"charles" wrote in message
...
In article , Rod Speed
wrote:


"charles" wrote in message
...
In article l.net,
Dave Liquorice wrote:
On Sun, 14 Apr 2019 08:00:12 +0100, Brian Gaff wrote:

its affected by proximity, sounds more like a parasitic oscillation
of some sort.

That's what I'd be looking for. Monitor the cuurent draw, does it
follow the buzz level? The buzz is a symptom of the PSU running out of
steam, do the driver chips/transistors get warm/hot?

As it takes a while to appear and does so slowly I'd guess that it's
only just unstable and requires a signal to kick it off.

as I said - check the power supply.

Pointless with two new devices with a decent brand like that.

somebody in purchasing thought they could shave
?0.1 off the cost by buying cheaper compoents?

Doesn't happen with that brand and clearly now that it is clear
how to get rid of the buzz, it isnt a power supply problem.

The BBC once sent back a whole batch of AVO8s
because they were inaccurate. It does happen.

Different issue entirely.