Preamp Deal of the Century

Another point I want to bring up regarding a.c. coming into your home.Residential and commercial construction through out North America in the past few years has been incredible. This has put a strain on the grid in some areas resulting in poor supply, inconsistent supply of a.c. to your home. Where we use to live tens of thousands of new homes have been built along with many commercial factorys and business.Moving to another area, far less population, I have noticed consistent performance with my system . Like your vehcile,if its getting proper air density /fuel mixture it will perform at its peak....

Here is a link with some more info on transformer hum induced by DC on your AC line.
http://www.diyaudio.com/forums/showthread/t-83784.html

Thanks for the thoughts and observations on the hum issue. I will check the voltage at my panel to see if it really is 120v. I have also tried unplugging all components except the pre with all other breakers off to see if it was interference from another component but there was no change. It's not a major issue because it is only noticeable from a few feet away. I will also check the bolt tightness. I had not considered that because it's a new unit. Thanks again.

Thanks for the explanations everyone. I am fortunate enough that my Chenin, after making the initial mistake of swapping tubes right away as soon as I received it, only had one small issue since 2004. I have this paranoia about the R channel on the phono a little lower in output than the L channel at identical gain pot settings. I wrote my concern to Mick and he sent me an schematic diagram to measure the voltages and make proper adjustments. After that, it's been working fine (knock on wood as I type this!) so far without hum or hiss for almost three years now.

regards

In my latest effort to deal with the "glaring" issue associated with my Cortese referred to above, I acquired and tried the RCA gray glass (actually, the earlier "lightening bolt" logo 6SN7GTs that preceded the VT-231 incarnation) and the KenRad 6SN7/VT 231s. In my system, just as in Ooslik's, the RCAs sounded somewhat bright and glarey here and there. The KenRads virtually eliminated the stridency entirely, but a bit of the upper midrange lost a touch of the air and ambient detail I had with my Raytheon 231s and General Electric 6SN7GTBs. I then replaced my Tungsol 5881s with some Sylvania 5881s, and restored just a bit more of that ambient detail. The trick involves getting involving upper end detail and musicality without the glare or stridency. Now, I feel more confident than before about getting there. My next step is securing a good, but not super expensive moving coil. (I've been using the low output--1.5mv.--Grado Sonata.) I also should soon be receiving those Tungsol 6SN7/VT231 Round Plates. Incidentally, in case I failed to relate before, I did not make a single tube roll until I arrived at 200 hours burn in of both the phono and linestages of the Cortese.