Restoration of a 1965 Sylvania SC773C Stereo Console

by 11jwolfe2 in Circuits > Audio

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Restoration of a 1965 Sylvania SC773C Stereo Console

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Hello World!

This is a guide on restoring an old stereo console! I am an Electrical Engineering student and loved this project! I figured I would write my first Instructable and hopefully help everyone trying this themselves!

Some may ask where I got this and how much I put into this, the answer is easy, my local Goodwill and $10.

If you need more help or have any questions please ask as there is a lot of knowledge and every unit is different.

Also this will be updated this summer, my girlfriend and I plan to restore the wood finish to a grayish color and re do the dated fabric speaker covers. We also plan to make the inside a little more interesting, stay tuned.

*Please remember to look at all pictures as most have comments that might help identify parts.

Research!

This is probably the most important step! You will need to find everything about your console as possible. After searching the internet for weeks I was able to find all of the tools needed to begin this project.

First, start by discovering the issues with your particular unit. Mine made an awful HUM! (later discovered to be what is called a 60Hz hum, for AC wall outlets). Also my units record charger would not transfer sound out of the speakers, this was caused by a bad cartridge. So find your issues so you know what you will need to fix.

When powering on your unit be careful if it has not been turned on in decades as the electrical surge can harm some of the transistor tubes in your stereo. I did not know this before powering mine on but luckily none of my tubes were damaged. If paranoid about damaging your tubes use a varactor (slow increases voltage to your stereo) if possible. This is not necessary though.

Second, find all documentation possible on your stereo as possible; schematics, wiring diagrams, parts lists, anything and everything. Attached are two PDFs for my specific console and record changer. I was able to get these by calling my local library and asking for them. If your library does not have your specific documents, search the internet they might be out there for free. Otherwise you can use https://www.samswebsite.com/ to find yours, they do cost about $20+.

Third, learn the types of components you're about to restore. In my unit I only needed to replace the electrolytic capacitors and some old wax/paper capacitors. All other components in my unit were operating normally. The best sites for this are http://www.antiqueradio.org/recap.htm and http://www.wjoe.com/capacitorinfo.htm.

Both of these will teach you about the vast differences between old components and new.

I also found these beginners guides to vinyl that were very helpful:
https://www.reddit.com/r/vinyl/comments/1t1zw1/new...

https://www.reddit.com/r/vinyl/comments/fiedy/my_...

Demolition

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Now its time to take apart your console to get to the inside components that you plan to replace. During this phase I would recommend taking more pictures than you think you need to put it back together. I have a very good memory when taking things apart and putting them back together. However, we all have done a repair and had the unit back together and had extra screws and think "hmmm, wonder where these go, hope these are not important". Above I have pictures of my unit as I took out the top and bottom electronic units.

Repair of Inside Electronics

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For this you will need a good soldering iron and some schematic reading skills.

First, read from your schematics and find all the electrolytic capacitors that you will need to replace and use visual inspection to find wax/paper caps to replace (find the wax and paper cap values in your schematic or from their bodies as some are labeled). Once you have made a complete list of all the caps needed to be replaced you need to purchase replacement caps.

Remember to always double check and triple check your list. I rewrote my list about a dozen times and I still ended up ordering a wrong value capacitor.

I purchased about 35 caps total. About 8 from http://www.mouser.com/ and the rest from http://www.wjoe.com/capacitors.htm as they were convenient, relatively cheep, and very helpful.

When buying caps make sure that they are the same value and the voltage is the same or HIGHER, never lower!

Some of my large 3 Part Caps were 80uF 350V. For these I used 2 40uF 450V Caps in parallel as they were cheaper and easier to find. If you plan to do this, I suggest you do a lot of reading from the sites in Step 1.

In my unit, and I assume yours, there will be some three stage large can capacitors (those tall silver things in my pictures). For these there are several things you can do, rip and replace with new caps, disconnect and install new ones, or whats called stuffing. To find out more about these, look at the resources in section 1. I wanted to go with the stuffing route to make things look as authentic as possible. However, with a high end soldering station and a blow torch for extra heat I was unable to de-solder them from the chassis of my unit. Since I was unable to remove them I took to the modern era and I 3D printed new ones. Attached are my basic 3D Models I used for the three caps I made.

If you plan to 3D print new ones like I did measure a lot and do not be afraid to reprint as I had to. I removed the tall can caps by breaking the leads and prying them out (very barbaric). However, this worked and my unit looks nice.

Repair Turn Table Cartridge

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For some they might not need this step. I, however, really needed this one.

So, the turntable that came with my console was supposed to be a Garrard AT-6 or Autoslim per the manufactures instructions. However, I think what I actually have is more like a Garrard 3000. They are all very similar just with different tone arms. When fixing mine to make sure it would play a record properly it took me awhile, it was the longest part of this whole repair.

I started by figuring out what type of cartridge was already in my unit, a Tetrad Uni, which is a ceramic cartridge. Ceramic cartridges were mainly used in the 50's-60's, until being replaced by moving magnet type cartridges.

I bought my Tetrad on ebay as it was the cheapest and readily available. However, after installing my new cartridge and spending many many hours testing my stereo, pre-amp, and turntable. It was bad. I contacted the ebay seller for a replacement and they sent me another.

In the mean time though I did some researching and found how bad ceramic type cartridges really are. They add a lot of strain on your records and produce lack luster audio quality. So I began doing some research and found that a magnetic cartridge was right for me. I went to the local audio shop to purchase one. I ended up spending 3 times the price, so do not make this mistake and order yours here:

(http://www.amazon.com/Technica-CN5625AL-Half-inch-...

From what little I have found out about cartridges, if your original console used a ceramic cartridge in order to upgrade to a magnetic cartridge you will need a pre-amp. My unit had a built in pre-amp so I was good to go. However, if yours does not, I unfortunately do not know how to help. I'd say surf the internet, you will find something.

Also, the audio technica cartridges come in yellow (lower quality, cheep), green(mid quality, mid price), red(higher quality, higher price), and blue(very high quality, very high price).

See the beginners guides under research for more information.

After installing my new magnetic cartridge everything worked and sounded amazing! I'm in love!

Put Back Together, Start Collecting Vinyl, and Enjoy!

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*All those pictures you took at the beginning should help you reassemble your console.

After putting it back together, test it to make sure it works, all that is left is to enjoy your new stereo console!

One suggestion before getting to far into a record collection is to make a https://www.discogs.com/ account. This will keep a status on your record collection and the value of said collection.

This video is my unit in action, please watch and listen.

To make this more of a home piece, we restored the unit and gave it a makeover here.

EXTRA!

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These are extra photos I took while fixing my console, they may or may not be useful to you.