2275 Has Arrived! Recap Underway!
- Thread starter MarkyM
- Start date
I picked up one on Black Friday. The owner was still using it in his pole barn with one channel out and a old mouse nest inside. I thought it to be one of the easiest to work on.
Nice pictures, you will enjoy it when finished.
BTW how was the plastic lamp holder? Mine was melted pretty bad. Got new lamps in but had to remove the dial panel anyway to replace the velum.
Barney
Nice pictures, you will enjoy it when finished.
BTW how was the plastic lamp holder? Mine was melted pretty bad. Got new lamps in but had to remove the dial panel anyway to replace the velum.
Barney
Nice find! Yes. very easy to work on (except for that @#$% MPX board and the PS01 board). This thing is built better than a lot of professional gear is today!
Thanks, the lamp holders are fine. All the fuse lamps were burned out and I suspect they were original.
There doesn't seem to be a lot of hours on this unit.
Thanks, the lamp holders are fine. All the fuse lamps were burned out and I suspect they were original.
There doesn't seem to be a lot of hours on this unit.
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catrafter
Marantz Specialist
I posted this back earlier in the thread, it's kind of hard to see, the white wires go to the negative and the red leads go to the positive leads of the cap pair and attach to the cap with ring terminals.
Here's a better picture, this is of a 2325.
Tom
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A Nichicon KA of that value was not available so I used the Panny FC.
I will provide a cap list at some point.
Indeed you are!
Electrolytic capacitors have a finite life span and go bad (generally) after 15-20+ years. This receiver is nearly 40 years old!
This from our own resident expert echowars:
"Depends on the age, the amount of ripple current the cap is regularly subjected to, and the ambient temperature in its environment. All of these contribute to the aging of the cap. My own rule of thumb: if it's 15 years old or older, replace it. When it is in doubt, replace it. If something weird is happening on that board, replace it. New low ESR caps are so much better than anything used in older gear that the reasons NOT to replace them pale in comparison to the benefits."
And this from cap manufacturer Elna:
Reliability of Aluminum Electrolytic Capacitors
Klipshman
Well-Known Member
I use to repair old tube radios from the 30's-50's and always replaced the electrolytic caps, which there was very few of those. Many times there was three in a metal can. Old wax capacitors got replaced as you could visually see some had leaked.
With more "modern" mylar, etc, caps I never replaced those unless the radio was causing some problem.Sometimes when I found a nice radio someone had already changed out some of the caps with mylar ones and I left it alone. The biggest problem was the electrolytics or an IF transformer out of sync. I've never tackled a receiver as it looks like a daunting chore.
With more "modern" mylar, etc, caps I never replaced those unless the radio was causing some problem.Sometimes when I found a nice radio someone had already changed out some of the caps with mylar ones and I left it alone. The biggest problem was the electrolytics or an IF transformer out of sync. I've never tackled a receiver as it looks like a daunting chore.
Some are definitely a pain! Some are a piece of cake. I am in also in the recap it camp. Every 30-40 year old receiver I've gone through has had at least 10 caps swollen out the end and nearly all (90%+) sound better afterwards.
Klipshman
Well-Known Member
My only Marantz receiver to date is the 2265 and it looks and sounds about as good as it gets. I don't recall what all was done to it but I've been well pleases with the sound. That's not to say there may be some swollen/leaky caps but if so you can't tell it by the sound. All functions work flawlessly.
I know one thing for sure, a 1930 Philco radio is far and away much easier to completely overhaul than any receiver I've seen. You've got a football field to work in instead of everything being cramped up like in a receiver.
I might add that replacing some of the caps in a Marantz and you've lost that golden mellow sound as I doubt you could find a good match.
I know one thing for sure, a 1930 Philco radio is far and away much easier to completely overhaul than any receiver I've seen. You've got a football field to work in instead of everything being cramped up like in a receiver.
I might add that replacing some of the caps in a Marantz and you've lost that golden mellow sound as I doubt you could find a good match.
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Indeed, it makes this job a lot easier.
Boy, the service manual procedure for FM alignment is kinda strange. In Step 5 it says: "Decrease the signal generator output until the audio output level decreases with the decreasing generator output". Huh??? This is not AM
Must be a poor translation from Japanese. I assume what they mean is decrease the signal generator output to where the audio starts to get noisy (and reads low on the signal strength meter) and tune the adjustments for maximum signal (sensitivity), then increase the signal generator output and fine-adjust for minimum distortion.
catrafter
Marantz Specialist
Indeed, it makes this job a lot easier.
Boy, the service manual procedure for FM alignment is kinda strange. In Step 5 it says: "Decrease the signal generator output until the audio output level decreases with the decreasing generator output". Huh??? This is not AM
Must be a poor translation from Japanese. I assume what they mean is decrease the signal generator output to where the audio starts to get noisy (and reads low on the signal strength meter) and tune the adjustments for maximum signal (sensitivity), then increase the signal generator output and fine-adjust for minimum distortion.
You are correct in your assumption, you want to peak up the tuner on a weak signal so the AGC doesn't mess you up as to where the actual peak is.
Sometimes you have to rely on experience, Marantz manuals generally suck. It's also interesting when you find that the particular tuner you are working on bears no resemblance to the one in the service literature.
If I could change one thing about the SG-80, it would be to add presets for common generator frequencies. I guess you could do it with automation if you could find or build the correct interface. Do you have one for yours? It came in RS-232 and IEEE-488 versions.
Tom