While I was helping my dad clean out a storage area I found my old UK Rega Planar 2 turntable. It has some sentimental value and I'm thinking of taking it back to the US with me.
After a bit of reading up on the interwebs I see reference to the 9904 111 31813 motor being used and after looking at the datasheet it appears that all I have to do is take out the resistor for use in the US on 110VAC 60Hz.
I popped off the motor cover on the underside of the plinth and I find that the motor is marked 9904 111 04802 but I can't find a datasheet for that.
I'm not sure that is a 6.8K resistor, but does anyone know if the 04802 motor is the same as the 31813 in that all I have to do is remove the resistor it should be OK to use at 110V?
I know that I will have to change the pulley for a 60Hz one and that it may be better to switch out to a DC motor, but I'd like to get it up and running first and then look in more detail at all the upgrade paths.
After a bit of reading up on the interwebs I see reference to the 9904 111 31813 motor being used and after looking at the datasheet it appears that all I have to do is take out the resistor for use in the US on 110VAC 60Hz.
I popped off the motor cover on the underside of the plinth and I find that the motor is marked 9904 111 04802 but I can't find a datasheet for that.
I'm not sure that is a 6.8K resistor, but does anyone know if the 04802 motor is the same as the 31813 in that all I have to do is remove the resistor it should be OK to use at 110V?
I know that I will have to change the pulley for a 60Hz one and that it may be better to switch out to a DC motor, but I'd like to get it up and running first and then look in more detail at all the upgrade paths.
Last edited:
9904-111-xxxxx is the same motor as far as i remember and the only difference is the options for mounting flanges making up the last 5 numbers. philips, premotec, airpax etc.etc were all the same motor. they are 110v 60hz 300rpm.
That appears to be a 12K resistor. It may be a low voltage motor; some of the Premotec series motors we 24V and they used a different resistor with 120 and 230VAC.
Why don't you measure the voltage between the red and gray wires when the motor is operating, that should tell you the voltage it needs.
Why don't you measure the voltage between the red and gray wires when the motor is operating, that should tell you the voltage it needs.
Its very likely the motor pulley have to be replaced to suit 300rpm and used at USA. Early Linn and Rega export models to USA have a different pulley and circuit mod to suit USA voltage and frequency.
A 12K to 15k resistor would be fine if this Rega motor is 230VAC/50hz operation. Ideal operating voltage would be somewhere 75 to 90V at each phase, the closer the difference the better. There's too much vibration at higher motor phase voltage. The datasheet 6.8Kohm isn't suitable in practice for Rega tt. 12kohm is what Rega install in nearly every model that works on 230V.
A 12K to 15k resistor would be fine if this Rega motor is 230VAC/50hz operation. Ideal operating voltage would be somewhere 75 to 90V at each phase, the closer the difference the better. There's too much vibration at higher motor phase voltage. The datasheet 6.8Kohm isn't suitable in practice for Rega tt. 12kohm is what Rega install in nearly every model that works on 230V.
Last edited:
Yes, you have to change the pulley to 60 Hz size, after modifying the motor circuit.
The Planar 2 won't have the 24V DC motor, it will use the 120/240 AC motor.
The Premotec spec sheet has everything you need to know about operating 120 or 240V.
http://www.farnell.com/datasheets/1685512.pdf
The Planar 2 won't have the 24V DC motor, it will use the 120/240 AC motor.
The Premotec spec sheet has everything you need to know about operating 120 or 240V.
http://www.farnell.com/datasheets/1685512.pdf
Last edited:
I wasn't suggesting it was a 24VDC motor, but it may be a 24VAC motor. Premotec did make a series of low voltage AC synch motors.
The good news is it doesn't cost anything to test the motor as I described.
The good news is it doesn't cost anything to test the motor as I described.
> Premotec spec sheet
That motor is line-locked. 50Hz gives 250 RPM, 60Hz gives 300 RPM.
This can not be changed electrically (except by line frequency).
To give split-phase drive needed to turn, it uses a capacitor. This should be 0.22uFd for 50Hz, 0.18uFd for 60Hz. (Nearly the same as the 50:60 ratio; the cap value only has to be close not exact.)
The base rating is 110V, 1.8 Watts. So 0.016,36 Amps. If you work this out it is like a 6,722 Ohm resistor. While a motor is not really a resistor, apparently this one is close enough that an added resistor of equal value (6,800 standard value) gives about the 2:1 split needed to run with 220V power.
And the smaller cap.
> taking it back to the US
Shorting the resistor will let it spin on 110V (I'm sure 125V won't smoke it; or use 800-1K series), BUT the motor will turn 300RPM not 250RPM. Your 33s will spin at 40RPM. You want a smaller pulley. While a very sharp machinist could turn it down to size, there are allowances for belt thickness and slip which will not be an exact 50:60 ratio. A "right part" would be best.
At a mere 2 Watts, a 50Hz source is not a major build for an experienced audio DIY-er. 12V DC supply, car-sound amp, a 6.3VAC CT to 120V transformer, and of course a stable 50Hz (or tunable but stable) sine-like oscillator.
That motor is line-locked. 50Hz gives 250 RPM, 60Hz gives 300 RPM.
This can not be changed electrically (except by line frequency).
To give split-phase drive needed to turn, it uses a capacitor. This should be 0.22uFd for 50Hz, 0.18uFd for 60Hz. (Nearly the same as the 50:60 ratio; the cap value only has to be close not exact.)
The base rating is 110V, 1.8 Watts. So 0.016,36 Amps. If you work this out it is like a 6,722 Ohm resistor. While a motor is not really a resistor, apparently this one is close enough that an added resistor of equal value (6,800 standard value) gives about the 2:1 split needed to run with 220V power.
And the smaller cap.
> taking it back to the US
Shorting the resistor will let it spin on 110V (I'm sure 125V won't smoke it; or use 800-1K series), BUT the motor will turn 300RPM not 250RPM. Your 33s will spin at 40RPM. You want a smaller pulley. While a very sharp machinist could turn it down to size, there are allowances for belt thickness and slip which will not be an exact 50:60 ratio. A "right part" would be best.
At a mere 2 Watts, a 50Hz source is not a major build for an experienced audio DIY-er. 12V DC supply, car-sound amp, a 6.3VAC CT to 120V transformer, and of course a stable 50Hz (or tunable but stable) sine-like oscillator.
I mentioned the need for a 60Hz pulley in my original post and they are readily available - Enjoy life with LP's and Turntables: Standard Metal Pulley suitable for Rega turntables.
So, it would seem that by removing the resistor from the circuit and adding a 60Hz pulley is all that is required. Seems very straightforward and easy.
I should be able to borrow an MMU in the next day or two.
So, it would seem that by removing the resistor from the circuit and adding a 60Hz pulley is all that is required. Seems very straightforward and easy.
I should be able to borrow an MMU in the next day or two.
You might find the following links to fora helpful. I don't know how much it will cost you to have a pulley made, but the motor control unit detailed in the SG4 thread can be completed for around 100USD.
DIYAudio member presents some very well thought out projects.
http://www.diyaudio.com/forums/anal...sinewave-generator-turntable-motor-drive.html
http://www.diyaudio.com/forums/analogue-source/288730-3-phase-bldc-motor-turntable-use.html
http://www.diyaudio.com/forums/anal...tal-tachometer-record-player-lcd-display.html
Hal
DIYAudio member presents some very well thought out projects.
http://www.diyaudio.com/forums/anal...sinewave-generator-turntable-motor-drive.html
http://www.diyaudio.com/forums/analogue-source/288730-3-phase-bldc-motor-turntable-use.html
http://www.diyaudio.com/forums/anal...tal-tachometer-record-player-lcd-display.html
Hal
OK, so my brother came round armed with a MMU and in the time it took for me to make him a cup of tea he had drawn the circuit diagram and measured the voltages.
As per the diagram, the wires on the transformer measured the below with an input of 236V
Blue + Grey = 99V
Red + Grey = 88V
Blue +Red = 149V
As per the diagram, the wires on the transformer measured the below with an input of 236V
Blue + Grey = 99V
Red + Grey = 88V
Blue +Red = 149V
Last edited:
I have a Rega P2000 (year 2000 model) with 110V motor. Rega changed the circuitry (to a slightly more complex one and more component count than just a resistor and capacitor) for UK voltage to operate at much lower voltages than you measured. The lowest among the 2 phase was somewhere 75V and the other tad higher, perfectly fine for purpose and intent. The only drawback is it when operating at higher voltage, motor torque is higher but vibration is also increased. When its lowered to 75 to 80V, the torque is lowered a bit but vibration is also lower and that could translate to better sound quality. I believe it was their intent to reduce vibration and sacrifice a bit of torque (sometimes have to nudge the platter a bit to start) for better sound.
When bringing it to the States, I reckon its not just remove the existing resistor and plug in 110V. I still think it would need a dropper resistor much lower value than 12K to match those voltages you've measured earlier. If you can achieve 80 & 85V, that could be ideal, it should work fine there.
When bringing it to the States, I reckon its not just remove the existing resistor and plug in 110V. I still think it would need a dropper resistor much lower value than 12K to match those voltages you've measured earlier. If you can achieve 80 & 85V, that could be ideal, it should work fine there.
Last edited:
Thanks for the replay coolmaster.
I emailed Mclennan to see if they had any information and got an email from them this morning indicating neither they nor the actual manufacturer has a datasheet. They have also shot off a request to Rega customer service to see if they have any info.
I emailed Mclennan to see if they had any information and got an email from them this morning indicating neither they nor the actual manufacturer has a datasheet. They have also shot off a request to Rega customer service to see if they have any info.
Hi Ianp, If cost isn't much of a concern, could I suggest rather than all the trouble to alter the motor circuitry and pulley change, I think it would be practical to acquire the Hercules II Mose outboard power supply. The Power supply output can be wired to the Rega motor terminals. The PSU is switchable to 230V or 110V internally by changing the fuse position.
It doesn't matter 50/60 cycle mains. This PSU will work on any Rega or Linn 110V Premotec motor made for 230V/50hz mode and spin your Rega to correct speed.This product was meant as upgrade for Linn LP12 but works for Rega with the same motor.
Dealer for Hercules in UK. about our products - Stamford Audio
It doesn't matter 50/60 cycle mains. This PSU will work on any Rega or Linn 110V Premotec motor made for 230V/50hz mode and spin your Rega to correct speed.This product was meant as upgrade for Linn LP12 but works for Rega with the same motor.
Dealer for Hercules in UK. about our products - Stamford Audio
Last edited:
Thanks for that, but more expensive than the Rega upgrade path - 24VDC motor for GBP 130 - which offers benefits over the existing motor.
> it would seem that by removing the resistor from the circuit and adding a 60Hz pulley
The motor data says it wants a different capacitor at the higher frequency.
"0.22uFd for 50Hz, 0.18uFd for 60Hz."
By motor theory, this *may* not be essential. A slightly "wrong" cap is less torque, starting and running. My experience with 2-Watt phono motors is that they have little torque to spare, but it should run.
The motor data says it wants a different capacitor at the higher frequency.
"0.22uFd for 50Hz, 0.18uFd for 60Hz."
By motor theory, this *may* not be essential. A slightly "wrong" cap is less torque, starting and running. My experience with 2-Watt phono motors is that they have little torque to spare, but it should run.
You can buy a fully machined motor pulley ( 0.000x tolerance) from Tangospinner for $US 30 (aluminum) or $35 (brass)
Tangospinner - Products
You will want the single belt model (manual change to 33/45) or if you don't want to play 45's or if you plan to use an outboard speed controller (such as the SG4 previously suggested by member Frogeye in post #10), a double belt model for the same price. You may have to upgrade to a machined subplatter (same vendor) to use the double belt pulley.
We've already established from the Premotec part # (9904 111 xxxxx) in his original post referring to his existing table that he has a 120/240V motor.
Last edited:
So, I just missed out on a motor from a US bought Rega 3 as my esnipe bid was too low. There was one photo showing the components on the circuit board, but I had no luck getting the value of the resistor from the seller.
The cap looks to be marked .15K 400 which I think translates to 0.15μF 400V in today's money.
Anyone got any thoughts on the resistor ?
The cap looks to be marked .15K 400 which I think translates to 0.15μF 400V in today's money.
Anyone got any thoughts on the resistor ?
- Status
- Not open for further replies.