Did anyone ever get the schematic
HI
Did anyone ever find a schematic for the KUBE 200 ?
I need to build a balanced version to work with my amp/preamp
Can anyone clarify wether this is just a Linkwitz transform ? and if it is what are the unequalized Fo and Q of the Kef 105/3 bass section
Thanks for the help
Dam
HI
Did anyone ever find a schematic for the KUBE 200 ?
I need to build a balanced version to work with my amp/preamp
Can anyone clarify wether this is just a Linkwitz transform ? and if it is what are the unequalized Fo and Q of the Kef 105/3 bass section
Thanks for the help
Dam
Hi Ritchie
I had thought of both of these answers however I do not want to add two extra stages to each of hot and cold lines
Also
1. I'm not sure that the KUBE is JUST a linkwitz as it has a high frequency control
2. To measure the Fo and Q it must be a bare drive or drives and I'm not really willing to get inside the 105's to eliminate the X over and conjugate impeadence matcher
Dam
I had thought of both of these answers however I do not want to add two extra stages to each of hot and cold lines
Also
1. I'm not sure that the KUBE is JUST a linkwitz as it has a high frequency control
2. To measure the Fo and Q it must be a bare drive or drives and I'm not really willing to get inside the 105's to eliminate the X over and conjugate impeadence matcher
Dam
If you don't want to add extra stages then you are stuck. 99.9% of all line level circuitry is unbalanced and just has a converter stage at each end.
It may be a Linkwitz Transform plus some kind of shelving tone control for the high range then.
Actually you MUST measure Fc and Qtc in the box or it's all pointless in this scenario. However, if there is a conjugate network on the bass that will possibly screw up the readings a small amount, but maybe nothing disastrous.
It may be a Linkwitz Transform plus some kind of shelving tone control for the high range then.
Actually you MUST measure Fc and Qtc in the box or it's all pointless in this scenario. However, if there is a conjugate network on the bass that will possibly screw up the readings a small amount, but maybe nothing disastrous.
Sorry if this is a bit off-topic, but since there are some knowledgeable KUBE people in this thread, I have been wondering:
The KUBE instructions with my 104.2 state that the KUBE has a better S/N ratio when inserted into the tape loop rather than between pre-amp and power amp. I have not done a direct comparison of the two configurations, because of the inconvenience of changing all of the interconnects.
Placing the KUBE between pre-amp and power amp would be more convenient for me for several reasons. When playing a DVD with a 5.1 soundtrack, the surround sound decoding may be disabled when using the tape loop on my preamp-processor (Sherwood P-965). So I would prefer to place the KUBE between the preamp and the power amp. How much S/N ratio will I lose that way? Thank you.
The KUBE instructions with my 104.2 state that the KUBE has a better S/N ratio when inserted into the tape loop rather than between pre-amp and power amp. I have not done a direct comparison of the two configurations, because of the inconvenience of changing all of the interconnects.
Placing the KUBE between pre-amp and power amp would be more convenient for me for several reasons. When playing a DVD with a 5.1 soundtrack, the surround sound decoding may be disabled when using the tape loop on my preamp-processor (Sherwood P-965). So I would prefer to place the KUBE between the preamp and the power amp. How much S/N ratio will I lose that way? Thank you.
It's impossible to say what degradation will occur as it depends entirely on the individual amp. The s/n ratio of the Kube is actually identical in either configuration, what they are getting at is that if you connect it in the tape loop the volume control will come after the Kube thus attenuate any noise it makes.
Hmm ... I had assumed something different, namely that at normal listening level, the tape loop has a higher signal voltage than the preamp output. If the KUBE adds the same noise floor in either configuration, then the overall signal-to-noise ratio would be higher in the tape loop configuration. The difference would be greatest at low volume and would disappear at loud volume.
Perhaps we are just using different words to say the same thing.
Perhaps we are just using different words to say the same thing.
) , sure, I don't see why not. In case you're wondering, I worked with AJ on all the Kubes.
Just a quick note to clear up a couple of loose ends on this thread.
1. KEF Kubes did not use the "Linkwitz transform" circuit. They used the Friend circuit. The original J.J. Friend paper is available from the IEEE but the analysis and practical synthesis are much better described in "Principles of Active Network Synthesis and Design" by Gobind Daryanani. A very good book now sadly out of print.
The Friend circuit is a true general biquad using only 2 capacitors. There are some limitations which make it unsuited for use as high or low pass but a Sallen & Key topology would have less component sensitivity for those anyway.
The Linkwitz circuit uses 4 capacitors to do a biquad and is a b*tch to design for production
. As you can imagine it's not easy to get responses to within a fraction of a dB using 1% components and E96 resistors, so the fewer components the better.
2. The comments re noise ARE both saying the same thing. The fixed outputs of Kubes have a fixed output noise level so you need to run them at maximum level to get the highest signal to noise ratio. You can do this by using the tape monitor loop. Kubes were designed to take full output from a CD player without overload, but I have heard from one user that his Kube overloaded when used in this way. He didn't say which preamp he was using. An input attenuator would cure this.
1. KEF Kubes did not use the "Linkwitz transform" circuit. They used the Friend circuit. The original J.J. Friend paper is available from the IEEE but the analysis and practical synthesis are much better described in "Principles of Active Network Synthesis and Design" by Gobind Daryanani. A very good book now sadly out of print.
The Friend circuit is a true general biquad using only 2 capacitors. There are some limitations which make it unsuited for use as high or low pass but a Sallen & Key topology would have less component sensitivity for those anyway.
The Linkwitz circuit uses 4 capacitors to do a biquad and is a b*tch to design for production
. As you can imagine it's not easy to get responses to within a fraction of a dB using 1% components and E96 resistors, so the fewer components the better.2. The comments re noise ARE both saying the same thing. The fixed outputs of Kubes have a fixed output noise level so you need to run them at maximum level to get the highest signal to noise ratio. You can do this by using the tape monitor loop. Kubes were designed to take full output from a CD player without overload, but I have heard from one user that his Kube overloaded when used in this way. He didn't say which preamp he was using. An input attenuator would cure this.
Hi there,
Could I get a copy of the Kube 200 Schematic also ?
Regards
Anthony Kirby
Electroant1@googlemail.com
Could I get a copy of the Kube 200 Schematic also ?
Regards
Anthony Kirby
Electroant1@googlemail.com
Hi Ricobasso
At the bottom of the reply window there is an Attach file box click on browse to find the file on your hard drive. But if you have recently joined the administrator might not allow attachments, I am not sure.
I thought the Kube was a device to convert a fourth order alignment to a sixth order and hence would simply have been an underdamped sallen and key high pass filter.
Were you at Kef in the days of Cooke, Fincham and Small? I think it was one of the best speaker companies in the world at that time.
At the bottom of the reply window there is an Attach file box click on browse to find the file on your hard drive. But if you have recently joined the administrator might not allow attachments, I am not sure.
I thought the Kube was a device to convert a fourth order alignment to a sixth order and hence would simply have been an underdamped sallen and key high pass filter.
Were you at Kef in the days of Cooke, Fincham and Small? I think it was one of the best speaker companies in the world at that time.
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