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CSP owners: amount of hum? (Read 9493 times)
JimJ
Ex Member



CSP owners: amount of hum?
03/06/06 at 01:05:39
 
Hey all...

After almost a year, I'm an owner of a Decware product again Cheesy 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.
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Zygi
Ex Member



Re: CSP owners: amount of hum?
Reply #1 - 03/06/06 at 02:46:54
 
Jim J

 My CSP is dead quiet with Torii I, Torii II and Taboo, It did hum with the mono blocks which was a ground loop.

   BobZ
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JimJ
Ex Member



Re: CSP owners: amount of hum?
Reply #2 - 03/06/06 at 03:08:16
 
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 Smiley 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...

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« Last Edit: 03/06/06 at 03:09:47 by Jack_Frost »  
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crazy bill the eel killer
Ex Member



Re: CSP owners: amount of hum?
Reply #3 - 03/06/06 at 03:08:33
 
Hello JimJ,

throw a cheater plug on it and see if the hum goes away.

If it does, it's a ground loop.

If not, your first thought is a definate possibility.

Cheers,                 Bill                  :D
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crazy bill the eel killer
Ex Member



Re: CSP owners: amount of hum?
Reply #4 - 03/06/06 at 03:13:20
 
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
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JimJ
Ex Member



Re: CSP owners: amount of hum?
Reply #5 - 03/06/06 at 04:11:41
 
Why can't anything be simple in this hobby?  :'(

I plugged the preamp in with one of those adapters inline, and while it took care of a lot of the noise, there's still a lot of noticeable background hum - more than a regular SET hum.

What should I be looking at now? I've seen listings for isolation transformers/line conditioners on Ebay...is this the sort of thing that'll take care of the rest of the noise? Could I build such an isolator myself?

Sorry for the n00b-ish questions Tongue
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chrish
Ex Member



Re: CSP owners: amount of hum?
Reply #6 - 03/06/06 at 12:53:35
 
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
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JimJ
Ex Member



Re: CSP owners: amount of hum?
Reply #7 - 03/06/06 at 14:59:14
 
I posted this over on AudioAsylum, see if any of those tech-heads has an answer, they usually do Cheesy
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brucevtx
Ex Member



Re: CSP owners: amount of hum?
Reply #8 - 03/06/06 at 15:52:59
 
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
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Sam in USA
Ex Member



Re: CSP owners: amount of hum?
Reply #9 - 03/06/06 at 19:03:19
 
I don't have any hum with CSP when I use with Taboo. There is a little bit of hum with the select but that could just the hum from select. I am thinking of using a choke in place of the 1K power resistor in the select.  :)
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JimJ
Ex Member



Re: CSP owners: amount of hum?
Reply #10 - 03/06/06 at 23:23:30
 
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.
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JDW
Ex Member



Re: CSP owners: amount of hum?
Reply #11 - 03/07/06 at 18:08:14
 
Sorry for the noobish question. What is a cheater plug. My Select is dead quiet, so is my P-P amp. I do notice a slight bit more noise with my CSP.
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crazy bill the eel killer
Ex Member



Re: CSP owners: amount of hum?
Reply #12 - 03/07/06 at 18:33:13
 
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
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JDW
Ex Member



Re: CSP owners: amount of hum?
Reply #13 - 03/07/06 at 18:38:01
 
Thanks Crazy Bill
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JimJ
Ex Member



Re: CSP owners: amount of hum?
Reply #14 - 03/13/06 at 03:57:29
 
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... Sad
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