Hi Diggy
Looking at that diagram is it the case that the bass and treble frequencies have been spit in the amp.
Or is that just passive to each drive unit. 
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Help me through this please;
No bottomless money pit to spend on hifi but I can let my hair down a bit, so here are a few assumptions, would this work?
Buy Selekt, add 2 x amp modules - do they both need a DAC or just one?
Buy Kudos Super20A connect amp modules as detailed in diagram
Have I got this right or am I way off?
To do this using a Naim set up would involve a good few black boxes, and a lot of cabling?
If there is a better way of doing this more simply with a Naim setup I am keen to know what it is.
This is exactly a home demo I am trying next week. Iâm using stereo Organik DAC in each of the Amp modules. You need one stereo DAC for each amp module. Will be wired as per @DiggyGun diagram above.
After listening to that for a week or so to get used to the Linn effect Iâm going to try taking the Kudos S20A out and insert Kudos Titan 606.
We will see how it goes. Good luck with your sessions.
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From the forum FAQâŚ
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I have gone down the road of 222 into ATC50 Actives, no complaints.
I had the privilege of seeing my 50 Actives being made at the factory.
There is a lot more to the active crossovers than smaller components. The filters are done using, what looked like, operational amplifiers, where the gain, rolloff frequently, slope, phase, etc. are all set with small potentiometers. Once the speakers are completed and run in they are set up in front of reference microphones and manually tuned to be exactly as required. Try doing that with large passive inductors and capacitors!
This is just some of the magic of the ATCs.
Paul.
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Paul, you are exactly right. The primary technical advantage of an active system arises because the crossover is placed before the power amplifiers which means that the crossover works on low level signals. As you note, this allows some fairly sophisticated circuitry (such integrated circuits) that allows better control/alignment through the crossover regions. It also allows the designer to âEQâ the signal before it reaches the power amps in order to fine tune the performance of the amp/speaker combination or more closely match the frequency response from the left and right channels.
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Thank you, good luck with your auditions, look forward to your update.
You would need two DAC Modules, one for each Amp.
One thing to remember, they offer three levels of DAC;
- Standard @ ÂŁ220
- Katalyst @ &1500
- Organik @ ÂŁ3400
Depending on budget you could start of at a lower level DAC then upgrade as funds permit, or start passive with Organik, then upgrade to active as funds permit.
DGâŚ
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Hi Diggy. To run a Kudos 20A active surely you also need an active crossover to replace the built-in passive one? Otherwise youâd be bi-amping. Apologies if Iâve got this wrong.
Roger
There are several ways to skin this particular cat, but to keep it simple, and taking the ATC SCM19 as the speaker and Naim 222 as streamer preamp, you could:
A) connect 222 to a power amp, NC250, say and then this to passive speakers, or
B) connect 222 directly to active speakers.
In both cases youâd use a balanced cable from 222 and probably a long one in case B).
But weâre all talking about our own preferences and systems here. I really think you should go and arrange some auditions. When I first became interested in active ATCs I had an audition of active 19s vs passive 19s driven by a Naim 250DR. Another customer at the dealerâs sat next to me throughout the couple of hours spent comparing them. At the end I knew I wanted actives but my companion said he found the actives too in-your-face and wouldnât be able to live with them. Since itâs your money and ears, only you can decide which setup would bring you the most enjoyment. Off to the dealers âŚ.
Roger
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And as a consequence the amps are directly connected to the voice coils without, especially in the case of the all-important-to-grip bass driver, an inductor or other circuitry in between, so maximising the âdamping factorâ.
Regarding active crossover functioning, a passive XO uses inductors and capacitors, while analogue AXOs use resistor-capacitor networks, while digital AXOs use DSP.
Digital AXOs usually allow easy selection/adjustment of crossover frequencies, cutoff slope and characteristic (e.g. 6,12,18 or 24dB/8ve, Butterworth or Linkwitz-Riley etc), and sometimes additional user-selectable DSP. Some analogue AXOs allow frequency selection, either switchable between a few presets, or using plug-in resistor networks. Both types allow setting of relative level for each driver, and phase (time delay), or should!
Crossover frequencies and slopes are usually set to match those chosen by the speaker manufacturer for passive versions, while a measuring microphone and software like REW (invaluable), make levels and phase easy to set up, and facilitates other DSP, or playing with XO frequencies and slopes.
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Hi Roger
In the Selekt, the Exact technology is acting as the external crossover and splitting the signal in the pre-amp section.
DGâŚ
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Thanks IB. Inserting a passive crossover between the power amps and the speaker does reduce the overall damping factor of the speaker/amplifier system when compared to connecting the power amps directly to the driver. However, there are several technical articles (which I will reference if I ever find them again) which show that the effect of a passive crossover on the effective damping factor is quite small if the power amps have a high damping factor to start with. This might have been an issue 40 years ago but most modern, well designed, power amps now have much higher damping factors than previously.
Full disclosure: I have a pair of passive SCM40s driven by Naim monoblocks. But I also recognize that a pair of active ATCs with a NSC222 sounds really good and is a much more cost effective way to get great performance.
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Auditions are in the pipeline.
At the moment I am trying to get my head round the technology and terminology, otherwise I end up buying stuff I donât need and miss out on stuff I do want as I donât understand the language and patter used in the stores.
Learning lots thanks to all the replies.
Very understandable. Work with one or more good dealersâŚthey wonât be talking a foreign language and certainly not patter, imhe.
Start with the type of music you like, which I mentioned on another of your threads and which iirc hasnât been described. The minutiae will fall into place as you audition different systems. There are lost of system choices out there, but the best is to build a rapport with those dealers you choose. The good ones do have vast experience, but the very best also value feed back from established clients, so they have a genuine awareness for advising their clients, new or existing.
Good luck.
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Yes, the Exact technology in the pre-amp acts as the external crossover which splits the treble and bass to the two power amp cartridges.
There are three amps in my Selekt;
- Pre-amp is part of the main board which includes the Exact technology (fixed)
- Two Stereo Out Power Amp Cartridges (variable)
Similar to the Naim format of NAC 282 (pre amp) to SNAXO 242 (external crossover) to two NAP 250 (power amp) [one for the treble and one for the bass].
This is from my system set up showing the connections.
And this is from the Kudos website showing the connections.
Hope this helps.
DGâŚ
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Mmm
Thatâs Bi Amp not Aktiv
Or Wonky activ
Exakt and all the other system software Space Optimisation etc isnât a crossover.
I used to run my MK2 Kans like that for a while with two LK280s = four channels one for each drive unit.
I ran my Selekt DSM this way in the past using multiple power amp modules, looks like youâve covered all the obvious background info already!
Thanks for trying to explain but unless the frequencies are split and unique to that range of the drive unit the same as a separate Aktiv crossover works.
Iâd be very interested to try the treble wires into the bass unit and see if itâs frequency generated or not.
I get all the processing before the power amps but unless the power amps are split to the different drive units frequency range then Iâm not convinced with the terminology.
Maybe Iâm having a Father Ted morning. 
