Playing a CD this evening and after an hour of moderate volume, simple music the system started making loud high frequency cracking or spitting noises, mostly but not exclusively, on the right channel. The music was double bass and vocal, so no high frequency sound to speak of.
I immediately shut it off to protect everything rather than messing about. It has never done anything like this before. I don’t know if the sustained bowing of the double bass had heated up certain components more than usual and caused something to overheat, however, the heat sinks on the amp were only mildly warm.
Before I dive in to the amp, if anyone has any thoughts of what might cause these spitting noises, I should be very grateful. For example, could the ageing MOSFETS be complaining perhaps?
Musical Fidelity A3.2 CD player, fully recapped 12 months ago with Elna Silmic II caps. Fitted with Burson Audio V6 Vivid opamps 6 months ago.
Musical Fidelity A308 integrated amp, serviced and levels set 3 years ago. Recapped with DNM smoothing caps and Elna Silmic II 10 months ago.
Monitor Audio Gold GR20, replaced crossovers with Mundorf caps and inductors and Mills 12W resistors. All components of higher than original ratings and point to point wired.
It doesn't help that there are no manuals available for MF gear, of course.
Thanks for your wisdom in advance
I immediately shut it off to protect everything rather than messing about. It has never done anything like this before. I don’t know if the sustained bowing of the double bass had heated up certain components more than usual and caused something to overheat, however, the heat sinks on the amp were only mildly warm.
Before I dive in to the amp, if anyone has any thoughts of what might cause these spitting noises, I should be very grateful. For example, could the ageing MOSFETS be complaining perhaps?
Musical Fidelity A3.2 CD player, fully recapped 12 months ago with Elna Silmic II caps. Fitted with Burson Audio V6 Vivid opamps 6 months ago.
Musical Fidelity A308 integrated amp, serviced and levels set 3 years ago. Recapped with DNM smoothing caps and Elna Silmic II 10 months ago.
Monitor Audio Gold GR20, replaced crossovers with Mundorf caps and inductors and Mills 12W resistors. All components of higher than original ratings and point to point wired.
It doesn't help that there are no manuals available for MF gear, of course.
Thanks for your wisdom in advance
You'll have to narrow it down further. Hook up some junk speakers.
Does the volume control reduce the noise? If not, it's probably in
the power amplifier section.
If the noise reduces with the volume control, swap channels at the CD output
and see if the noise swaps as well. If not, it's probably the amplifier.
If it swaps, it's in the CD player.
Does the volume control reduce the noise? If not, it's probably in
the power amplifier section.
If the noise reduces with the volume control, swap channels at the CD output
and see if the noise swaps as well. If not, it's probably the amplifier.
If it swaps, it's in the CD player.
Thanks folks. I have a sneaking suspicion that it may be the CD player, and anyway, I have a new laser and belt to fit, so I’m going there first. When I fitted the carriers for the opamps there was one cross-strap on the top of the board that looked a bit iffy. If the board warmed up and the bass was shaking the board it might have caused momentary breaks and hence the spikes.
Now it’s cool this morning, there’s no evidence of the problem. So, tonight’s job is to sort that strap out with a bypass.
Now it’s cool this morning, there’s no evidence of the problem. So, tonight’s job is to sort that strap out with a bypass.