Mapleknoll Questions/ Trouble shooting


Hello,

I am trying to help a friend set up his Mapleknoll after being in storage for several years. After new oil in the pump, new hose and ensuring the plenums are air tight, there are still a couple of annoying problems:

* The arm will not cue accuratley it tends to drift to the center of the record well dropping

* the arm hangs up part way through the record.

The table is absolutely level , the paddle is not bottoming out, the wires are not hanging up & the arm moves freely when cued up in the horizontal plane (or at least appears to)

What are some good next steps to look at next. The manual does not seem to help much. Thanks in advance.
nkj
Give up. A friend of mine who designs and builds electronics from scratch has one and I don't think he has set it up in years. When he had it set up it took all his talent, which is considerable, just to keep it running. When it is running it is a great turntable, unfortunately that is not often.
Hear LLC
Brooklyn, N.Y.
Ph: (718) 377-8010

HIGH END AUDIO REPAIR

They state that they are a repair center for Mapleknoll.
Worth a try contacting them.
The arm hang-up problem may be because the pump is weak, or at least not getting enough air to the arm for some reason. This is what happened with an ET-2 arm I had back in the early 90s.

But too many people have had major problems with the Mapleknolls, and I think Stanwal has the right idea.
Had one 20-25 yrs ago, tremendous sound but extremely fussy to set up. Used to have the same problem with the arm 'sticking', a stronger pump fixed it. If you go for an 'audiophile' pump it'll cost you. I found my solution at an art supply store, a pump for airbrushes worked fine.
nkj. Strongly disagree with the first responder about giving up. they can be a pain to get right, but once set up right, they are pretty simple to keep going. I will suggest you refer to my thread i started a few years ago about maplenoll and you will find a lot of information. I own three of the top end maplenolls and every one of them required some pain to set up but once completed, was a joy to listen to. just recently purchased the apollo which has the airbearing platter and arm plus a vacuum system. I have it up running now and its spectacular. Sorry for my pitch, but i do like these tables. I will help you any way i can. First i need toknow the model of maplenoll to try to help. I have more experience with the ariande than any other maplenoll but they are very similar to teh other lines. Concerning the arm. Here are some initial pointers. First recognize level table does not mean level arm. It should, but i found on my first maplenoll that i got the table perfectly level and the arm would drift back to the left. The final leveling must be done with the arm perfectly balanced (not an easy task but well worth the effort. You can balance with the cartridge on or off but i prefer on. If you have a cartridge cover for the stylus, i strongly recommend you use it. you will need some putty to balance the tonearm, but take the counterweight and adjust or add putty to the counterweight until the arm floats. on most of the arms, it may drift up or down a little but you want it to where it does not go all the way up and the counter weight is dragging or to low where the cartridge is dragging. Once you do this slowly adjust the level till the arm kinda drifts to one direction . This is an indication you have gone to far. Back off just a little, it will drift the other way. keep going back and forth until it stays somewhere in the middle. My next tip is to gently blow on the arm and see does it drift easily. If so, you are very close. If it hangs up in a particular point, note where the hangup point is and see if the arm has some gunk or buildup. I like to clean the arm once a month with a damp cloth and and alcohol. If the arm hangs up, wipe the entire arm down with alcohol and see if it still hangs up. Usually it hangs up either because the arm is dirty, the level is off or the air pressure is too low. By now you should have eliminated the level issue or the dirty arm. If its still hangs up, then its very possible that the air pressure is too low. If you have a pressure gauge/regulator, check the air pressure. The arm likes high pressure, usually 35 to 45 psig works well. Most of the maplenolls have one air line that splits or divide the air flow to the platter and arm. It the pump is the supplied air pump, it will have enough pressure usually and the problem is often too much air to the platter. This can be checked by turning on the pump and motor and letting the platter turn. Close the valve (Should be a needle valve) until the platter hangs up or makes a rubbing sound. then back off slightly until the sound disappears. THis is critical. once complete, you have max air to the arm. If the arm still hangs up, then you will need to clean the air spindle block. Occasionally, the air holes get clogged. If this happens the arm will not float properly. if you get this far and it does not solve the problem, shoot me another line and i will help u with step s to clean the air holes. One last possibility is the arm is not perfectly straight. Its rare, but i saw it with another person. I do have some spare spindles if that is the case