High “whistling” noise from my guitar/bass amplifiers in my home recording facility

[ecc83]

Yeah... just a philosophical remark on that. We all and more sink in an "ocean" of a Financial Dictatorship led by a bunch of Invisible Dictators and their mindless puppets the politicians.

As someone who was involved in the design and manufacturing process, albeit in a tiny way, I DO understand the need for engineers to keep costs in check but there is a different between that and making total crap. ....Atrib Alan Sugar (who else!) "There is very little in this world that someone cannot make a little cheaper and worse".

Dave.

 

[Bad Disciple]

Well, I only know a bit of the RF stop measures I used years ago. Way back in the day we had TV diss amps in flats and hotels and they were housed in stout diecast boxes with copper braid bonding straps on doors. I notice these day the companies use PLASTIC cabs and of course the kids kick the ***t out of them.

If you have one locally a "Ham Radio" club could be willing to help.

Dave.

Well, let me first hear what from that tech-man (hoping that he will know all its skills) and then I'll see. Dave, I'm prepared even to pay you if it comes that you do some extended help for me! No effort must remain uncompensated! That's a law of nature in the whole Universe, discovered and offered to us by the greatest thinkers like Herakleitos, Pythagoras, Newton, Tesla, Einstein, Hawking, to name but few... ;-)
And not to forget that I still have to ask you a question about my Marshall head problem. But one thing at a time.

 

[Bad Disciple]

As someone who was involved in the design and manufacturing process, albeit in a tiny way, I DO understand the need for engineers to keep costs in check but there is a different between that and making total crap. ....Atrib Alan Sugar (who else!) "There is very little in this world that someone cannot make a little cheaper and worse".

Dave.

GREAT ! And so true! Hail the Sugar guy !

 

[ecc83]

B.D. Fitted an extra filter stage to the box and posted it back to you today. I have to say, if THIS does not fix the problem I am out of ideas!

Your best bet is with a local technician.

Dave.

 

[Bad Disciple]

B.D. Fitted an extra filter stage to the box and posted it back to you today. I have to say, if THIS does not fix the problem I am out of ideas!

Your best bet is with a local technician.

Dave.

Awaiting with great impatience! Even if it doesn't fix the problem, I'll be very thankful for your help, Dave. I already asked from the Federal Organism of Posts and TV-distribution to send a qualified technician and they said he will come, but... things seem to be really slow as after 10 days no one has even called to get in touch with me.

By the way, I had such a thought: If I turn lower the tone control knob of my guitar, the "whistle" gets diminished and if I turn even lower, it disappears! So that's FILTERING it, right? But... of course then without the high freq my sound becomes too dull and less clear, so not what I want. That logically means that your idea for more filtering must work. I only am curious to see if it will alter my sound the same way...

 

[PSR]

Resolving Interference Problems || Audio-Technica US

Gives some quite detailed ideas on the causes of this sort of thing.

Have you tried taking your amps to a neighbour's house and trying them there?

 

[Bad Disciple]

Resolving Interference Problems || Audio-Technica US

Gives some quite detailed ideas on the causes of this sort of thing.

Have you tried taking your amps to a neighbour's house and trying them there?

Yes, I've tried in two friend's houses in areas away from mine and it does NOT have that "whistling" noise. It's only i my neighborhood. And it's relatively recent, I didn't have that before.

That site gives really good informations but it's about a wireless system which is not my case. I get that noise just when plugging a cable in an amp. So far, after all tests and efforts made (described in my previous postings), nothing seems to fix the problem. I'm still badly blocked from recording work.

Thanks for your feedback anyway.

BD

 

[Bad Disciple]

B.D. Fitted an extra filter stage to the box and posted it back to you today. I have to say, if THIS does not fix the problem I am out of ideas!

Your best bet is with a local technician.

Dave.

Hi Dave, today I got the pack. As disappointing it could sound to you, it's twice and more frustrating for me, it doesn't make ANY difference. The "whistling" is always here, not even diminished!!! I wonder WHAT on earth could that ugly thing be??!! Again, I'm so thankful to you for your help but unfortunately it doesn't fix the godforbidden thing. I'm just ready to yell !..........

 

[PSR]

Yes, I've tried in two friend's houses in areas away from mine and it does NOT have that "whistling" noise. It's only i my neighborhood. And it's relatively recent, I didn't have that before.

OK. I thought it might be one of the amps itself oscillating. I have come across this when fixing them sometimes (usually at a much higher frequency though. Have you tried some others? - may be less susceptible.

One other thing you might try, and you may need some help to do this, is to get a coil (you can use a coil from a relay) and a capacitor that resonate at this frequecy, attach them by a long screened cable to a mic input and then move it about the place to try and find where the signal is coming from.

I think someone already suggested trying to get help from a local radio ham - I would do this if I had this problem - I used to be one but they often have people who have years of experiece with electronics. A electrician is in no way able to help - you need a technician or an electrical / electronics engineer.

 

[Bad Disciple]

Hi all fellows who responded in good will. After 1 month of efforts, here a recap:

1. Since some time I've got a "whistling" noise when I plug cables with or without guitar(s) in any of my FOUR amps (three tube and one modeling Line6). Frequency of the noise +/-2,5 kH. I've never had that problem before.
2. To exclude the possibility of interference from a unit, from lights LED, or else, I shut down the power in my house (switching off all the breakers in the service panel) leaving only one wall socket, so absolutely everything disconnected - but the "whistling" is still present !
3. I tested by bringing one amp and a guitar to neighbors in the one and the other end of my neighborhood and the noise is present everywhere !
4. One of the neighbors (a just retired electrician) got the power supply in his place through a transformer (as a filter) and a stabiliser - still the noise was present.
5. That neighbor measured the ground and voltage in my house and they're in good limits: 10 Ohm, 238V. (My house is just 15 years old.)
6. I also tested by going to two other friends' places in different areas further away from me and... NO NOISE over there !!
7. That all suggests that my problem is NOT related to power lines or to grounding, but to an electro-magnetic emission coming from somewhere.
8. I tried passing through a DI box - the "whistling" still present !
9. I borrowed from a friend a wireless system (transmitter on the guitar and receiver on the amp) - the "whistling" still present !
10. I made an XLR mike cable "one-end-bond-shield", so the shield connected to ground from the one end only like sort of a "Faraday cage" for the cable - the "whistling" still present !
11. I was advised and assisted to make a filter with inductions and capacitors corresponding to the frequency of the noise (+/-2.5 kH). That filter was made but... gave no solution - the "whistling" noise IS always present !
12. An interesting detail, when having a guitar plugged, if I turn the Tone Control knob lower, the noise goes weaker till disappearing. So the Tone Control works like filtering it. But then my sound goes too dull which is not what I want. And that's not an acceptable situation.

I'm brought to extreme frustration, as my work is totally blocked. I guess I'll have to bring a qualified electronic tech person to possibly find a solution. Hopefully it won't be extremely expensive...

 

[Chili]

Man, I feel for ya. It sucks to have a problem where you can't isolate the cause. It seems there is some kind of radio interference. I wonder if there is a radio transmitter close by... maybe a new amateur radio operator or a new broadcasting tower close by.

 

[miroslav]

4. I also tested by going to two other friends' places in areas further away (in two opposite directions) and... NO NOISE there !!
5. That all suggested that my problem is NOT related to power lines or a grounding, but to an electro-magnetic emission coming from somewhere.

Not necessarily...it could very well be the power in YOUR area....transformer issues...some device the power company hooked up for monitoring purposes...someone in your area running some sort of electrical device that is dirtying up all the power in the area...etc.

I've called my power company when I've seen power issues...and they told me there were some devices they had installed for monitoring...and then they removed/turned off the devices...and all back to normal.

So I would most definitive start with the power company for your area....and ask them to investigate. You should be getting clean power.
Of course...if there is some sort of high power, radio transmission tower, industrial machinery in you area...then it may very well be the cause.

 

[ecc83]

Hi Zac. Desperate idea! You could build a "sniffer". You will need 4 Germanium point contact diodes, OA90/91 and a moving coil meter, preff' one of 100 micro amps FSD sensitivity.

Wire diodes as a bridge and connect meter across + and - wire a connector, jack, RCA to the "AC" side. A short "aerial" should show a reading and you might have to rig a pot across the meter to shunt it as you approach the source of the RFI (if indeed you can).

OR...The aforementioned radio ham (or CB Rubber Ducker) might have one or a "scanner"?

Dave.

 

[Bad Disciple]

Not necessarily...it could very well be the power in YOUR area....transformer issues...some device the power company hooked up for monitoring purposes...someone in your area running some sort of electrical device that is dirtying up all the power in the area...etc.

I've called my power company when I've seen power issues...and they told me there were some devices they had installed for monitoring...and then they removed/turned off the devices...and all back to normal.

So I would most definitive start with the power company for your area....and ask them to investigate. You should be getting clean power.
Of course...if there is some sort of high power, radio transmission tower, industrial machinery in you area...then it may very well be the cause.

Yes, that all makes sense by itself and I may also call them. But... to me it makes less logic because the noise appears ONLY when I plug a cable into an amp. An amp without plugging a cable is completely silent. So... it seems to me that the cable (and the guitar) works like an antenna that captures the crap thing.

 

[Chili]

So... it seems to me that the cable (and the guitar) works like an antenna that captures the crap thing.

I think that's what happening. Sanity check, have you tried a different cable? Checked the connectors? Does it do it with the cable plugged into the amp, but not plugged into the guitar? (You might have said so earlier)

 

[miroslav]

Yes, that all makes sense by itself and I may also call them. But... to me it makes less logic because the noise appears ONLY when I plug a cable into an amp. An amp without plugging a cable is completely silent. So... it seems to me that the cable (and the guitar) works like an antenna that captures the crap thing.

OK...but if the problem was centered around the cable/amp....it would follow the cable amp.
You said at some other locations the problem was not there...so, it may very well be the cable/amp that identifies it, bit it's something else causing it in YOUR general area.
Unless there are transmitting towers nearby or some kind of industry...the only thing it could be then is your power, or some device in the area attached to the same power your using, IMO.

Not sure how it is with your power company...but I've had them come out to my place on more than one occasion, and they check out the power, the transformers with their equipment...and once they left a device hooked up for a couple of days to monitor things so they can check if it was something intermittent.
What I'm saying is...calling them to complain of power noise/issues is usually not a band thing...most times they are willing to send someone out to check the situation.

Hey...it could be one of your neighbors with some sort of device that is dirtying up the lines for everyone around...but only your are noticing it because of the cable/amp thing. IOW...basic home power users would not notice things like that when using your typical home appliances.

 

[Bad Disciple]

I think that's what happening. Sanity check, have you tried a different cable? Checked the connectors? Does it do it with the cable plugged into the amp, but not plugged into the guitar? (You might have said so earlier)

Oh yes, I've tried different good quality cables that I've got. And yes, even with only a cable plugged without a guitar, even the shortest one (12cm).

But another detail, when having a guitar plugged, if I turn the Tone Control knob lower, the noise goes weaker till disappearing. So the Tone Control works like filtering it. But then my sound goes dull which is not what I need.

 

[Bad Disciple]

OK...but if the problem was centered around the cable/amp....it would follow the cable amp.
You said at some other locations the problem was not there...so, it may very well be the cable/amp that identifies it, bit it's something else causing it in YOUR general area.
Unless there are transmitting towers nearby or some kind of industry...the only thing it could be then is your power, or some device in the area attached to the same power your using, IMO.

Not sure how it is with your power company...but I've had them come out to my place on more than one occasion, and they check out the power, the transformers with their equipment...and once they left a device hooked up for a couple of days to monitor things so they can check if it was something intermittent.
What I'm saying is...calling them to complain of power noise/issues is usually not a band thing...most times they are willing to send someone out to check the situation.

Hey...it could be one of your neighbors with some sort of device that is dirtying up the lines for everyone around...but only your are noticing it because of the cable/amp thing. IOW...basic home power users would not notice things like that when using your typical home appliances.

Well, I have no reason not to try with the power company and I'll do that too. But one of the neighbors where I tested got the power supply through a transformer (which should filter the possible power "pollution") and a stabiliser, but still the noise was present.

So all indications lean towards suspecting an El-Magn emission.

Also another detail, when having a guitar plugged, if I turn the Tone Control knob lower, the noise goes weaker till disappearing. So the Tone Control works like filtering it. But then my sound goes dull which is not what I want.

 

[Bad Disciple]

.... It seems there is some kind of radio interference. I wonder if there is a radio transmitter close by... maybe a new amateur radio operator or a new broadcasting tower close by.

As of my knowledge there is not one but... Man, that's frightening, cause IF it's the case, how will I get rid of it ??...

 

[miroslav]

So all indications lean towards suspecting an El-Magn emission.

Also another detail, when having a guitar plugged, if I turn the Tone Control knob lower, the noise goes weaker till disappearing. So the Tone Control works like filtering it. But then my sound goes dull which is not what I want.

OK...but where/what would causing the EM interference only in your neighborhood...?
Again...what is near/around you?
If it's pure residential for a couple of miles around you...then...what could be causing that?
Where do you live...what's the environment like around you?

The tone controls are just glorified volume knobs for your H/M/B...so yeah, turn them down, and you are simply turning the noise down. It's not really getting filtered out.