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I use a Macbook Pro (2016 with 1TB SSD) that is used exclusively with JRiver 23 and Tidal which goes via data-only USB to a PS Audio PWD II. The PWD is isolated with dedicated 15A line and a 15A balanced power transformer and the Macbook PS is connected to a separate AC line that also powers a reading lamp in my music room. The Macbook Pro and lamp are protected and share a TrippLitte surge protector.

I recently put a GE LED bulb into a lamp and noticed that I would get some flickering. It occurred a few times per minute. Cleaned contacts, no change. A second, identical GE LED bulb presented with the same random appearing flickers. Very annoying and made me start thinking about having to check wiring and circuit breakers etc.....

Yesterday, my wife mentioned that with my audio system off, there was no flickering. I checked this and it is true. Now my amps are on a separate dedicated 20A line and all my sources are on a dedicated 15A line. I found that the laptop power supply was causing the flicker in the LED bulb. If I paused or started music, the bulb would start it's random flicker. I eventually ran the lamp from the same wall socket using a separate extension cord and the Macbook runs off the same outlet but through the now dedicated Tripplight. No LED bulb flicker.

I don't think this is a current issue? The Tripplight should handle 15A 1800w so a lamp and a laptop should not be an issue?

SoundMods wrote:On with the witch hunt! Yours is one of those problems like chasing a hum -- it can drive you to drink.

How about 18 year old Jameson Reserve.

It's a noise issue. Your laptop power supply is putting noise into the line. When the LED lamp is plugged into the same side of the Tripplight as your power supply the noise from the PS is going straight into the LED lamp. When you plug the lamp in somewhere else the Tripplight is filtering the noise enough so that it doesn't affect the LED. A ferrite core on the AC line to the PS may help. Pretty on both counts, PS and LED.

That would make the flicker.....more smooth!

tomp wrote:

SoundMods wrote:On with the witch hunt! Yours is one of those problems like chasing a hum -- it can drive you to drink.

How about 18 year old Jameson Reserve.

Yea, that occurred to me. The Tripplite has 2 banks of outlets. Bank 1 is less filtered and Bank 2 is more heavily filtered. I first tried reversing the laptop and lamp plugs to different banks. No difference. I then tried adding a ferrite to the laptop power supply cord. This also did not seem to make a difference. Then used the Tripplite exclusively for the laptop (in Bank 2) and that did it. It took both banks of filtering to clean up the noise.


Now I am thinking of going around my whole house with a lamp and the GE LED bulb to see what outlets are noisy!

DaveR wrote:It's a noise issue. Your laptop power supply is putting noise into the line. When the LED lamp is plugged into the same side of the Tripplight as your power supply the noise from the PS is going straight into the LED lamp. When you plug the lamp in somewhere else the Tripplight is filtering the noise enough so that it doesn't affect the LED. A ferrite core on the AC line to the PS may help. Pretty on both counts, PS and LED.

If my wife had to noticed this by reading in silence (something I never do, I almost always have at least background music going), I would still be trying to figure this out.

SoundMods wrote:On with the witch hunt! Yours is one of those problems like chasing a hum -- it can drive you to drink.

Does the lamp have dimmer?

Just build a linear supply for the laptop

Nope! No dimmers in my entire home.

Cogito wrote:Does the lamp have dimmer?