Vishnupriya1999
New Member
Hi everyone,
I’m seeking advice from fellow members who are using US-imported subwoofers in India, specifically the Pioneer SW-8MK2 (Andrew Jones). I am facing a persistent humming issue that I haven't been able to solve.
The Setup:
Subwoofer: Pioneer SW-8MK2 (120V / 60Hz US Version)
Current Step-down: LiteFuze 750W Toroidal Transformer (220V to 110V)
Previous Step-down: Used a UMI 100W unit for over a year with zero hum.
The Problem:
I am getting a loud, constant hum from the subwoofer. Here is what I’ve tested so far to narrow it down:
The Isolation Test: The hum persists even when the RCA/LFE cable is completely disconnected from the AVR. It starts as soon as the power is turned on.
Transformer Swap: I upgraded from a 100W UMI to a 750W LiteFuze Toroidal unit, thinking it was a power headroom issue, but the hum is still there (perhaps even louder).
Physical Distance: Moving the transformer far away from the sub does not change the hum volume.
Polarity: I’ve tried flipping the 2-pin US plug 180 degrees; no change.
My Theory:
Since the hum happens with no signal cable attached, I suspect it’s either:
Mechanical Hum: The internal US transformer (60Hz) is vibrating physically due to India's 50Hz frequency.
Component Failure: Perhaps the filter capacitors have aged or are struggling with the frequency mismatch.
Questions for the forum:
Is anyone else running this specific sub in India? If so, which step-down transformer are you using?
Has anyone successfully converted this unit to internal 230V by swapping the internal transformer? If yes, what were the secondary voltage specs required?
Are there any recommended technicians in Bangalore who specialize in "US to India" power conversions for Hi-Fi gear?
Looking forward to your suggestions. Thanks in advance!
I’m seeking advice from fellow members who are using US-imported subwoofers in India, specifically the Pioneer SW-8MK2 (Andrew Jones). I am facing a persistent humming issue that I haven't been able to solve.
The Setup:
Subwoofer: Pioneer SW-8MK2 (120V / 60Hz US Version)
Current Step-down: LiteFuze 750W Toroidal Transformer (220V to 110V)
Previous Step-down: Used a UMI 100W unit for over a year with zero hum.
The Problem:
I am getting a loud, constant hum from the subwoofer. Here is what I’ve tested so far to narrow it down:
The Isolation Test: The hum persists even when the RCA/LFE cable is completely disconnected from the AVR. It starts as soon as the power is turned on.
Transformer Swap: I upgraded from a 100W UMI to a 750W LiteFuze Toroidal unit, thinking it was a power headroom issue, but the hum is still there (perhaps even louder).
Physical Distance: Moving the transformer far away from the sub does not change the hum volume.
Polarity: I’ve tried flipping the 2-pin US plug 180 degrees; no change.
My Theory:
Since the hum happens with no signal cable attached, I suspect it’s either:
Mechanical Hum: The internal US transformer (60Hz) is vibrating physically due to India's 50Hz frequency.
Component Failure: Perhaps the filter capacitors have aged or are struggling with the frequency mismatch.
Questions for the forum:
Is anyone else running this specific sub in India? If so, which step-down transformer are you using?
Has anyone successfully converted this unit to internal 230V by swapping the internal transformer? If yes, what were the secondary voltage specs required?
Are there any recommended technicians in Bangalore who specialize in "US to India" power conversions for Hi-Fi gear?
Looking forward to your suggestions. Thanks in advance!
