Mission 775s Running Fast

cmcguire

Active Member
I picked up a very nice Mission 775s yesterday for an absolute song and I'm noticing that it's running a little fast. I've searched for a solution but given the relative obscurity of this table it's difficult to find much info. I have read the original manual and it doesn't mention any ability to control speed, only that it takes about ten seconds to get up to proper speed.

It still has the original belt which I constricted slightly by gently heating it (It had been slipping a little). Would a new belt make it run slower? I'm also considering applying a higher viscosity oil to the bearing in hopes of slowing it. The manual doesn't mention what type of oil I should use.

I'm really impressed with this machine and I'd like to get it running perfectly. Any help would be greatly appreciated!

I should note that I cleaned all surfaces in contact with the belt, pulley, etc.
 
Maybe this is your issue with image from the service manual. Maybe you have the belt in the wrong 50/60hz step in the pulley. I would not try to alter the speed by using thicker oil. Find the actual problem, don't try to outsmart it!
upload_2018-2-13_13-6-27.png

Edit: USA is 60hz by the way. Wasn't sure where you are located, but it varies by region.
 
[Frantically checks completed auction prices on ebay UK since he was previously unaware of that universal pulley]

[Remembers postage rates from the UK have gone through the roof and sighs]
 
Maybe this is your issue with image from the service manual. Maybe you have the belt in the wrong 50/60hz step in the pulley. I would not try to alter the speed by using thicker oil. Find the actual problem, don't try to outsmart it!
View attachment 1113809

Edit: USA is 60hz by the way. Wasn't sure where you are located, but it varies by region.
Thanks! That's my pulley! I don't have the service manuals so this image is invaluable to me. I believe I have it in the correct groove but I'll double check.
 
You can register for free at vinylengine.com (no affiliation), and you can download the service manual there. If you verify that the belt is in the correct groove, my next step would be to just get a new belt. Old belts can cause all kinds of speed issues.
 
Belt thickness affects speed - the belt bends around the pulley as if it were infinitely thin but bending at half its thickness. So a thicker belt acts as if the pulley is bigger, leading to higher speed.
 
New belt ordered! Thanks to everyone for the timely and helpful advice. I'll post the results from the new belt when it arrives.
 
You can register for free at vinylengine.com (no affiliation), and you can download the service manual there. If you verify that the belt is in the correct groove, my next step would be to just get a new belt. Old belts can cause all kinds of speed issues.
I'm having a heck of a time finding the service manual over at vinylengine- all I can seem to find is the owner's manual. I must be missing something totally obvious. Kinda like when I lose the coffee cream in the fridge. Or the ketchup. Or the milk. Or whatever I'm looking for at that exact second!
 
Yup, the new belt sorted it out! Running at a solid 33.3 right now. Just need to sort out the issue of my Shure Premier cartridge (just an M95ed) picking up some electromagnetic badness from the a.c. motor. Thanks for the great advice!
 
What Arm did your 775 come with? Having recently aquired a Sota with a Mission 774sm tonearm, I am very interested if your 775 came with the original 774 arm or one of the later incarnations.
 
What Arm did your 775 come with? Having recently aquired a Sota with a Mission 774sm tonearm, I am very interested if your 775 came with the original 774 arm or one of the later incarnations.
Funny you should ask! It came with the Jelco 774lc arm but just today I replaced it with the original 774 arm, the one with the fluids damping thingie. Seems to work pretty well! I think arm selection was optional when this table was first available.
 
Looks like you are well on your way to a fine set up. Please post a pic when you can!
 
Looks like you are well on your way to a fine set up. Please post a pic when you can!
Thanks and I will! I bought the table and arm separately and its really cool to bring them together and have a top of the line front end from the 80's. This is a VERY solid table, is extremely heavy and is super impervious to outside vibration for a non suspended design.
 
New belt ordered! Thanks to everyone for the timely and helpful advice. I'll post the results from the new belt when it arrives.

Sorry to resurrect a dead thread, but if you are still listening, would you mind telling me where you got your Mission belt?
 
My pulley doesn't appear to be "universal". It doesn't have as many notches to go between as the one in the image above, only 45/33rpm... does this imply my pulley/turntable was designed for 50hz only?
 
My pulley doesn't appear to be "universal". It doesn't have as many notches to go between as the one in the image above, only 45/33rpm... does this imply my pulley/turntable was designed for 50hz only?
Depending on your location, I suppose. Mine has only the two speeds as well but it's for the 60hz North American market. I didn't even know it came with a universal pulley until I read this thread.
 
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