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Life after Naim

Mr Pig said:
It was one of the reasons I switched. The 250 struggled to drive Isobariks and was worse with Saras! Sounded nasty at high volume and shut down often. At that time, Naims answer was 135s, double the money for 15 watts more.

Enter the Meridian 105s. 40wpc more than the 250, and a more rounded, musical sound. Never felt any desire to change them.
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Once again, it’s got nowt to do with Watts.
 
I kind of agree a little with the above. The 82/180 combo I used to own was really great with smaller scale stuff but when it came to orchestral it often became a little hard and constricted or congested in some recordings. The Yamaha has no problems with this and sounds even handed in all genres. It lacks the slight doubt I had with the Naim. Great mid level kit though all the same.
 
Mr Pig said:
Mmm, it does really though.
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Yes, it does. The idea that available power, whether transient or steady state, has nothing to do with Watts is a contradiction in terms, even if it’s more nuanced than simple wattage. Unless of course the power laws have suddenly changed and every Hifi company and electrical engineer, ever, are wrong.
 
pocketkitchen said:
The idea that available power, whether transient or steady state, has nothing to do with Watts is a contradiction in terms..
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Older Naim amps were very good at delivering big gobs of power for a very short time, which is now the Nait got away with 13wpc, but that trick has its limits. Sparse recordings without much in the way of sustained bass work ok but condensed rock music or anything with more sustained power demands and you've got a problem. I think it confuses a lot of people. They know their system sounds great on some music and rough on other kinds but they don't realize why. They might assume the recording quality is poor when it is just that their amp isn't powerful enough.
 
The power laws are the same. So is Naims output circuit from CB up to the 500. Statement a different kettle of poisson.
 
Whether it is watts, volts or amperes, the symptom the 135s would exhibit when playing a heavy bass transient loudly was the sound of a 'crack' rather than 'thump'. No, it wasn't my loudspeakers' woofer hitting their end stops. Not even close. Apparently, the more learned members of the forum then suggested it was the SOA circuit activating to limit the output current, or something like that.
 
James said:
Whether it is watts, volts or amperes, the symptom the 135s would exhibit when playing a heavy bass transient loudly was the sound of a 'crack' rather than 'thump'. No, it wasn't my loudspeakers' woofer hitting their end stops. Not even close. Apparently, the more learned members of the forum then suggested it was the SOA circuit activating to limit the output current, or something like that.
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That’s interesting, both my 135’s and 250(s) would simply S/D. Same issue though, not enough current available to meet the demand. From memory, if they were asked to do 15amps for more that 10ms, then they would trip and a hard reset was required. PITA.
 
Maybe the SOA wasn't set correctly. The fans used to come on quite early in the piece, even when the case is not overly warm. The only time I manage to shut down the 135s was by (accidentally) shorting the outputs. That also required a hard reset. Inconvenient, but less so than blowing output transistors.
 
James said:
Maybe the SOA wasn't set correctly. The fans used to come on quite early in the piece, even when the case is not overly warm. The only time I manage to shut down the 135s was by (accidentally) shorting the outputs. That also required a hard reset. Inconvenient, but less so than blowing output transistors.
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Yeah, there are twp trips on the 250/135. A thermal at 65C which was a soft reset (wait 15 mins or so and it sprang back to life) and the over current as described above. People say that the 180 is the ‘magic’ amp, as it only has the thermal trip. Hah! It just destroys your tweeters instead.
 
I don’t have these problems with my NAP 110 and 160BD.
Never go higher than 95 dB though.
With my NAP 160, the green light of the power switch will dime a bit when pushed hard, does that count as a protection circuit ? :eek::D
 
Gervais Cote said:
I don’t have these problems with my NAP 110 and 160BD.
Never go higher than 95 dB though.
With my NAP 160, the green light of the power switch will dime a bit when pushed hard, does that count as a protection circuit ? :eek::D
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Hi, don’t know the 160 bolt down at all. I have very fond memories of my time with a 110, many years ago now, but with the right speakers, I remember how ‘listenable’ it was, if that makes any sense. The 110/140 just had the thermal trip. I presume that the 160BD would be the same? When the thermal trip activates, the power light goes out and you have to wait for it to cool down. By the sound of it, could be that your 160BD is on the ‘edge’ of a thermal trip when the light dims?
 
The other difference is the 250 and 135s have regulated power supplies. The 'lesser' amps don't. I'm led to believe the downside of power supply regulation is protection could be triggered if the drain is sufficient to cause sagging, whereas the unregulated would just run out of puff or get too hot.
 
James said:
The other difference is the 250 and 135s have regulated power supplies. The 'lesser' amps don't. I'm led to believe the downside of power supply regulation is protection could be triggered if the drain is sufficient to cause sagging, whereas the unregulated would just run out of puff or get too hot.
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Or cause clipping in the tweeters…..
Don’t get me wrong, I loved my time with Naim amps, my Olive 135’s with the WH mods were sublime…..when they were partnered with speakers that didn’t ask to much of them.
 
Gervais Cote said:
Below is the interior of my 160. I don’t see any thermal switch so they need to be handled/pushed with care.....

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As I said, don’t know the 160BD. As above, ensure your speakers have good efficiency and a kind impedance curve and it’ll be fine.
 
Gervais Cote said:
With my NAP 160, the green light of the power switch will dime a bit when pushed hard, does that count as a protection circuit ? :eek::D
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I found the power switch light dimmed in time with the bass on my bolt down 160 when I auditioned a pair of Saras.
It stopped me buying the Saras, and it put me off the 160 as well!
I'm older & wiser (?) now!
 
@MJS of this parish will know more about the 160BD than the rest of us put together and can answer the question of whether it had a thermal trip. From memory, Sara’s dipped well below 4 ohms when the music called for it, not surprised the 160 struggled!
 
All Naim power amps have a thermal trip. The BD160 has one mounted to the extrusion near the output devices. The early NAITs (1-5) didn't have one and I'm not sure about the later ones.

One reason the BD160 is one of the best Naim amps out there is due to the fact that the reservoir caps are right next to the boards and output devices. The 110 is also very musical for the same reason. CB160s and the 140 (and very much the 180) have long wiring between the PSU and amp boards.

The 180 is a capable amp but it never quite lives up to the 160. It was a parts bin amp - transformer from Hicap, Uprated PS from 140, boards from 250.
 
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