I have been given an amplifier, a Marantz 1060 from the late '70s It came from its original owner and is in beautiful condition with a sound to match. However, when I switch it on there is a rustling scratchy sound through my speakers (LS3/5a) for two or three seconds. This is independent of volume setting. I am reasonably happy weilding a soldering iron, but where do I start? Instinct tells me some capacitors need changing, I assume in the power supply. Am I on the right track?
Despite its age, this seems to be a highly sought after amplifier in the USA with lots of rebuild and capacitor kits for sale there, and I would like to continue using it.
Thanks for any advice.
Despite its age, this seems to be a highly sought after amplifier in the USA with lots of rebuild and capacitor kits for sale there, and I would like to continue using it.
Thanks for any advice.
You said speakers, plural. This means the problem is most likely in common parts of the amp, being the power supply as the most suspected.
Is there a snubber cap across the mains switch? If so, you could try desoldering one leg and see it the fault remains or not.
Best try with an old speaker.
Is there a snubber cap across the mains switch? If so, you could try desoldering one leg and see it the fault remains or not.
Best try with an old speaker.
I would be looking at the power section caps.
If in original condition from the 1970's, there is a fair chance of dried out electrolytics.
If in original condition from the 1970's, there is a fair chance of dried out electrolytics.
Nice layout , but old ... old.
Even properly derated or less stressed caps will have the electrolyte paste lose the water. No way around it.
You might find the one cap that crackles , but many are not far behind.
As a "vintage" kit , I've seen re-capped and cleaned up models like this sell for many hundreds. Looks like a 60-80W unit.
OS
Attachments
Crackle being a somewhat typical
wormhole of descriptions.
Usually from old equipment can be yes
DC not being blocked from old caps.
More likely is dirty switches , dirty relays
dirty pots. So a basic cleanup service.
On / Off switch has pits from arching
or output relay has same issue.
Otherwise Crackle on startup with signal.
Then stops after warm up. Could mean low bias
settings already from factory, and slight warm up
bias stabilizes. Would check bias pots and settings.
Often smart to not do much since losing the pot powered
up can launch amps into full on and boom.
So clean and check unpowered.
Then measure powered after clean up and meter check.
wormhole of descriptions.
Usually from old equipment can be yes
DC not being blocked from old caps.
More likely is dirty switches , dirty relays
dirty pots. So a basic cleanup service.
On / Off switch has pits from arching
or output relay has same issue.
Otherwise Crackle on startup with signal.
Then stops after warm up. Could mean low bias
settings already from factory, and slight warm up
bias stabilizes. Would check bias pots and settings.
Often smart to not do much since losing the pot powered
up can launch amps into full on and boom.
So clean and check unpowered.
Then measure powered after clean up and meter check.
That old , EVERY cap is bad. 1990-1995 amps , all the caps were failed or way off spec.
That's a 70's amp !
It could be the switches , but the caps are still bad. Unless it has already been re-capped.
OS
That's a 70's amp !
It could be the switches , but the caps are still bad. Unless it has already been re-capped.
OS
Hi,
Thanks to all who responded, I'm really grateful for all the advice. I think I'll start with the power board and go from there!
Thanks again!
Thanks to all who responded, I'm really grateful for all the advice. I think I'll start with the power board and go from there!
Thanks again!