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Norton Air Power. Is it eternal _

Chris

Chris

pfm Member
It's just occurred to me that I plugged my LP12 into my Norton about 20 years ago and have never thought about it nor questioned its speed nor anything ever since. I know it's all based on a ratio between secondaries on a heavy toroidal and just one cap so there's not much can wear out nor go wrong but just as a matter of interest how accurate is it, speed/wise _ not that it worries me and I have no plans to change as I have never noted any variations by ear. Just wondered, as everything else seems to wear out or need TLC.
 
And what about its speed constants ? Has anyone ever measured them? Do they matter ? I did much prefer it to my Lingo 1 but I never really attributed it to a question of speed accuracy, more to the meatiness of the sound
 
It's locked to the mains frequency. Any speed variation issues would be down to motor, belt or set up issues, not the Norton.
 
Hi Chris,
I had a Norton once and kept it for many years until Radikal came along. Kept it so long as it was better than Lingo, Herc or 'gedden to my ears as it sounded more relaxed and natural as in composed which is exactly the direction Radikal carries further. I'd say let your ears be the judge of its accuracy but for measurement buy a tool or try the 'rpm' app' on IOS if you have iPhone and sit it on top of a platter ; it'll tell your rpm and wow/flutter. Of course as said proper set up is involved too.
 
Chris said:
It's just occurred to me that I plugged my LP12 into my Norton about 20 years ago and have never thought about it nor questioned its speed nor anything ever since. I know it's all based on a ratio between secondaries on a heavy toroidal and just one cap so there's not much can wear out nor go wrong but just as a matter of interest how accurate is it, speed/wise _ not that it worries me and I have no plans to change as I have never noted any variations by ear. Just wondered, as everything else seems to wear out or need TLC.
Click to expand...
Isn't this how the quest for the perfect load capacitance started? :D

Assuming that AirPower connects directly to the motor, the only part that is likely to eventually become faulty is the 0.22mF cap; although this appears to be a high quality polypropylene type that tend to last. Regardless, you'll know when a turntable phase control cap is on its way out as the motor with either not start, run intermittently, vibrate badly, and/or start spinning the wrong way round.

I've always been intrigued by Leigh Norton's AirPower Kit which is based upon a modification of his original supply that employs two transformers, one for each motor phase (with 80V on red and 60V on blue, or, alternatively, 2 x variacs and adjust for minimum noise/vibration).

AirPower Kit schematic (credit: Leigh Norton):
Circuit-Diagram.jpg
 
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wylton said:
It's locked to the mains frequency. Any speed variation issues would be down to motor, belt or set up issues, not the Norton.
Click to expand...
To quote Tuesday's 'Turntable Drift' thread...

"...the National Grid is obliged by its licence commitments to control the frequency within ±1% of 50Hz so it can fluctuate between 49.5Hz to 50.5Hz. However the normal operational limits are 49.8Hz to 50.2Hz."

The synchronous speed of an AC motor is determined by the frequency of the mains and the number of poles. Motor RPM is calculated by multiplying the frequency by 120 and dividing the result by the number of pairs of poles.

Example: Philips/Airpax/Premotec 24-pole on 50Hz mains...

Mains Fq at 50Hz = motor runs at 250RPM
Mains Fq drop to 49.5Hz = motor runs at 247.5RPM (249RPM if mains within 'normal operational limits' (above) vs. ±1%, resulting in 33.16RPM with Linn Sondek LP12 pulley vs. sub-platter diameters ratio)
Mains Fq increase to 50.5Hz = motor runs at 252.5RPM (251RPM if mains within 'normal operational limits' (above) vs. ±1%; resulting in 33.43RPM with Linn Sondek LP12 pulley vs. sub-platter diameters ratio)​

It should be noted that the National Grid frequency operational limits are per over the course of a day. Here is an interesting article from National Grid on the subject, entitled 'Voltage and Frequency Dependency'.
 
Mains frequency fluctuations are load dependent and are used as a signalling system for load easing.
+-5% is normal and load can vary wildly within a 10 min window.

grid load is obviously as dynamic as when everyone puts their kettle on at the same time.

It occurs to me that Netflix might have had a significant effect on evening peak load.

People who like Norton psus often also like mana supports, Aro tone arms and ATC’s.
 
david ellwood said:
People who like Norton psus often also like mana supports, Aro tone arms...
Click to expand...

Well, I do have an AirPower, & Yes, you're ticking two of my boxes!

Whenever I compare the Norton to the Lingo 1, I prefer the former; to me it's especially noticeable at the top end, which to my ears is less grainy with the Norton.

I did fit mine with an Avondale soft start module though, to solve the tripping issue I had whenever I plugged the Norton in!
 
Craig B said:
I've always been intrigued by Leigh Norton's AirPower Kit which is based upon a modification of his original supply that employs two transformers..
Click to expand...

That's what I had. I asked Leigh about the sonic difference between it and the single transformer with two windings and he said there was nothing in it.

The transformers were custom made. Someone asked me to build one some years ago and I contacted the company who made them. They said they could make them but, because it was a one-off, they'd be expensive. If I remember correctly, it was about £130 for the two transformers? By the time you buy a box and the other bits you're still well under £200 though which is still good value I think.

I had both the Norton and Avondale TAPS at the same time and the Norton is better.

Rem if you're using a phone app to check the speed on an LP12 you'll need to center the phone on the platter or you're going to get a very ill reading.
 
No, I won’t be checking the speed unless my system suddenly goes off and I doubt it even then. It’ll be something much more simple like cartridge capacitance or my Mana, having a screw loose.
 
The system going off is a headache, you get used to a level of performance and a 5% drop creates such angst. There’s no end to the improvements you can install but every one soon becomes part of the status quo.
 
david ellwood said:
The system going off is a headache, you get used to a level of performance and a 5% drop creates such angst. There’s no end to the improvements you can install but every one soon becomes part of the status quo.
Click to expand...

Fortunately my hearing has dropped far more by my age - it´s known as analogue error protection. Must be awful having perfect - pitch.
 
david ellwood said:
The system going off is a headache, you get used to a level of performance and a 5% drop creates such angst. There’s no end to the improvements you can install but every one soon becomes part of the status quo.
Click to expand...

Very true, it’s a matter of finding a level of satisfaction & sticking with it. I’ve had some good improvements this year, with the NAC32.5 replacing the NAC102, the Kit Ryan boards & the Olive NAXO 2-4 replacing the CB NAXO.
 
Craig B said:
Isn't this how the quest for the perfect load capacitance started? :D

Assuming that AirPower connects directly to the motor, the only part that is likely to eventually become faulty is the 0.22mF cap; although this appears to be a high quality polypropylene type that tend to last. Regardless, you'll know when a turntable phase control cap is on its way out as the motor with either not start, run intermittently, vibrate badly, and/or start spinning the wrong way round.

I've always been intrigued by Leigh Norton's AirPower Kit which is based upon a modification of his original supply that employs two transformers, one for each motor phase (with 80V on red and 60V on blue, or, alternatively, 2 x variacs and adjust for minimum noise/vibration).

Circuit-Diagram.jpg
Click to expand...
Hi Craig, I am going to build one of these, please can you tell me what F1 is. ? Is it a fuse?
 
Rob Tom said:
Hi Craig, I am going to build one of these, please can you tell me what F1 is. ? Is it a fuse?
Click to expand...
Hi Rob, Yes F1 is a fuse.

I've no idea what the rating would be.

Perhaps someone with a Norton will chime in here. Just be aware that the optimum rating will also depend up what specific transformers you end up using, as well as the 'appliance' draw and possible fault conditions.

If experimenting, lower rating fuses and fast blow are the safest way to go.
 
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