I have just picked up a Marantz MR2020 for my daughter.
It has a buzz on one channel:
I was going to open it up and have a poke around with my DSO. I am expecting that it is faulty capacitors. I do have a copy of the service manual with the schematics.
Any other suggestions of what could be wrong and where I be starting starting?
Many thanks, George
It has a buzz on one channel:
- fault is in the amplifier, not the cables or speakers
- buzz remains on all sources
- buzz is a constant volume
- the buzz goes at volume 0 plus when other muting operations are in progress
I was going to open it up and have a poke around with my DSO. I am expecting that it is faulty capacitors. I do have a copy of the service manual with the schematics.
Any other suggestions of what could be wrong and where I be starting starting?
Many thanks, George
Use the good channel (carefully) and compare readings with the bad channel.
With a DVM, check the circuits after the volume control, and fuses.
Is there high DC output offset at the speaker? Scope is probably not needed.
But watch out for slips of the probes, which will do great damage.
With a DVM, check the circuits after the volume control, and fuses.
Is there high DC output offset at the speaker? Scope is probably not needed.
But watch out for slips of the probes, which will do great damage.
Well, thank you for teh suggestion. That is an excellent approach.
After the ampp being turned on for twelve hours or so, the bussing has not returned. It did not return even after having the power removed for a while. Hmmmm.
Still, the suggestion is really useful as I have an old Aura amp that is buzzing in both channels, which suggests that it is something with the single common PSU.
After the ampp being turned on for twelve hours or so, the bussing has not returned. It did not return even after having the power removed for a while. Hmmmm.
Still, the suggestion is really useful as I have an old Aura amp that is buzzing in both channels, which suggests that it is something with the single common PSU.