Hey all...

After almost a year, I'm an owner of a Decware product again This time, it's an SE84CSP...



Going to have a walnut base and brass Audio Note knob shortly.

However, I have a question. I'm getting a fair amount of hum with my current speakers (Klipsch Forte II's, 96dB/W efficient). I don't remember my Zen ever having this much hum. Do you think it's because I'm running the CSP into the power amp input on my NAD 3020 integrated? I'm thinking the CSP provides simply way too much gain for it, and the hum is a byproduct...

I know I'm probably worrying unnecessarily, but the actual amps I'm going to be using for this aren't due to come in for about a month or so.

Any advice for how I could set my amp and the CSP up, for now, so I can avoid a ground loop? I'll be running monoblocks eventually, so I guess I need to fix this problem now rather than later It would also make me feel better if I could get this quiet, right now it's almost unlistenable at half-volume with the level of the background hum.

Thanks in advance...

Hey Jim,

Ground loops occurr when the individual grounds from each component are not at the same potential, causing currents to flow in the grounds, causing hum. Try my fix above, if it works, there are ways to fix it depending upon your present power delivery setup.

Let me know how you make out.

Bill                    :D

I'm curious about this one too. My CSP is dead quiet with the Taboo.  It hums with Welborne DRD45 mono blocks.  I've tried all combinations of lifting the grounds using cheater plugs.

I wonder if it relates to the  DRDs only needing about  half the gain that the CSP provides?

Chris

Jim
I have a CSP connected to the "amp in" on my SS McIntosh Integrated. The only time I hear noise is when I turn the volume up with no source playing. I'm running 6dj8 Amperex BBs and a Mullard GZ34 rectifier. Initially replaced the Sovteks with JAN 6922s and a Mazda 5y3. Sounded good. Saved up for the BBs and Mullard. Sounds great.The Tubes may make a difference. The CSP does have gain pods that can be adjusted to better match your amp. There is a disscusion on the site somewere from a while back that addresses the subject. Hope this helps.
Bruce

Now that I think about it, the RCA cable connecting the CSP to the power amp was missing one of the metal barrels on the power amp side...do you think that this exposed connection might be a place for excess noise to enter the system?

I'm out of town for a week, but when I get back this weekend I'm going to try swapping out the cables and bonding the chassis with ground braid.

Also, would one of those "ground loop isolator" things for the RCA's work? The ones sold by Scosche, Metra, etc...for isolating the interconnects.

Hello Jim J

If your hum is caused by a ground loop, isolating the ground in the offending piece of gear will get rid of it. A cheater plug is the adaptor that changes a 3 prong grounded plug to fit into a 2 prong receptacle. It simply eliminates the ground wire from the equation.

Bill                  :D

Some updates.

I replaced the RCA cable with one that has good ends on both sides...still noise.

The NAD 3020 integrated amp is wired with a two-pronged AC cord, so I don't see how the ground loop is coming in. Removing the RCA cables between the units kills the noise, and using a cheater plug on the preamp doesn't do anything now.

I would hate to sell this, but it's not looking good unless I can get these gremlins out...