Hum from a toroidal transformer

[Steven Holt]

I had the electrical system inspected a year ago, that's how I know it's not a grounding problem either.

That's good, but that's not what I'm talking about. I'm talking about a ground loop in the unit itself (and I would take a hard look at that chassis). Tell me, do you feel a slight 'sting' when you touch the unit when it's on?

 

[mhardy6647]

Do "we" know if this IFI "DC Blocker" is in fact a capable piece of equipment? I mean, I don't know...

EDIT: PS The simplest solution (still) appears to be a switchmode P/S "upgrade"!

 

[pjug]

Do "we" know if this IFI "DC Blocker" is in fact a capable piece of equipment? I mean, I don't know...

EDIT: PS The simplest solution (still) appears to be a switchmode P/S "upgrade"!

I assume you mean simple to change the amp + power supply component, not just the power supply!

 

[mhardy6647]

I assume you mean simple to change the amp + power supply component, not just the power supply!

I actually, honestly don't know -- something was said early on as to why a linear P/S...

 

[pjug]

I actually, honestly don't know -- something was said early on as to why a linear P/S...

I understand the amp is returnable so the easy thing is to get something else! Worth taking the hit returning to China and maybe there is a lesson somewhere in there. Don't mean to sound condescending -- I have learned my own lesson about buying gear from companies where returns are problematic.

 

[JSmith]

I actually, honestly don't know

Look, all I know is this talk of toroidal transformers is making me hungry...

If I take a leak near a high-voltage livestock fence, I’m not sure how much voltage it has, but I always make sure to keep a safe distance no matter what.

electric fences

Have you both seen the Mythbusters episode where this concept was tested on electric fences and even a HV rail line? Outcome was pretty much nothing in the end, as the stream of fluid wasn't constant enough, which could be seen when viewed with high speed cameras.

Mythbusters

n0tWorthy writes "The Mythbusters tested the myth that you could be electrocuted by peeing on the 3rd rail. The myth was 'busted' as the stream would be broken up due to distance and there wouldn't be a continuous path for the electrical current to follow. This seems to be refuted by a Monsanto...

science.slashdot.org

JSmith

 

[mhardy6647]

I love donuts.
But I digress.

 

[Angel II]

I never had a hum problem in my home until I bought an Atoll amp. Hum audible at the listening position ... My Hifi system has a dedicated mains supply so switched off everything else in the fuse box, amplifier kept on humming ... Installed a DC blocker, problem gone (https://audiosciencereview.com/foru...-to-help-stop-transformer-hum.948/post-874360). Replaced the Atoll with a Cambridge Audio amp (again with a lineair power supply) a year later, no hum problem without DC blocker (unless you put your ear against the speaker).

If the hum is audible from the listening position it is definitely a problem. My Atoll in80 signature I hear a slight hum when I put my ear close to the amplifier at 200 mm (absolutely negligible). I would say that it is physiological to hear a slight hum, but not further than 1 meter away.

 

[Maciekw]

PROBLEM SOLVED

Investigation so far has pointed to a faulty transformer as the reason for the hum.
To avoid playing with customs, instead of sending the amplifier back to Hong Kong for repair, I decided to replace the transformer myself.

Cymax sent me, at its expense, a new tested transformer. And after receiving it, I proceeded to replace it. It took me about an hour and a half, as I was forced to slightly modify the transformer shielding box. The new one was a tad bigger and did not fit on one side in the box.
As a precaution, I put pieces of damping mat on the shielding box.

And after screwing the case together, I turned on the amplifier with the new transformer.

It's SUPER! Zero hum from the transformer. ABSLOLUTE SILENCE!

And the amplifier itself is worth buying.

I hope that from my case CYMAX will start testing not only the electronics, but also, in the case of analog power supplies, whether the transformer does not hum.

On the other hand, I cannot recommend UPS as an international carrier. They are very greedy for your money. For the pickup of the transformer, I paid UPS its equivalent.

 

[Stereoed]

PROBLEM SOLVED

Investigation so far has pointed to a faulty transformer as the reason for the hum.
To avoid playing with customs, instead of sending the amplifier back to Hong Kong for repair, I decided to replace the transformer myself.

Cymax sent me, at its expense, a new tested transformer. And after receiving it, I proceeded to replace it. It took me about an hour and a half, as I was forced to slightly modify the transformer shielding box. The new one was a tad bigger and did not fit on one side in the box.
As a precaution, I put pieces of damping mat on the shielding box.

And after screwing the case together, I turned on the amplifier with the new transformer.

It's SUPER! Zero hum from the transformer. ABSLOLUTE SILENCE!

And the amplifier itself is worth buying.

I hope that from my case CYMAX will start testing not only the electronics, but also, in the case of analog power supplies, whether the transformer does not hum.

On the other hand, I cannot recommend UPS as an international carrier. They are very greedy for your money. For the pickup of the transformer, I paid UPS its equivalent.

I'm glad your hum problem is solved. What I noticed, though, is that the photos of the amplifier's interior don't show any measures to secure the cables. And the speaker terminals are soldered. Is that correct? I think these soldered terminals should have been insulated. I also hope they could have been crimped better, because a soldered joint unnecessarily increases the resistance. When did you buy the amplifier? Are you from Europe? Then, of course, a CE certificate would also be necessary. I don't see any CE marking.

Regards
Ed

 

[Maciekw]

I'm glad your hum problem is solved. What I noticed, though, is that the photos of the amplifier's interior don't show any measures to secure the cables. And the speaker terminals are soldered. Is that correct? I think these soldered terminals should have been insulated. I also hope they could have been crimped better, because a soldered joint unnecessarily increases the resistance. When did you buy the amplifier? Are you from Europe? Then, of course, a CE certificate would also be necessary. I don't see any CE marking.

Regards
Ed

I am from Europe. I purchased the amplifier directly from the manufacturer's website. The speaker cable connections to the terminals are soldered. I did not pay attention to the CE marking confirming (manufacturer's declaration) compliance with the required product standards. I don't really care about that in such simple devices as amplifiers. In terms of electric shock safety, everything is OK. Overall, I am very satisfied with the amplifier, especially since it offers exceptional value for money. And I have a lot to compare it to, given my long experience (over 40 years) in using audio equipment.
Best regards, Maciej