Unstable 250 - fact or fiction?
Posted by: plynnplynn on 29 January 2004
Picked up the following comment on another discussion list today.
"Of course, highly capacitive cable used with an unstable, amplifier - such
as a Naim NAP250 - and driving a difficult load will modify total system
behavior, but that's because one of the elements is very clearly defective."
I have seen others also refer to Naim amps as unstable. I would appreciate technical comment from members who can explain what on earth these non-Naim users are talking about - or it it just nonsense?
Terry
CDS2/XPS/82/Supercap/250
Posted on: 29 January 2004 by Paul Ranson
The clearly defective element is the cable.
Where on the Internet is the spinning going on? Look at it another way. Take the OP's preferred amplifier, remove some internal components, see how stable it remains...
Paul
Posted on: 29 January 2004 by plynnplynn
Paul
A couple of comments made in the LS3/5a mailing list in a discussion about cables.
Terry
Posted on: 29 January 2004 by Manu
James is right.
Try 2*50' of NACA5 at the end of an other brand amplifier, will it be stable?
No for sure!
Same thing, amplifier used in wrong conditions.
Emmanuel
All opinions are my own, and reflect those of the organisation i work for, even if not stipulated.
Posted on: 30 January 2004 by Noel
I seem to recall that the 250 had some fun with the Quad ESL63 protection circuitry. Quad ESL57s were fine. This was 20 years ago so I may be wrong.
Noel.
Posted on: 30 January 2004 by Phil Barry
This sort of statement really gets me angry.
The arrogant and ignorant SlOBs who make and repeat the statement make assumptions that are untenable.
Most amp makers design their amps so that they'll work with most cables. Fine.
Naim does not. Naim specifies at least 3.5 meters of NACAx-type cables to ensure stability (and don't they put a limit on the length, too?).
Naim is very clear on this - If you don't like the cable, don't buy Naim, although some dealers apparently stray from the line.
This is purely and simply a valid design choice.
Now, if Naim didn't publish the spec, we'd have something to complain about. But they do, and the idiots who claim the design is defective do not. Let them spend their time effing themselves instead of writing their crap.
I really hate it when people push their truth on everyone else. Naim does not - they tell it like they see it and encourage the customer to make the choice they prefer. These idiots have blinders on.
Phil
Posted on: 30 January 2004 by Paul Ranson
Back before there was Naim speaker cable Naim amps were quite happily used with ordinary third party cables. The fashion for odd and inappropriate speaker cable came later.
Naim publish a spec the cable should meet, and I think I've seen a list of cables they approve of technically, although it does seem simplest and probably cheapest to just use NACA5.
The ESL63 problem was because the early models had an over-eager crowbar protection circuit. This would cause the amp output to be short-circuited when the fridge turned on or off. This isn't good for it.
Paul
Posted on: 30 January 2004 by plynnplynn
quote:
Most amp makers design their amps so that they'll work with most cables. Fine.
Naim does not. Naim specifies at least 3.5 meters of NACAx-type cables to ensure stability (and don't they put a limit on the length, too?).
Naim is very clear on this - If you don't like the cable, don't buy Naim
Yes this is the way I see it too. I cannot, however, understand why other people do not accept this simple explanation.
Terry
