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Naim house sound

clownfish

clownfish

It's all in the details
The often quoted mid/bass hump with Naim equipment seems a strange viewpoint to me. Thats not to say I don't understand the phenomenon being described but it's the way it is attributed that bothers me.

If the amp has a flat frequency response then how can it have a designed in lift in the mid, bass or anywhere else?

Is it not just the case that Naim amps (typically) are designed to dump current as required, giving them a fast slew rate which means leading edges of signal can be reproduced faithful giving the music lots of attack - compared to some other amps?

Surely any self respecting amp can't be putting in stuff that's not there in the source?

O.k. I may just have revealed a lot of ignorance here but am genuinely interested to understand the above stated perception of Naim amplification..

Hard hat on, ready for what's coming my way 😎
 
Most Naim amplifiers have significant output resistance, unusual in solid state designs.
This modifies bass response with typical ported speakers
 
slew rate is the rate of change of voltage. Any amp capable of >20KHz ish will have a high enough slew rate to represent any waveform you can really hear. Sure it's good to have some additional margin, however this doesn't really have much to do with 'attack' and transients. Probably you're thinking of the amps ability to handle dynamic peaks in loads. Attack is the initial part of a sound that conveys the rising and often harmonic rich starting dynamics. The attack of a sound will comprise many many cycles of the waveform, it'll have nothing to do with slew rate really.

As for Naim, I'm not sure what the rumour is. Any full Naim system I've heard typically sounds a bit lean and thin to me, however piece by piece some of their stuff is decent enough.

If you're happy with the sound, why worry.

BTW, all hi-fi is about getting closer to the original source material. So in a way anything short of perfect hi-fi is exactly about the unwanted "putting in stuff that's not there in the source".
 
Has anyone ever published a graph of the frequency response of a Naim phono preamp? I'm curious if there's a "house" curve that varies from a strict RIAA playback response?
 
Hi Guys:

As some of you already know from my previous postings, I own three naim amplifiers, an early “bolt-together” NAP 160, an Olive 140 and an Olive 250. I have used all three with various speakers including KAN’s, NS1000’s and ELAC 207.2’s. I am yet to experience this fabled “mid bass hump”.

Niam amplifiers are bandwidth limited but within the audio bandwidth they are dead flat and there is no “mid bass hump”.

“Most Naim amplifiers have significant output resistance; unusual in solid-state designs. This modifies bass response with typical ported speakers…”
Click to expand...

This is true to a point as naim amplifiers have a 0.33 ohm resistor rather than a series output coil but in reality the output impedance is still quite low when compared to valve amplifiers and valve amplifiers don’t all have the “mid bass hump”. The response modification of a naim amplifier driving a typical loudspeaker would be less than the total variations on the actual speakers response curve. Stereophile measured the nait 5si sometime back and John Atkinson measures the response into a simulated speaker load as well as a flat resistive load. His test showed a variation of less than +/- 0.3 dB into the simulated speaker load while the resistive Loads were dead flat from 20Hz to 20kHz.

1014NAITfig01.jpg


Interestingly I pulled up some other amplifier reviews and the solid-state amplifiers all showed similar variations in response on the simulated speaker load. Then I looked at a few valve amplifiers and these can vary up to ±1.5 dB. My own much loved QUAD II’s waver to just over 1dB either side of the 0dB centre-line. :eek:

In terms of slew rate, all that is needed is enough rise time for the amplifier to pass a 20Khz signal at the amplifiers full output (which, with normal music would never actually happen). The bandwidth limiting of a naim amplifier means that only a moderate slew rate is required. Any higher slew rate is inviting instability.

In truth there is no “mid bass hump” but in the odd case with very difficult speakers the slightly higher output impedance may cause a slight loss of bass damping. I emphasise the word “may” and “slight”.

Quite often a reviewers observation is quoted out of context and all of a sudden it becomes a statement of fact. I think this is what has happened with this so-called naim “house sound” attribute. The fabled naim “mid bass hump” is nothing more than a gross generalization that someone subjectively observed in a rare situation that probably had more than one factor (such as reactive/capacitive speaker cables, unusually difficult speakers and poor room acoustics) contributing to the observed effect.

LPSpinner.
 
Bloody hell! Accurate advice for once....:D

The output resistor is actually 0.22R on Naim amps not 0.33 but other than that... This will limit the damping factor to 16 with a 4 Ohm load.

They are not a fast amp by solid state standards and I personally like to see more bandwidth and slew rate than the classic Naim designs which are limited by the early 70's topology in many respects. The bandwidth limiting tends to offset any slew rate limiting but this is not ideal and may well contribute to the slightly "grey", "grainy" sound many report.

I believe the newer designs, not based on the NAP250, are properly engineered and should give good results.

There is no mid bass hump BTW.
 
Arkless Repairs said:
...The output resistor is actually 0.22R on Naim amps not 0.33 but other than that... This will limit the damping factor to 16 with a 4 Ohm load...
Click to expand...

Oops well spotted … I must swap the two and the three keys on my keyboard. :D

Arkless Repairs said:
... I believe the newer designs, not based on the NAP250, are properly engineered and should give good results...
Click to expand...

Yes, I’ve seen them use a complementary output stage rather than the older quasi-complementary output from ye older days. :eek:
Perhaps its now cheaper to buy smaller separate quantities of NPN and PNP output tranies rather than the bulk price on twice as many NPN devices plus the cost of a baxandall diode, or am I just being cynical.:p

LPspinner.
 
Thanks to all for the replies, especially so to LPSpinner & Arkless, Exactly the kind of information I was hoping for!

Arkless Repairs said:
They are not a fast amp by solid state standards and I personally like to see more bandwidth and slew rate than the classic Naim designs which are limited by the early 70's topology in many respects. The bandwidth limiting tends to offset any slew rate limiting but this is not ideal and may well contribute to the slightly "grey", "grainy" sound many report.

I believe the newer designs, not based on the NAP250, are properly engineered and should give good results.

There is no mid bass hump BTW.
Click to expand...

Do you think the new designs are faster and have less grain? What might be a good example of a fast amplifier in the NAP 250 price range?

LPSpinner - Baxandall diode is a new one on me. I had to google it. Brilliant, thx for broadening my horizons 😃
 
There is definitely some part of the music that my 32.5 portrays that makes it sound fast, exciting and a little bit thin. I have also found that this can override some of the subtle nuances in the recording. When my son was born I packed away my 32.5\B.D.160\TC\821a and TT and I replaced it with an Exposure X and for the last year I have really been enjoying it.Over the weekend I brought everything out to play again and thought it sounded broken in comparison, lacking in warmth and bass. I am sitting back listening to Frasey Ford as I type and the X is sounding very nice indeed. I need to give it another week and I will try again but it's not looking good for my naim kit.........
 
Thin, definitely thin when I hear it. I think that's what makes it seem 'fast'. In reality I've no idea what makes it faster than other amps. Some amps should be faster, in the real sense of the word. With direct high bandwidth, low output impedance output stages going flat up to 100KHz or more and also with large over engineered power supplies handling transients with great ease, to boot. It's all good equipment, but 'fast' is some sort of marketing ploy if you ask me ;)
 
clownfish said:
The often quoted mid/bass hump with Naim equipment seems a strange viewpoint to me. Thats not to say I don't understand the phenomenon being described but it's the way it is attributed that bothers me.

If the amp has a flat frequency response then how can it have a designed in lift in the mid, bass or anywhere else?

Is it not just the case that Naim amps (typically) are designed to dump current as required, giving them a fast slew rate which means leading edges of signal can be reproduced faithful giving the music lots of attack - compared to some other amps?

Surely any self respecting amp can't be putting in stuff that's not there in the source?

O.k. I may just have revealed a lot of ignorance here but am genuinely interested to understand the above stated perception of Naim amplification..

Hard hat on, ready for what's coming my way 😎
Click to expand...

If you're just talking about amps and not Naim CD sources and speakers, then I think the power amps are largely neutral, however earlier pre-amps such as the NAC32.5 were not exactly phase linear - ie the treble and mid band were slightly out of phase with each other as a result of some filter circuits which were largely replaced in the NAC72 (if I recall correctly)

Personal experience with the naim "High end" which at the time was 52/Supercap/NAP500 revealed an excellent open sound especially from CDS2 as a source, however, the whole system got a bit shouty past about 1pm on the volume pot through NBL speakers. When I replaced the lot with a different digital source (CD and Squeezebox through DAC1 from benchmark, and preamp from ATC - SCA2 and active speakers from ATC - SCM50ASL) all that shoutiness around 1 o'clock went away. I think the problem was probably in the capability of the speakers to deal with the current delivery from the NAP500, although other people, notably Nick / Jek, reported that the NAP500 couldn't cope with difficult loads such as the large PMC speakers.

Anyway, I don't think 552/500 or 252/300 have a "naim sound" they just sound neutral to my ears.
 
nirvanah said:
There is definitely some part of the music that my 32.5 portrays that makes it sound fast, exciting and a little bit thin. I have also found that this can override some of the subtle nuances in the recording. When my son was born I packed away my 32.5\B.D.160\TC\821a and TT and I replaced it with an Exposure X and for the last year I have really been enjoying it.Over the weekend I brought everything out to play again and thought it sounded broken in comparison, lacking in warmth and bass. I am sitting back listening to Frasey Ford as I type and the X is sounding very nice indeed. I need to give it another week and I will try again but it's not looking good for my naim kit.........
Click to expand...

I'm guessing your naim amps need a service, and you might want to swap out the 32.5 filter boards for the 72 ones.
 
clownfish said:
The often quoted mid/bass hump with Naim equipment seems a strange viewpoint to me. Thats not to say I don't understand the phenomenon being described but it's the way it is attributed that bothers me.
Click to expand...

To my mind the classic 'flat earth' sound comes from the warm and bouncy pre-Cirkus LP12 at the front and the similar period Linn or early Naim speakers (Kans, Isobariks, SBLs etc) at the end of the system. The amps are neutral, but the source and speakers anything but! This is emphasised by how bad CD tended to sound in such a system.

There was someone at Scalford a couple of years back running a little blind test between a 32.5/Hicap/250 and a little Yamaha S500 integrated amp into some small speakers that I can't remember. They sounded astonishingly similar to my ears, in fact I picked the Yam as favourite twice! Certainly no noticable tonal imbalance between them and the dem wasn't pushing the amps at all so any additional headroom the big Naims may have had wasn't a factor. It was a fun dem!
 
Thin , grey , grainy.

Yikes ! For real ?

Not my experience at all.

I did have an old olive Nap 250 that was a bit overly warm and thumpy in the bass. In need of a service ( caps ?). A later serviced one sounded pretty different - and really rather good. Thin , grey , grainy. Er, nope.
 
Some Naim amplifiers are run at very low bias and have mild crossover distortion. Others are more conventional and measure very well, so you cannot really say that "grainy" is a house sound
 
davidsrsb said:
Some Naim amplifiers are run at very low bias and have mild crossover distortion. Others are more conventional and measure very well, so you cannot really say that "grainy" is a house sound
Click to expand...

Indeed. All the Vereker "designed" power amps that sound thin grey and grainy.
 
Apart from the standard split between fans of Naim and those who detest it, there also appears to be a tendency towards the older CB and olive kit. Having moved from CB 62/90 to modern 202/150x I am probably a pariah for many Naim fans. However, to my ears, the black generation kit has a more balanced character whilst retaining much of the punch and attack that I have always enjoyed. I can also vouch for the fact that adding a power supply, a TeddyCap in my case, was a very cost effective upgrade that added a huge amount of bass weight.
 
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