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Magnatone with broken tone pot stem....

Posted: 30 Aug 2012 5:11 pm
by Butch Pytko
I just received my Magnatone D-8 and I immediately was struck with the feeling that I have bought some steel guitar history! This guitar truly enforces my love of Hawaiian steel guitar, even more! The seller was honest enough to state that the tone pot stem was broken-off before-hand, so it can be seen in the picture. I have both knobs, just wanted to see what the good volume pot stem looked like, next to it. I've followed a few of the pot replacements here on the forum, but I've never done it. Is it pretty self-explanatory understanding the code? Can anybody recommend an electronics place to buy it? Also, the picture of one of the pick-ups--on the end/edge--is rough. Is that chrome plating? If it is, I don't want to go through the plating and make it worse, with say, a real gritty polish. Would it be OK to use emery cloth? Can anyone comment on that. The legs are a little rusted, but not too bad. I had a hard time trying to telescope the legs, but I finally broke them free--they just need a good cleaning inside, so they'll telescope-out easily. All-in-all, it's got some marks on it, but for being over 50 years old, I think it looks great. After the tone pot replacement, a good cleaning, and new strings, it should look even better!

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Chrome

Posted: 31 Aug 2012 2:12 am
by Johann Uhrmann
Flitz makes a very good metal polish, and can be found at a marine supply store. Some music stores carry it in small tubes for cleaning tuners, etc. Elderly Instruments carries it for that purpose, but I'm sure you can find it locally. I would trust a good quality metal polish before using emery cloth.

Posted: 31 Aug 2012 10:21 am
by Butch Pytko
I think you're right about the various metal polishs, which I have. I'll use the polish with my dremel buffer-wheel. The more I've thought about the emery cloth, the more I think it's a bad idea--polish only for now! My main priority though is the tone pot. Just did a search here on the forum and came-up with a wealth of info concerning guitar VOLUME and TONE POTS--values, tapers, and how to read the pot code. About the tapers--I see the info on the long and short tapers--BUT, all I want to do here is replace the PROPER CODED VALUE as Magnatone intended. Also, in the search I found-out about 2 recommended electronics suppliers--Stewmac and Guitar Parts Resource. Any other thoughts?

Posted: 31 Aug 2012 5:12 pm
by John Billings
Emery Cloth? Yikes! NO! California Custom Purple Polish, and their Deoxidizer, work wonders, and remove rust. Find your local Mack truck dealer, as they usually stock CC products.

http://www.californiacustom.com/ourproducts.html

If you really want to clean and rejuvenate the finish, start with Meguiare's Swirl Remover 2.0, then use CC's M-RON polish. The Meg's will remove all surface gunk, without effecting the guitar's aged patina. The M-RON is #1 Carnuba, and is incredible! My mangy old Tele was totally gunked up, but now looks as if you can see through it! And the disgusting old Perm body? Really nice!

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Posted: 31 Aug 2012 8:54 pm
by Stephen Cowell
Butch Pytko wrote:I think you're right about the various metal polishs, which I have. I'll use the polish with my dremel buffer-wheel.
Your Dremel can go right through the chrome... start without it. Folks don't think a Dremel is very powerful... but it puts that power into a tiny place.

Butch Pytko wrote:The more I've thought about the emery cloth, the more I think it's a bad idea--polish only for now!
Anything that can abrade the metal is bad... especially around magnets, where the filings will collect.

Butch Pytko wrote:My main priority though is the tone pot. Just did a search here on the forum and came-up with a wealth of info concerning guitar VOLUME and TONE POTS--values, tapers, and how to read the pot code. About the tapers--I see the info on the long and short tapers--BUT, all I want to do here is replace the PROPER CODED VALUE as Magnatone intended. Also, in the search I found-out about 2 recommended electronics suppliers--Stewmac and Guitar Parts Resource. Any other thoughts?
It's actually possible to replace the shaft and keep the original taper and pot case (with date codes!)... all you need is a pot from the same manufacturer of the same time period. The case can be opened with a tiny screwdriver, pry up the tabs, then bend them back with needlenose pliers. The shaft just pulls out and the new shaft just pops in. Replace the case and bend the tabs back over using the needlenose or small channel-locks.

Posted: 1 Sep 2012 8:44 am
by Butch Pytko
OK, John! Boy, it looks like I won't be able to mess-up with you around! NO emery cloth--bad bad!!! Will look into your polish suggestions. Thanks AGAIN for your help!

Stephen, you're right and I'm so wrong on the Dremel. I want to fix/recondition this guitar, not destroy it! On the tone pot shaft replacement, I really like that idea. But, how do I go about getting the pot from the same time period? I'm going to start taking the guitar apart right now and get the info off the pot. So far, of the 2 electronic suppliers, only Guitar Parts Resource has the 1 Meg. linear taper listed--the dimensions are given, so will have to compare that to the pot in the guitar. Also, of the tone pot info I got from my search here, it was mentioned to get a HIGH QUALITY tone pot. The tone pot shown at Guitar Parts Resource is $5.00--is that HIGH QUALITY or not?

Posted: 1 Sep 2012 9:49 am
by Tom Pettingill
The tone pot shown at Guitar Parts Resource is $5.00--is that HIGH QUALITY or not?
Those are CTS pots and would be a good choice. They have the typical US sized 3/8" bushing and 24 spline for the knobs which appears to match what you have on the volume. $5 is about the going rate, but the bummer is shipping a single small part is always hard to swallow. CTS is a very common brand and I'd hunt out whoever has the best shipped price. This one on Ebay comes in at $7.40 shipped.
http://www.ebay.com/itm/NEW-1-Meg-Linea ... 53ec69af99

Posted: 1 Sep 2012 10:39 am
by Stephen Cowell
Butch Pytko wrote:(snip) But, how do I go about getting the pot from the same time period? I'm going to start taking the guitar apart right now and get the info off the pot.
That will help... give us pictures and we'll either help you find one or send you one from our (collective) hoard of junk (I'm not alone out there, am I?). The thing with period electronics is: some are expensive (your guitar) and some were very cheap (like an old radio etc). The correct shaft for your pot lives in things like old stereos, which abound for dirt cheap/free.

Posted: 2 Sep 2012 11:15 am
by Butch Pytko
Tom, thanks for the pot info & it looks like you are going along with changing-out the whole pot.
Stephen, you're thinking about repairing this pot, so I'm sort-of caught-in-the-middle of what to do. Here are pictures I took to keep my wiring correct--what pictures do you want--what angle? I can easily do it!
The numbers on the tone pot are in 2 groups--one group with a space in the middle is: 137 735
The other group of numbers has 4 digits, with the middle 2 covered with solder: first number is 5 & the 4th number is 8. The volume pot has 137 735 & 5548 on it. Now, I'm going to take-off the other neck's cover to clean the under the pick-ups, because under this pick-up cover things are really filthy, so when I do that maybe I can see the numbers better on the other tone pot.

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Posted: 2 Sep 2012 11:45 am
by John Billings
Butch!
Sorry about the repeat performance! I'm just passionate about old guitars! My hobby is restoring them.
Another good place for old, and quality parts is a Hamfest. There's one in Orlando on 9/15/12, at the Bahia Shrine. I used to get great tubes at hamfests, but they've all wised up now!

Posted: 2 Sep 2012 11:56 am
by Peter den Hartogh
Are you sure that is a tone pot?
I cannot see a capacitor and the wiring looks like that of a mix pot, which mixes or blends the 2 pickups like a Stringmaster.

Posted: 2 Sep 2012 12:02 pm
by John Billings
I was lookin' for the tone cap too Peter. I just assumed it was out of the frame.
Butch, how about a pic of the whole electronic cavity? And,,,, there are two pups per neck, so a mix/blend knob would make some sense.

Posted: 2 Sep 2012 1:01 pm
by Butch Pytko
John, you can perform all you want on my posts, I enjoy anything you want to say! Hamfest on 9/15, I'll be there!
OK, John & Peter, here is full underside shot. When I got this guitar a few days ago, I plugged it in to make sure everything worked. In the picture, the top pot is the tone pot(when it's laid-down, it becomes the bottom control from the players side)--I was able to work it with a screw driver(broken pot stem) & it seemed to operate like a tone control should. Same on the other neck, the tone pot from the players side would be the BOTTOM knob--just like my Stringmaster--top knob(volume), bottom knob(tone). Man, I hope I'm not that whacked-out where I can't tell the difference between volume & tone controls!!!!

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Posted: 2 Sep 2012 1:21 pm
by John Billings
Butch,
The Deluxe 8 that I'm selling has a blend knob under the flip-top bridge cover, and bending in the front pup changes the tone quite a bit. But I'm assuming that the switch is a pup selector switch. The black circular object is the cap, rated at .02 right? I shoulda looked at the previous pics a bit closer, as the rating is clearly there!

Posted: 2 Sep 2012 4:48 pm
by Butch Pytko
John, yes the pick-up blend wheels work the same way you're talking about on my 4-neck Stringmaster. I just went to my Magnatone file, and according to Jeff Au Hoy, the Magnatone tone knob is similiar to but different than how the Fender blend wheel works. He says the Magnatone tone knob has a double function--it tapers "HIGHS" AND the neck pick-up. That switch is also on the other neck, they're strictly on/off types & the cap is .02 value.

Posted: 2 Sep 2012 4:52 pm
by John Billings
" the Magnatone tone knob has a double function--it tapers "HIGHS" AND the neck pick-up."

Interesting!

Posted: 2 Sep 2012 6:57 pm
by Stephen Cowell
Thanks for the pictures. It looks like these might not be the original pots... the 'blend/tone' pot has solder on the shell that doesn't go with the installation. I'd expect this guitar to have solid shaft pots anyway... anyone know if these are the original knobs? The '137' is CTS, IIRC... the '735' is 35th week of either 1957, 1967... by '77 they were to a four-number thing I believe. The '5548' is a part number.. I just checked, the pots had 4-digit numbers by the '60s so your pots are 1957 and should be original to the guitar.

http://home.provide.net/~cfh/pots.html

For steel guitar, and especially if you do 'boo-wah' tone control stuff, you need a heavy-duty pot. I'm definitely not used to seeing split-shaft pots on classic American guitars of this period, someone else may educate me further here.

Posted: 2 Sep 2012 9:07 pm
by David Matzenik
Very interesting thread. What a killer guitar! :whoa:

Posted: 2 Sep 2012 9:25 pm
by Peter den Hartogh
This is not the right guitar, but you can see how some pots were wired in those days.
It might even explain the solder spots on the shell of the pot.

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Before you start working on the pot, it might be a good idea to draw your own
circuit diagram of the existing connections on this neck and also the other neck.

Posted: 3 Sep 2012 11:22 am
by Butch Pytko
Stephen, took the other pick-up cover off, same split shafts, same numbers. One of the pictures shows the underside of the other pick-up cover--no solder mess here! Just wondering about the tone pot--why didn't they stamp the 1 meg. value on there? How do the pot makers know which is which? Thanks for taking the time to look-up the date info.
Peter, thanks for the diagram. Will use it as a guide to make a diagram for this guitar. Could the solder spots just be soldering sloppiness?

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Posted: 3 Sep 2012 11:27 am
by John Billings
Different cap? The green one? What's it's value?

Posted: 3 Sep 2012 11:35 am
by Butch Pytko
It says 02, just a different color. But, I am wondering WHY it's a different color?

Posted: 3 Sep 2012 11:40 am
by John Billings
Well,,,, I was thinking that maybe the side with the sloppy soldering had the cap changed, cuz the side with the green cap looks pretty neatly done

Posted: 3 Sep 2012 12:04 pm
by Butch Pytko
Just rechecked the other cap--it's green, just a darker green. Because it was darker, I must of glanced at it, thinking it WAS another color--my mistake!

Posted: 3 Sep 2012 2:11 pm
by Butch Pytko
I'm getting confused about this 1 meg. linear tone pot value. I'm starting to make a wiring diagram for my guitar and don't see a tone pot value on Peter's 53 Magnatone diagram. I rechecked the tone pot info I got from my search and discovered the 1 meg. linear recommendation was for a Fender Custom, also, I found a Stringmaster pickup wiring diagram that shows a 1 meg. linear tone pot. So, is this 1 meg. linear, a sort-of universal value for all guitars? I'm just trying to understand this.