Flat earther?

This PRaT thing? For me it's a euphemism for "good bass" combined with the ability to handle percussive transients - drum strikes - that extend up into the midrange.

A system with poor to mediocre bass is not good at PRat in my book.

What makes good or bad bass?

For me good bass equals dynamic bass, textured bass, bass with some physical impact that you can feel as well as hear even at low to medium volumes, tight bass.

Bad bass is: too lean, or too one notey - both of which can be indicated by frequency response curves. Or it's smeared / bloated / woolly - ie it doesn't have the staccato stop and start of good bass.

On that basis the Naim amps that I've heard are good at PRaT. They've got good bass and they're punchy and dynamic into speakers with awkward loads.

However the LP12 - a product very much associated with the Flat Earth PRaT thing - has better bass than a Dual CS505 or Rega Planar 3 because the LP12 is more dynamic than both those tt's. But compared to a good idler like the Garrard 301 / 401 the LP12 has a woolly bass and therefore isn't as good in the PRaT department.

As for Linn speakers of the 1980's being good at PRaT well: Kans - too lean. Saras - OK for small speakers but not particularly extended in the bass. Briks are better, but I strongly prefer the bass of my Bozak Symphonys which make the Briks sound thin, lacking in impact and texture. So even Linn's flagship speaker wasn't that good at PRaT compared to other high end speakers around at the time.

So, to me this PRaT thing was marketing bullshit from Linn, but summarises the strengths of Naim amps well.

Naim amps were compromised in the Round Earth aspects, which for me are detail retrieval, soundstaging - precision of left right and front to back imaging - naturalness of instruments and vocals, the ability to show the accent emotion and inflection of the singer. In these respects I find that Naim amps and indeed all ss amps that I've heard - tend to sound rather mechanical and synthetic compared to a good valve amp. Also, into easy load speakers I find that good valve amps are more dynamic than good ss amps. Although I've not heard any valve amps yet that beat a good ss amp in the bass department.
 
lindsayt said:
Although I've not heard any valve amps yet that beat a good ss amp in the bass department.
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It is a slower surging dynamic that influences the sound of valve amps. The sound comes in waves that are very visceral, where as SS amps punch more.

Now this is character and again can become just another bullshit like the Linn one, and it has with many valve exponents (and I don't mean you Lindsay).

I can largely reproduce this valve character in varying degrees very simply with a solid state amp by using output transformers or by simply using a fairly low value high power wirewound resistor on the output. So this character is an *addition* not a subtraction, as extra components have to be added to simulate it.

Valves or transistors are not better than each other as it is subjective, in objective terms a solid sate amp will always murder a valve amp as valves are just not linear either in frequency or dynamics, but if that is what you like then so what. Personal subjective choice is the most important thing as it is your music, just don't presume other will follow the same course or preference, down this road lies the next brainwash, and some bottleheads are trying to create this!
 
h.g. said:
Have these characteristics ever been identified/measured in a physical sense? That is, like valve sound, horn sound, ribbon sound, and similar.
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Hi HG

I have had a lot of valve amps in my home over the years, and a smaller number of horns.

It's quite possible to have a horn system which is not instantly recognizable as such by the sound, or a valve amp that is indistinguishable from a solid state amp. It all depends on the implementation in my experience of these things.

I only mention this because many people believe it's instantly possible to recognize one of the above audibly, but I know this greatly 'depends'.

Likewise I feel this is the same with Naim/Linn equipment. Many Naim speakers in particular (not all of them mind you) are characterful, even recognizable. You could say they have a house sound I suppose. Then, Naim make a speaker (like the Ovator) which sounds unlike the rest.. blowing the terms apart.

As an aside, I believe much of the characterfullness of Linn/Naim flat earth systems comes from the speakers being used. I had a friend with a full Naim system into B&W speakers, and later IPL speakers. The character of the Naim equipment was hardly recognizable.
 
I'd also add that I prefer the bass and therefore the PRaT of my Bozak Symphony speakers with my push pull valve amp to the bass / PRaT of my Briks with an Avondale ss amp. So yes, speakers may well be more important than amps for PRaT.

The best bass that I've heard in my system has been the Avondale with the Bozaks. Bi-amped with the Avondale connected directly to the bass cones with no crossover inbetween.

I've also found that if you've got a source with a woolly bass then you can't unwoolly the sound of your system with the amp or speakers. The woolliness will always be there.
 
> It's quite possible to have a horn system which is not instantly recognizable as such by the sound,
> or a valve amp that is indistinguishable from a solid state amp.

Agreed. For typical examples the cause of horn/valve sound is well known, easy to measure, audible in blind tests and, as Richard mentions, reproduceable by other means. But is this the case for PRaT?

> Likewise I feel this is the same with Naim/Linn equipment. Many Naim speakers in particular (not all
> of them mind you) are characterful, even recognizable. You could say they have a house sound I suppose.

Perhaps in the case of speakers but PRaT is also assigned to solid state amplifiers which one would not expect to have a sound of their own at least under normal operating conditions. Unlike many audiophile terms, Pace, Rhythm and Timing does have some meaning in a physical sense but I have seen nothing reflected in relevant transfer functions. In fact, I have seen no examples of anything except as a term for sounds subjectively attractive in some undefined way.
 
The subjective nature of PRaT is very music genre dependent, which is why Linn Naim dealers have a play list and don't like you bringing other music into the dem (especially so called classical music). The whole thing of PRaT is an imposed artifice, it was instigated originally by the LP12 (in reality an Ariston RD11 copy) which because of its suspension acting as an upside down pendulum always trying to find equilibrium (which is why it is so difficult to set up) and the belt drive, means it imposes a timing character on all music it plays. This character is suited to rock, female vocal and some mainstream jazz and tends to make that sort of music artificially swing. The added influence of early naim amplifiers was to present a forward, immediate, in yer face sound, akin to a home PA system (remember the original naim amp was designed as a PA / studio / rock radio station monitor amps). That naim character has been modified and tamed a little over the years as has the LP12 but it is still very much part of the sound.

So PRaT is an artifice with little connection with reality, it is an imposition of character, and any customer who becomes convinced (brainwashed) into thinking that is the way things *should* be is always looking for it.
 
Richard Dunn said:
I can largely reproduce this valve character in varying degrees very simply with a solid state amp by using output transformers or by simply using a fairly low value high power wirewound resistor on the output. So this character is an *addition* not a subtraction, as extra components have to be added to simulate it.
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Agree completely.

It can sometimes be of benefit though, when partnering vintage loudspeakers voiced when driven by this kind of amplifier.
 
lindsayt said:
This PRaT thing? For me it's a euphemism for "good bass" combined with the ability to handle percussive transients - drum strikes - that extend up into the midrange.
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There is much in this and the two classic Linn products LP12 & Kan illustrate it perfectly.
I exclude Naim amplifiers as I find any character to very mild and probably due to the tight bandwidth limiting in the pre amps and higher than usual output impedance on the power amps, but nothing to get excited about IMO.

looking at the Kan, the first thing you notice is no low bass and that the mid bass is shelved down considerably. This type of balance always sounds lighter, snappier and subjectively faster than a speaker with good, even bass performance.
Look further up the range and you see rising output which again has the subjective effect of pushing vocals forward and adding edge, presence and attack to percussive sounds, or 'leading edges' as they used to be called.

It is simply the manipulation of sound for effect.

Ditto the Sara and the Naim SBL - in fact diito all of the Naim SBL/IBL derivatives over the years.

The LP12 is slightly different.
I still regard it as a very good TT though certainly not the best.
Generally it is pretty even but older versions did have some upper bass character - a slight boost in this area, and slightly boosting upper bass subjectively improved bass speed and impact.

Put all of these things together and you have something that will appeal to certain ears, especially with some hard sell tactics used to push what are sonic anomalies as benefits.

These FE systems were great for your Ben Sidran, George Benson, and Grover Washington Jr records but the problems were soon obvious if you had broader musical tastes.

As one of these flat earth bone heads during the 80s and early 90s it is interesting to look at my record collection.
Lots of Sidran, Benson, Washington etc and what you can loosely call jazz-fusion. Then in the late 90s onwards the musical variation becomes huge and you can find examples of just about any genre.
There is clear correlation between system sound and choice of music here for sure!
Thankfully no longer the case for me.
 
Rob,

What specification or measurement explains the PR&T with their CDPs, tuners, preamps and amps? They exhibit this same effect with non-FE speakers.

Also, the bulk of my listening is with classical music, followed by traditional jazz, world music and folk with rock or pop the least consumed. My system has been all Naim-based including speakers for the last three years and I'm thrilled with what it delivers. Where have I gone wrong?;-)

regards,

dave

P.S. Oddly, I dislike most rock and pop unless it's played on a Naim system- even then, only some catches my ear. Jazz-fusion, however, is hopeless for me on any rig including a six-pack.
 
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Dave Simpson said:
Rob,

What specification or measurement explains the PR&T with their CDPs, tuners, preamps and amps? They exhibit this same effect with non-FE speakers.

Also, the bulk of my listening is with classical music, followed by traditional jazz, world music and folk with rock or pop the least consumed. My system has been all Naim-based including speakers for the last three years and I'm thrilled with what it delivers. Where have I gone wrong?;-)

regards,

dave

P.S. Oddly, I dislike most rock and pop unless it's played on a Naim system- even then, only some catches my ear. Jazz-fusion, however, is hopeless for me on any rig including a six-pack.
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Because that is what you are used to, it is what you look for, it is a form of brainwashing which shows in your attachment to the concept.

PRaT probably represents maybe 10 to 20% of what music is all about and yet for you it is primary, that should at the very least make you think about your position and maybe do a bout of self de-programming. The first step is an acceptance of that you *may* be wrong.
 
What specification or measurement explains the PR&T with their CDPs, tuners, preamps and amps? They exhibit this same effect with non-FE speakers.
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Dave I don't think there is anything to explain as their electronics don't display any particular PRaT benefit. Pure myth IMO.
Down at the very low, 'barely perceptible' level there are a few indicators that might cause those prone to hyperbole to proclaim extreme PRaTiness. The amps have high (for SS) output impedance which will usually add a little thump around the main driver/box resonance, and the CD players are as a little rough in terms of distortion compared to the very best. But these are very small differences indeed.

Where have I gone wrong?;-)
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You haven't, you simply like Naim speaker colouration.
No thing wrong with that at all, you like what you like.
 
RobHolt said:
looking at the Kan, the first thing you notice is no low bass and that the mid bass is shelved down considerably. This type of balance always sounds lighter, snappier and subjectively faster than a speaker with good, even bass performance.
Look further up the range and you see rising output which again has the subjective effect of pushing vocals forward and adding edge, presence and attack to percussive sounds, or 'leading edges' as they used to be called.

It is simply the manipulation of sound for effect.
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Well if this was in fact the case it was largely accidental. Linn were under pressure from their dealers to find a cheap speaker to go with the LP12 for the source first theory. Naim were also asked to produce a cheap amp but refused, so Ivor T *selected* the NAD 3020 as the cheap PRaT amp and manipulated it in the market in order to sell more LP12s.

The facts are that a company with a BBC LS3/5a licence called Chartwell Acoustics went bust and the company that supplied them with cabinets had high stocks. Linn did a deal and bought the bankrupt stock for little money and fitted the same drivers as the LS3/5a but with next to no crossover, they did it in a hurry and hadn't a clue what they were making, it was just another simplified rip-off.

By accident the speaker had the characteristics you describe so a genre was born, and Linn went on to refine it and change it, but interestingly amongst the Linn cognoscente those originals were considered to be special as they were extremely PRaT-ish.
 
Looking at the early Linn years, I'm quite happy to accept that it was accidental :)

The comparison with the LS3/5 is very interesting.
I don't like LS3/5s at all but do like the bigger BBC speakers. I don't think the BBC speaker cabinet ethos scales down properly to a tiny loudspeaker (you can't have a floppy cabinet that small unless you use cardboard!) but even so, comparing a Mk1 Kan to a 3/5a is interesting. Speech, light classical, simple choral and what I'd call gentle music sounds far better than on a 3/5a. Conversely, Rock and anything majoring on impact/transient ability can benefit form the oddities of the Kan.
Dynamically the Kan is clearly superior. Swings and roundabouts - very big ones!

Comparing the crossover in something like the larger Spendor BC1 or the Rogers Export I have at home to the 3/5a is also interesting and shows how much extra signal manipulation is required in the small speaker.
The Rogers Export (a domestic LS3/6) has second order crossovers and none of the additional passive EQ circuitry found in the tiddler*.
I don't think doing that much passive EQ in crossover is good at all - it kills dynamics.
The larger BBC designs manage to sound neutral without all of this additional circuitry, and the floppy box idea works better as intended.



* The crossover in the larger BBC speakers can look more complex than it actually is, because they used parallel wired film caps in order to achieve the tight spec required for the licence.
So a glance at the board will often raise an eyebrow when you see so many caps, but the actual circuit is pure second order - indictor/cap on the bass and cap/inductor on the HF.
Nice film caps too, unlike many speakers of the day.
 
This is entirely due to the crossover. The BBC design is crossover manipulation in extremis, the total opposite of my design ideas which is simplest crossover possible and do the tailoring in the drive unit selection and doping. The BBC engineers couldn't do this as available drivers were very limited (almost entirely limited to KEF). So consider the Kan as a LS3/5a in the raw before the crossover manipulation.

Now as you say this is a swings and roundabouts process as complex crossovers can smooth things but also remove most of the dynamic musical projection due to created phase anomalies, where as raw unmatched drivers will bounce and play music but are bound to have frequency and character anomalies. As with all things in Hi-Fi we are looking for acceptable compromises as nothing is perfect.
 
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Good point re the Kef drivers.
Notable that the bigger BBC speakers used bespoke drivers for bass/mid and the excellent Celestion HF1300 for HF.
See my addition to post 35 above.
 
RobHolt said:
* The crossover in the larger BBC speakers can look more complex than it actually is, because they used parallel wired film caps in order to achieve the tight spec required for the licence.
So a glance at the board will often raise an eyebrow when you see so many caps, but the actual circuit is pure second order - indictor/cap on the bass and cap/inductor on the HF.
Nice film caps too, unlike many speakers of the day.
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Well personally I still don't like them, they are still too complicated for me. Any filter is a compromise whether mechanical or electrical of either passive or active variety.

All filters kill music, so do without as many as you can.
 
I don't think it's brainwashing to like something that highlights the leading edge of a note. Few hifi systems of capable of reproducing the instantaneous dynamic swings that live music provides. So maybe a little bit of help in faking something that has a similar sound might not be a bad idea.

All recorded music lacks 'bite' compared to the live experience, not so much amplified electric stuff, but real instruments don't sound anodyne, the way they do on a hifi, in real life.
 

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