I have a pair of Kef Model 105's:
http://www.kef.com/history/1970/model105.asp
My father purchaced these from new in 1978, he's passed them onto me but my sitting room isn't nearly big enough to do these justice...i think i'd have to get rid of my sofa in order to accomidate them.
I'm looking to sell them on to fund some smaller speakers, but before i do i'd like to make sure they are servicable and worth selling. They are physically immaculate and have the origional covers, they are functioning as my father and i hooked them up and tested them. They are totally unmodified, we even have the origional manual.
I was wondering if anyone here knew what to look for to make sure these are still serviceable as they're 30 years old now, if there is anything that usually degrades over time or anything we should check a little closer before selling them.
http://www.kef.com/history/1970/model105.asp
My father purchaced these from new in 1978, he's passed them onto me but my sitting room isn't nearly big enough to do these justice...i think i'd have to get rid of my sofa in order to accomidate them.
I'm looking to sell them on to fund some smaller speakers, but before i do i'd like to make sure they are servicable and worth selling. They are physically immaculate and have the origional covers, they are functioning as my father and i hooked them up and tested them. They are totally unmodified, we even have the origional manual.
I was wondering if anyone here knew what to look for to make sure these are still serviceable as they're 30 years old now, if there is anything that usually degrades over time or anything we should check a little closer before selling them.
get rid of the sofa, they look great....
Check that all drivers are working, and check the condition of the surrounds (Where the cone is attached to the edge of the speaker). That should do it.
Anyone who bought them would probably be well advised to replace any electrolytic capacitors in the crossover, but that's a job for someone who knows about the intestines of these things.
Check that all drivers are working, and check the condition of the surrounds (Where the cone is attached to the edge of the speaker). That should do it.
Anyone who bought them would probably be well advised to replace any electrolytic capacitors in the crossover, but that's a job for someone who knows about the intestines of these things.
!n 1978 Hi-Fi Choice (UK) ran a comparison of dozens of speakers including the YAMAHA NS 1000M. The 105's streeted the field by a considerable margin. This was no "golden ears subjective fest" but a serious report run/edited by Martin Colloms.......I'm with the others....sell the house. And be grateful.....as the Good Book says!
The electros could be upgraded. Some won't like the cored inductors, and there are a lot of them. At least 8 per speaker. There is also a funny large cap in the feed to the bass unit if I remember correctly. They were looking for 3rd order bass roll off and put a 600uF cap in the +ive line to the 12 unit I think. Many would think there was scope for further inprovement but get into the local KEF site in the UK. They are v.good on this sort of thing. I'll just chase up the site...back in a moment.
Back again. It sound inocuous but try "hifiloundspeakers" in Google and there should be a KEF owners site on the first page. These bods have sections on drivers....forums etc.
Good luck and a jealous greeting from Oz, Jonathan
The electros could be upgraded. Some won't like the cored inductors, and there are a lot of them. At least 8 per speaker. There is also a funny large cap in the feed to the bass unit if I remember correctly. They were looking for 3rd order bass roll off and put a 600uF cap in the +ive line to the 12 unit I think. Many would think there was scope for further inprovement but get into the local KEF site in the UK. They are v.good on this sort of thing. I'll just chase up the site...back in a moment.
Back again. It sound inocuous but try "hifiloundspeakers" in Google and there should be a KEF owners site on the first page. These bods have sections on drivers....forums etc.
Good luck and a jealous greeting from Oz, Jonathan
they were big on complex 3rd order xovers:
http://www.hifiloudspeakers.info/Anatomy/Crossovers/105.2/105.2CrossoverIndex.html
http://www.hifiloudspeakers.info/Anatomy/Crossovers/105.2/105.2CrossoverIndex.html
This is not a loudspeaker to sell. Keep them. (And that comes from someone that woudl buy these on the spot). You might some day move to a bigger house and then you will enjoy having them.
The drivers in these are pretty stable over the years. The rubber surrounds hold on well even after 30 years or so, so if the cones are clean nothing more to say about them.
The caps are an issue as always and may need checking - replacement.
The drivers in these are pretty stable over the years. The rubber surrounds hold on well even after 30 years or so, so if the cones are clean nothing more to say about them.
The caps are an issue as always and may need checking - replacement.
Phill
I also have some Kef 105's and I think they are a superb speaker.
They may not be as detailed as some more modern speakers with faster mid range units and simpler crossovers but, they I think they give a very impressive presentation of the music that leaves a lot of speakers a long way behind.
I have replaced all of the electrolytic capacitors in mine. I also replaced all the electrolytics in the direct signal path of the mid and treble units with polycarbonate capacitors. I conversed with Kef about this They advised replacing with polycarbonate/polyester caps of the same value plus a series resister of 1 ohm per 10 uf of capacitor replaced to make up for the lost resistence of the electrolytic capacitor. It works although some others have been sceptical of this.
As advised above the 600 uf cap forms part of a low freqency roll off for the base unit to prevent damage to the base unit from frequencies below 20hz or so. If your amplifier and record player are up to scratch you probably do not need this - I have removed these in my speakers.
I have not had any trouble with speaker surrounds as they seem to be a rubber/ silicon compound that has not shown any sign of stiffening or decomposing.
I think the only things you need to do are replace the old electrolytic capacitors in the crossover and tighten ( but not overtighten ) the speaker hold down bolts and then sit back and listen.
Don
Don
I also have some Kef 105's and I think they are a superb speaker.
They may not be as detailed as some more modern speakers with faster mid range units and simpler crossovers but, they I think they give a very impressive presentation of the music that leaves a lot of speakers a long way behind.
I have replaced all of the electrolytic capacitors in mine. I also replaced all the electrolytics in the direct signal path of the mid and treble units with polycarbonate capacitors. I conversed with Kef about this They advised replacing with polycarbonate/polyester caps of the same value plus a series resister of 1 ohm per 10 uf of capacitor replaced to make up for the lost resistence of the electrolytic capacitor. It works although some others have been sceptical of this.
As advised above the 600 uf cap forms part of a low freqency roll off for the base unit to prevent damage to the base unit from frequencies below 20hz or so. If your amplifier and record player are up to scratch you probably do not need this - I have removed these in my speakers.
I have not had any trouble with speaker surrounds as they seem to be a rubber/ silicon compound that has not shown any sign of stiffening or decomposing.
I think the only things you need to do are replace the old electrolytic capacitors in the crossover and tighten ( but not overtighten ) the speaker hold down bolts and then sit back and listen.
Don
Don
Worth checking things, models etc. I've been working on the assumption that they were the early ones. The later 105.2 were a good bit different. I'm pretty sure that the original was a 4th order time aligned model crossover. They were after a 3rd order bass roll off but I suspect that the cross over of Colin's is not the one for phil1012k's unit.
I'll dig around a bit more today.
I'll dig around a bit more today.
Hi PeteMcK...yes I agree. I'm sure there would be a 1st order lobby that would end up with a KEF105/B&W DM6 sort of arrangement. I must admit to being a bit confused re; cross overs. The one you found is clearly 3rd order (electrical) but has the same component count as the original 105 which claims to be 4th order etc. I wonder if it is an "acoustic 4th order" in the way that they upgraded the original 104 to a 104ab. I'd be intersted in anything you come up with.
BTW Pete, phil1012k has been a bit quiet lately......perhaps he's upgrading his "Home and Contents" policy!!! Ha ha.
I guess, getting back to his original post (which we all ,regretablly, have to do from time to time) one solution would be to make the mid-tweeter enclosures satelites (however you spell it) and make the 2x12" bass units a sub' a lot of work but a good challenge.
Jonathan
BTW Pete, phil1012k has been a bit quiet lately......perhaps he's upgrading his "Home and Contents" policy!!! Ha ha.
I guess, getting back to his original post (which we all ,regretablly, have to do from time to time) one solution would be to make the mid-tweeter enclosures satelites (however you spell it) and make the 2x12" bass units a sub' a lot of work but a good challenge.
Jonathan
The best speakers KEF ever made - Laurie Fincham's magnum opus. In terms of driver quality and sophistication of the crossover, as good as anything made today, and way better than modern $tereophile-approved speakers in the $10,000~$60,000 price range. The 105 (and the preceding 104 series) has always been one of my benchmarks for dynamic speakers.
The weak point are the very mediocre caps - KEF back then thought that "all caps sound the same", so they used what we would now consider floor sweepings in the crossover. They were designed before Walt Jung's paper made people think more deeply about caps, so I'm sure you find back-to-back "nonpolar" electrolytics and bargain-basement Mylar caps.
You don't need to go crazy with the crossover - which would cost a fortune considering the complexity - but a gradual upgrade of the tweeter circuit with decent foil-and-film polypropylenes would result in a much more transparent speaker, while retaining the ultrasmooth and low-coloration response the 105 is famous for. Be careful with the crossover board, because you don't want to lift any traces - big hassle to fix if that happens.
The caps that matter the most are in the series part of the circuit for the tweeter and the midrange - the others are less important, and you can tackle them later.
The weak point are the very mediocre caps - KEF back then thought that "all caps sound the same", so they used what we would now consider floor sweepings in the crossover. They were designed before Walt Jung's paper made people think more deeply about caps, so I'm sure you find back-to-back "nonpolar" electrolytics and bargain-basement Mylar caps.
You don't need to go crazy with the crossover - which would cost a fortune considering the complexity - but a gradual upgrade of the tweeter circuit with decent foil-and-film polypropylenes would result in a much more transparent speaker, while retaining the ultrasmooth and low-coloration response the 105 is famous for. Be careful with the crossover board, because you don't want to lift any traces - big hassle to fix if that happens.
The caps that matter the most are in the series part of the circuit for the tweeter and the midrange - the others are less important, and you can tackle them later.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.