[jwbrent]

Hi there,
I've been trying to solve an issue that's come up with my Bellari VP130. It's making this high pitched squeal/static that seems to vary and cut in and out. I've tried different tubes, power supplies, and outlets and even using it with nothing plugged in and the problem is consistent. I initially thought it was because of the infamous hum with the unit but after turning on my Vox AC4 it had the same issue with nothing plugged in.

I live in San Francisco, and maybe .5 miles from the Bernal Hill telecom tower and all the rooms here face the street with huge windows. We're also across the street from a hospital and some pretty big powerlines.

Does anyone know if there's a way to stop this squeal/static that seems to impact all tube devices?

Thanks!

Do you have dimmer switches in your home? If so, they are notorious for being an rfi source. To confirm, turn off all your dimmer switches to see if the noise on your amp lessens. Good luck!

 

[Nada]

Since no other speakers in the house have this issue I am inclined to think SF is just not suitable for tubes.

Your statement " I am inclined to think SF is just not suitable for tubes." is extremely unlikely.

Is your tubed phono/headamp faulty?

Is the noise there with both ground and phono disconnected ie only power and headphone cable connected, the input RCA shorted (NOT the outputs), different tubes, tube sockets cleaned, different PS , PS plugged into a filtering power board with nothing else and the whole amp wrapped in plastic except the tube, then wrapped in twenty layers of aluminum foil and tested for just seconds before it overheats?

If so its either really bad noise on your mains power or much more likely a faulty amp.

Next test - take the amp and headphones to work/friends/on a trip and listen. Same noise with no amp inputs in multiple places = return the amp.

 

[TandrewTan]

Do you have dimmer switches in your home? If so, they are notorious for being an rfi source. To confirm, turn of all your dimmer switches to see if the noise on your amp lessens. Good luck!

This is good to know. The switches have been off and setting them to 0 has not fixed it, but they are all wired without a ground which I think speaks to how the power was wired in this building.

Your statement " I am inclined to think SF is just not suitable for tubes." is extremely unlikely.

Is your tubed phono/headamp faulty?

Is the noise there with both ground and phono disconnected ie only power and headphone cable connected, the input RCA shorted (NOT the outputs), different tubes, tube sockets cleaned, different PS , PS plugged into a filtering power board with nothing else and the whole amp wrapped in plastic except the tube, then wrapped in twenty layers of aluminum foil and tested for just seconds before it overheats?

If so its either really bad noise on your mains power or much more likely a faulty amp.

Next test - take the amp and headphones to work/friends/on a trip and listen. Same noise with no amp inputs in multiple places = return the amp.

PS dont get paranoid about distant RFI unless you have a ham radio dude right next door or you work for the CIA and the KGB want to microwave your brain. Remember the inverse square law and how far you are from radio towers. Power lines carrying 50Hz would make a hum so not your problem. Hospitals are very low RFI/EMI for obvious reasons. Might be time to ease back on the bud bro?

Additionally, the main reason I suspect RFI might have something to do with the issue is when I move the amp toward the window a radio station does come through and the squealing gets noticeably louder when nothing else is plugged in (just the headphones and power). I'll take a look into taking it to work to test there or getting a filtering power board.

The main reason the amp being faulty seems unlikely to me is because the exact same noise and issue happen on my guitar tube amp so it does seem related to the environment in some way. Additionally, it's only in the two devices I have that use tubes. Powered speakers, TVs, headphones connected to laptops and desktops all do not generate the issue.

 

[Nada]

Additionally, the main reason I suspect RFI might have something to do with the issue is when I move the amp toward the window a radio station does come through and the squealing gets noticeably louder when nothing else is plugged in (just the headphones and power)

Oh sorry - thats really important. I must have missed it. I edited my last post.

So you can hear the radio over the amp with no inputs? Thats outrageous!

Can you try this;
1. go to the window and listen to the radio station like before
2. Wrap aluminum foil around the headphone cable
3. If theres still noise short the RCA inputs.
4. Stlll noise then wrap the amp in twenty layers of foil as above. Radio and noise gone now?

 

[msing539]

2. Wrap aluminum foil around the headphone cable

4. Stlll noise then wrap the amp in twenty layers of foil as above. Radio and noise gone now?

Nice try, Mr. Reynolds. JK

 

[TandrewTan]

Just wanted to give an update that I tried wrapping the headphone wire in foil to a slight difference and was able to get a layer of aluminum on the unit which did eliminate the static squeal but made the radio come in clearer.

To be honest, I think this hobby is over for me after this. It's been comparatively so stressful trying to get a remotely good listening experience when every other casual listening experience has 0 of these problems. Thank you all for your help and time.

 

[Alcophone]

Just wanted to give an update that I tried wrapping the headphone wire in foil to a slight difference and was able to get a layer of aluminum on the unit which did eliminate the static squeal but made the radio come in clearer.

To be honest, I think this hobby is over for me after this. It's been comparatively so stressful trying to get a remotely good listening experience when every other casual listening experience has 0 of these problems. Thank you all for your help and time.

I thought (may have misread) that you had only problems with tube amps, there are wonderful solid state amps out there.

 

[TandrewTan]

I thought (may have misread) that you had only problems with tube amps, there are wonderful solid state amps out there.

That is true and thanks for the reminder. I'll get some time away from this and reconsider.

 

[bagwell359]

How about throw together a home made faraday cage? Even a single 18" square sheet of steel - under, over, sides, back?

Using shielded cable is however likely your first move.