Engineering optimal PRaT (Pace, Rhythm, and Timing)

The Wikipedia entry for Naim audio notes PaRT (Pace, Rhythm, and Timing) as that company’s distinguishing “sonic character”. I’ve read many reviews that seem to specifically support this description -- and generically associate PRaT (and, perhaps, tonal accuracy/neutrality) with myriad UK brands. In the same reviews it is also noted that the Naim units may somewhat lack in detail, transparency and spatial rendition.


(1) What specific measurable (tweakable?) “parameters” are linked to PaRT? E.g., slew rate or damping factor of op-amps.

(2) What design (engineering) topologies optimize for PaRT (Pace, Rhythm, and Timing)? The PRaT designs of the analog section of a CDPs or DACs may also apply to pre-amps and amps.

Although I have no experience with Naim, Arcam, etc., some “obvious” answers may be:

- Use external PS box to house transformers.

- Use lots of regulators, notably LM317-based.

- Wiki notes:
“Their unique design approach can be seen, for example, by their use of materials — the semiconductors, heavy toroidal transformers, iconoclastic solid aluminium black cases — their obsessive attention to earthing, screening and isolation from electronic interference, through to their preference for XLR, DIN connector and the BNC connector (as opposed to the RCA connector used by almost all other manufacturers).”

- What else?

(3) What are the trade-offs when designing for PRaT (e.g., detail and transparency, as noted above for Naim?)?
What design (engineering) topologies optimize for PaRT (Pace, Rhythm, and Timing)? The PRaT designs of the analog section of a CDPs or DACs may also apply to pre-amps and amps.

hot air and a compay shill at wiki

Oh - I forgot - grab a handfull of terms that mean absolutely nothing in relation to technical equipment from the toolkit of the audiophool.
Interesting topic. Obviosuly Prat is not easy to define in subjective terms and completely impossible in objective. It somehow makes more sense applied to turntables rather than amps. I have very little experience with Naim equipment but my own designs have occassinally exhibited more Prat.

(1) Seems like a joke. Objective parameters/measurements don't seem to correlate with obvious sonic features such as tonal balance let alone something as elusive as Prat.

(2) Obsessive star grounding, attention for ground returns and PS distribution; multiple power supplies feeding each stage all contribute towards better timing.

I also believe there is an optimal amount of PS capacitance which offers the best Prat.

(3) I don't think trade-offs are inherent to better Prat. Naim like using really bad coupling caps which simply filter out high frequency detail.
If it were my concern, I'd just build things the way they do for sound reinforcement equipment. I've been to many concerts where the musicians got the whole audience moving in rhythm or even dancing, even more where the timing subtleties are compelling (try Live at Leeds or the live side of Wheels of Fire), so apparently PA systems aren't deficient in that regard.

The orthodoxen will just get the low end flat and free from distortion and overhang, then let the musicians do the Prat work.
analog_sa [/i][B]Objective parameters/measurements don't seem to correlate with obvious sonic features such as tonal balance let alone something as elusive as Prat. [/B][/QUOTE] ...and... [QUOTE][i]Originally posted by I_Forgot said:
Subjective qualities depend on the motivations, mood, and preferences of the observer. You can't design those things into electronic equipment or measure them with test instruments.
Somewhat disagree here. This is why I specifically suggested slew rate and damping factor.
Take some other subjective terms like digital "glare" or "harshness". Statements along the lines of the two quotes above were more likely, for example, until jitter was "discovered" in the late 1980s.
This is my humble opinion of course. But, TTBOMK, the association with causation is not a post-hoc fallacy.
To me, the main components of PRaT are rhythm and timing. I've always thought of rhythm as being contained mostly in the low end of the frequency spectrum, while timing being a function of the systems ability to change quickly - so we are talking about the ability to reproduce and control the bass end, IMO. I would guess loudspeakers would play a big part here...

Its kind of a stretch to connect a subjective quality (prat) with technical jargon (do opamps have damping factor??). Most of that stuff is marketing bs, and has nothing to do with using LM317 regs. Don't go looking for tweaks or general topologies to satisfy your 'prat' - its all in execution, or how you work everything in together.

And in a larger sense, it really comes down to the performance/recording to convey pace, rhythm and timing, among other things.
In all honesty, the terminology is meaningless to me. It doesn't relate to any technical aspect of the signal chain, and I doubt twenty people would agree on whether a system possessed it or not. IMO, it's just high end BS designed to advance the agenda of whoever is using the terms. A serious conversation requires terms with well understood and accepted meanings.


Disabled Account
2006-11-02 6:15 pm
My view of this:

The term PRaT was most likely dreamed up by a reviewer who wanted to remain a reviewer. In other words the reviewer needed to be seen to be *important*, *knowledgeable* and a *guru* on his chosen subject in order to reinforce his ego and self-esteem, and keep his cosy income and easy job.

From a technical view point it is absolute nonsense and illustrates all that is wrong, or at least questionable and disappointing, in hi-fi marketing.

If the output waveform is an amplified true likeness of the input waveform then the music / sound derived will have whatever pace, rhythem and timing the performer and engineers recorded onto the media.

If you want to know what influences that then you are on the right path to interesting and involving experimentation, except that you have asked the wrong initial question.

Good luck,
Gordy, IIRC, the term was made up by Martin Colloms. It strikes me as total nonsense (from a technical POV, but it's a brilliant way to sell magazines) as my PA reference above would suggest. It also strikes me that, if this were real, it would be exceptionally easy to test for- even duff listeners like me can be acutely aware of musicians' timing.