Phonoland

So, I have had a new issue arrise with my Magic Mind turntable in the Webcor. Here is the breakdown:

When playing 45's, change cycle initiates without issue. However, when playing 33's I have some problems.

1. When cycle is started, everything runs smoothly.
2. When record is finished, change cycle is NOT always initiated. This is not the case with every record, but only some.
If tonearm is lifted and manually moved just above record, change cycle is initiated, however, sometimes this requires moving tone arm back to rest position and then back towards spindle. When change cycle begins at this point, there is no issue.

Here is what I know (at least I think)

1. This was not previously a problem (did something get lubricated that shouldn't have?)
2. So far as I can tell, as the tonearm tracks, a thin, counter- weighted 'rod' moves along with it eventually actuating (pushing) a lever that initiates change cycle. I am not sure that this lever is getting reset during the cycle. Or maybe it isn't tracking with the tonearm?
3. If, for example, I play the first song and then lift the tone arm to move to the last song, the cycle begins when it should.
4. Finally, cycle has some problems swithing to 45 before shutting off as it should. Would this affect the cycle? It isn't every time, but most of the time.

Let me know if more info is needed!

Nate

- Some variations of Magic Mind have manual play. This occurs if you start the turntable after an automatic shutoff by lifting the pickup arm and placing it on the record (instead of pushing down the speed knob to start it). The changer is not supposed to trip at the end of the record if this is the case.

- The trip parts on this changer must be clean and dry to work. Lubrication prevents tripping.

- The felt washer under the trip finger may have worn away.

- The speed change mechanism has no connection to the trip mechanism. Look for a sticking semaphore (size sensor) if the speed change doesn't work right. It may be failing to move fully to the 7'' position at the start of the change cycle.

Thanks for the info. I have cleaned up some residual lubrication around the lever in hopes that it will resolve this issue. Perhaps the change cycle was functioning ok during 45 play because there is more speed during the 45 cycle.

I do have a few questions regarding the cartridge on this unit if you have any suggestions.

1. The cartridge it uses is a Sonotone 8T and appears to be original but functional (this is a mono unit). It does seem to be a bit dirty/dusty, though. Do cartridges degrade over time or are they either functional or not? Can I clean what I have (and if so how) or should I consider replacement and if so...

2. Should I replace with a vintage original, or is there a more readily available new replacement that would be suitable for adaptation?

--Nate

Ceramic and crystal cartridges slowly lose their ability to produce voltage over time. Moisture changes the crystal structure.

Unfortunately, any vintage cartridge has also been exposed to moisture, unless it was stored in a desert area.

Clean it with an artist's paintbrush.

One possibility is that the trip arm is binding or gummed with lubrication, so the trip finger doesn't actuate it. Another possibility is a bent trip arm. If the reset tip pushes it back too far, the tonearm has to move farther in one turntable rotation to trip the changer.

The velocity trip compares tonearm motion to the rotation of the turntable. There are actually two operations going on at the same time:

1. The tonearm, moved by the record groove, moves toward the center of the record. It pushes the trip finger through the friction clutch. The trip finger then moves the other trip parts toward the tripping-position.

2. The rotating turntable activates some kind of reset mechanism once per rotation. This reset mechanism pushes the trip parts away from the tripping position. The friction clutch slips when this happens, preventing the tonearm from being affected by the reset motion.

The changer trips when the pickup arm moves fast enough to move the trip parts into the tripping position before the reset mechanism comes around to reset them.

Just an update...

It seemed as though the trip arm was not following the tracking of the tonearm as it should. I thought, perhaps, it was because the trip arm was not making correct contact when following the tonearm. I raised the small cork piece that helps push the trip arm about 1/16th of an inch and re-attached it. Since then, I have had no problems with the change cycle initiating. I am assuming the cork was dried out and had shrank, and therefore wasn't making proper contact with the trip arm.

Nate

That makes sense