rega p3 - question: replacing old capacitor & resistor

[custom_made]

I opened up my rega p3 for a bit of maintenance, and it appears the capacitor is a bit fried and cracked. It still works but I'd like to replace it none the less.

It's an older model and I'd just like to confirm with a knowledgeable person whether I'm looking at the correct replacement parts.

 

Which one of these would be suitable? Or perhaps a someone could recommend a better capacitor.

 

250V AC Mains - Metallised Polypropylene Capacitors - X2 22N

http://www.jaycar.com.au/productView.asp?ID=RG5232

or

250V AC Mains - Metallised Polypropylene Capacitors - X2 220N

http://www.jaycar.com.au/productView.asp?ID=RG5238

 

Any information would be very helpful, thanks.

 

Here is the capacitor in question:

Edited March 6, 2014 by custom_made

[Sierra]

Good idea to replace that cap.

Mine went faulty on my Planar 3 some 18 months ago and caused the motor to go completely eratic.

But instead of replacing the cap I took the opportunity and fitted the 24v motor upgrade kit instead.

It was a mod I had planned to do ... so the cap going faulty just brought it forward in time.

I don't have the electronic knowledge to confirm if the caps you are looking are a direct replacement ... but others will.

[Addicted to music]

0.22uf X 1000 = 220nf. Is the correct value.

If you have notice that brown or orange resistor, it looks like it has been heat stressed. The color bans around it determines the resistance value and tolerance accuracy of the value but because the heat has discoloured it and the way the picture has been taken its hard to determined the value. If it still works than the next best thing is to desolder the resistor and measure the resistance with a multimeter. I never determined the resistance value by the color of the bands, I always place a meter across it when I am constructing projects. That resistor looks like a 5watt carbon type( don't quote me on it, I'm guessing), you are better to replaced that with a metal film, wire wound or a metal oxide type.

[A J]

I reckon that resistor looks A-ok - you shoulda gone to spec savers pchan !!

[Addicted to music]

I reckon that resistor looks A-ok - you shoulda gone to spec savers pchan !!

I do go to spec savers AJ, look at the centre of that resistor, can't you see that the centre is darker than the outer section? there isn't much detail there to tell what its doing but the resistor and cap looks like its in series. The cap has also been heat stressed as the sides are cracked and bulging out which the OP is concerned about. If that was my piece of equipment I'll be replacing both. If the resistor was over an electrolytic cap for discharge duties then I wouldn't be too concern, but this looks like a PSU for a motor. If the circuit was performing under what I believe is normal conditions you would not see a cap to bulge and crack the outer protective shell and a resistor to darken like it has. Its obvious either due to age or the the manufacturers going cheap and used underrated components.

[A J]

Maybe I should go to spec savers then

I would not however rely on a resistance measurement on a resistor that has overheated as it may have wandered form spec. A quick google throws up a few others with similar issues - seems it could be a 12K 3watt but I would spend some time verifying this first.

[Addicted to music]

Maybe I should go to spec savers then

I would not however rely on a resistance measurement on a resistor that has overheated as it may have wandered form spec. A quick google throws up a few others with similar issues - seems it could be a 12K 3watt but I would spend some time verifying this first.

Don't disagree with you but for carbon type its 5% is within tolerance, so measuring out of the circuit under normal temp and assuming that its still working properly will give you a workable figure, alternative a circuit diagram will pin point the value.

[Sierra]

Considering the age of the TT and the price of the components makes sense to replace both of them.

[Addicted to music]

Considering the age of the TT and the price of the components makes sense to replace both of them.

Yep, hit it in one go! And it's dirt cheap, less than $4.00

Edited March 4, 2014 by pchan

[Telecine]

There are quite a few threads on this, usually related to a failure resulting in the motor running backwards. Do a search and the correct value of the resistor will be in the resultant list.

[custom_made]

thanks for the help, guys 

 

looks like i'll be picking up a 
250V AC Mains - Metallised Polypropylene Capacitors - X2 220N
http://www.jaycar.com.au/productView.asp?ID=RG5238&form=CAT2&SUBCATID=967#1

 

I'm reading all different values online for the resistor but i'm leaning towards
12k ohm 1 watt 5%
http://www.jaycar.com.au/productView.asp?ID=RR2800
or
10k ohm 1 watt 5%
http://www.jaycar.com.au/productView.asp?ID=RR2798

I'll probably pick up both resistors as they are really cheap, and just hold on to them until the original resistor dies/needs replacing.

 

The capacitor i'll replace right away.

If someone out there has definitely locked down the resistor value, i'd love to know. thanks

[rocky500]

I think you might want to buy a resistor that has a higher watt value as the original is noted to be a 2 to 3 watt one.

Edited March 4, 2014 by rocky500

[custom_made]

jaycar don't seem to carry 2 watt resistors

besides the 1 watt, theres only a 1/2 watt in the 10k ohm and 12k ohm range

anyone know where i can pick some 12k ohm 2w to 3w 5% / 10k ohm 2w to 3w 5%resistors?
i've only found them on ebay at ~$10(because of shipping) for 5 of the same type

and on
digikey which is $34 shipping!!! but their range is pretty comprehensive.
http://www.digikey.com.au/product-detail/en/PNP300JR-73-12R/12AECT-ND/2059156

 

still not found the exact value.
i'll just replace the capacitor for now.

[rocky500]

You could try these for $4.50 delivered.

http://www.ebay.com.au/itm/12K-Ohm-Metal-Oxide-Film-Resistors-5W-5-Watts-x5PCS/400244720975?_trksid=p2046732.m2060&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D27%26meid%3D5258348362943803836%26pid%3D100040%26prg%3D1011%26rk%3D3%26rkt%3D4%26sd%3D190818921688%26

[oldrose]

jaycar don't seem to carry 2 watt resistors

besides the 1 watt, theres only a 1/2 watt in the 10k ohm and 12k ohm range

anyone know where i can pick some 12k ohm 2w to 3w 5% / 10k ohm 2w to 3w 5%resistors?

i've only found them on ebay at ~$10(because of shipping) for 5 of the same type

and on

digikey which is $34 shipping!!! but their range is pretty comprehensive.

http://www.digikey.com.au/product-detail/en/PNP300JR-73-12R/12AECT-ND/2059156

 

still not found the exact value.

i'll just replace the capacitor for now.

Element14 au.element14.com will have them. Shipping will be in the order of $10

[skippy124]

Are you sure of the resistor value?

An bit of an internet search shows that it is 6.8k ohm - but that may or may not be correct. I will check my RP3 tonight and confirm.

3w, 4w and 5w resistors in 6.8k, 10k and 12k are available from RS components.... And shipping is free.

http://australia.rs-online.com/web/c/passive-components/fixed-resistors/through-hole-fixed-resistors/?applied-dimensions=4294855758,4294863640,4294870767,4294519164,4294519110,4294519230&esid=cl_4294967294,cl_4294958141,cl_4294957611,cl_4294958338,cl_4294957725,cl_4294957684&m=1

I don't believe that the resistor in your unit has suffered too much heat stress, normally you would see evidence of browning on the PCB around the mountign holes and the mounting pads if such a resistor has been subjected to excessive operating temps.

Cheers

John

Edited March 5, 2014 by skippy124

[custom_made]

skippy124, I'm not sure at all about the resistor value haha..
I've been reading around and have also seen 6.8k, 10k and 12k listed. The bands indicate that it's 10k 5% (brown/black/orange/gold)

 

if you could confirm, that'd be great

 

 

UPDATE:

I replaced the capacitor and it's working great! the motor seems quieter now, and it cost $1.15! Very pleased.

Edited March 5, 2014 by custom_made

[Number 9]

The Permotech factory spec calls for a 6k8 2.5 watt resistor and that's what Roy fitted. What he didn't allow for was the power derating with temperature. When the resistor is in an ambient temperature environment it's a 2.5 watt resistor. When the same resistor is in a tiny enclosed dead air space with a motor that can reach 50-60 degrees after a long listening session, it's power rating drops to maybe  1 watt.  In my 20 years as a Rega Dealer this was the cause of 90% of Rega Failures. You need to increase The rating to 5 watts, the resistor pictured is already showing signs of heat stress and WILL fail.

 

Don't use Jaycar caps most of what they stock these days is pure crap, I wouldn't trust a jaycar cap in any critical application. Vishay, Epos or RIfa From Element 14, RS, Mouser or Digikey.

 

Steve

Edited March 5, 2014 by Number 9

[custom_made]

ok i couldnt find exact brands you mentioned for the parts on RS or element14. not going to buy from mouser or digikey because their shipping is $39 and $38.

Element14 only had ILLINOIS CAPACITOR branded caps in the correct spec.

RS had Panasonic brands for both the capacitor and the resistor. I read that panasonic make good passive components.

Any objections to buying the panasonics from these links:

capacitor 275Vac  220nf  +-10%
http://australia.rs-online.com/web/c/passive-components/capacitors/polypropylene-film-capacitors/?applied-dimensions=4294400689,4294512154,4294518476,4294518922&esid=cl_4294967294,cl_4294960523,cl_4294957611,cl_4294957413,cl_4294958851,cl_4294520147&m=1&aaaExp=Y

resistor 5w  6.8k ohm  5%
http://australia.rs-online.com/web/c/passive-components/fixed-resistors/through-hole-fixed-resistors/?applied-dimensions=4294519164,4294738585,4294870767&esid=cl_4294967294,cl_4294958141,cl_4294957611,cl_4294958338,cl_4294957725,cl_4294957684&m=1&last-removed=4294965862&aaaExp=Y

 

side note: I know the jaycar capacitor probably won't stand the test of time.. but it's kicking ass right now  :lol:

Edited March 5, 2014 by custom_made

[Number 9]

It's worth the effort to do the job properly. Both the components you've selected from RS will be fine. I understand your reluctance regarding the heavy freight costs from Digikey & Mouser but unfortunately for the small manufacturer in Oz, if you want to use premium components, there is virtually no-one to buy from. RS & Element 14 only hold a limited amount of stock at any given time , so when you need something a tad exotic, and you need it NOW, it's worth paying a kings ransom to FedEx.

 

Please consider while you're at it, drilling some ventilation holes thru the plinth from the motor compartment, this will greatly prolong the service life of your TT. As evidence, I present the venting I used on my deck.

 

Edited March 5, 2014 by Number 9

[rocky500]

The thread I was reading mentioned a 6.8k resistor but then a couple of posts later they mention 12k when the table is for the UK.

 

Some bits quoted below

Hi Kimmo,
It should be a 6.8Kohm 2.5w resistor. Have a look at the motor data sheet. It may be a good excuse to get the Rega upgrade motor and electronics.
http://www.mclennan.co.uk/datasheets/european/synchronousdata/990411131813.pdf
Hope this helps.
kffern

 

and the follow up

 

I assume you're in UK. Its 12k ohm (2-3watt) for 220V-240V Rega. Replace the 0.22uF capacitor if found defective.

 

Could this be why there are different values listed for the resistor on the net. Different power in different countries?

[custom_made]

Ok i've been doing my own research on the matter and have come to this conclusion.
Let me know what you think

Australian and European Standards specify 230v mains.

"In 1983 Standards Australia adopted a 20 year plan to convert Australia from the nominal 240 volts to 230 volts, to align with European Standards – IEC38. The aim was to align Australian manufactured products with our main trading partners." -David Burger - http://www.ewh.ieee.org/r10/nsw/subpages/history/Australian-AC-Line-Voltages.pdf

As of 2000 the standard allows for tolerances of +10% -6%. Meaning that the mains voltage can be anywhere between 216v and 253v. I have measured Queensland mains voltages from my house and can report voltages between 248.5v and 250.5v. Seems a bit high, but it is still within the standard. 

Now to the resistor values.
I've measured the Wattage drawn by the Rega Planar 3 using an energy monitor(same device used to read the Voltages)

3.5w every now and then it jumps to 3.6w.

The Rega TT uses a 110v 50Hz 250rpm motor.

 

Using the formula: Amps = Wats / Volts

0.014056224899598393 Amps = 3.5w / 249v

 

So now we know that
Voltage in = ~249v

Current Draw = 0.014056224899598393 Amps

Output voltage required = 110v (for the motor)

 

We can now use these values to solve for the Voltage-Drop Resistor

There's more maths... but lets just use this calculator http://elecurls.tripod.com/drop-res.htm

The result.. 

9889 Ohm dropping resistor with a minimum wattage of 1.9538

If we use the standards at the time of the Rega P3's release in the late 1970s (240v) : 8914 Ohm 1.8958w resistor.

This is the circuit for the new 24v rega motor upgrade. I used the same method(240v) and the numbers come in quite close to the circuitry 14.811k Ohms (14.3k Ohms in circuit)
I'd imagine that the 24v motor has decent tolerances and can handle being slightly over powered.

The 110v motor which I assume uses a 10k Ohm resistor is slightly under powered even when taking into account the +-5% on the resistor

Picture of 24v motor upgrade circuit

Edited March 6, 2014 by custom_made

[Number 9]

Fine.

 

Now maybe try the calcs again taking the impedences and phase angles into account.

Edited March 6, 2014 by Number 9

[VanArn]

Assuming the motor in the Rega 3 is the original 31813 ,  110V   1.8W motor;  then the resistor which has been  obviously over heated  could be replaced with two wire wound   3.3kOhm , 5W resistors They should be wired in series to give a  resistance of 6.6kOhm which is the nearest calculated value for a  230V Mains.The Jaycar Part No. is RR-3310.

[Number 9]

Assuming the motor in the Rega 3 is the original 31813 ,  110V   1.8W motor;  then the resistor which has been  obviously over heated  could be replaced with two wire wound   3.3kOhm , 5W resistors They should be wired in series to give a  resistance of 6.6kOhm which is the nearest calculated value for a  230V Mains.The Jaycar Part No. is RR-3310.

This is just getting silly. Why would you use two 5W  3k3 resistors in series to reach a value within 3% of the manufacturers recomended value with no increase in power handling using dodgy Jaycar resistors that are at best 5% tolerance and probably 10+% .Why? 6k8 is an E12 value! The motor has a -15/+10% operating voltage tolerance , for god's sake.

Edited March 6, 2014 by Number 9