2. amps-preamps
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Conrad Johnson 2300A help needed

Hi All,
I am the new owner of the amp referenced above and absolutely love its sound with my recently aquired Thiel 2.4s and Threshold FET 9 preamp. But, as has been reported in comments on it, it has a pronounced mechanical hum from the transformer which is noticable any time the program material is very soft. I'm not talking obnoxiously loud, but definitely noticable enough to be distracting in my otherwise very quiet room. It is soft, but clearly audible 15 feet away if listening for it. I'll be calling C-J Monday to discuss this, but wonder if anyone has had a similar issue which they successfully addressed.
Thanks in Advance!
drjay
6 responses Add your response
lloydelee21
1,202 posts
 
Hi DrJay,

Two comments:

1) Ed at CJ is amazing...he typically answers the phone in Service. I have dealt with him for years on questions and queries, upgrades, voltage conversions, etc...always great.

2) If you physically dampen the chassis, does it lessen at all? I doubt it, but if it does...try an HRS damping plate...incredible damping power. No idea how, but it works.

If its totally internally (almost certainly the case), then a power conditioner can [occassionally] help but i would suspect Ed is your best bet to help.

good luck and pls post updates.
ejman's avatar
ejman
62 posts
 
I have a dedicated 20A line to the same amp (great sounding amp by the way) and can barely hear a mechanical transformer hum from about 1 ft away. I think the quality of the power to the amp is a deciding factor.
phd
1,320 posts
 
The 2300A is a Very Good sounding amp! The one I own has a mechanical hum and I have yet to own a CJ amp that don't have this condition to some degree or another. Considering the massive size of the Ecore transformer this is not surprising or unusual. You can try tightening the transformer bolts or call CJ Monday because I do believe they sell a damping pad that reduces mechanical hum & inserts between the transformer and mounting plate.
drjay OP
27 posts
 
Hi Everybody,
A quick update for those who are interested. I contacted Ed at C-J and he said that their suggested fix was a set of elastic isolators that go under the transformer between it and the amp chassis. He offered to send them to me at no charge rather than me having to send the amp to them which was really appreciated. I'll post an update when they are installed.
lloydelee21
1,202 posts
 
great!
stevecham
3,340 posts
 
Ed at CJ is an excellent person to work with. Let us know if this helps with the vibration hum. CJ are tops with me.
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