Tunebox?

Music at Home · Post by **Music at Home** » 2009-01-30 13:15

Hi Fredrick,

Have you ever thought about making a tunebox? Possibly one that could accept the new-style Chakra Aktiv cards or active filters of your own design?

Not sure how much of a market there would be for such a product but if it's as cost effetive as the Kikkin, I for one would welcome such a device so I could still retain my klimax twin and play around with aktivating katans without the expense of klimax aktive filters (if such a thing could even be found).

Just as a suggestion, perhaps such a device could hold up to four cards. So one Lejonklou Tunebox would be sufficient for activating a two-way speaker like katans. A pair of tuneboxes (L and R) would be required for activating 3 or 4 way speakers like 109's, 140's, 212's, etc. There's even an upgrade path there for those with 2-way speakers to employ a seperate Tunebox for each side.

m@h

ThomasOK · Post by **ThomasOK** » 2009-01-30 18:43

Although I don't know how big the market is for this I like the idea. I would suggest a box that can hold at least 5 cards so that 2 of them would cover any pair of Linn speakers. Then again maybe six allowing one box for three ways and accommodating the 6 way speakers Linn must eventually produce. :)

Even better if you can design them with their own level controls with much finer resolution than what the Charka cards seem to support themselves.

Post by **lejonklou** » 2009-02-01 14:29

Thanks for the idea, m@h!

A tunebox for Chakra aktiv cards is not a bad idea, as long as there is no such product from Linn. The Chakra cards don't have any voltage regulation on board, so a tunebox for them would probably require a lot more electronics than what was in Linn's original tunebox for the older cards. More electronics means more things to optimise in order to make it perform well, but I'm quite sure it can be done.

I agree with you, Thomas, that 5 or 6 cards and much finer resolution would be preferable. I'll see if I can find the time to look into this more closely.

bonzo · Post by **bonzo** » 2009-02-03 19:24

i think rthis is a great idea.. to be able rto go aktiv with my kct without having to get klimax filters would be a Huge interest to me,and im sure many others

otro5 · Post by **otro5** » 2010-07-28 17:26

You can go aktive with klimax (KCT or solos) using an old tunebox for ninka or speks. Linn can you supply the adptaters to this tuneboxes for instance for chakra aktiv cards to 242 or 350P. I have them.You need this:

"Chakra Aktiv modules can be installed into the Tunebox. The revision of Tunebox you own uses the Slimline power supply and this will be located close to the mains inlet filter"

DeQMaster · Post by **DeQMaster** » 2010-08-03 16:46

It would be indeed a sucessful product, since there is no such thing from Linn.

It will enable ppl to go aktiv in very different ways.

go for it.

Post by **lejonklou** » 2010-08-03 23:35

Many thanks for your input!

I struggled this spring with a large enclosure, which would be necessary for a product like this. It was quite difficult and I'm still not happy with the finish of it.

Regarding the fine tuning of the aktiv filter cards, recent experiments have made me wonder whether it's better with a small step level adjustment or none at all. There is some additional sound quality to gain by completely removing the level adjustment. This just might outweigh the gain in sound quality by fine tuning the levels.

If the owner doesn't use the level adjustment, the tunebox will of course sound better without any level adjustment circuitry.

DeQMaster · Post by **DeQMaster** » 2010-08-19 23:31

Did you see this thread at Linn forum?

http://forums.linn.co.uk/bb/showthread. ... 64&page=14

Seems, definetly, that a product like the one we´re talking here about, is not a bad idea.

Take note Fredrik!

Post by **lejonklou** » 2010-08-20 10:41

I don't get it, DeQ.

Not having read through it all, it seems that some people are dissatisfied with the aktiv 'Chakra' cards for Keltik. Correct?

Now, imagine I had made a tunebox in which people put their cards. The most likely result would be that people suspected there was something wrong with my tunebox, not the cards. And when people finally started suspecting the cards, Linn might tell them that they are out of warranty if they've ever been placed in Lejonklou's tunebox.

This is a fictional example, but indicates that it's not an easy road for one company (mine) to make accessories for another company's (Linn) products. Especially if that other company doesn't approve of it.

DeQMaster · Post by **DeQMaster** » 2010-08-20 13:38

Yeah

But if that box could be made with the ability of mixing old and new card, the freedom would be awesome.

Lets take the keltiks as an example. Use chakra cards for every thing but the mids, which seems to be the fault there, uing an old card for that.

Anyway that would be usefull to make a tunebox out of the chakra card without having to depend on any specific amps, like mixing old and new linn stuff or even non linn amps.

I see a product on that ;)

Tony Tune-age · Post by **Tony Tune-age** » 2010-08-20 13:41

DeQMaster wrote:But if that box could be made with the ability of mixing old and new card, the freedom would be awesome.

Anyway that would be usefull to make a tunebox out of the chakra card without having to depend on any specific amps, like mixing old and new linn stuff or even non linn amps.

Good idea, that's thinking outside the box... :!: 8)

Post by **lejonklou** » 2010-08-20 15:00

DeQMaster wrote:Lets take the keltiks as an example. Use chakra cards for every thing but the mids, which seems to be the fault there, uing an old card for that.

Probably not a good idea. Mixing different generations of aktiv cards usually doesn't sound good. In addition, Linn have several times altered the parameters (like crossover frequencies) on their different generation aktiv cards, for the same type of speakers.

Apart from that, it's not easy to make a good tunebox that takes both old and Chakra types of cards, as they are very different in construction. The old ones had a lot of stuff on them and were intended to be fed straight from a power amp power supply. The new ones require most of the circuitry to be on the board it connects to. So, two different solutions, with the Chakra being the smarter one in my opinion.

Anyway that would be usefull to make a tunebox out of the chakra card without having to depend on any specific amps, like mixing old and new linn stuff or even non linn amps.

Yes, I understand that's the main reason for a tune box. But was there anything in that Keltik thread that shed any new light on this?

If a lot of people really want it, you should probably be asking Linn for one. I think that if I made one, I could be asking for trouble. And I wouldn't be surprised if Linn released their own a couple of months later.

EDIT: Changed "not possible" to "not easy". Everything is possible!

DeQMaster · Post by **DeQMaster** » 2010-08-20 15:36

ok, sorry if disturbed.

Post by **lejonklou** » 2010-08-20 18:44

You certainly didn't. Thanks for your input!

One thing I wanted to point out was the potential problems associated with these kind of products (accessories for other companies' products). When I first made the Hudik MM phono board for the Exotik, people called Linn and asked them whether it was ok to install a Hudik into an Exotik.

I don't know what kind of answer they expected, but Linn replied that the Exotik warranty would be instantly invalidated. Linn then contacted me and demanded that I add information about their warranty position and that they didn't in any way commend or endorse Hudik. The letters were far from gentle, I must add.

Then very quickly the upgradeable Exotik was transformed into New Exotik (later renamed Akurate Kontrol), where both phono and DA boards were already fitted. This wasn't any good for the customer, but their main goal was apparently to prevent people from installing alternative boards, like Hudik. And no internal card slots have been seen since, in any of their products. The only exception being aktiv cards in power amps.

Hudik was a plug-in card for a Linn product. A tunebox would be a product for their plug-in cards. I'm not sure what Linn would do about it, but it wouldn't surprise me if they either changed the cards, introduced power amps that had them already fitted, or released a tune box of their own.

To sum it up, I do understand the point of a flexible tune box. But my current focus will remain on completing my own range of compact, high performance products.

optics · Post by **optics** » 2010-10-02 07:38

Hi Fredrik,

i totally understand your thinking;

The question is about the difference between the cards;
is it just the x over frequency ?, compared with alterated
frequency responses ??, if so maybe only a tunebox with adjustable filters would be fit the whole range ???

Please forgive me but lets throw in a little blasphemy;
for example is the Katan really better aktiv , or is aktiv just better
because of 3db more bass response and really poor passive x overs ??

There is for sure scientific evidence aktiv is superior to passive,
but afaik LINN is the only company using this approach.

They also claim about toll on filtering; do these frequencies show up with digital sources or only with vinyl ?

Besides the theory is aktiv only a build in equalizer ? (sorry for that)

So much for Philosophy ...

cheers

johannes

Post by **lejonklou** » 2010-10-02 22:28

Johannes,

I think you're right. A good solution would be to have a five way all-adjustable active filter, in which you could set roll on, roll off, level and bass shelving (lower bass eq) entirely as you please. Or at least within certain ranges, to make it fit everything from two way to five way speakers. Of any brand and model!

But it would be a very complex product. Which in turn makes it difficult to optimise performance! To make it better than the current aktiv cards would probably be a challenge.

In my opinion the passive crossovers of Linn speakers, including Katan, are very good. I once tried making better passive filters for some Linn speakers, but they became large and expensive, sounded a bit impressive but not really any better than the originals.

You can remove the bass shelving on e.g. Katans, and they will still sound better when driven aktiv. So I remain convinced that the aktiv approach is good, if your active filters don't degrade the signal too much. If they're not good enough, you're better off with a passive filter. The shelving of the bass (and when it comes to 109's, the lowest frequency roll off) is the icing of the cake in active filter design, not the main reason why they're better. In my humble opinion.

Although active filters aren't that common in the consumer audio business, they're quite common in the professional audio world. Many speakers with active filters also have the power amps built in, making them fully active and requiring only a preamp signal and mains power. One reason why Linn have been able to push this concept is probably because they make the entire range of products, not specialising in just speakers or amplifiers. And aktiv speakers sells a lot of power amps.

By the way, in our kitchen we have a Panasonic micro system with two way speakers and it has dual stereo power amps with active filters. One with treble output, the other with mid/bass output, feeding the drive units directly. It sounds ok, but not great. I have a strong suspicion that the cut off frequencies aren't exactly optimised...

rowlandhills · Post by **rowlandhills** » 2010-10-03 12:29

There's an interesting post from Philbo, the Linn speaker designer, over on the Linn forums, where he says (my bold highlighting):

Generally I develop a prototype Aktiv system first. This employs a set of adjustable digital filters which allow me to quickly evaluate various filter types and orders.
From this pseudo-Aktiv system I then design the passive crossovers, one filter at a time and substitute these in place of the pseudo-Aktiv filters until I have a full multi-amp passive system. All of these filters are implemented on perforated hardboard with components soldered directly together, so link plates are not possible, so to start with multi-amp is just easier (why not, the amps are just lying around waiting to be used ).
Finally this gets checked as a single wire passive system (normally using multi wire to a single deltron into which I connect the single wire from the amplifier). If there are any issues with the combined impedance of the single wire system the passive filters may be re-evaluated.
The passive design is then laid out for assembly on a printed circuit board. When ready I am then in a position to test the system with links in place as a true single wire passive speaker.

Once this is complete I redesign the pseudo-Aktiv system including a few extra tweaks not possible with a passive crossover, and this is converted (normally by DanielE) into lovely Linn Aktiv cards.

For more context, see here: http://forums.linn.co.uk/bb/showthread. ... 0#pid87900

SaltyDog · Post by **SaltyDog** » 2011-12-18 05:14

The Tundra thread leads back to this one.

Rereading the thread, I'm glad not to bring it up in the Tundra thread, I understand your view.

However the goal of active speakers and Lejonklou value is hard to not see.

Is it worth considering a way to use Linn cards in your amps?

Post by **lejonklou** » 2011-12-19 14:26

SaltyDog wrote:Is it worth considering a way to use Linn cards in your amps?

Active is worth considering, but my amps won't take Linn cards. One reason is that if I tune the design as far as possible, it has to be tuned either with cards or without cards. I can currently not see how the power amp could be optimised for both.

SaltyDog · Post by **SaltyDog** » 2011-12-19 16:44

I consider it to have been considered now.

Post by **lejonklou** » 2011-12-19 17:32

SaltyDog · Post by **SaltyDog** » 2011-12-19 18:16

One of the most important things I have learned in HiFi is who to trust.

My highest compliments to you, Sir.

Post by **lejonklou** » 2011-12-19 22:11

Thank you very much, Salty!

sunbeamgls · Post by **sunbeamgls** » 2012-09-28 18:26

For what its worth, I think the idea of a Lejonklou equivalent to the Tunebox, only compatible with Chakra cards to keep it as simple as possible, has a great deal of merit. It could be modular in design in a similar way to Linn's power amps so there could be C21, C31, C41 and C51 versions, if that's not too cheeky! All in the same box, just a different number of slots.

It opens up so many more possibilities for active amplification, including Tundra of course.

It could be called the Dekrypt.

And for the cynical out there, just think how many more Tundras you'd be able to sell on the back of a Tunebox ;-)

ThomasOK · Post by **ThomasOK** » 2012-09-29 15:53

There are parts of this idea I like and parts I don't. I do like the idea of a configurable tunebox but it would make no sense to have 2, 3, 4 and 5 channel versions as the cost difference would be slight and the sales of each version wouldn't justify it. All you really need is a box that could handle all the channels you could foresee needing and you would use whichever ones you needed. Since the box is mostly just wiring anyway, with very little circuitry you would be paying almost zero for the additional capacity. The original LK tunebox was such a device with the ability to take 2, 3 or 4 cards. With modern speakers you would want 5 or 6 channels to be on the safe side.

But that brings up problem two: using the Chakra cards. While the Chakra cards are musical, and it means you don't need do redesign the wheel, there are many of us who are not happy with the 1dB adjustment increments. Anyone who has played around with a crossover with 1/4dB adjustment increments, like the original Isobarik crossover, will know the importance of that level of tuning. One simple example of the usefulness of this is changing something like a Kaber from the original tweeter to the Espek/Ninka tweeter (a significantly more musical device). The new tweeter is .75dB less efficient than the older ceramic tweeter so without .25dB adjustments you can't get the level quite correct.

Of course, the ideal crossover would allow you to reconfigure ALL the parameters so it could be set for any speakers, with any practical number of divisions, and with precise fine tuning available for levels, rolloffs, frequencies and phase characteristics. A device like this could be configured for anything from original Kans and Isobariks up through 242s and beyond. The problem is that this would be damn near impossible to do with all analog circuits as the complexity would be enormous. It could be done digitally and would be much simpler to implement, although it would still require a lot of R&D work. The big question is could the D to A and A to D internal conversions necessary be transparent enough to be musically competitive with current all analog designs. Only time will tell the answer but seeing as Linn have a digital crossover on the Kiko it is obvious they are working on the idea. We'll have to wait and see if they develop it into a more high end product. It would certainly be enticing from a practicality point of view: no more different crossovers for each different speaker, no more having to make new crossover boards when a speaker is updated (such as 242 to Mk2 or Artikulat to Klimax) and the ability to make a crossover for a brand new speaker design just by reprogramming the software. Imagine the advantage of being able to change any parameter you want while in the process of designing a new speaker! Obviously this idea has to be very appealing to Linn if they can make it work.

As to the suggested name, Dekrypt would be appropriate if it was a digital crossover as it would have to encrypt to digital and decrypt back to analog. On the other hand it also sounds like The Crypt when you speak it which would give a less wholesome connotation. ;-)

Tunebox?

Tunebox?

it is possible with old tunebox and Linn adapters