EROS Major Hum

[olegreg]

I have a major hum coming from both channels on new build.
Also, there is no separation between channels. Source connected to one channel comes out on both sides.

[olegreg]

I wanted to add that the input is shorted to rule out outside sources.

[Paul Birkeland]

How are your DC voltage checks?

Summing channels would tend to indicate a substantial miswire, which should also throw off the DC voltages.

[olegreg]

Rechecked
1A 235 vdc
1B 230
OA 155
OB 156
OC 98
OD 98
OKA 99
OKB 100
OKC 1.63
OKD 1.89

[Paul Birkeland]

Can you post some build photos? 

[olegreg]

Here you go

[olegreg]

Hum was with SUT wired in per instructions. Rewired without SUTs (pictured) and no hum through headphone.
I must have done something wrong with the SUT wiring.
It was not clear on where to land A1 and B1. I landed on 2 and 15 putting the loading resistor on the secondary of SUT.

[olegreg]

New Hum...
Open or shorted input sounds the same.
Repeating sewing machine sound
I tried to send video with sound, won't accept mp4

[debk]

From the pictures it looks like D2 on the B side of the shunt regulator board is in backwards

[Paul Birkeland]

Repeating sewing machine sound

That kind of noise is often wireless interference from a nearby device.

[olegreg]

First: Debra K, Good eye!  Those LED Diodes where probably the hardest component to install on a board. I'm surprised the VDC all checked out, but on close inspection in a darkened room, it was not glowing.  Thank you, Debra

Second: On the sewing machine hum. Paul nailed it... My Sonos sound bar is causing the hum. I will just have to turn it off when I want to listen to music. Thank you, Paul.

BTW, first couple of minutes listening, the EROS sounds great.

I have SUT questions on a different thread.

[debk]

Glad you got it working