Hi guys this is my first post , i live in uk Scotland to be exact, I need some help advice on a turntable motor . A few yers ago I decided to buy a ar turntable which looked in pretty good condition for its years but when i got it home it was completely dead , led light on front was lighting up , so thought must be the motor , I no nothing about electrics but thought it must be the motor which did not appear to be doing anything, i removed motor and decided to try and strip it down without much success , anyway I held on to turntable in the hope i would be able to buy second hand motor or replacement which would drop straight in . heres my question I think I have found a motor can anyone tell me if this will be an easy swap over its a Promotec 9904 111 31813 it seems to match but not really sure , original motor was Airpax . I also heard that hurst also was fitted to this turntable but when i contacted hurst they just said yes this motor 3001-001 is fitted in a few turntables can anyone help remember it needs to run on 240 supply , I would love to get it going .
cheers Robert
cheers Robert
Not sure about 220V motors. You might want to post at VinylEngine in the AR forum. Not so much traffic as here, but maybe more AR-specific people.
Best,
Conrad
Best,
Conrad
arteta23
Ar turntablres used Haydon or Hurst motors in the US. The Haydon is the better motor but is no longer available. The Hurst will work consult wiring diagram for 220 it will need a resisitor. Speed of motor 250rpm or 300 is a function of frequency in UK any of these motors Hurst,Haydon,Airpax or premotec will run at 250 RPM(50HZ) if your table had airpax motor your pulley is sized for 250rpm(50Hz) power. see premotec website for how to wire. Hurst should be same also see instructions on their website. caution Hurst motors will work but are noisy.
Ar turntablres used Haydon or Hurst motors in the US. The Haydon is the better motor but is no longer available. The Hurst will work consult wiring diagram for 220 it will need a resisitor. Speed of motor 250rpm or 300 is a function of frequency in UK any of these motors Hurst,Haydon,Airpax or premotec will run at 250 RPM(50HZ) if your table had airpax motor your pulley is sized for 250rpm(50Hz) power. see premotec website for how to wire. Hurst should be same also see instructions on their website. caution Hurst motors will work but are noisy.
Hi, first up.........which model AR table is this?
The Airpax motor has a different diameter shaft than a hurst or haydon (most of the time) at least every AR i've seen in the states with the airpax had a different shaft. Which of course means sourcing a pulley may be difficult. Shaft size on the haydon and hurst is 1/8" diameter, airpax about 5/64th
you can pm me for some ideas, or my email is BaMorin@AOL. I do some rehab work on AR's
Marc
BaMorin's post on shaft size is interesting and may address arteta23's original question, would premotec 9904 111 31813 work? I believe its shaft size is 3mil(slightly less than 1/8 ") . I know this is "redneck engineering" but would plummmers(teflon) tape on the shaft resize the shaft allowing stock AR pulley 50 or 60 hz as appropriate work?
I am interested in suitability of premotec as well , since the Haydon motor failed on my AR xa failed I purchased to Hurst 3001-001's neither operates at a noise or vibration level that is acceptable, in fact the noise is so bad it can be heard across the room or during quiet passages in music.
Rega sells a premotec kit with thrust bearing cup for motor and self adhesive vibration damped mounting gasket( no need to drill mounting holes as when replacing Haydon motor with Hurst motor .
I am interested in suitability of premotec as well , since the Haydon motor failed on my AR xa failed I purchased to Hurst 3001-001's neither operates at a noise or vibration level that is acceptable, in fact the noise is so bad it can be heard across the room or during quiet passages in music.
Rega sells a premotec kit with thrust bearing cup for motor and self adhesive vibration damped mounting gasket( no need to drill mounting holes as when replacing Haydon motor with Hurst motor .
AH, yes, the 3W hurst (3001-001) can be noisey.......that can be fixed as well. As mine are as quiet as quiet gets. The 1.5W haydon motors I have in a "refurb" state. Some of the issue with the motor noise in the XA is the top plate becomes like a soundboard on an acoustic guitar. the large center hole makes a tremendous amount of sound. There are some easy solutions to cure that. Regarding building up the motor spindle to accept the normal pulley size really isn't an option. If the pully does not go on the shaft with a snug fit, it will knock.....and any out of round really screws with speed issues. I have the standard 60hz pulley that fits the small shaft in NOS. I don't have one that's needed for 50hz. If you still have your 1.5W haydon, and it spins but is noisey, I can refurb that for you, or I can refurb the 3W motor you have as well. Bracing the top plate, and mass loading around the large center hole in the top plate will reduce the "normal" AR noises in the XA/XB by 9-12db. There's a bunch of simple inexpensive little tweaks that can be done as well to make it a top performer.
I sent some modified springs and different spring perches along with a mass loaded/damped pully to this gentleman @ Acoustic Sounds inc. I'll be sending him a complete suspension upgrade for his The Turntable
Marc,
Damn I love these AR 'tables!
Just screwed my little $60. EB101 together with a Sumiko Blue Point No.2 cartridge I had laying around on the stock arm/armboard.
After dialing it in with just a 5mm achromat and doing the spindle refurb along with that good oil I asked my cohort if I could put it in his system to listen.
Long story short, it blew away his brand new ClearAudio Concept ($1,500) using a very good Ultra 500 Shure pickup.
The AR was much more open & natural sounding (less mechanical / more organic) and I never knew those little Harbeth P3ESR loudspeakers could actually make bass!
Cannot wait to get my big TT rig going.
I'll keep you posted.
All the best,
Chad Stelly
I'm not here trying to sell a bunch of stuff, just letting the AR folks know there are some easy inexpensive solutions to comon issues
Hurst motor
Robert
Thanks for the response I contacted Hurst due to the fact that although motor is listed on website it does not allow for postage overseas , they sent back and said we dont send overseas and gave me the name of a company allied electronics but got no response back do you know anyone else that possibly could supply motor thanks
Robert
Some hints on the noisy motors. CAUTION- these are line voltage circuits and you risk death if you don't know how to work with such. Never work on a live circuit. Use a fused isolation transformer for all tests.
First, the vibration of the motor is dependent on the running cap value. The cap needs to be the value marked on the motor. People are way too casual about this. Example- 0.33 does not equal 0.25! If you have a suitable (HV) cap box, you can actually determine the value that gives least vibration. It will be very close to the marked value, but you'll get a few percent better performance than just stuffing in the standard. If you can't test, pad HV film caps to get exactly the marked value on the back plate of the motor.
Next, the new motors don't need full line voltage to run quite acceptably, and the vibration levels goes down dramatically with voltage. One can put a (HV film) cap in series with the motor to reduce the operating voltage without loss. Again, use the cap box to find a value that gives good starting, but no more.
Conrad
First, the vibration of the motor is dependent on the running cap value. The cap needs to be the value marked on the motor. People are way too casual about this. Example- 0.33 does not equal 0.25! If you have a suitable (HV) cap box, you can actually determine the value that gives least vibration. It will be very close to the marked value, but you'll get a few percent better performance than just stuffing in the standard. If you can't test, pad HV film caps to get exactly the marked value on the back plate of the motor.
Next, the new motors don't need full line voltage to run quite acceptably, and the vibration levels goes down dramatically with voltage. One can put a (HV film) cap in series with the motor to reduce the operating voltage without loss. Again, use the cap box to find a value that gives good starting, but no more.
Conrad
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