[TandrewTan]

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!

 

[msing539]

Sounds like RFI... and it makes it with no source plugged in, power only?

 

[TandrewTan]

Sounds like RFI... and it makes it with no source plugged in, power only?

Yep. The sound doesn't change when I do plug in the source either. How do I manage RFI? Should I just buy ferrite beads for the power cable or is it just going to be a constant with tubes?

 

[Nada]

First you need to diagnose the issue if you want a cure.

Try a SS amp in the position as the tube amp with the same cables. If the same noise continues its not the tubes. Try well shielded cables with a dedicated ground wire and strip. If that fails then power needs filtering eg with a balanced trannie.

If noise goes with a SS amp shield the tubes eg- make some grounded metal tube chimneys. Any metal will do. Al foil for a test would take a minute. Copper pipe looks nice but will cost. Mild steel pipe will be cheap and thick. Fine copper mesh would be more elegant.

 

[msing539]

It's a switched mode power supply on that, right?

You can try a power conditioner from the wall, but if the RFI is being injected after, that probably won't help much. If I were you, I'd try a linear power supply.

But as @Nada said, you need to figure out if it's the PS or the tubes directly.

 

[Nada]

It's a switched mode power supply on that, right?

Dam. That cant be good. But the the Vox guitar amp is noisy too. Better pull all the SMPS out.

 

[TandrewTan]

Dam. That cant be good. But the the Vox guitar amp is noisy too. Better pull all the SMPS out.

I'm still pretty ignorant to all this so apologies if this response doesn't make sense but I have tried both the packaged power adapter and the aftermarket Enercell and the noise doesn't change. I also did try wrapping the unit in aluminum foil to no avail as well. But yeah the Vox Amp makes it to a lesser, maybe liveable extent in contrast (when I try to record the sound off the vox it mostly picks up the hum). Since no other speakers in the house have this issue I am inclined to think SF is just not suitable for tubes.

 

[Alcophone]

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?

First question is: do you use PowerLAN? If so, try whether getting rid of that helps.

Other than that, I'd take care of the fundamentals first: Is your electrical wiring up to code? You can get a cheap receptacle tester to look for various possible shenanigans.



Also wondering what the voltage is like where you are, I've had < 110V at times and close to 130V at others, lately it's been quite stabe at 119-120V. A Kill-A-Watt is a neat device to test power consumption and also shows the voltage, but for longer term observation (nerdy), DROK makes these neat voltage displays.



I'm not an expert, but I doubt that too low/high voltage would manifest in the way you describe, though.

I'd be very curious if a power conditioner makes a difference, but that can be expensive. There are some power banks with AC outlets which could be a nice way to test that (though I suppose there's no grounding in that case). They can also come in handy when there's a power outage, so not a bad investment in general.

Something like a Trifield TF2 might also be able to confirm RFI.

 

[Alcophone]

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

Outer Sunset and SoMa are fine in my experience.

 

[TandrewTan]

hahaha, my spouse and I have wanted to be in the Outer Sunset for quite awhile, but now a baby is on the way so we aren't moving soon, but this will be definitely added to the reasons why that should be where we move next.

 

[dougms3]

Unfortunately, apartments tend to be really bad for noise. All kinds of stray emi, wifi, bluetooth, cell phone signals wandering all over the place. Then theres the shared power also contributing to that as well.

You'd have to determine if thats from line level or power. What does your audio chain look like?

 

[TandrewTan]

Unfortunately, apartments tend to be really bad for noise. All kinds of stray emi, wifi, bluetooth, cell phone signals wandering all over the place. Then theres the shared power also contributing to that as well.

You'd have to determine if thats from line level or power. What does your audio chain look like?

I think it is likely coming from power/environmental since the issue is the exact same when everything is unplugged.

My set up is fairly simple it's just: Pro-Ject Debut Carbon -> Bellari VP130 (with Electro Harmonix 7025) -> Grado SR225e or Etymotic ER3SE.

The issue is the same when it's just the Bellari VP130 -> the Grado or Etymotic or a powered set of Audioengine A2s and additionally, I have tried moving the Bellari around since it's hand holdable and noticed the closer I get to the window the more an actual radio station comes through.

Also, I should note the same issue comes up with my tube Vox AC4 completely unplugged, although it's to a lesser extent.

 

[dougms3]

I think it is likely coming from power/environmental since the issue is the exact same when everything is unplugged.

My set up is fairly simple it's just: Pro-Ject Debut Carbon -> Bellari VP130 (with Electro Harmonix 7025) -> Grado SR225e or Etymotic ER3SE.

The issue is the same when it's just the Bellari VP130 -> the Grado or Etymotic or a powered set of Audioengine A2s and additionally, I have tried moving the Bellari around since it's hand holdable and noticed the closer I get to the window the more an actual radio station comes through.

Also, I should note the same issue comes up with my tube Vox AC4 completely unplugged, although it's to a lesser extent.

Is the source a PC or laptop?

Lol if you're picking radio stations, I'm going to guess you are in a skyscraper.

Its difficult to say which component is picking up the noise. It could be the amp itself, could be the power, could be line level. All are possibilities. Probably best to try shielded cables first, since you can't really do much if its the amp itself picking up the noise through the air.

 

[TandrewTan]

Neither

Is the source a PC or laptop?

Lol if you're picking radio stations, I'm going to guess you are in a skyscraper.

Its difficult to say which component is picking up the noise. It could be the amp itself, could be the power, could be line level. All are possibilities. Probably best to try shielded cables first, since you can't really do much if its the amp itself picking up the noise through the air.

Neither actually! It's a turntable.

And surprisingly I am in a pretty small, 4 unit building, but we're sandwiched between two radio towers with line of sight (Sutro and Bernal) so I think they just transmit at a pretty far distance and I'm assuming the hospital is a contributor as well.

And that all makes sense in terms of shielded cables since it's the most affordable option and this is a rental.

 

[dougms3]

Neither

Neither actually! It's a turntable.

And surprisingly I am in a pretty small, 4 unit building, but we're sandwiched between two radio towers with line of sight (Sutro and Bernal) so I think they just transmit at a pretty far distance and I'm assuming the hospital is a contributor as well.

And that all makes sense in terms of shielded cables since it's the most affordable option and this is a rental.

Yeah thats a bad situation. Well at least you know its not the source

Its probably both dirty power and stray EMI.

Try shielded cables one at a time and see if it mitigates any of the noise. A power conditioner is definitely going to help but they do get expensive.