Post by Owen Y on Jun 19, 2018 17:42:37 GMT 12
Another early Rega Planar 3 has 'fallen into my lap' for some TLC.... This one is similar vintage to my nephew's Rega Planar which I twiddled & tweaked a little back in 2016.  
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Post by Citroen on Jun 19, 2018 17:52:31 GMT 12
Just like the light wood LP12's, I've also always preferred the aesthetics of the Rega 3 with this light wood trim.
Back in my teen days a friend bought one, while I bought a Dual. I would never admit to him that I preferred his TT.
The arm dates it though.
What are the issues? Or is just a check up required?
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Post by Owen Y on Jun 19, 2018 18:21:12 GMT 12
I had a pal, back then, who also preferred light wood for all his hifi components - TTs (LP12), amp (A&R A60), lspkrs. You will all note too, that the tonearm is an early Linn Basik LV-V. Not sure of the problems exactly, until I look more closely - speed issues reportedly.
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Post by michaelw on Jun 19, 2018 19:15:33 GMT 12
i had one of those, another fine product locally assembled by avalon audio.
one thing i never got around to doing was try an ittok on it
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Post by Owen Y on Jun 19, 2018 20:59:30 GMT 12
The edge trim looks like Oak or similar timber. Simply butt-jointed corners, but nicely done. 
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Pundit
Post by neilsan on Jun 19, 2018 21:39:46 GMT 12
Still got mine I bought new,with a Grace 727 arm on it.Put a new motor on it a few years ago.Probably was only the cap gone on the old one but.....!
The Grace has hardly been used as I bought my FR64fx soon after and fitted it on the 3,until another ttable came along.
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Post by michaelw on Jun 19, 2018 22:26:06 GMT 12
avalonassembled regas originally had grace 707arms then switched to linn.
Made in Britain ? i was told the rega + linn arm was an nz import duty special. the only other time i've seen a rega with non-rega arm was on the cover of an ancient aus hi-fi mag, a rega 2 with dynavector arm !
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Post by Owen Y on Jun 20, 2018 7:48:25 GMT 12
The attached cartridge is a mystery to me. Not obviously an Audio Technica as far as I can see. Suspension still seems good, stylus possibly conical/spherical  
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Pundit
Post by nakmad on Jun 20, 2018 17:50:54 GMT 12
The edge trim looks like Oak or similar timber. Simply butt-jointed corners, but nicely done. I always though the edge trim was beech....
Never play Leapfrog with a Unicorn.
Cassette Fetishist
219 posts
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Pundit
Post by neilsan on Jun 20, 2018 18:19:12 GMT 12
avalonassembled regas originally had grace 707arms then switched to linn.
Made in Britain ? i was told the rega + linn arm was an nz import duty special. the only other time i've seen a rega with non-rega arm was on the cover of an ancient aus hi-fi mag, a rega 2 with dynavector arm ! Yeah,but I wanted to be able to swap cartridges,so asked for the 727.Dealer must have swapped it.
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Pundit
Post by neilsan on Jun 20, 2018 18:21:47 GMT 12
Check on the top of it Owen.
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Post by Owen Y on Jun 20, 2018 18:37:54 GMT 12
I always though the edge trim was beech.... Yes I think you could be correct, it looks like Beech - more fine grained & slightly pinker than Oak. Was this mentioned by Rega back in the day?
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Post by Owen Y on Jun 20, 2018 18:42:39 GMT 12
Check on the top of it Owen. Good idea, will do, in due course after I take a listen & check it's speed stability, which seems a bit variable, +/- 1-2% at the mo.
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Post by Owen Y on Jun 20, 2018 19:04:24 GMT 12
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Pundit
Post by neilsan on Jun 21, 2018 8:31:42 GMT 12
I meant the cartridge!!
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Post by Owen Y on Jun 21, 2018 9:35:00 GMT 12
OK we appear to have a NZ assembled Planar 3. (Although there seem to be Planars with LV-V arms in AU & USA too.) A point to note is that Linn arms have 211mm mounting distance (to spindle), whereas Rega mounting distance is 222mm. Linn tone arms are thus around a centimeter shorter in Eff Length - which means swapping in a Rega arm say, could be problematic, depending on cartridge, adjustment available in the h'shell slots and/or slotting the mounting hole a bit. The Linn mounting hole bore is also 25mm I think, technically a bit bigger than Rega's 23mm but likely inconsequential 2mm.
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Post by michaelw on Jun 21, 2018 11:53:21 GMT 12
i vaguely recall seeing some nz regas with linn basik lvx arms too. avalon must have gotten a bulk deal on basik lvv arms
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Post by Owen Y on Jun 21, 2018 12:00:13 GMT 12
Arm bearings seem good, no obvious play. Main bearing seems OK - in fact tight enough 'suction' that will make getting the shaft out a bit of an effort. Platter speed is 33.8 at start-up, dropping to ~31.5 after 20 mins, eventually settling to 33.0 to 33.3rpm but with fluctuation, after 30+ mins - apparently some speed/temperature issues. Possibly the phase split cap and/or resistor are tired after all these years. A little bit of heat on the motor cover underneath. 
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Post by Owen Y on Jun 21, 2018 14:18:23 GMT 12
At startup... 
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Post by michaelw on Jun 21, 2018 15:03:32 GMT 12
is the belt in good condition ?
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Post by Owen Y on Jun 21, 2018 16:10:52 GMT 12
Hard to tell, a bit stretched possibly, not the modern white 'upgrade' belt. Maybe should go for a new one anyway?
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Post by Graham on Jun 21, 2018 16:20:51 GMT 12
I think you will find the speed variation is due to a worn or incorrect belt.
While the motor phasing cap and resistor can get out of spec with age IMO neither will affect the speed of a synchronous motor. The motor is locked to the supplied frequency, in this case the 50hz mains, and variations in voltage and/or cap value have no effect on rpm.
I have experimented extensively in this area and found a 115v synchronous motor runs at the same rpm with voltages ranging from 65 - 125 and caps from 0.15 - 0.33.
Maybe as the belt warms up its flexibility is changing resulting in different cross section as it is squeezed into the V pulley.
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Post by Owen Y on Jun 21, 2018 17:51:09 GMT 12
Yes only freq affects speed technically, but phase split cap condition affects mtr vibration & I've found mtr speed fluctuations as a resullt. But the belt is main culprit & needs renewing first up.
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Post by Owen Y on Jun 22, 2018 15:04:03 GMT 12
As is often the case when something is attached to wood-based material, wood moves & shrinks. The main bearing is secured by one large (~7/8") nut, which was slightly loose. Big pipe wrench to the rescue  
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Post by Owen Y on Jun 22, 2018 15:09:18 GMT 12
The underside, with motor cover removed. 
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Post by Owen Y on Jun 22, 2018 15:17:20 GMT 12
As seems to be the case with every Rega Planar of this vintage, the phase split capacitor (Rifa 0.22uF) has deteriorated with age/heat, its casing has cracked open - letting in moisture, obviously not satisfactory for a 250v 'Class X' mains voltage cap The last phase split cap I took out of a Rega, had also drifted +70% in uF value. 
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Post by Owen Y on Jun 23, 2018 11:23:59 GMT 12
The SS bearing shaft (8mm) has no obvious play. Looks mint, no wear marks, as should be expected with a brass bushing. The ball is there but not a lot of oil in the well, a drop maybe in the bottom. 
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Post by Owen Y on Jun 27, 2018 17:43:08 GMT 12
These commonly used Premotec/Airpax AC motors are designed for turntables, 110vac supply volts, max speed 250rpm & have 2 windings for 'Permanent Split Capacitor' (PSC) operation - which means being able to get the motor to turn on only single-phase AC mains supply. The circuit is like this:  The motor has 2 windings & the capacitor cleverly delays the current to the second winding so that the the motor is able to start up & keep turning forwards. Ideally.... - the voltage on each winding should be same (A & B volts) - the 'phase' delay created by the cap should be 90 degrees, so that the AC current pulses are as equal as poss across a 360 deg AC cycle. Both of the above will minimise motor vibration. Another trick recommended by Premotec to minimise vibration, is to reduce supply volts down to ~90vac. (Which reduces torque too however, so maybe longer start-up.) As Graham sez, motor speed is technically determined only by mains freq, which is pretty constant 50Hz here - but other factors can come into play...
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Post by Owen Y on Jun 28, 2018 12:55:17 GMT 12
Ideally for minimum motor vibration: 1) the 2 'phases' (each winding) should be nicely balanced - ie. receive the same voltage. 2) the 'phase difference' created by the capacitor between the 2 windings should be 90 deg. With this 30+(?) yr old Planar 3 however: - the measured platter speed at startup was around 33.8rpm, decreasing to 32.8rpm (after 30 mins) & 33.1rpm after 1 hour. - the measured AC voltages after 30 mins are A = 67.5v, B = 81v, C(between windings) = 54.3v. Clearly A & B windings are not balanced & not at the 90-110 specified supply volts. Secondly, using standard triangle maths, we can calc that the phase angle between A & B windings is presently around 43 degrees - ie nowhere near the ideal 90 deg! Next, to lift & measure the R1 dropper resistor (marked 12k ohms) & the phase split cap (marked 0.22uF).
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Post by Owen Y on Jun 28, 2018 20:46:17 GMT 12
The red 12 kohms resistor (in pic above) measures ~11.87 kohms - pretty good, well within its 5% tolerance. The cap however, was +50% out.... 
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