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CSP owners: amount of hum? (Read 9476 times)
rmt
Ex Member



Re: CSP owners: amount of hum?
Reply #15 - 03/14/06 at 22:24:55
 
[quote author=JimJ  link=1141610739/0#14 date=1142222249]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
[/quote]

I wonder why you are trying to push a signal from a tube preamp with gain into an integerated amp.  It just sounds like a mismatch from the start. Perhaps the problem stems from the NAD not having a grounding type plug.  Would imdedance mismatch cause problems?  From the NAD site.  Input impedance 11k ohms for the 3020 integrated.  No mention of an amp input just line level inputs for phono, aux, tuner.

I would send that NAD on its way long before I considered selling a CSP.  I just don't see them as being good matches gearwise.
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JimJ
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Re: CSP owners: amount of hum?
Reply #16 - 03/14/06 at 22:41:12
 
[quote author=rmt  link=1141610739/15#15 date=1142375095]

I wonder why you are trying to push a signal from a tube preamp with gain into an integerated amp.  It just sounds like a mismatch from the start. Perhaps the problem stems from the NAD not having a grounding type plug.  Would imdedance mismatch cause problems?  From the NAD site.  Input impedance 11k ohms for the 3020 integrated.  No mention of an amp input just line level inputs for phono, aux, tuner.

I would send that NAD on its way long before I considered selling a CSP.  I just don't see them as being good matches gearwise. [/quote]

Quote:
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.


This is just for a temporary setup Smiley

It does have a preamp output and input to bypass the internal pre, though. There's a little U-shaped metal jumper that goes into each center pin when it's functioning like a normal integrated, take the jumper out and there's a seperate preamp and PA in the same box.

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Sam in USA
Ex Member



Re: CSP owners: amount of hum?
Reply #17 - 03/14/06 at 22:47:18
 
I have no problem driving my HK receiver that has 200mV input sensitivity. But the input impadeance is also fairly high at 47K
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rmt
Ex Member



Re: CSP owners: amount of hum?
Reply #18 - 03/14/06 at 23:03:20
 
So I tested my comment about a gain tube preamp and an integrated amplifier.  I experimented with driving my Sony reciever with the CSP.  I heard no hum whatsoever through the Sony amp being driven by the CSP using Klipsch 96db speakers.  The Sony does have a grounding plug.  

I had to turn the CSP all the way to 10 to get much out of the Sony amp.  I cannot explain that.  It seems that the Sony is louder w/o the CSP.  Anyway it did improve the sound. No hum though.

My CSP and 2 watt Select blow away my 100watt Sony.  Strange how that it is.  Good luck with your hum problem, I have no answers.  I know you will solve it and be very happy combining it with your monoblocks?
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« Last Edit: 03/14/06 at 23:04:10 by rmt »  
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Sam in USA
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Re: CSP owners: amount of hum?
Reply #19 - 03/14/06 at 23:07:09
 
He has put it up for sale  :(
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Mr Content
Ex Member



Re: CSP owners: amount of hum?
Reply #20 - 03/25/06 at 23:30:59
 
I have had hum with my CSP to, I have just lived with it, but since I got the Charlize amp ,which is really dead quiet, not make believe dead quiet, I could not stand it any more. It also eats tubes like they are free. Sit on the shelve making a good dust catcher now. Angry

Mr C
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Joel
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Re: CSP owners: amount of hum?
Reply #21 - 03/26/06 at 17:38:17
 
How about elaborating on that "eating tubes" comment. I thought they were supposed to have long life in the CSP. I'm a little sensitive, had a pinched waist 6922 die in the cathode follower position. Big loss. I'm running in front of a CEX. Had been putting the 6922 in the CSP instead of CEX in hopes of longer life. It boosted both an amazing amount. In the CSP it really helped the F1 with some tube life.
Thanks-
Joel
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Mr Content
Ex Member



Re: CSP owners: amount of hum?
Reply #22 - 03/27/06 at 05:44:58
 
No worries Joel. The tubes that shipped with the CSP lasted 61 days. The rectifyer died in the morning, and the 6922's by the evening. I spent about $90 on a good recifyer in the hopes that it would last, but alas it only lasted about 4 months.  I need another 3 6922's, so I just parked it. Gathers dust nicely. Had it cheched out by a friend, and he couldn't see why it was eating tubes so much. BTW, I left it on 24/7 as recommended. O well. Sad

Mr C
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gnat leader
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Re: CSP owners: amount of hum?
Reply #23 - 03/29/06 at 19:27:02
 
I don't leave mine on 24/7. I have no problems with hum in either my CSP or TABOO using the 96db HDT speakers. I use 6n1P's in the CSP and have been using the same (cryo treated) tubes for a year so far.  I use tj 274B rectifiers in both CSP and TABOO and have been using them for multiple years (had used one of them in the CS I had before moving to the TABOO).
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« Last Edit: 03/29/06 at 19:28:06 by Brad »  
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Mr Content
Ex Member



Re: CSP owners: amount of hum?
Reply #24 - 03/30/06 at 03:53:59
 
[quote author=gnat leader  link=1141610739/15#23 date=1143660422]I don't leave mine on 24/7. I have no problems with hum in either my CSP or TABOO using the 96db HDT speakers. I use 6n1P's in the CSP and have been using the same (cryo treated) tubes for a year so far.  I use tj 274B rectifiers in both CSP and TABOO and have been using them for multiple years (had used one of them in the CS I had before moving to the TABOO). [/quote]

Thanks for the info Brad, Me thinks that there is something seriuosly wrong with my unit. It may have to take the flight back to the good old US of A

Mr C
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veryoldcat
Ex Member



Re: CSP owners: amount of hum?
Reply #25 - 03/30/06 at 06:22:42
 
Hi Nigel,

There's gotta be something fishy going on the inside of your CSP. I've had mine on 24/7 since I got it in October of 2004 w/o difficulty.

I had one particular rectifier fail, but it had flashed purple since the very first hour of service (bad vacuum integrity, apparently). My current rectifier has been going constantly since last October.

I've had the same BB 6dj8's running constantly since November of 2004, 24/7, also with no difficulty. Everything fresh as a daisy.

Sorry about having to ship stuff to Decware from Oz. Shipping's gotta hurt from there, let alone the down time.

Karl
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Mr Content
Ex Member



Re: CSP owners: amount of hum?
Reply #26 - 03/30/06 at 07:23:58
 
Hi Karl, thanks. Down time is no worry, I dont use it now anyway. I have to think if the postage is worth it or I just leave it in the cupboard. Dont know ???

Mr C
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Doug_C.
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Re: CSP owners: amount of hum?
Reply #27 - 04/04/06 at 21:41:12
 
I purchased a CSP about a month ago and initially had a bad hum. After being powered up for several hours the hum was reduced by about 1/2 but still anoying. May have been a tube? I have had tubes hum initially only to settle down after being powered up for a while.

In an effort to eliminate the remaining hum I tried everything mentioned by others here. The hum was from both speakers and was noticable from the listening position. With everything Off except the CSP and Select Amp the hum level was the same regardless of where the CSP volume knob was set. Setting the volume down on the Select would reduce the audible hum. After a couple days this was frustrating!

The CSP was sitting off to the side of my main rack as a temporary hook-up until I could move the other equipment around to make a permanent space for it. When I did finally get time to move things around I turned everything on and No Hum, None. I have no idea what changed because the electrical connections were all the same.

In any event I'm now very very pleased with the CSP / Select / Klipsch combo that I have. I debated for a long time about the CSP. I really liked my system without it and did not think it would make a $650.00 improvement. Well in my case it's worth every penny. The added detail pulled out by the CSP is really amazing.

Doug C
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Mr Content
Ex Member



Re: CSP owners: amount of hum?
Reply #28 - 04/05/06 at 06:44:10
 
Well Doug, maybe I shoul try mine somewhere else. But hang on mine doesn't hum, its just always hungry.  :'(

Mr C
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chrish
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Re: CSP owners: amount of hum?
Reply #29 - 04/05/06 at 12:30:48
 
Hello Mr. C

I had initial problems with my CSP being hungry.  Trying to find quiet NOS tubes was not easy.  Also, a rectifier was lost due to a powering up, or maybe it was down, something that I did screwy or out of sequence.  After trying two pairs of noisy Bugle Boys, I found some Matsushita 6922s that were quiet and I like the sound.  Also, in the front position, a bugle boy that was quiet, developed a hum in one channel.  A humble Ei 6DJ8 sounds good there and is quiet. From what I've read the 6922/6DJ8 type were not made for audio originally so that noise was not a parameter that was looked at closely when it was developed. The last time that I tried the stock JJ 6922 tubes, IIRC, one or more were noisy.  I went back and reread this paragraph of the CSP manual…..

Remember, with any tube product, it is WISE to have a complete set of spare tubes on hand. Anytime there is a problem with tube gear it is 9 out of 10 times a tube. If you have spare tubes you can easily trouble shoot it yourself. While not common, tubes can go bad for no reason, or get noisy—especially N.O.S. tubes. Be careful when spending tons of money on N.O.S. tubes that originally only cost a few dollars when they were new.

All the best

CH
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