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Saturn 63 replica build


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I finally started to work on the replica I want to build for my Dad.

It was about time because I plan to give it to him on his wedding anniversary that coming early August 😅

Here is my CAD model and bellow are some progress pictures:

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* I changed the logo on the pickguard to spell my father's name instead of "Hopf". I kept the same style of calligraphy.

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I recently found a schematic for the mysterious 4 positions rotary tone switch but I can't figure out how it works.
I'm trying to reproduce it in CircuitLab and it don't seems to work like intended.

Maybe someone could help me break it down? I can't figure out how there is only one resistor for a band pass and also I don't understand where ther "R. M." switch comes from.

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54 minutes ago, Polymaker said:

I changed the logo on the pickguard to spell my father's name instead of "Hopf". I kept the same style of calligraphy.

That's a thing I like! Paying homage to the original without building a fake.

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Posted (edited)
13 minutes ago, Drak said:

That looks like Spruce topwood?

It actually genuinely looks like what they would have used on a Saturn.

Like.

Yes it is! 😁 Also you can't really see it from theses pictures but I used flamed maple for the back to match the original.

And thanks to you I also have the closest thing to the actual bridge that was used 😉

I used a slab of basswood between the spruce top and maple back to get the proper body thickness.
Hollowing-out a ~2" slab of maple seemed a bit ridiculous and expensive 😂

Since the burst get solid black on the edges it won't show that there is three layers of wood.

Edited by Polymaker
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43 minutes ago, Polymaker said:

I used a slab of basswood between the spruce top and maple back to get the proper body thickness.
Hollowing-out a ~2" slab of maple seemed a bit ridiculous and expensive

Perfect choice.

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11 hours ago, Polymaker said:

Maybe someone could help me break it down? I can't figure out how there is only one resistor for a band pass and also I don't understand where ther "R. M." switch comes from.

It's easiest if you imagine the two sections of the switch moving clockwise in sympathy from position 1 to 4 and then follow the trail it makes from pickup to volume pot, like following a train on railway tracks as the points move across (ignore the 'R-M' thing for the moment);

  1. The top section shorts out the 2nF cap and bypasses it completely, but the 22nF cap gets connected between the pickup and ground, effectively making it equivalent to a typical tone control set to zero (aka the 'T- Low pass' setting). Lots of highs are lost and the sound is warm/muddy/dull/bassy etc
  2. The 22nF cap is again connected to ground, but the 2nF cap bypass gets removed and is allowed to remain in circuit. The 22nF again acts as a low pass filter, but the 2nF acts as a high pass filter at the same time, resulting in a narrow band of frequencies to pass (you lose some lows through the high pass and lose some highs through the low pass, what's left is the 'untouched' stuff in the midrange, aka the 'T+ B- Band pass' setting).
  3. The 22nF cap gets disconnected and the 2nF cap gets bypassed again. The pickup is effectively connected directly to the volume pot with no filters applied (aka the 'T+ B+ Filters Bypassed' setting). Not dissimilar to a tone control on max.
  4. The 22nF cap remains disconnected but the 2nF cap gets inserted back into the pickup signal. It acts as a high-pass only, which cuts the bass out of the pickup signal (aka the 'B- High pass' setting). The sound becomes thin/weedy/shrill/bright etc

It's not clear what the 'R-M' switch is for, but if you close the switch the extra circuitry gets bypassed and has no effect on the pickup signal. If the switch is open the extra 470k/1nF circuit is added in series with the pickup signal, which acts as a kind of additional high-shelf filter; high frequencies can pass freely through the cap, but lows are forced to travel through the resistor, which slugs some of their energy on the way to the output. You'd probably end up with a moderate bass cut/treble boost when you activate the circuit.

I wonder if 'R' and 'M' stand for something like the German terms for 'bright' and 'normal' or 'rhythm' and 'lead'? 

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@curtisaThanks for the thorough break down of the circuit!

I thrust your explanations but to my (basic electronic) knowledge, low-pass and high-pass filters uses a combination of a resistor and a capacitor, but in this circuit there is no resistor except for the "rhythm" circuit that can be bypassed. Since pickups have high resistance, do they act as the resistors? 

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1 hour ago, Polymaker said:

Since pickups have high resistance, do they act as the resistors? 

Yep. The circuit relies on the inherent resistance (and inductance) of the pickup itself to complete the low- or high-pass filtering effect

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  • 2 weeks later...

I made some progress last weekend 😁

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I installed the frets and shaped the back of the neck. It still needs some more sanding.

I also finished carving the inside of the top.

You may able to see in the picture that I left untouched the area were the vibrato unit will rest on the top.
What you might not see is that I also left a 'lump' under the bridge.

I originally planned that both the bridge and vibrato areas would rest on the 'center block' since I did not want to use bracing as in a traditional archtop.
The main reason is that the acoustic properties are not a priority for this build and I wanted to keep the build as simple as possible.
But even though the acoustics are not a priority, I still would like that it had at least some acoustic volume if possible.

So that's why I changed my plan and removed some material under the bridge. I don't know if it will change much in the end but at least there is some room for the top to vibrate and it should still be sturdy enough. 

 

Some variations of the Saturn 63 had a kind of chrome ridged molding on the side of the guitar. I found an aluminum molding that looks very similar at Home Depot.
Sadly it was only available in gold but someone in a review on the product page said that he used muriatic acid to de-anodize it because he needed to have it in silver.

I will give this method a shot. Does anyone knows if it needs to rest for a long period of time in the acid or can I apply-it with a brush? 

I also thought that it could be easier to apply the acid if the molding is pre-shaped instead of a long flat bar. I feared that it could crack when bending around 'sharp' corners so I used a blowtorch to heat-it up a little and it went well.

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I would most definitely try the muriatic acid on a scrap piece first, of course.

That will tell you everything you need to know about how long it will take and whether the finished look is something you like or not.

Looks great so far!

I used to own several of those old '60's semi-hollow jobs, Mine were Japanese Matsumoku's, but basically the same thing.

What they did was to take a little piece of wood, about 1" x 2", and literally stick it right under the bridge area for support.

I'm not sure if it was glued in or not, but the three I had I could pull them all out by hand.

You had to tug on them, they were a tight fit top to bottom tho.

Not saying or recommending it, just giving you some reference on how they dealt with that.

On mine, I removed those and installed two new posts and drilled them for TOM's.

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  • 2 weeks later...

I am a bit slow on the updates because I currently spend all my spare time working on the guitar.

I planned to give the guitar to my father at his wedding anniversary that is tomorrow... Fortunately, we will celebrate their anniversary the next weekend so I may be able to finish it in time.

Here are the outlines of my progress (picture will follow after):

Last week I made a custom tailpiece for the vibrato. I'm still not sure how it will attach to the vibrato though 😅

Last Friday I stained the guitar. I had some issues with the spruce top, it does not behave like maple and I had to sand back the top and restart.
The burst is still a bit "blotchy" to my taste but I did not want to sand back a second time and I think it will look good anyway,

Up until last weekend I was still not sure what to do with the headstock logo. Do I put my logo or do I replicate the saturn logo?
Since the model name is Saturn, I had to use that logo but I was not sure how to do it. I did not have the time to order a custom waterslide decal.
The other solution was to draw it by hand with a silver paint marker, but I thought it would be too difficult.
In the end that's the method I used. To help draw the logo, I taped to the headstock the printed logo, then I lightly cut a line thought the center of each letters with an scalpel.
Then I had to just follow the scratches with the marker. I did some tests and my wife had a steadier hand than me so it's her that did the logo on the headstock.

For the logo on the pickguard I did also try to draw it by hand with a marker (a couple of weeks ago) but I wasn't pleased with the results.
I was also not sure how to do the numbers and letters on the control plate.
Finally I found a small engraving company nearby and I will laser engrave the acrylic pickguard and diamond engrave the aluminum control plate.
They should be ready later today.

Finally I have put the clear coats on the body and neck last weekend. I also sprayed another guitar that I built last summer.

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* As for the pickguard logo, I changed the headstock logo a bit. My last name is Turner so I changed the number 63 for "er" so it reads "Saturn er"

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* The neck for the Saturn is not on those photos because my wife was drawing the logo while I put a first coat.

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It all looks really well executed, Bravo! Yes, if you had asked, I would have gladly told you Spruce doesn't dye like a Maple and not to try and dye it directly. The general rule is to clearcoat the Spruce first, level-sand, then add your colors as shader coats mixed into your finish medium. Then more clearcoats to lock it in, like a sandwich. And not to dye the wood directly, as Spruce is known to react in a blotchy way to direct dying.

If the Spruce reacts in a certain favorable way to direct dying, the 'blotchyness' can add a certain character to the look you couldn't otherwise achieve.

But you never know going in, you just take your chances doing it like that.

I love what you did with the logo, pretty trick-'er'.

Its going to look great!

P.S., did you wind up keeping the gold side-banding?

This is also a Spruce top, clearcoated first, then some slight shader added to the finish in later coats.

No blotch, and you can clearly see the Spruce grain underneath.

v0iUXxs.jpg

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  • 3 weeks later...
Posted (edited)

Sorry for the lack of updates, the past few weeks have been busy!
I used 90% of my spare time to work on the guitar and the rest of the spare time was spent planning my upcoming trip to Los Angeles (I'm leaving Saturday morning 😆)

So I have the pleasure to announce that the guitar is finished!

My dad was overjoyed and almost shed some tears when I gave it to him!

The guitar sounds and plays great but there are two small issues that I'll fix after my trip.

First, the bridge pickup is too far from the strings. I designed the guitar before receiving the bridge and I assumed that the surface-mounted pickups were the tallest things... Turns out the minimum height of the bridge is too high and I had to shim the neck to adjust the break angle, So I will make a plastic shim/riser for the bridge pickup.

The other thing is that the tone circuit needs some adjustment because the difference between the different modes is very subtle.. I used the capacitor values from the schematic on the website I found (see older post) and since the build was a bit rushed to reach my deadline I didn't have time to play around with other values,

Here are some shots of the final guitar:

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Edited by Polymaker
adjusted images sizes
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That's simply gorgeous! The blotchiness of the spruce top makes it look even more true to the era - although the builders back then did perfect finishes, the memories of the sixties tend to have such a blotchy vibe. Think about the Soviet Lomo cameras who have given the name for Lomography, an art form mimicking the pictures taken with poor quality toy cameras. Or just old photos and colour prints from catalogs to record covers from the late fifties, early sixties... Even the movies from that era look washed and a bit off-focus! You've managed to catch that all!

I'm not sure about shimming the pickups, at least not before you've done the changes in the electrickery. Old electric guitars weren't too loud so the output may be just right for "rhythm".

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4 hours ago, Polymaker said:

First, the bridge pickup is too far from the strings. I designed the guitar before receiving the bridge and I assumed that the surface-mounted pickups were the tallest things... Turns out the minimum height of the bridge is too high and I had to shim the neck to adjust the break angle, So I will make a plastic shim/riser for the bridge pickup.

First off, it looks Fabulous.

Second, I'm sure you probably already know this, but if you use the pair of screw studs that I shipped with the bridge instead of those rubber feet, it will lower your bridge height considerably. It will nearly sit on the deck with them lowered. The rubber feet were meant for surface mounting the bridge, but I've rarely ever seen them used on production guitars. Using the rubber feet assembly actually gives your guitar a little bit more notoriety since they're rarely ever seen, and I would believe were probably for a full-sized archtop install. Most of the times you see that bridge they used the screw studs, as they're used in the Ovations I have as well. You nearly never ever see the rubber feet option utilized.

I was thinking maybe the rubber feet were needed for the additional height for the trem.

But my Ovations (which are very similar in depth to yours) used the screw studs, even with their trem.

Also, back then, most pickup shims were made of wood, usually Rosewood, at least the ones I have from that era are..

And if you're hesitant about drilling the body for the screw studs, or there's no wood meat underneath them to support them, probably easier to just make a pickup shim at this point.

Reguardless, Wowza does that look fantastic. I wasn't expecting it to look THAT good!

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