Micromatic needle replacement issue

Hi all,

Newbie here. So after it being in my family for 44 years (20+ of that in storage), I bought replacement needles for my Astrosonic and went to install them last night. When I did, a small piece of plastic popped out when I took the needle out. Since I couldn't see the underside of the cartridge when I was doing the work, I don't know where this piece should go, and if it can even go back in at all!! Help!!!

I've included pics below - one with the needle for scale, and the other of just the stray piece, which has kind of a wishbone appearance (click on the pics for hi-res versions). Thanks for any assistance you can offer.

Andrew

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Looks like you are having a bad day. That's the retainer for the needle.

Thanks for the info and pic. So can I just put this back in? The same piece? OR is this now damaged and I need a new one?

I see that you got one of those needles with the longer rear "stem". I mistakenly bought some of those and had to use some nail clippers (for a quick fix) to shorten that rear portion.

That "retainer" thingy can be slid back on the two connections carefully with some tweezers. I would maybe use some type of rubber treatment on it to keep it pliable. Just for a few seconds. Some of that stuff can be pretty strong.

If you have a newer Micromatic (W620/W621) with the skinny tonearm that uses something lika an EV275 or Astatic 165D, just loosen the single screw underneath that holds the cartridge in place. If you have an older Micromatic with the black, curved tonearm with one of the larger cartridges, loosen the screw on top of the tone arm and the whole assembly should fall right out. That way, you don't have to do contortions getting a neckache and backache looking upside down under a tonearm that doesn't pull back completely.

I've got three different needles with subtle differences, but they all work, and the EV275 has the numbers 742 and 802 which I am clueless. I recognize the Magnavox 560345. Notice the rear "stem" on each.--BB

Bobby Basham
Tucson, Arizona

Awesome!! This is really helpful!! I appreciate it!

The only thing I would be concerned about is the two broken ovals that fit over the ceramic bars. They should not be split like that and may be why it fell off.

By way of an update, I did in fact manage to slip the retainer back in (after about 30 minutes of effort) and the needle in over it. Your input saved me $75-100 for a new catridge!

Now I just have to find some de-oxidizer for those scratchy pots!

Thanks again!!

Thom,

As I looked at that pic again, I noticed that the ovals were split. Well, I did notice it the first time and didn't think much of it, thinking that was the nature of that particular cartridge...never seen anything like that before. Maybe the thing is dry and brittle and may crumble to pieces if you try to remount it.

Would it be possible to soften it up, then maybe use a tiny drop of Super Glue to close the ovals? Hell, I'd give it a shot. I've made alot of lemonade out of lemons throughout the years. Desperate times call for desperate measures (if you're desperate...LOL). Even if it did work, those ceramic bars could be bad. I think that's the issue with some of these extra deadbeat cartridges I pictured. The volume will drop real low on one channel, and when you gently tap or press the top of the tone arm (bad for the record while it's playing), the channel pops back to normal volume.

Oh Andrew, I see your post popped in while I was in the midst of editing mine. Glad you got the thing reassembled. Was that piece still pliable or stiff? --BB


Bobby Basham
Tucson, Arizona

The piece was very pliable, and I don't know how I might have gotten it back in had the ovals been closed, since I had to use a pin to push the open ends around the ceramic bars. I did see a little ceramic dust come off on the pin when I scratched the bar by accident, but I just finished listening to a Claudine Longet album, and just put on AC/DC and it's sounding great!

Are there any steps you would suggest to keep her running strong for another 44 years? Feel free to point me to any postings on here; I tried to read through, but it gets hard to keep all this infor straight!

Sometimes, I feel like these things wear like iron. Other than scratchy pots, I would problably get the turntable serviced, for preventative maintenance, since it's all mechanical and things do wear out. Make sure idler wheels haven't hardened, the same with motor mounts, look for old dried/gummy linkages. Make sure the motor gets up to speed right away and doesn't drag or waver. Some parts are meant to be greased/lubed while others should be clean and dry to operate correctly.
I'm not telling you to do this yourself, just a FEW things a knowledgeable tech would look for.

Over time, those electrolytic caps will fail. Your unit may sound fine know, but what a difference a cap job can make. I've done cap jobs on several of mine and it resolved alot of other issues. I should start checking resistors, too. One little resistor caused a problem that I thought was transistor/cap related so replaced all those. Not so. I found out after the fact and that was money wasted, not big bucks, though. --BB

Bobby Basham
Tucson, Arizona

Wow Bobby, you ought to price out those low power transistors for late 60's Zeniths. Hard to find and the lowest price I found was $20.00 apiece at auction. If I was sure they get weak over time I'd replace them. But at that price and the fact that they are NOS I am a little hesitant.

Thom,
Save your money--transistors do not get "weak"--they either work or not, for the most part-- Ron Rich

Thanks Ron. Good to know.

My mistake,

I wasn't referring to the power transistors, and have replaced a few of those, but was referring a single carbon film(?) resistor in the audio chain that was WAY out of tolerance. I can't remember right now, but it either went completely off the scale on my meter or didn't register at all. My bad. --BB

Bobby Basham
Tucson, Arizona

Then are you saying transistors can weaken over time?