I have just completed restoring a pair of Kef 107R's that I recently purchased:
Attached is a link to some pictures of my restoration journey
https://www.flickr.com/gp/194401210@N06/LuQ72h
- refoamed the bass drivers(used nitrile rubber glue, and replaced the rubber grommets in the driver frames)
- replaced the caps in the driver crossovers and the tweeter/mid head crossovers (used original manufacture ALCAPS from falcon acoustics.co.uk)
- replaced the ferrofluid (Ferrotech through springfieldspeaker)
- The Kube is original, seems to work fine, and was taken apart and visually inspected with no apparent issues, therefore I have not replaced any components. (Question: Do the adjustable resistors / trimpots affect the sound if so how and if any risk to the Kube or other components if adjustments are made... the trimpots (red) are shown in the last pic of the flickr file)
Attached is a link to some pictures of my restoration journey
https://www.flickr.com/gp/194401210@N06/LuQ72h
Impressive, I admire your dedication.
The images will be useful to somebody in the future.
A guess is that the selector switches on the pcb were used to configure gain or slope for the particular speaker or differing KEF models.
Maybe somebody with knowledge of the Kube may drop in and provide further info.
Also a search for Kube schematics could help understand this ??
The images will be useful to somebody in the future.
A guess is that the selector switches on the pcb were used to configure gain or slope for the particular speaker or differing KEF models.
Maybe somebody with knowledge of the Kube may drop in and provide further info.
Also a search for Kube schematics could help understand this ??
Yes for anyone iconsidering the restoration I have additional pics and a number of notes on disassembly/assembly.
The 107R Kube schematics seem to be difficult to obtain: also Andrew Jones (one of the designers of the 107R Kube) was a member on DIY but last post was a year ago or so.....with some luck who knows , maybe i can get some additional info.... and if not all is good , I consider myself very fortunate to obtain the speakers/Kube, the system sounds great and was more than well worth the effort!
The 107R Kube schematics seem to be difficult to obtain: also Andrew Jones (one of the designers of the 107R Kube) was a member on DIY but last post was a year ago or so.....with some luck who knows , maybe i can get some additional info.... and if not all is good , I consider myself very fortunate to obtain the speakers/Kube, the system sounds great and was more than well worth the effort!
Hello rbg1
I got my pair of Kef 107 about 2 years ago, it was already restored. The refoam job is really well made, the crossover to, all with good quality Solen caps at the right specs. The wooden edge on the cabinet are not in great shape, they’re going to need a little bit of love. The difficulty is to have natural walnut edge, only dark walnut available.
My tweeter started some distortion 3 weeks ago, I’ve opened my Kef to make sure the connectors were not loose, it was not the case, so option two was the ferrofluid, but knowing they had been restored three years ago, strange. So I’ve started doing my research on the net about the T33 sp1210 and FRF, to my surprise a saw the old ad on Canuck of my speakers and in the texte the tech said that he didn’t put any ferrofluid and he had put in new Peerless voice coils and new diaphragm. lucky me I was able to buy a pair off original SP1210 that I should receive in the next couples of week.
So I was wandering rbg1 if you had any difficulty to center your voice coil after doing the FRF or they go in
naturally ? I plan to do the peerless to, it’s going to be fun to compare. Btw your pictures are really good and helpful, I was happy to see the inside of the head assembly before I jump in.
I did change the caps and opamps in my Kube, you can look up on aka [ Kube opamp upgrade]. While your there, there’s a official Kef 107 Owners registry.
When I want to threat myself to the music I bring my Kef 3 feet’s from the back wall.
If you have the chance to put some gliders under, they are quite heavy to move.
Your Nak 7, wow that’s a nice beast, I would love to hear the Kef 107 on the Nak probably a really nice match.
Nice knowing a new Kef 107 owner.
Jp
I got my pair of Kef 107 about 2 years ago, it was already restored. The refoam job is really well made, the crossover to, all with good quality Solen caps at the right specs. The wooden edge on the cabinet are not in great shape, they’re going to need a little bit of love. The difficulty is to have natural walnut edge, only dark walnut available.
My tweeter started some distortion 3 weeks ago, I’ve opened my Kef to make sure the connectors were not loose, it was not the case, so option two was the ferrofluid, but knowing they had been restored three years ago, strange. So I’ve started doing my research on the net about the T33 sp1210 and FRF, to my surprise a saw the old ad on Canuck of my speakers and in the texte the tech said that he didn’t put any ferrofluid and he had put in new Peerless voice coils and new diaphragm. lucky me I was able to buy a pair off original SP1210 that I should receive in the next couples of week.
So I was wandering rbg1 if you had any difficulty to center your voice coil after doing the FRF or they go in
naturally ? I plan to do the peerless to, it’s going to be fun to compare. Btw your pictures are really good and helpful, I was happy to see the inside of the head assembly before I jump in.
I did change the caps and opamps in my Kube, you can look up on aka [ Kube opamp upgrade]. While your there, there’s a official Kef 107 Owners registry.
When I want to threat myself to the music I bring my Kef 3 feet’s from the back wall.
If you have the chance to put some gliders under, they are quite heavy to move.
Your Nak 7, wow that’s a nice beast, I would love to hear the Kef 107 on the Nak probably a really nice match.
Nice knowing a new Kef 107 owner.
Jp
Yes rbg I was talking about the diaphragm voice coil assembly. I saw the video you mention and it give a good idea and great trick. I was just wandering how it went for you, when it was time to re-assemble back the parts together.
So you did answer my question.
Your new crossover (caps) had the time to settle down, so when you have a chance to say what do you think about your Nakamichi with your Kef. I’m starting to look for a pre/power amp combo, my Naim 5si is great but it’s not powerful enough.
you have a really nice setup!!!
The feat on my Kef are SVS SoundPath plus some glider. They do a excellent job to minimize the vibrations on a hard floors. I know you have carpets, I put it there for general infos.
( English is not my mother language )
So you did answer my question.
Your new crossover (caps) had the time to settle down, so when you have a chance to say what do you think about your Nakamichi with your Kef. I’m starting to look for a pre/power amp combo, my Naim 5si is great but it’s not powerful enough.
you have a really nice setup!!!
The feat on my Kef are SVS SoundPath plus some glider. They do a excellent job to minimize the vibrations on a hard floors. I know you have carpets, I put it there for general infos.
( English is not my mother language )
With respect to how the Kefs sound when paired with the Nak7:
I had the opportunity to compare the Kefs/Nak7 combination to my previous system:
Some other general comments as you are likely aware of:
- speaker positioning, room dimensions, room materials/furniture/reflective vs soft surfaces can make a significant difference in the audio quality
- there is a very large range in the quality of recordings (albums, cd's, other digital sources) from bad to excellent, recordings with low bass to mid/high ratios to recordings with high bass to mid/high ratios, etc etc ..... so what i did when I was doing sound comparisons was to use a song that was a very good quality recording with a broad dynamic range, playing the same song (at a range of volume levels) while making changes. (for me that worked well)
Getting back to your question of what pre/amp power combo .... the best situation would be that you can take the amp combo home to try it on your system so that you can compare prior to purchasing.
I hope this helps.
- what can I say as I (and my friends that have heard the system) are not audiophiles, so my description would be that they sound great with very good soundstage and separation, the clarity is exceptional
- bass and midrange are excellent, some experts would say the tweeters are good not excellent, but my friends and I would not be able to make that judgement
I had the opportunity to compare the Kefs/Nak7 combination to my previous system:
- my previous system was an early 90's Polk Reference speakers and a mid range NAD amp that had approx 60 watts per channel (Kef recommends an amp with between 50 watts and 150 watts @8Ohm resistance.... although my understanding is that the Kefs require a high current amp as well in order to fully realize their potential)
- my previous system (Polk/NAD) sounded good but at very high amp volumes, distortion would be apparent
- with the Polk/Nak7 again good sound and distortion would be delayed to higher volumes than with the NAD amp
Some other general comments as you are likely aware of:
- speaker positioning, room dimensions, room materials/furniture/reflective vs soft surfaces can make a significant difference in the audio quality
- there is a very large range in the quality of recordings (albums, cd's, other digital sources) from bad to excellent, recordings with low bass to mid/high ratios to recordings with high bass to mid/high ratios, etc etc ..... so what i did when I was doing sound comparisons was to use a song that was a very good quality recording with a broad dynamic range, playing the same song (at a range of volume levels) while making changes. (for me that worked well)
Getting back to your question of what pre/amp power combo .... the best situation would be that you can take the amp combo home to try it on your system so that you can compare prior to purchasing.
I hope this helps.
I didn’t had the chance to hear a lot of gear with my Kef. I’ve heard them when I bought them with Rotel 1090 power amp. The sound was magical, I had goosebumps mostly all along the listening even if the room was a little bit small for them. A friend of mine Lend me a Modwright KWS 100 that I a/b with my Naim, the sound was good but there was not a significant difference between the two amp. I like my Naim, I feel the groove, the swing in the shuffle rythme, it present a well balanced image with good detail even at low volume and that is really important for me. But I miss the magic, I can hear that even if they are efficient speakers, they would benefit from, having more power. Well that’s what I remember and memory could be a tricky things.
Thanks for your input on Amp/Kef matching.
Thanks for your input on Amp/Kef matching.
I was looking forward to reading your post "I did change the caps and opamps in my Kube, you can look up on aka [ Kube opamp upgrade]." but have not been able to find it. Is it on this DIY web site and if so how is the best way to find it.
Thanks in advance.... by the way let me know what amp combo you end up getting.
Thanks in advance.... by the way let me know what amp combo you end up getting.
Found it quite easily:
https://audiokarma.org/forums/index.php?threads/kef-r107-kube-opamp-upgrade.552874/
https://audiokarma.org/forums/index.php?threads/kef-r107-kube-opamp-upgrade.552874/
jpdspin:
Not sure if you had seen my previous question I had posted wit respect to the Kube.....
Do the adjustable resistors / trimpots affect the sound and if so how, and if any risk to the Kube or other components if adjustments are made to the adjustable resistors/trimpots.
The adjustable resistors/ trimpots (red) are shown in the last pic of the flickr file tat I had previously posted https://www.flickr.com/gp/194401210@N06/LuQ72h
Not sure if you had seen my previous question I had posted wit respect to the Kube.....
Do the adjustable resistors / trimpots affect the sound and if so how, and if any risk to the Kube or other components if adjustments are made to the adjustable resistors/trimpots.
The adjustable resistors/ trimpots (red) are shown in the last pic of the flickr file tat I had previously posted https://www.flickr.com/gp/194401210@N06/LuQ72h
Hello Rbg, after my inquiry on my tweeters I open my Kef to look a little closer, I made a nice discovery. Both head assembly Xover have partially melted from overheating of the parallel 15ohm resistors. It dated before theses boards were recap. Now I’m in the process of restoring the Xover with new resistors farther away from the board and putting caps value to specs. Again your pictures saved my life and I would like to use 2 of them to put in my Kef 107 HF crossover thread if you give me the permission ?
I can image the lack of oumph and music imaging is due to the Xovers with values not enough close to the original specs, some of them higher than 10% different.
Even if the seller said that everything is was to its original specs, you can have some surprises, still I don’t regret it but I should have open them of before buying them for a more adequate price.
I can image the lack of oumph and music imaging is due to the Xovers with values not enough close to the original specs, some of them higher than 10% different.
Even if the seller said that everything is was to its original specs, you can have some surprises, still I don’t regret it but I should have open them of before buying them for a more adequate price.
Attachments
Just a thought I wonder what these speakers would sound like if you replace all the drivers with NEW Modern ones eg. SB Acoustics and with DSP xover? I think it would sound totally different these drivers will give you a more forward and dynamic sound with even greater clarity. The sound will give you a modern presentation of music.
I think you may want to consider this approach once you are tired of the "old" sound(not necessary obsolete sound). Old equipment is not necessarily obsolete.
Good job, enjoy them for now.
Yes it would be interesting to see how replacement with high quality modern components would change the sound .....maybe someone has else has done so.
When i undertook this restoration project one of my goals was to keep the Kefs as original as possible. The restored Kefs sound amazing and should not require further restoration or repair for a long time. If at some point in the future, additional repairs are required and I cannot source original components then i will utilize modern components. So until then I will enjoy them in their near original state.