Author Topic: Plinth Modification for 1957 Magnavox Serenade  (Read 14177 times)

Magnavoxland

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Plinth Modification for 1957 Magnavox Serenade
« on: May 21, 2015, 05:37:34 PM »
I have a very nice Micromatic changer coming for my 1957 Magnavox Serenade.  Long gone will be that humming, clunky RC-456 continental series Collaro changer, and in its place will be a smooth operating, very quiet Micromatic.  I knew I had to modify the plinth for the Micromatic, and I was dreading having to do it.  Then, last evening, I was talking on the phone to a restorer friend of mine in Detroit, who indicated that the plinth might be held into the cabinet with screws, and that it just may be removable from the cabinet.

I checked afterwards and sure enough, the plinth in the Serenade was just held in place with 12 screws.  I had to remove three screws on the top front of the board, and the rest of them were underneath.  There were three screws on each of the two support boards that support the plinth, and another three screws at the very back of the plinth.  Once the screws were removed, the plinth came right out of the back of the cabinet.  Isn't this nice that Magnavox made provisions for removing the plinth in the future if someone wanted to upgrade their changer?  I think that is a very nice feature.  Many other manufacturers simply glued these plinth boards into place.  Magnavox, on the other hand, had a vision for the future.

I pulled the Micromatic changer out of my Berkshire to use as a guide for the modifications.  The job would have been much faster with a jigsaw, but I don't have one, and I didn't want the plinth to look butchered like someone did to my Berkshire's plinth.  I noticed last night that the plinth board was brown fibre board, and not wood, so I decided to try my dremmel on it with a good sanding attachment.  I made marks on the plinth on where and how much to dremmel off, and I took the plinth outside to make the mods.  I would dremmel a bit, then bring it back inside to see how it worked with the changer laying on its back.  This took considerable time, but it left the plinth looking like a professional had done it, and not butchered.  I am very proud of how it turned out.  The Serenade is now ready for its new changer!

The first picture below is the Serenade's modified plinth for a Micromatic changer.

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #1 on: May 21, 2015, 05:41:19 PM »
It only took me about 15 minutes to reinstall the plinth in the Serenade's cabinet.  I would suspect any of the good Magnavox cabinets, including even the Concert Grands and Imperials, would have removable plinths like this one has.

amglow

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #2 on: May 21, 2015, 05:48:09 PM »
Excellent work Larry.  You are now a craftsman of multiple trades:  Electronics technician and cabinet maker!  8)   Thanks for the heads up on the plinth removal.  That is good to know for future reference.
Paul

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #3 on: May 21, 2015, 05:51:52 PM »
Thanks.  This work is tedious and time consuming, but it actually only took me about 3 hours to modify it and reinstall it.  I was very careful to not get too close to the edge of the changer as you don't want to see any gaps between the changer and the plinth.

Pat L

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #4 on: May 21, 2015, 05:53:02 PM »
Very nice work Larry😃 and why shouldn't a Magnavox have an even nicer changer in it. I am wondering about your RC456 though. I can't imagine that it's just not good enough. I think that there is a correctable underlying issue to resolve the issues you had with it. To put my money where my mouth is (figuratively) I stripped one exactly like it down to individual parts this week. I told my wife I was going mad scientist on it.

Like you I was disappointed with it but for an entirely different reason. I just couldn't get the autochanger to work properly. I've been afraid to do this before, but I've come to the conclusion that anything else is a half measure bound to give lackluster results. When I finish putting it back together I'll do a new post on the process I used. And of course report out the results.
Pat

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #5 on: May 21, 2015, 06:04:20 PM »
Pat, these Continental series changers may have been just fine when they were new.  But through the years the bushings wear, the rotor might get slightly warped, who knows what, and therefore they are noisy today.  This one I had was so noisy I couldn't stand it.  The hum was even picked up by the cartridge and you could hear it way across the room.  I have no tolerance for that.  There is absolutely no hum or noise to a Micromatic four pole motor... they run as quiet as a mouse.......

I think these earlier changers with the motor attached directly to the motorboard was a huge design flaw, and maybe that's why they were dumped in favor of the quieter Micromatics.  Any phonograph motor attached to the motorboard without motor mounts will have some degree of hum or noise.  And, that noise will be even far worse if a stereo cartridge is in the tonearm, which mine had.

Pat L

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #6 on: May 21, 2015, 06:08:43 PM »
Larry, I'm not convinced that it can't be made perfect. I do agree that all things being equal the rubber mounts will be quieter, but not to a degree that you should readily notice. Let's see what kind of luck I have.

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #7 on: May 21, 2015, 06:11:54 PM »
Perhaps the Continental series changers can be made quieter, but they are still clunky sounding in cycle, and I absolutely hate the record support arm.  You have to manually lift it up and place it over the record near the spindle or you will scratch the top of the record.  That was another design flaw.  The Micromatic support arm just swings over the record and drops down, like RCA and VM record support arms do.

The raised speed selector/on/off/reject control also is a nice feature of the Micromatics, particularly in sets like the Serenade where there isn't much room around the changer.  It is somewhat difficult to get your hand down there in some of these changers to reject it, particularly if you have an LP record on top of the spindle.

624Magnificent

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #8 on: May 21, 2015, 08:03:55 PM »
Great job Larry!!!

I tried to pull the plinth out of a 1964 Astrosonic the other day. I removed all the screws but it wouldn't budge. It was built into other layers of wood that were installed afterward and also seemed to be glued although I couldn't tell for sure. I was trashing the cabinet anyway and just wanted the plinth for a template. I ended up using cardboard. So it looks like the nice engineering that you found seemed to disappear at some point.
Tom

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #9 on: May 21, 2015, 08:11:13 PM »
Well, if you haven't noticed, the Magnavox cabinets got cheaper looking as the years rolled by.  They had outstanding cabinetry in the 40s, 50s and through about 1961.  Of course some cheaper models were even made during those years too.  By the 70s they looked like they had plastic fronts and they must have been made of press-board.  I'm not surprised that the plinth wouldn't come out of your cabinet.  Did you try hammering it to see if it would knock out? 

TC Chris

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #10 on: May 21, 2015, 10:30:48 PM »
It only took me about 15 minutes to reinstall the plinth in the Serenade's cabinet.  I would suspect any of the good Magnavox cabinets, including even the Concert Grands and Imperials, would have removable plinths like this one has.

The answer is "yes" for the 1956 Provincial Serenade, as I discovered tonight.  I was making a new board for the "new" changer.  I carefully measured the inside dimensions of the changer compartment and then spent some time cutting a piece of plywood--what I had on hand--to the right size.  Then I started fitting it to the cabinet from the top and came to see that it is intended to slide in from the rear.  The rear edge is secured with screws upward from the bottom, while the other three edges are secured with screws down from the top. Since mine was cut to the inside dimensions, it's too short  to overlap at the back, so it can be secured with screws.  I think I'll find another sheet of material and make another one to the right size.   Live and learn.

Chris Campbell

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #11 on: May 22, 2015, 01:17:27 AM »
Both my 1961 Imperial and 1958 Berkshire also have removable plinths.  Look inside your changer compartment.  If you see 9 screws around the changer, the plinth should be removable.

Consoleman

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #12 on: May 22, 2015, 08:33:51 AM »
That's interesting. The plinth in my '56 Berkie was hacked up by a previous owner and I tried to remove it. Even with the screws removed it would not slide out. I gave up trying because I was afraid I would damage the cabinet and just worked on it in place.

The Conquest in this console is a F200C, not original to the unit. It also has the motor hard mounted to the chassis and it's totally quiet. I think the Collaros are superior to the Micromatics in a couple of ways - speed can be changed while the platter is turning, and the changer mech is driven off the motor instead of the platter which means it always runs at the same speed.
Mark

Magnavoxland

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #13 on: May 22, 2015, 10:45:19 AM »
Mark, your plinth will come out.  I thought after removing the screws that mine wouldn't come out, but I pushed down and rapped my fist on one side of the plinth and it broke loose, and came right out the back.  You might have gotten yours out easily by rapping it all the way around with a rubber mallet. 

Pat L

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Re: Plinth Modification for 1957 Magnavox Serenade
« Reply #14 on: May 22, 2015, 06:54:43 PM »
Just finished a complete teardown on my RC 456 out of my 58 CG. I would say it's about a 98% success on the first try. It turned on, dropped the record and the tonearm perfectly. The only issue was some skipping on a brand new copy of The Last Waltz. I set the tonearm spring pressure lighter (making the arm heavier) and that's fixed. The cartridge and needle are NOS EV26 from Gary at VOM. The only other issue is a fussy power switch that on occasion won't turn on.

I cannot hear the motor at all. Larry, I'm of the opinion that these changers will work beautifully, but to do so need a complete teardown and reassembly. I've avoided this job for years as I was afraid of it. Now I'm thrilled, what a sense of achievement. Upgrade your changer if you prefer the newer models. Perhaps once you have your unit operating the way you want with the Micromatic, you could tear deep into the Continental. You'd have nothing to lose, throw it out if it doesn't work as you expect once finished.