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Looking for Kube200 for my KEF 105/3
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deckard
Intermediate Contributor 25+


Joined: 10 Sep 2012
Posts: 32

PostPosted: Thu Dec 13, 2012 3:42 pm    Post subject: Reply with quote

zaktech wrote:
Steve, its me Zak. I started this thread when I started my search for the Kube a few weeks ago. As you know I've found a few since and I've figured out the power supply as well, since a few folks out there have them without power supplies. Well I can help solve that problem now.


Are you saying you have acquired a few KUBE 200's? I would certainly like to purchase one from you if so.
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deckard
Intermediate Contributor 25+


Joined: 10 Sep 2012
Posts: 32

PostPosted: Thu Dec 13, 2012 3:47 pm    Post subject: Reply with quote

speakerguru wrote:
Turns out the two PSUs I have are US ones! Embarassed


I may hit you up about this one day, as I am in the US.
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clubsport911
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Joined: 26 Aug 2012
Posts: 157
Location: Cheltenham, UK

PostPosted: Thu Dec 13, 2012 4:42 pm    Post subject: Reply with quote

@ speakerguru

Quote:
Also, if there really is enough interest and KUBE200s are that hard to get get hold of, I could re-create the pcb design and make them available in some form or other. I don't want to get involved with procuring parts or metalwork, though.


I would indeed, pay you for such a concept ! I have access to 10 layer PCB design and a load of contract oem's for electronics.

I think, you could easily charge others as well (beer money ?)
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zaktech
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Joined: 08 Oct 2012
Posts: 16
Location: Leeds, West Yorks, UK

PostPosted: Sat Dec 29, 2012 2:45 pm    Post subject: Reply with quote

@deckard

PM me and I will tell you of a Kube 200 available in North America. I may part with my (no longer used) USA PSU, if someone is desperate for 110vAC PSU for Kube 200 or Kube 107/2.

I do also have a Kube 107 for the 107MK1 speakers. This is the Kube with three adjusters at the front - with the 18vAC PSU. Let me know if anyone is in need of a Kube107 for 107Mk1 speakers.
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speakerguru
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Joined: 18 Nov 2005
Posts: 954
Location: Green Hut, Tovil

PostPosted: Fri Jan 04, 2013 12:58 pm    Post subject: Reply with quote

In between grandchildren, work and mince pies I have re-laid out the KUBE 200 pcb over Christmas. I want to get quotes for manufacturing it properly, double sided, plated through holes with solder resist and component ident silk screened layers top and bottom. It would be helpful to have some idea of numbers to get a more accurate quote. How many people are interested?
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clubsport911
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Joined: 26 Aug 2012
Posts: 157
Location: Cheltenham, UK

PostPosted: Fri Jan 04, 2013 11:55 pm    Post subject: Reply with quote

Yes. Thanks for giving up your time to do this. If I were you, I think some of the other forum (sp.) might be Interested to hear this and perhaps, that will swell the numbers

I'm curious... What you "improve" the design or replicate as is ?

Thanks

S
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proffski
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Joined: 22 Aug 2003
Posts: 1296
Location: Tewkesbury UK

PostPosted: Sat Jan 05, 2013 12:08 am    Post subject: Reply with quote

I'll never be lucky enough to own a pair of these excellent loudspeakers ever again, deep sad sigh... SIGH!
Unhappily the usual physics gets in the way; you will never get something for nothing.
Bass extension will compromise power handling and eventual SPL.

The only way forward that I can see is the cube and a proper brace of proper subwoofers correctly integrated into the system. Just love your transducers!
I have seen too many fried and baked as well as smoked KEF voice coils in my life so far and I also admit my guilt on many occasions!
_________________
I contend that for a nation to try to tax itself into prosperity is like a
man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill
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deckard
Intermediate Contributor 25+


Joined: 10 Sep 2012
Posts: 32

PostPosted: Wed Jan 16, 2013 7:09 am    Post subject: Reply with quote

Happy New Year!

So, as you can see above, zacktech had a lead on a KUBE 200. Curiosity got the best of me and I decided to go for it.
$250 CA including shipping from a from a very nice fellow forum member in Montreal. Thank you Zak!

Now that I actually have this thing in my hands, I am wondering about connections.
I've read the KUBE 200 manual, but I want to confirm the best way to hook it up so ONLY the LF is affected.

I have 2 amps and one preamp with no processing or tape loop, so I will have to insert the KUBE between the preamp outputs and power amp inputs.
Not thrilled about this, as I've always thought that you'd want a constant level at the input of an EQ, but there is no mention of this in the manual so maybe I'm off on this point.

What I plan to do is connect 1 of my preamp outputs (mine has 2) directly to the power amp that I will use for HF.
I would then connect the 2nd preamp output to the Signal inputs on the KUBE 200.
Now as far as I can tell, I could use either the Signal outputs OR the Equalized Auxiliary output with the level control.
Since the amps are matched, I don't think I would need the level control.

At this point, the KUBE would only affect the LF amp. I would imagine that the HF Contour would have no audible effect here and I can begin messing with the LF Contour (albeit with proffski's sentiments about fried and baked voice coils in mind). Wink

Zak, I couldn't quite tell from your post, are you using the KUBE on both the HF and LF or just LF?

Also, I may have the ability to get my hands on some better gear to try, but both the preamp and amps are balanced.
How would I convert the balanced preamp outputs to the unbalanced KUBE inputs and vice-versa for the KUBE outputs?
What's worse, more kit in the signal chain using transformers or loss of signal/noise rejection with XLR to RCA cables, etc.
That being said, it would be interesting to find out if there are points anywhere inside the KUBE that could be tapped into to gain true balanced inputs and outputs.

If anyone has any other suggestions or info on KUBE connections, I would be most appreciative to hear them!
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deckard
Intermediate Contributor 25+


Joined: 10 Sep 2012
Posts: 32

PostPosted: Fri Jan 18, 2013 3:04 pm    Post subject: Reply with quote

speakerguru wrote:
In between grandchildren, work and mince pies I have re-laid out the KUBE 200 pcb over Christmas. I want to get quotes for manufacturing it properly, double sided, plated through holes with solder resist and component ident silk screened layers top and bottom. It would be helpful to have some idea of numbers to get a more accurate quote. How many people are interested?


Would it be possible to create a balanced version?
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zaktech
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Joined: 08 Oct 2012
Posts: 16
Location: Leeds, West Yorks, UK

PostPosted: Sat Jan 19, 2013 2:45 am    Post subject: Reply with quote

Deckard, I'm glad you got a Kube. I use the Kube for LF only. I have different amps on the HF and LF so I use the variable gain output. I've previously tried on amp and had the Kube200 via the tape loop which allowed me to adjust HF and LF. I prefer bi-amplification with the Kube only on the LF. Download the Kube200 user manual from the KEF museum, listed with 105/3 speaker brochures. That document covers all the connection options I good detail.
Do tell me if you could live with without the Kube once you've tried it in a biamp configuration. I simply cannot.
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zaktech
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Joined: 08 Oct 2012
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Location: Leeds, West Yorks, UK

PostPosted: Sat Jan 19, 2013 2:56 am    Post subject: Reply with quote

Deckard, I read your post again. You have the connections correct for bi amplification. Having the Kube between the pre and the LF power amp. Since they matched amps, I'd use the direct/fixed outputs on the Kube. The other preamp output should go directly to the HF amp. Notice that the HF adjustment on the Kube is useless in this configuration.
I'd try the variable output if you wanted to alter the LF to hf balance of your music, it helps when I want more bass from a poor recording at times. I read you have the Kube connection instructions, so you're sorted.
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zaktech
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Joined: 08 Oct 2012
Posts: 16
Location: Leeds, West Yorks, UK

PostPosted: Sat Jan 19, 2013 3:01 am    Post subject: Reply with quote

Balanced connections - I'm clueless! I need to read and learn about the differences other than noticing balance connections are louder. I think I read balanced is 6db louder.
I like to read and learn about this, and to figure out if it's possible to simply stick an rca connector at the other end to go in and out of a Kube eq.
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deckard
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Joined: 10 Sep 2012
Posts: 32

PostPosted: Sat Jan 19, 2013 5:04 am    Post subject: Reply with quote

Hey Zak - I will definitely post here once I get the KUBE installed and play around with it a bit. Thanks again for the lead!

As for Balanced vs. Unbalanced, there are some really good documents over at the Rane site (pro audio gear manufacturer).

Here is a general Audio spec overview:
http://www.rane.com/note145.html

This one is especially useful for matching connections:
http://www.rane.com/note110.html

I don't mean to get too far off point here, but it is handy to note the mention of Pro Audio levels (+4dBu) vs. Consumer Audio levels (-10dBv).
A common misconception is that if the wire is balanced, it means the signal level is +4.

Balanced/Unbalanced is about how the signal gets from from A to B.

Signal level (-10dBv, +4dBu, mic level, inst level etc.) is about the strength of the signal.

Here is the main link for the "RaneNotes": http://www.rane.com/library.html = Lots of good stuff here!

Also, as for the whole "6dB louder" thing, go here: http://en.wikipedia.org/wiki/Balanced_audio and scroll down to "Differential signalling" for an explanation of where the extra gain comes from.
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zaktech
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Joined: 08 Oct 2012
Posts: 16
Location: Leeds, West Yorks, UK

PostPosted: Sat Jan 19, 2013 5:25 pm    Post subject: Reply with quote

Thanks for that Deckard. Don't delay, connect the HF amp direct to the pre and take the second pre output to the Kube signal in. Connect the LF amp to the Kube fixed or variable output. This mean only LF amp is fed via the Kube.
I keen to hear your comments on the difference.
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speakerguru
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Joined: 18 Nov 2005
Posts: 954
Location: Green Hut, Tovil

PostPosted: Sun Jan 20, 2013 11:04 am    Post subject: Reply with quote

deckard wrote:
Would it be possible to create a balanced version?

Yes. Been there, done that, got the T-shirt. It was called a ProKube. I designed versions for all the KEF models at that time, though not all were manufactured. Did not sell well. Not more than a few hundred ever made. I still have a few leftover rusty chassis somewhere......
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