 by Al.M

[Misternavi]

@Al.M tempting.
Could you use this:

LS3/5a speaker cabinet off Ebay?

[Al.M]

Possible to use those cabinets but would be better to wait for used Kans to turn up, the Kans are 19x16x30cm and the tweeter hole diameter may be different size as the Ls3/5a uses the Kef T27 tweeter but whole can be modified if needed.

 

I didnt measure the inductor values and the cabinets are all sealed up now but they may be available elsewhere.

Edited May 15, 2018 by Al.M

[Addicted to music]

MKP in line with the tweeter is a serious improvement compared to the stock standard electrolytic bypolar equivalent.  I did that experiment in my early 20s with the 6ft ribbons I currently own.  Remov8ng the electrolytic cap with a power correction motor cap with the MKP ( metalised polypropylene)  removed the harshness and smoothed out the tweeter response with the added bonus of increasing details...  its one of the best upgrade for any 10yrs + speakers of cheap no name speaker.  The specs are also backs what you hear,  a fraction in figures for absorption rate, higher dv/dt are some of the technical improvements you’ll notice that’s far greater than a change in speaker cable or terminal where you’re paying mega dollars with very little improvements.

yes you do need a sub to do it justice, but with the right amplification 500W @ 8ohms and placed with the back right up against the back wall,  with no sub you swear that’s the sound stage and bass are  coming   from a much larger speaker!   I had a 500w Perreaux driving them 30+ yrs ago....  farking amazing! 

Edited May 15, 2018 by Addicted to music

[Al.M]

5 hours ago, Addicted to music said:

MKP in line with the tweeter is a serious improvement

I’ve discovered this about 15 yrs ago also, even piggy backing low value 0.1uf less costly metal film caps onto existing electrolytics in a crossover in series will make a huge difference maybe about 20% subjectively, on normal polypropylene caps about 10% improvement. I’ve tried many times in another speaker metal cap on and off and heard consistent subjective difference as you stated. Higher value metal film caps cost quite a bit so the lowest value ones work for me.

 

Do you have any favourite currently available metal film cap brands or are they similar? Soundlabs Aust have many nice looking Mundorf caps on their website. I usual get my caps from WAR audio Perth but havnt bought any in recent years.

 

Soundlabs have many different caps described as metal poly etc a little confusing as to which is good without spending too much https://www.soundlabsgroup.com.au/c/Mundorf-Tubecap/Mundorf+TubeCap.html any thoughts?

 

Will try some of my 200w SS amps later with the Kans as you suggested and switch from the KT88 60w tube amp once the lower jaw frees up a bit.

Edited May 15, 2018 by Al.M

[Addicted to music]

I’m done with audiophile approved branded components!   I bought some obbligator gold series MKP from that audiophile component store in US.  One of the purchase I regretted for the rest of my life...  this branded caps had high praises here on this site and from that one  who did  the capacitor cook book!   I’ll never followed that advise even if it did have sonic improvements.  As I said the best was power correction MKP cap of a photocopier when they were using AC motors.  This is what made me pursues MKP not just for cross overs but for amplifiers too.   I then had MKP Custom made by Ericsson’s when they had there capacitor winding machine here in Melb back in the 90s and had 50uf 400V wound up!  These tear to Shreads sonically anything I used!   They are a keeper for my ribbons.  To bad they no longer have this facility today!

They are getting cheaper, here’s a Panasonic range that has excellent healing properties,  the plates are segmented so if an area becomes a short it isolates phyically to the rest of the wound!  Check the video out when you search for these caps!

 

 

https://au.rs-online.com/web/c/passive-components/capacitors/polypropylene-film-capacitors/?sort-by=P_breakPrice1&sort-order=desc&applied-dimensions=4294965862,4292338678

 

if i were to buy caps this is what I’ll be considering, there are ones designed for AC power coupling and ones for power factor corrections,  the ones I’d be looking at are ones that have high dv/dt low ESR! 

[electricnerve]

On 14/05/2018 at 12:25 PM, Al.M said:

I restored these 1980s speakers recently and replaced the old cheap electrolytic capacitors with new and better quality ones in the critical circuit path with Aeon polypropylene and tin foil capacitors, got professional original new rubber surrounds for the Kef B110 woofers, and replaced the tweeters with new matching Scanspeak D2008/8511 ferrofluidless tweeters from Australian supplier.

 

The whole restoration took several weeks for parts to arrive, woofer surround replacement and with some dead end decisions like ordering Kef B110 surrounds from a EU supplier that turned out be too thick vs the original ones. Speaker Doctor in Perth was able to find  originals that match and did a fine job. The crossover soldering and scraping the gluey stuff out from the drivers and holes took about 6 hours.

 

Nice job. How did you go about removing the drivers? I need to replace the rubber surrounds too. I can remove the tweeters easily enough, by lightly screwing a larger self-tapper in the existing holes of the tweeter housing, and patiently levering it out with a claw hammer. The woofers, however, are not susceptible to the same approach. Is there a way to lever them out without damaging the cabinet?

[Al.M]

8 hours ago, electricnerve said:

removing the drivers?

My rubber surrounds were also cracked and needed replacing so get a large flat tip screw driver and slide it between cracked surround and underside of driver, wedge it onto a short wood piece 10x20mm high between tweeter and woofer, preferably sitting inside the edges to stop wood damage. Doesnt need much pressure to lever it up. Repeat same procedure to top of woofer.

 

If you are into the crossover could you measure the inductor values and report back here as I have sealed mine up already.

[legend]

On ‎8‎/‎07‎/‎2018 at 4:54 PM, electricnerve said:

Nice job. How did you go about removing the drivers? I need to replace the rubber surrounds too. I can remove the tweeters easily enough, by lightly screwing a larger self-tapper in the existing holes of the tweeter housing, and patiently levering it out with a claw hammer. The woofers, however, are not susceptible to the same approach. Is there a way to lever them out without damaging the cabinet?

You should be able to remove the woofers by the same method as the tweeters - that is the way we did it when I worked for Linn in the mid-late 1980s.  However they are held in with silicone sealer so may require a bit more patience and/or muscle as it will probably have well and truly hardened by now - and you need to place something hard between the baffle and the claw hammer.

Edited July 15, 2018 by legend
additional info

[legend]

The real problem with the Kans was not so much the crossover components but the design of the crossover itself - which as Martin Colloms said in a review was fundamentally broken.  I was told by a colleague that it was designed by winding down inductors until the sales guys liked the sound - but given they liked simple voice/guitar music from the 1970s it really only worked for that - and made pianos sound like honky-tonks.  Its frequency response had a very deep 'hole' from around 1500 to 2500 Hz because this shutout the distortion from cone breakup of the woofer - and the Hiqphon tweeter could not go low enough to fill it in.  Replacing the tweeter with a Scan-Speak would probably help but the Xover itself needs redesigning - simply throwing more expensive components at the existing circuit will not sole its fundamental problem.

[Al.M]

The original tweeer I replaced is labelled a Scanspeak model 2008 but didn’t say which version either the 8511 ferrofliudless voice coil or the 8512 but went on some web advice that is was the 8511. Hiqphon which looks very close to a Scanspeak 2008 model, perhaps Scanspeak makes them for Hiqphon at their requirements or licenced by Hiqphon to produce a variant.

 

Perhaps also whether Linn used both Scanspeak and Hiqphon at different model stages.

 

The crossover parts were what I had lying around. I struggled high and low trying to find an exact screw to fit the woofer holes and lever out and there isn’t much room behind as the threaded bit on the other side of the baffle gets in the way for any screw to get a grip. The actual force to lever it out isn’t much.

Edited July 15, 2018 by Al.M

[legend]

Linn never used Scan-Speak drivers on the Kans - they were always made by Hiquphon.  Your Scan-Speak must have been added subsequently.

[Al.M]

This is the only Kan I’ve opened up but the picture below shows a Linn product labeled tweeter with Scanspeak 2008 written on it as well. The tan coloured sealant on the back of the tweeter and faceplate is also the same look and age of that behind the woofer so it looks to have been in there from date of manufacture.

 

There is discussion on the Linn and Pink fish forums as well about the use of both Hiqphon and Scanspeak tweeters in different models.

[Piker]

Hi, from the looks of the picture of the crossover, the 4.5uf is connected between the woofer hot to ground.  

[Al.M]

50 minutes ago, Piker said:

Hi, from the looks of the picture of the crossover, the 4.5uf is connected between the woofer hot to ground.  

 

50 minutes ago, Piker said:

Hi, from the looks of the picture of the crossover, the 4.5uf is connected between the woofer hot to ground.  

Thanks, so the 4.5uf makes up the second order 12dB leg of the crossover for the woofer?

 

I now wish I had gone to the trouble of peeling the glue off the inductors to measure them to complete the crossover schematic so that people could clone these provided the original woofer and tweeter was not customised. I’m sure someone has the full schematic somewhere.

Edited September 14, 2018 by Al.M

[Piker]

Yep,  2nd order on the woofer. It also looks like the polarity might be reversed on the woofer.   Thank you for posting the picture.  I personally think that the crossover topology of a speaker contributes something to the subjective sound of a speaker.   So even if you are not cloning this specific design it may be useful for future designs if you like the sound of the Linn Kan mk1. 

[Al.M]

The woofer does not appear customised as the labelling on it seems stock Kef with no other designations on it like say for example Proac speakers have theirs. The original tweeter dome in my example has a shiny coating on it that the replacement Scanspeak tweeter does not but. But if my old sonic signature memory in my ears serve me correctly they sound very similar to the last pair I had some years ago.

 

The last time I googled for a Lin Kan crossover diagram there wasn’t one even on such popular sites as Linn and Pink fish audio forums.

 

Edited May 3, 2019 by Al.M

[TB10]

It looks like the crossover could easily be routed to two sets of inputs, and be bi-wired.

[Al.M]

Yes crossover is a simple parallel circuit and easily biwired.

[dd845]

I have a pair of Linn Kan 1 which tweeters were damaged, want to have same restortion, can you please let us know how the B110 and D2008 drivers be taken out? thanks!

[Al.M]

On 11/01/2020 at 10:12 AM, dd845 said:

drivers be taken out?

See pictures below. I have a spare old working tweeter for sale.

 

For tweeter take out screws and fit a slightly larger screw to grip on plastic tweeter faceplate and stick out to allow claw hammer or similar tool to gently lift out all three screw points until finally free.

 

For woofer do similar but it is harder to find a larger screw to grip. If the woofer roll surround needs replacing then it is easier to slip a large screw driver under and between woofer cone and outer metal frame, lift gently on all sides.

 

Place a wooden batten like in the pictures between hammer and speaker surface to protect and leverage.

 

The glue is not very strong once you initially lift, its like dried blu tack or kids play dough and easily scrapes off. Reseal with something like silicone sealant.

Edited January 15, 2020 by Al.M