Dirty power filter ?

[FerK]

I live in a 120 year old house with very old wiring. All sockets are apparently properly grounded (I say apparently because over here in Switzerland regulations are quite strict, and landlords to abide by them). My Roland 120W cube combo crackles a bit when plugged to certain sockets (unfortunately all the ones in my music room). It only started happening about a week ago (when I installed some new PLC conductors to carry my internet connection through the electrical cables, as WiFi doesn't really reach into the bedrooms upstairs). Removing that is not a good option.

On the other hand my tiny 15W amp (one that came for free with my latest bass) makes no noise at all when connected to the same sockets. Perhaps it's because it uses a transformer.

Either way, I wonder if any of the more experienced people around here can think of anything to filter my power to remove this annoying crackling noise. I was thinking in the lines of a power-conditioning power strip, some type of DI box, etc.

Ideas ?

[beans-on-toast]

There has been a lot of controversy over the noise that is emitted by power line communication systems. Google "ARRL BPL" to see what is going on in the US.

By all means try a power line conditioner and see if it helps. I would also contact your service provider's technical department and see if they have any suggestions as to how you might filter the power line on your amp. They may recommend, or be able to provide you with, a filter that clamps onto your power cord. It is possible that the noise is high frequency and not something that a standard power line conditioner can help with.

[1958Bassman]

Originally Posted by FerK

I live in a 120 year old house with very old wiring. All sockets are apparently properly grounded (I say apparently because over here in Switzerland regulations are quite strict, and landlords to abide by them). My Roland 120W cube combo crackles a bit when plugged to certain sockets (unfortunately all the ones in my music room). It only started happening about a week ago (when I installed some new PLC conductors to carry my internet connection through the electrical cables, as WiFi doesn't really reach into the bedrooms upstairs). Removing that is not a good option.

On the other hand my tiny 15W amp (one that came for free with my latest bass) makes no noise at all when connected to the same sockets. Perhaps it's because it uses a transformer.

Either way, I wonder if any of the more experienced people around here can think of anything to filter my power to remove this annoying crackling noise. I was thinking in the lines of a power-conditioning power strip, some type of DI box, etc.

Ideas ?

Does the Roland use a wall wart for power? If it does, you could build a filter circuit for the DC voltage and house it in a box that would be used at home, but if you don't have this problem when you use the amp elsewhere, you could just leave it. The wall wart would plug into the box and the box would have a wire with the same kind of plug. If you have an electronics store nearby (I know Radio Shack is world-wide, but I don't know if they have a store close to you), they should have the parts.

Otherwise, yes, a filtered power strip or smaller module should be able to help. You may want to contact the manufacturer of the PLC conductors for more info- I suspect they have already dealt with this kind of problem.

[FerK]

The 120W Roland does not use a transformer. It runs on 220v.

But you are right, I could leave it. It is a bit annoying though. I'm playing something "delicate"...call it "Portrait of Tracy". And all of a sudden there's this crcrkggrrkkr. Just a bit annoying.

I will go to my local electronics store and talk to the attendant and see if they have a filtered strip. What do I have to lose ?

Regarding the PLC manufacturer...they do state quite clearly in their instructions: DO NOT connect to a power strip, but rather directly to the wall. Many power strips filter our signal.

[Bob Lee (QSC)]

I think you should find out where the crackling is coming from first.

[seamonkey]

I highly doubt powerline noise is getting through the Roland power supply.

It's probably your bass or cables picking up the noise. Try different cables, move your bass 360 and see if it's lounder in certain positions.

I use powerline broadband myself and don't have any problems with any audio gear in the whole house.

[1958Bassman]

Originally Posted by FerK

The 120W Roland does not use a transformer. It runs on 220v.

But you are right, I could leave it. It is a bit annoying though. I'm playing something "delicate"...call it "Portrait of Tracy". And all of a sudden there's this crcrkggrrkkr. Just a bit annoying.

I will go to my local electronics store and talk to the attendant and see if they have a filtered strip. What do I have to lose ?

Regarding the PLC manufacturer...they do state quite clearly in their instructions: DO NOT connect to a power strip, but rather directly to the wall. Many power strips filter our signal.

I meant that you could plug the amp into a power filter, not the PLC. Have you unplugged the PLC to see if that definitely eliminates the noise? You may be able to check this by unplugging the cable from the router, at the PLC- it may help but won't be a solution.

[bmc]

Hey Ferk where are you? I'm outside of Geneva.

[FerK]

Originally Posted by seamonkey

It's probably your bass or cables picking up the noise. Try different cables, move your bass 360 and see if it's lounder in certain positions.

I tried with several instruments (2 basses and a guitar) and 4 or 5 different cables (after the second I was certain already), and it made no difference. I also tried the amp at the shop 2 min. away from my place where I bought it.

The strange thing is it doesn't affect the amp in all sockets, only in some.

Originally Posted by 1958Bassman

I meant that you could plug the amp into a power filter, not the PLC.

I know, but what I meant is that the PLC Operating Manual states that the signal CAN be filtered out by some strips. That gives me hopes I can find the right power strip. I sent a message to the PLC manufacturer...let's see what they say about the right frequency.

Originally Posted by bmc

Hey Ferk where are you? I'm outside of Geneva.

Buchs, SG. One could really say the exact opposite side of the country.

[seamonkey]

Originally Posted by FerK

I tried with several instruments (2 basses and a guitar) and 4 or 5 different cables (after the second I was certain already), and it made no difference. I also tried the amp at the shop 2 min. away from my place where I bought it.

The strange thing is it doesn't affect the amp in all sockets, only in some.

Wonder ...
Unplug the broadband powerline and see if it goes away.
Houses here are wired with 240v in, and split at the breaker box. Half the house gets fed from 120v on one side, the other half from the other 120v. In order for me to use the powerline broadband on the whole house, I had to install a cap in the breaker box so high frequency would bridge from one side to the other. I suspect in your case, the there are also two separate power feeds and some sockets are on one side, others on the other side.

[mjac28]

I would think the easiest way would be to get a better router for your internet? my house was built in 1887 and I understand your issues I use a Furman power conditioner and it works for me.

[FerK]

Actually the router wouldn't help. It's not just how far the router signal goes, but also how far the computer can reply. If the computer receives a super strong signal from the router, but the router can hear it back...then I might as well stick to my current router. I am afraid I already pursued that idea in the first place.