Output impedance

According to my measurements the black Naims are not more or less sensible to cabling than most other amps. Infact due to the reduced bandwith they hardly oscillate.

Being low feedback design they dont like extremely high capacity cables and due to the high output resistance, a low resistance cable can be benefitial.

With 99% of the cables available you dont need to worry and can simply choose the brand you like and the length you need. IMHO with NACA5 you will not be able to reach the full potential of the amp.

Combination with speakers is another thing, coz the amps dont like low and complex impedances. But even when driving such loads there´s no danger, it just doesnt sound that good. The newest models (SN and XS) dont even have this "issue" anymore and are more stable than 200/250.

quote:

Originally posted by yeti.fro:
According to my measurements the black Naims are not more or less sensible to cabling than most other amps. Infact due to the reduced bandwith they hardly oscillate.

Being low feedback design they dont like extremely high capacity cables and due to the high output resistance, a low resistance cable can be benefitial.

With 99% of the cables available you dont need to worry and can simply choose the brand you like and the length you need. IMHO with NACA5 you will not be able to reach the full potential of the amp.

Combination with speakers is another thing, coz the amps dont like low and complex impedances. But even when driving such loads there´s no danger, it just doesnt sound that good. The newest models (SN and XS) dont even have this "issue" anymore and are more stable than 200/250.

Have you considered that the proper length of Naim cable will allow the amp to drive a difficult load and still sound like a Naim amp should. Naim speakers tend to be of low impedence and use high order networks. I agree that on a bench, the amps aren't more or less stable and considering the lack of output preload, it's remarkable but it has the capability to be more stable in use when used as recommended. That you think it may not sound as good when used differently is exactly the point of my posts to cat345. It doesn't mean that you have to use NACA5 but in an amp that uses wire as part of the load calculation, it may not be a bad idea. It's still a lot better than using an inductor/resister pair in the output as other amps do so that you can use your favorite exotic wire.

Just on a point of information:
Naim POWER amps are NOT low feedback designs!
The power amps have a huge open-loop gain which is fed-back.
The pre-amps use a combination of high local feedback with low-ish overall feedback.

Since Power amps are being discussed, they do use loads of feedback . Nothing wrong in that, if it is done properly with good high frequency capable output transistors (which Naim rightly cite as important)and the loop-gain, phase margin and class AB operation are implemented as wonderfully as they obviously are. The output stage does use a Zobel network (ab RC to ground to give the amps something to drive at VHF) but no series spring/inductor to decouple the amp from the speaker and lead impedances.
Naim obviously find that the additional control (and musical ability) the amp gains over the speakers was well worth the additional slight pain of using lower capacitance (NACA5 or similar) leads.

On another point, I've not found if the optimal speaker lead length is shorter or longer when you run then active, as the amp only drives the drive unit and not a more complex load. Anyone got any views?

Regards,

DB.

Sounds about right though I don't think the feedback excessive. The pre has a hand in allowing this feedback with it's controlled bandwidth. It's why the pre's work with every amp but the amps are more hit and miss with other pre's.

quote:

Originally posted by Christopher_M:

I could be wrong but I perceive your post as a request for help over speaker choice. I wonder what you would make of a pair of SBLs with your SN in your room. For me, fronted by a CDX2 or better, this is a blistering combination - for the reason I've already outlined.

Of course I may have completely got the wrong end of the stick, in which case I apologise.

Best, Chris

Chris, you are right to assume that I am looking for some speaker replacement.
This time I am looking for some large and efficient loudspeakers. My source is ok because I mostly listen to uncompressed analog fm and lp's. I dont believe in buying a cd player that cost the price of a Harley Davidson!

Hey, Hey! now we're getting somewhere. Ok, so you listen to vinyl and FM radio, good. And you're interested to find some new speakers.

You're going to have a look (and a listen) to large, efficient speakers, hopefully in your room. And after you've done that, please listen to some SBLs (have you noticed that's the third time I've mentioned them, yet I don't even own a pair!) or some SL2s. Add an n-Sub if you want to shake the room. Then you will hear what damped speakers can do with a relatively undamped amplifier.

I wonder how it will turn out?

Best, Chris

The problem is that I bought new Intro 2's a long time ago to replace my Rogers Ls7t and this had make me realise that it was not the sound I like. Fast= yes Incisive= yes Musical= no (for me).
Of course active SBL's or SL2's would be another matter, but the time you get there you have already paid half the mortgage on your house. Sorry to be brutally explicit but sometimes those things just have to be said! I wonder what the outcome would be if you compared Nait2 + Westminster Royal's vs. Nac 552/Nap500 + SL2? (musically speaking)

quote:

Originally posted by cat345:
This time I am looking for some large and efficient loudspeakers.

DBL.

quote:

Originally posted by kuma:

DBL.

Finding a non black pair of DBL's here is as hard as climbing the Everest barefoot

Patience...

Going active is a distraction in my view, which takes you away from the style of speaker that you might like with your SuperNait.

It seems a shame to write off Naim's highly damped speakers because of earlier experience with Intros. I have already demonstrated my limited technical understanding but they have a port, so IMO are not as damped as Naim's sealed box speakers.

DBLs would certainly fit your criteria of being large and efficient, and mine of being highly damped. If only you could find a pair in the right finish.

Interesting point about Nait 2 with Tannoy Westminster Royals. We sold them in a shop where I once worked years ago. They sounded great with a Musical Fidelity A1 but I've subsequently learnt that I prefer the Naim presentation. We weren't a Naim dealer so I never heard them with a Nait.

It could very well be that Naim's very damped speakers are not for you, possibly because with the exception of the DBL, they're not large enough. How about Yamaha NS1000Ms? They have bass from a quoted 20Hz and are a very damped sealed box.

Best, Chris

Um, how did it turn out?

Best, Chris