Welcome Guest! To enable all features please Login or Register.

Notification

Icon
Error

Login


Options
View
Go to last post Go to first unread
klo  
#1 Posted : Tuesday, February 8, 2011 9:21:12 AM(UTC)
klo

Rank: Member

Groups: Member
Joined: 11/15/2010(UTC)
Posts: 19

I have a simple hook up, yet encountering hum when I connect the dac direct to amp. I tried changing source, psu, amp without avail.

I run a twisted pair of cat5 for the spdif (unshielded), length approx 30cm, could this digital link cause humming?

Any advise would be appreciated. Thanks

Edited by user Tuesday, February 8, 2011 9:34:51 AM(UTC)  | Reason: Not specified

Brian Donegan  
#2 Posted : Tuesday, February 8, 2011 9:37:46 AM(UTC)
Brian Donegan

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 2,868
Location: Massachusetts, USA

Thanks: 2 times
Was thanked: 141 time(s) in 134 post(s)
Will need some more information about your setup and wiring to help. (Pictures help greatly)

Usually, hum is related to a ground loop somewhere in the system, so we will need to know how you have the power supply(s), Buffalo and amp wires specifically.

klo  
#3 Posted : Wednesday, February 9, 2011 8:56:11 AM(UTC)
klo

Rank: Member

Groups: Member
Joined: 11/15/2010(UTC)
Posts: 19

Hi Brian,

I managed to isolate the problem, as mentioned previously I had changed the psu without avail, and when I disconnect the SPDIF, the hum was gone, hence I could determine it is related to my CDP. Thanks for the pointer and general direction.
klo  
#4 Posted : Monday, February 21, 2011 9:04:51 AM(UTC)
klo

Rank: Member

Groups: Member
Joined: 11/15/2010(UTC)
Posts: 19

Just to update on my previous posting, I tried swapping a different power supply for the B-II, that help to reduce the hum a fair bit, but hum still persist in the background.

I have connected all the equipment behind a single isolation transformer and that didnt help in resolving the hum. All the equipment are 2 pin except the amp. When I connect B-II to different power supplies/direct to the mains or via the Isolation transformer - the hum varies with different harmonic textures :(

What should be the best practice for connecting B-II in view of reduced hum?
a) grounded or floating power supply?
b) necessity of using shielded DC cable? if so, where to terminate the ground for floating power supply?
c) interconnector - I am using Belden 1530A 75R cable with single shield. Should I use double shielding? If so, which end is the grounding (which usually is the receiver) - where to ground in B-II?

Thanks.

Edited by user Monday, February 21, 2011 10:04:37 AM(UTC)  | Reason: Not specified

Russ White  
#5 Posted : Monday, February 21, 2011 7:56:34 PM(UTC)
Russ White

Rank: Administration

Groups: Administration, Customer
Joined: 10/24/2006(UTC)
Posts: 3,979
Location: Nashville, TN

Thanks: 25 times
Was thanked: 89 time(s) in 83 post(s)
The is nothing in particular with the B-II regarding hum that is any different than any other piece of audio gear. You just have to track down your ground loop. Actually when used balanced out Buffalo/IVY or Legato is especially nearly immune to any sort of hum at all. You would have to have a sever issue to pick up any.
thomaspf  
#6 Posted : Thursday, February 24, 2011 1:13:14 AM(UTC)
thomaspf

Rank: Member

Groups: Member
Joined: 12/24/2008(UTC)
Posts: 100
Location: Seattle, WA

I guess the normal arrangeent is to ground the case but not connect the power supply ground to network ground.

Cheers

thomas
klo  
#7 Posted : Friday, February 25, 2011 11:12:45 PM(UTC)
klo

Rank: Member

Groups: Member
Joined: 11/15/2010(UTC)
Posts: 19

I managed to resolve the hum issue by connecting to GND instead of OUT-. Guess the issue is not always caused by source, power, routing.

However, the initial awesome organic sound that I heard abeit with the hum is now leaner and becomes ordinary.

Is there anyway I can use the OUT- rail when the transformer has only SE lead? Thanks.
Rss Feed  Atom Feed
Users browsing this topic
GuestUser (4)
Forum Jump  
You cannot post new topics in this forum.
You cannot reply to topics in this forum.
You cannot delete your posts in this forum.
You cannot edit your posts in this forum.
You cannot create polls in this forum.
You cannot vote in polls in this forum.