Magnavox 5914 Tuner & 8601 Amp Restoration

[GarywithanH]

Hello,

I'm a newcomer to the tube audio space. I'm mechanically and technically inclined, and excited to learn more about electronics and audio in the process of my vintage restoration. I picked up a 1961 Magnavox Radio/Record Console with an 8601-10 amp in it and a 5914-10 tuner in it. I've gone deep down the rabbit hole on this site, as well as scouring the internet for resources on how to tackle this project. If it matters, it all worked when I first got it a couple months back. Radio sounded good, although there was a loud hum from the old caps. I've since pulled it all out of the console for cleaning and inspection.

I feel fairly comfortable with the 86xx series amp and the parts I need to swap out to get it going right, but the tuner has way less information floating around. I have been trying to fill in the gaps before unsoldering things. I found a schematic that includes both the tuner and the amp, though my actual console is slightly different. I've also created a google sheet for the parts. The main item I'm having trouble with is some parts for the tuner. There are a few small caps in the sub chassis that I'm not sure what to replace with (if I even need to?) and the main body. Any of the items that have question marks on them (?) are because I'm not sure if they are film caps or disc caps, and what I should buy as replacements. If you have recommendations/suggestions, I'm all ears!

For purposes of keeping it (somewhat) simple, I will be replacing all film & can caps in both units and testing resistors as I go (and replacing as necessary) to bring it to its original glory. I'm not interested in doing any upgrades or mods yet, as the OE replacements are already a big learning experience for me.

Thanks

 

[chefaaron]

The attached file may be of assistance to you or may be what you already have. Regardless, what I have attached at least points out the caps and resistors with numbers/parts list which may help you eliminate some of your question marks.

If you are unsure which caps are what look at them. If they are coin-like in shape they are ceramic and if they are in the tuner they should be left alone unless you are 100%, no questions asked, certain they are bad. Replacing them usually means you will need to align that tuner and most people don't have the equipment or know how to do it right. Looks like there is one ceramic in the amp (c42) that should be replaced with a safety cap(x1). If there are any other ceramics in the amp they are likely fine and should be left alone.

Some advice from someone who isn't that far away time wise from being in your very shoes..
1. Start by replacing the electrolytics in the power supply and test your work there before you move on.
2. Make sure you let those caps discharge before you move on.
3. Once you are on to the paper caps replace a few in one section and test again. Its a lot easier to fix a mistake when you've only replaced 2 or 3 caps vs the entire thing.
4. Be safe, take your time and have fun.

 

[GarywithanH]

Thank you for the really valuable information.

To your point, I wasn’t looking to touch any of the ceramic (coin shaped caps) in either the tuner or the amp, but just to make sure I understand, I can replace the film caps in the tuner with no adverse effects, correct?

Additionally, what is the value of replacing c42 with a safety cap?

 

[chefaaron]

If you plan to use this regularly I definitely recommend replacing all of those capacitors. The big ones covered in wax are actually made of paper and if they aren't bad now they will be in due time. You can replace them with no ill effects. Its possible you won't find exact replacements but get them close in uf value. I replace them all with 630v rated caps because I'm cheap and thats all I buy. Most of those paper cap values should be easy to find but the electrolytics aren't. For instance c2 in the tuner is an electrolytic underneath a small metal dog house. It is rated at 4uf/50v. I replace those with 4.7uf with no problems.

c42 is your across the line cap. If that were to short out you could have straight wall voltage on all of the metal pieces which would not be good if you were to touch them. A safety cap will just short, but not to ground, hence the safety bit.