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LPC mechanism playing noise
Posted: Wed Dec 30, 2015 2:21 pm
by babycat
finally got my LPC-1 selecting fairly well, so i'm turning to sound quality next. i like to play at pretty low volume in my 2nd floor apartment, but there's a prominent noise coming from the player/mechanism. a hint of it seems to come through the amp, but it is physically prominent. here's a video where you can hear. unfortunately it does not register as strongly on the video, but you can definitely hear it at the very beginning by the dome glass, then again later around back of the mech.
let me know what you think!
https://www.youtube.com/watch?v=-s4JJHJGeIkcheers,
eric
Re: LPC mechanism playing noise
Posted: Wed Dec 30, 2015 2:51 pm
by Rob-NYC
Unfortunately, those noises are typical of an aging LPC, but here are some things to check;
1) Lube the mech properly and thoroughly w/20wt non-detergent oil. Remove the top bearing over the motor worm and oil that extra well. There is an oil hole in the thrust bearing nut, but old oil and glaze can displace new oil and make lubing that beaing difficult.
2) Check for a supple motor coupling. Replacements are available.
3) Check that the motor mounts are still rubbery but not allowing the motor to shift when reversing. Be sure that there is a rubber plug support under the bottom center of the motor.
Understand that the motor is getting approx 83 Hz when playing a 45 and this does raise the frequency of the vibrations from the motor and can induce mechanical harmonics.
In case you are wondering why Seeburg used a native 33rpm mech, it was because 33's had inherently lower output causing the amp's AGC to turn up the gain. Since the motor was going to make more noise when powered by the less-than-perfect sine from the speed unit, it was felt that the louder 45 would better cover that noise. This was explained myself and a friend by a rep from Seeburg in 1977 and it does make sense.
BTW: You mention the memory as being "electromechanical" -it isn't. It is an early form of NVRAM -all electronic. The toroids can retain their state essentially forever unless flipped.
In 1998, I rebuilt a Seeburg K that had been retired in 1961 and stored till I bought it. After complete washing and rebuilding I powered it w/mech connected and it detented at about 7 slots that must have been selected eons ago.
Rob
Re: LPC mechanism playing noise
Posted: Wed Dec 30, 2015 6:13 pm
by Ron Rich
Hi Eric,
Other then Rob's suggestions, there is one problem unique to both LPC models, that can, and will, cause "hum". If the hum is occurring, "louder" when the mechanism is playing any "7" or '8' numbered selection AND the latch solenoid is energized, check that "someone" has not removed the latch solenoid hum shield (see the parts manual). Ron Rich
Re: LPC mechanism playing noise
Posted: Mon Jan 04, 2016 11:44 am
by babycat
indeed it's the same noise on a 33 1/3 little LP. i finally sprang for some new styli, and with some work on the TSA, i've got the audio sounding a bit clearer and thus overcoming the steady mechanical noise. not too bad at living room levels, but i bet it can be better. some of this noise still gets picked up through the cart/tonearm, so i plan on following up on y'all's recommendations when i get a chance -
i'm wondering - can you do a full lube on the mech while it is installed? or do you need to pull it?
cheers and thanks guys!
Re: LPC mechanism playing noise
Posted: Mon Jan 04, 2016 1:22 pm
by Rob-NYC
No need to remove the mech.
Remove the cover (obviously) and park the mech at the far right side to gain access to the clutch. A hose oiler is big help here.
If you don't have a lube chart:
http://s1192.photobucket.com/user/Rob-N ... rt=3&o=166Rob
Re: LPC mechanism playing noise
Posted: Mon Jan 04, 2016 5:19 pm
by Ron Rich
Rob "forgot " one thing--it's possible to oil it with out removing the rear panel, but much easier if you do !
I have used a Valve Spout Oilier (brand) for about 50 years now--(Seeburg sold them, and sometimes we gave them away at factory service schools --these are still available from "Longs"--U.K. )(
www.longs.co.uk SMALL HOLE part # AV51145BS ). Ron Rich
Re: LPC mechanism playing noise
Posted: Mon Jan 04, 2016 11:38 pm
by Rob-NYC
Ron, I do know about, and use, the holes in the casting by the motor. I oil using a Zoom spout oiler with appropriate oil, When the mech is stationary in play mode you can feel the oiler hose touching the clutch shaft as it turns.
However, it is more difficult to get at the rest of the items such as safety lever and lift arm gears if you don't have a clear view f them. So for a newcomer it is best that they see the mech at least for the first lube.
Rob
Re: LPC mechanism playing noise
Posted: Tue Jan 05, 2016 1:30 am
by Ron Rich
Rob,
There are at least ten "oil points"on the clutch assembly, that I oil--Ron Rich