Following on from my “new amp” thread, I thought I might try and diagnose the issue with my current setup.

It’s an old (probably 20+ years) Denon mid-sized system with Technics floor standing speakers.

At the beginning of playback there is crackling sound which seems to go when driven harder, although it comes back during quieter sections.

I have replaced the speaker cable with good quality ones and changed the speaker connectors but it hasn’t made any difference.

As a result, I assume it’s either the speakers themselves or the amp. I don’t have a spare set of speakers to test.

Any thoughts?

Do all the connections in the speaker look ok? What condition are the speaker cones in? Have you tried a different music source?

I’d be getting some switch cleaner on the volume control, maybe even the tone controls too. Easy enough to do, just make sure to unplug, don’t drown the control, and wipe any excess off with a tissue. What system model is it?

Isolate the issue – try different speakers. Then you know if it’s speakers or amp.

Personally, my money’s on the amp, perhaps the controls as three fish said. Crackling noise getting worse as louder, I’d guess speakers.

But don’t let that sway you – find out.

Sounds like it could be the volume pot(entiometer) to me, give the volume knob a fair few spins back and forward to try and clean the internal contacts (or remove the cover and attempt to spray a smidge of electrical contact cleaner into them as three_fish mentions above)

Agree with the above. I had similar with my NAD 3130 ancient amp and it was definitely the volume pot. I never (have the opportunity to) run it loud and so it hadn’t been rotated much past the normal volume. With some turning all the way up (switched off…) it seemed to sort it – had to do the same with the channel balance pot too.

Thanks folks.

The amp is this model:

http://audio-database.com/DENON-COLUMBIA/amp/pma-6_5-e.html

Hamish: This is the same: The volume barely gets past 9 o’clock (starting position 6).

I have tried turning the volume all the way around and on first impressions it does seem to have made a difference.