Crackle/interference

[Guest]

I'm starting to get some intermittent noises, a bit like static, out of my hifi system. It's only about 7 years old - Mairantz CD player, NAD amp, B&W speakers.... Mostly from the left speaker. I've swapped the speakers over, it's still the left. The CDs are clean, and it's quite random/intermittent. The TV and Rega record deck are also plumbed through the amp, no problems there. The CD player is connected to the amp and the amp to the speakers with good quality cables. I've definitely got too much cabling in the area, but this has always been so.

What does this sound like to people? I'd hate to replace a component only to find it wasn't the problem! Any suggestions gratefully received.

When I bought this stuff I first of all bought an NAD CD player, but had to take it back as you could hear the track breaks in continuous music eg in opera, R Strauss tone poems etc., a problem that was discussed on the old forum - the shop swapped it for the Mairantz player.

[MrGongGong]

When you say you have "swapped the speakers over" do you mean you physically moved them from L>R and R>L OR swapped the cables?

If you swap the cables at the amp end and the noise now comes from the R speaker you can rule out a problem with the speaker.
The key thing I think is to isolate what piece of equipment is causing the noise then you can decide what to do.
I would start with disconnecting everything at the amp apart from the CD player and then see if you are still getting the noise.
Do you get the noise on headphones or just through the speakers?

Do you have a fridge on the same ring circuit and so on
There's no problem with having lots of cabling as long as you are careful with the mains cable routing (http://www.sonoloco.com/rev/stockhau...res/S14Gir.jpg)

[Bryn]

I had similar problems with an old Pioneer amp. In that case it was down to the left controlling pot. of the concentric gain control. Much as I liked the features of that amp, replacing the pot. was not an economic option, so I upgraded to an Arcam.

[Richard Tarleton]

Many thanks both.

I physically moved the speakers L>R and R>L. Was this a dumb thing to do?

I assume the fridge is on the same ring circuit (it's a small house - a cottage) - nothing is very far from anything else in this house but that has not changed though more appliances have been added over the years.

Haven't used my headphones for a while but will try them.

Yes it looks a bit like that photo in hi-fi corner but I'm careful with mains cabling.

I'll try disconnecting everything at the amp as you suggest.

One probably very stupid question, but I'll ask it anyway - the outlets/ports on the amp are labelled (from L to R) Tape 1 Monitor, Tape 2, Tuner, Aux, Video, CD, Disc...the satellite box (i.e. TV) is connected to Video, CD player to CD and record deck pre-amp to Disc. The headphones amp (X Cans) was connected to the Aux port, tho it's currently not connected.

Does it actually matter which appliance is connected to which port - are they interchangeable, or does each have different properties?

Thanks again

[MrGongGong]

Many thanks both.

I physically moved the speakers L>R and R>L. Was this a dumb thing to do?

No, but I would try swapping the cables at the amp first (to avoid walking about with speakers)

Haven't used my headphones for a while but will try them.

An easy test of whether it's the speakers or speaker outputs

One probably very stupid question, but I'll ask it anyway - the outlets/ports on the amp are labelled (from L to R) Tape 1 Monitor, Tape 2, Tuner, Aux, Video, CD, Disc...the satellite box (i.e. TV) is connected to Video, CD player to CD and record deck pre-amp to Disc. The headphones amp (X Cans) was connected to the Aux port, tho it's currently not connected.

Does it actually matter which appliance is connected to which port - are they interchangeable, or does each have different properties?

It doesn't usually make any difference apart from PHONO inputs (Disc on yours) which IS different
so AUX, CD, TUNER, TAPE, VIDEO etc are usually all the same and interchangeable

[Richard Tarleton]

Many thanks again

[richardfinegold]

Many thanks again

I'm guessing it's the amp.
The headphones test is a good place to start but your amp may have a separate headphone output stage and if that is working properly then the cans may
not sound bad. However, most amps, and more probably an amp of that vintage (7 years is actually quite long in the tooth these days for audio components, sadly), probably just re routes the regular output stage, so then the problem should be in the headphones as well.

[Richard Tarleton]

(7 years is actually quite long in the tooth these days for audio components, sadly)

Thanks richard ! Several replacements/upgrades this year - smart TV (and DVD player), computer....I just wish these things would spread themselves out a bit more

[kernelbogey]

Apologies this is slightly off-topic, but I have been thinking of asking advice.

After performing well for the eight years I've owned my (admittedly 17 year old) car, my car radio began to exhibit interference on FM. It seems to happen only when the signal is relatively weak so not continuous. This began after a recent service, and the garage (which I trust) could not think of anything they'd done which could have caused it: the only electrical work done was to change bulbs. I suggested perhaps the alternator as the speed of the ticking noise varies with engine speed, but the mechanic said he thought alternator unikely.

I don't know if a VW Golf c 1999 would have a discrete suppressor which might be replaced. I'd welcome any ideas. Many thanks.

[Dave2002]

Could we park the car topic for a little while .... maybe? Don't worry - we can come back to that.

Re the OP's questions, I'd always suggest cable swaps first, and preferably not moving the speakers unless absolutely necessary. Sometimes swaps aren't easy though, as the cables may be routed behind furniture, and difficult to switch over - and the connections at the rear of the amplifiers might also not be easily accessible making swaps at that end difficult.

Sometimes switching in a replacement cable might be easier - if there's a spare available.

The symptoms do sound a bit like a dry joint somewhere, either in the kit, or in a cable. Do the crackles happen when the music is loud? That might indicate microphony - a bad joint somewhere near a vibrating surface - or in a "flexible" cable.

One other comment - which I'm sure doesn't apply. There aren't any "odd" things on top of the speakers are there, such as piles of CD cases, or even lamps? Surely nobody round here does that ( ). Things like that can make unwanted noises due to cabinet vibration. Our OP hasn't left his guitar near the speakers by any chance? That might give rise to some extraneous sympathetic (unsympathetic?) noises.

I have had the faulty volume control pot, which Bryn has mentioned - a nuisance, and may be the death of an otherwise really good amplifier.

Sometimes after testing everything, and then putting all the wires back, the faults just disappear. That can happen.

[MrGongGong]

Apologies this is slightly off-topic, but I have been thinking of asking advice.

After performing well for the eight years I've owned my (admittedly 17 year old) car, my car radio began to exhibit interference on FM. It seems to happen only when the signal is relatively weak so not continuous. This began after a recent service, and the garage (which I trust) could not think of anything they'd done which could have caused it: the only electrical work done was to change bulbs. I suggested perhaps the alternator as the speed of the ticking noise varies with engine speed, but the mechanic said he thought alternator unikely.

I don't know if a VW Golf c 1999 would have a discrete suppressor which might be replaced. I'd welcome any ideas. Many thanks.

I used to have a similar thing which was caused by the rear screen heater
if it's changing with the engine speed it could be a cable routed near to one coming off the alternator ?

[Dave2002]

Apologies this is slightly off-topic, but I have been thinking of asking advice.

After performing well for the eight years I've owned my (admittedly 17 year old) car, my car radio began to exhibit interference on FM. It seems to happen only when the signal is relatively weak so not continuous. This began after a recent service, and the garage (which I trust) could not think of anything they'd done which could have caused it: the only electrical work done was to change bulbs. I suggested perhaps the alternator as the speed of the ticking noise varies with engine speed, but the mechanic said he thought alternator unikely.

I don't know if a VW Golf c 1999 would have a discrete suppressor which might be replaced. I'd welcome any ideas. Many thanks.

Is the car old enough to have a distributor? Probably not - but old cars did have them, and faulty condensers could make interference worse than usual.

[Dave2002]

I used to have a similar thing which was caused by the rear screen heater
if it's changing with the engine speed it could be a cable routed near to one coming off the alternator ?

This rings bells with me. I haven't noticed it recently - and indeed I can't now recall whether it's the newer car which had that symptom or the previous one. It was a nuisance as it was always worse first thing in the morning when I wanted to have the radio on, and also get the rear window clear. I think I reported it to the garage (must be the new car...???) but most are hopeless at checking that kind of thing.

[Richard Tarleton]

Could we park the car topic for a little while .... maybe? Don't worry - we can come back to that.

Re the OP's questions, I'd always suggest cable swaps first, and preferably not moving the speakers unless absolutely necessary. Sometimes swaps aren't easy though, as the cables may be routed behind furniture, and difficult to switch over - and the connections at the rear of the amplifiers might also not be easily accessible making swaps at that end difficult.

Sometimes switching in a replacement cable might be easier - if there's a spare available.

The symptoms do sound a bit like a dry joint somewhere, either in the kit, or in a cable. Do the crackles happen when the music is loud? That might indicate microphony - a bad joint somewhere near a vibrating surface - or in a "flexible" cable.

One other comment - which I'm sure doesn't apply. There aren't any "odd" things on top of the speakers are there, such as piles of CD cases, or even lamps? Surely nobody round here does that ( ). Things like that can make unwanted noises due to cabinet vibration. Our OP hasn't left his guitar near the speakers by any chance? That might give rise to some extraneous sympathetic (unsympathetic?) noises.

I have had the faulty volume control pot, which Bryn has mentioned - a nuisance, and may be the death of an otherwise really good amplifier.

Sometimes after testing everything, and then putting all the wires back, the faults just disappear. That can happen.

Thanks Dave. The guitar lives (in its case) near the other speaker ...there has been some sheet music carelessly left on the "offending" one (the speakers are on proper speaker stands on pointy feet) ....there is a new and larger sofa in the room....there is a new and slightly larger telly not far away (but the sound from the sat. box also comes through the amp and speakers without any problem, and the telly is off when the CD player is operational).....I thought briefly about posting a photo of the setup, but my living room might give purists with dedicated listening rooms apoplexy....

I'll continue to explore the variables. This morning, of course, it all behaved perfectly

[kernelbogey]

Thank you Dave and Mr GG - I'll follow up those ideas.
BW, kb