Conrad Johnson PV11...Extreme sibilance, harsh sou


Hello everyone,
I have an issue and was wondering if I might prevail upon the community to help me out. I am a seasoned audiophile, I would like to think, but I am sure this old dog can still learn a few tricks.
I have recently acquired a CJ PV11 preamp that is basically in mint condition and came with a brand new tube set from CJ. The tubes were installed around 7/10 and I received this amp on 7/28/07. (strange though, they used Electro-Harmonics tubes)
Anyway, After I installed the preamp, I now have very serious issues with harsh mid range and extreme Sibilance issues that I never had before.
My system is very revealing. I use NEW Walsh drivers based on the Ohm Acoustics design of the model "F" and "A". In fact I have both. These units I make and build myself.
I have not even attempted to use the phono section of this preamp yet. Just the line stage.
While I have never encountered this problem before, I have it now, so much so that I can barely stand to listen to my system. Nothing in my system has changed except the preamp. I intend to rebalance the room and speakers using my calibrated mic and high quality RTA. And even though I am a purist at heart, I do use a high quality graphic equalizer just to cope with some room acoustic issues, but it is set to a very low and flat curve and mainly compensates for low end reflections from my omnidirectional speakers.
I have read about the usual tube rolling, try different interconnects and ac conditioning, but most of that seems very subjective, even to those that suggested it.
I do use dedicated 30 amp lines and separate grounds for my system and even have an ac conditioner, but found the conditioner caused hum issues, strange as that might seem. So I took it out and run direct to the line.
My speaker cables unfortunately are long runs of 25 feet by necessity, but are high quality OFHC braided cables with a 10 ga. size. I also use silver interconnects that I have designed.
Does anyone have any ideas? I have put into CJ for help, but no response yet. (Holiday) and have also been in contact with Dr. Tube.
I would appreciate any help.
Thanks in advance.
Dale
dale_harder
Thanks aagian for the further input. Sorry I have not been able to give too much in further results... been sick with an abcessed tooth..Ouch!
Anyway, I have rebalanced my system with the B&K Mic and RTA and achieved some better results as of late last night. Tried to remove the EQ, but did not like the room effects. Bass was overwhelming with slight high absorbtion in the 16 to 20K range. Sill only about 2 db of loss here.
In addition, I may have some further info and perhaps I am now experiencing some poor quality tubes in another component shinging through. As I said, I use a modified Jolida JA100 CD player which is tube based. Part of the mods called for changing the original Chinese tube set for New Svetlanna 12AX7's. Talking with Dr. Tube, says he believes the Svetlanna tube to be very poor quality, so much so that he has discontinued selling them or supporting them. He says, only about a 30% yield was the norm and that 30% was mediocre at best. This is confusing to me as several High end places are doing the CD mod with the Svetlanna. Something I researched before i had it done..Oh well, Cest la vie.
This may be part of the problem, since the CJ is a very revealing preamp. Perhaps it is emphisizing what these tubes are doing. They are still very new with perhaps only 10 to 15 hours use on them. Still I have some problems with other input devices producing the same type of effect, i.e. tunner, or TV audio. Though these are not that important to me, as I use the CD or Phono most.
I guess I have much to do with trying different tubes and combinations. I will post with further results. Good listening. Dale.
Defending Svetlana: The "WXT" versions are very nice quality. I'd put them above most other new tubes. Maybe I've been lucky?
Elevick, Svetlana WXT. Can your compare against older NOS type tubes? Similar? Thanks, Dave
Sorry to be slow here. I'd put WXT's against Mullards any day. I have owned both. Don't care for most Amperex (except the ones made by mullard...), Telefunkens are always the best all around tube, Golden Dragons are the premium Chinese and are what I'm currently using along with Telefunkens and NOS Groove Tubes.