PRaT - please explain

[Firebottle]

I have never been a fan of the term PRaT. Surely pace, rhythm and timing are all associated with the flow of the music so what's the distinction?

Please explain succinctly.
No Naim bullshit in other words.

[AJSki2fly]

I have never been a fan of the term PRaT. Surely pace, rhythm and timing are all associated with the flow of the music so what's the distinction?

Please explain succinctly.
No Naim bullshit in other words.

Well I will try and come to this question from a purely musical background, having been an amateur musician and played in a number of bands I can relate to it, but only to an extent.

When you play a piece of music you want to perform it at a tempo(beats per minute) this reflects the feeling embodied by the piece, now this may sound like arty party bullshit but it really isn't, for example if you were to play the wedding march at half is scored tempo at least it would sound dour at worst a dirge, something a bride would not appreciate. So this is pace.

Now for rhythm, this is not as straight forward to define, well at least not for me, rhythm is how the piece is construction in terms of beats to a bar or measure, so for example in nearly all pop and rock music it is 4 beats to the bar, so called 4/4 time, in a waltz it is 3/4 time or 3 beats to a bar. So in 4/4 time we can count 1, 2, 3, 4 very often emphasise by a hi-hat or snare drum in rock/pop music. Now what needs to be understood is that the rhythm is obviously closely tied to the tempo, so if the tempo or how quickly or slowly you count 1,2,3,4 effectively speeds up or slow down the music or PACE. Got there in the end.

So what does PRaT have to do with a hifi system, well some cynics would say absolutely nothing, the system used of whatever quality should just reproduce what has been recorded which in itself where the PRaT is, by definition it is what is part of the musical structure, the rest is musical notes played on a selection of instruments and with gaps between them, or silences, put all together and you get a musical piece. However others would argue differently, and this is really I believe from a technical point of view, and I am not sure anyone has proved this to be true scientifically, what other would say is that the act of reproducing the music recorded require it to go through various electrical and even mechanical processes(think turntable and cartridges) so if any of these elements, electrical circuits for example cause delay or modification to the signal previously transcribed be it on a record, tape or on a digital medium then any aspect of PRaT maybe be changed. I hope that makes some sense.

Well I can see some sense to this argument, but you also have to consider the recording process as well, from microphones, amps, mixing desk, digital or analog through to recording master and then onto the pressing process(and I do not differentiate between digital and analogue) because in theory the PRaT could be modified during any of these stages if we agree with the above statement.

So I suspect when we see commentary from reviewers saying "the system has a great sense PRaT" what they really mean is that they think it is reproducing the music as they would expect it to sound or in fact in the case of a live recording it sounds like it did when they were at the concert. Whether this is actually true or just wishful thinking is another matter. IMHO if you took the best possible live recording you could think of then the only way you could get close to actually replicating in the real sense aurally would be to replay in in the original venue with the same number of people present and a system capable of replaying it as recorded. But even then it might not be accurate because of what happened in the record process but I suspect the PRaT would pretty good.

I apologise if some of you think this is a load of guff, you are probably right.

[walpurgis]

I can simplify this a bit. A rubbish system sounds shit!

[AJSki2fly]

I can simplify this a bit. A rubbish system sounds shit!

True, but it still might have PRaT.

[walpurgis]

PRaT was a bit of hype from the glory days of the Linn/Naim Flat Earthers. Pace, rhythm and timing are (amongst others) worthwhile and desirable attributes in a system. But of course, any decent Hi-Fi will have them. There's no mystique about this.

[Light Dependant Resistor]

PRaT was a bit of hype from the glory days of the Linn/Naim Flat Earthers. Pace, rhythm and timing are (amongst others) worthwhile and desirable attributes in a system. But of course, any decent Hi-Fi will have them. There's no mystique about this.

Sadly no, the majority of audio systems fail to address what is possible with timing in a audio system.

If we consider some circuitry and look at the way DC is used in audio systems, what we see is very lazy, abysmally lowest cost, implementation.

My specialist area, is the relationship - (which sounds extremely boring ) of the anodes of a shunt pair , cathodes of a shunt pair, the anodes of a series pair, and the cathodes of a series pair
of LDR's I have been investigating and improving this circuitry for over 11 years, and without reservation there is more in audio improvement to be found here, then any other part of a audio system.

This assumes the other parts of a audio system are very good, but not overtly so, My system is modest compared to some, it comprises good sources of Pioneer stable platter CD player, a suite of 5 Yamaha
CDR HD1500 recorders/ players, a stereo coffee attenuator, two quad 306 power amps, and various loudspeakers comprising ESL57, JR149 ( which i use the most ) and Gale GS401a. I use one pair of speakers
at any given time.

The work I have done finds what is missing in other audio systems principally aligning timing from the source component to the power amp, using akin to current drive -the load of the cathode to readdress the anode.
a thread where the circuit is discussed is here. https://www.stereo.net.au/forums/top...eamp-redesign/

[anthonyTD]

Chris, with all due respect, what your describing here will just go over most folks head, why not just show how linear your system is with say; a 50k to 200k Square wave from a 50 ohm source, comparison in and out of your Stereo Coffee LDR preamp, at diffrent volume settings, that may give a better understanding of what your trying to say about your design as far linearity, and its ability to reproduce signals as close to the original, in real time.

Sadly no, the majority of audio systems fail to address what is possible with timing in a audio system.

If we consider some circuitry and look at the way DC is used in audio systems, what we see is very lazy, abysmally lowest cost, implementation.

My specialist area, is the relationship - (which sounds extremely boring ) of the anodes of a shunt pair , cathodes of a shunt pair, the anodes of a series pair, and the cathodes of a series pair
of LDR's I have been investigating and improving this circuitry for over 11 years, and without reservation there is more in audio improvement to be found here, then any other part of a audio system.

This assumes the other parts of a audio system are very good, but not overtly so, My system is modest compared to some, it comprises good sources of Pioneer stable platter CD player, a suite of 5 Yamaha
CDR HD1500 recorders/ players, a stereo coffee attenuator, two quad 306 power amps, and various loudspeakers comprising ESL57, JR149 ( which i use the most ) and Gale GS401a. I use one pair of speakers
at any given time.

The work I have done finds what is missing in other audio systems principally aligning timing from the source component to the power amp, using akin to current drive -the load of the cathode to readdress the anode.
a thread where the circuit is discussed is here. https://www.stereo.net.au/forums/top...eamp-redesign/

[Macca]

a thread where the circuit is discussed is here. https://www.stereo.net.au/forums/top...eamp-redesign/

There's no discussion of the circuit on that thread, are you sure it is the right one?

[Macca]

A way to sell the new, smaller breed of speakers appearing at the time, like Kans and Acoustic Energy? Not much body to the sound but you handle that objection by suggesting that they are more exciting to listen to.

[Firebottle]

Adrian thanks for a comprehensive reply. I understand the construct of music even though I am not a musician.

However what I have always though when PRaT is mentioned is as you have said, it is part of the musical structure. What I can't grasp is why any kit might vary the relationship between the elements in PRaT, so why was this term invented (if not as a marketing 'tool') when in my mind these things can't be separated.

When people rave about the benefits of PRaT or otherwise are they mistaking transient attack (or speed if you like) and possibly a less than crisp bass line for failings in Timing or Rhythm respectively?