Yamaha R300

OMGCat!

Super Member
I'm so impressed with all of the different Yamaha models I've listened to. They all have the Yamaha clean and clear sound down pat no matter if it's a massive power amp or a little STK powered receiver.

I got this little one here for $15 dollars because it had no/bad sound.



I decided to go ahead because it's in nearly perfect condition with one small scratch on the tuner knob and a little scratch at the rear of the cover. Even the oft missing selector knob is present and accounted for.
One round of Peavey Silent Slider got the little guy humming along perfectly. I replaced the odd 28V bayonet bulb with a 12V car version in series with a 5w 51ohm resistor to bring it down to around 9V.
Aside from that I did a good cleaning on the inside, replaced the heat transfer paste on the STK and did a thorough cleaning and waxing on the exterior.

I'm currently listening to Journey, Captured through my Marantz TT and it sounds really darn good. I have no place to put it and will probably sell or give it to someone who needs to have good tunes in their lives. We will see. I am already starting to think of reasons to keep it though.
 
Nice looking little receiver. I like that line. I have a problematic R-700 that looks almost new. Need to get it figured out.
 
I replaced the odd 28V bayonet bulb with a 12V car version in series with a 5w 51ohm resistor to bring it down to around 9V.

Thanks for the tip! I also have a little R300 I picked up at my local Goodwill. I did a thorough cleaning, including DeOxit on all controls and it sounds great. Like yours, the 28V bulb on mine was burnt out. I priced the bulb and it was something like $27 - a bit steep for a $15 receiver. So, I'll give your trick a try with the automotive bulb.

Are you happy with the brightness of the lamp in series with the 51 ohm resistor? If you wanted something a little brighter, you could go down to 47 ohm, or even 39 ohm and still not exceed the lamp's voltage rating.

I'd like to get the lamp working so I can give this little unit to my son to use in his bedroom system.
 
The auto bulb with that resistor is pretty much on the edge of the brightness level I want to see. Any brighter and it would be too much IMO.

Be sure to use at a high enough rated resistor as even the 5w gets pretty warm. I have mine tucked into the last fin on the heat sync to help it stay cool. I can post a pic if you'd like.
 
Congrats on your find. I have R500 from 1983. Worked fine until a few months ago and now its starting to fail, as posted on this forum. I think I fell asleep at night with it on, and when I woke up the next morning, its hasn't been the same. Maybe that was the "stress test" that pushed it over the edge. I can't imagine 8 hours would do that. MTBF? I had new STK 2040 installed a few years ago, so I'm guessing that's still solid and its something else. I'd be open to suggestions on how to trouble-shoot. Regarding tuner bulbs, you can find exact fit on ebay for approx. $1.50. They ship from china, it takes 10 days and you pay $5 for shipping. I had to replace mine a few times. Order 2 so you have back up. You can also order the green plastic bulb cover if it gets damaged. These receivers have lots of nostalgia value and win the beauty contest on appearances. They are the last generation of analogue receivers before yamaha went digital black box.
 
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Thanks for the tip on the bulb. I will have to order a few so I can put it back to stock.

I was just reading your thread and from the way your R500 is acting it sounds like it could be a bad solder connection somewhere in there. If it was a bad component, chances are it wouldn't ever kick the relay on. The fact that it works sometimes sounds like a bad connection or possibly a dying relay.
From doing some reading here and there it sounds like Yamaha was a little skimpy with solder when they built it so you can have cracked solder joints after a bunch of years worth of thermal cycles.

I'd pull the top cover and get a non conductive poker (wooden chopsticks are great) and poke around while it's on and see if you can get the relay to act up or turn on if you gently push or tap on a specific spot. Other than that, turn it around and pull the bottom off and give the joints a good look. You might be able to see a cracked joint. If so it's just a matter of reflowing the damaged connection.
 
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