need help on transparent sounding 12au7 tubes


Hi,

I'm currently using NOS RCA clear top 12au7 in my Audio Valve Eklipse preamp. Looking for a 12au7 that's more transparent, detailed, maybe higher resolution to try with this preamp. Not looking for a tubey sound. Thanks.
scar972
Thanks for all the great recommendation, this is good information to know, will certainly use these recommendation down the line. I plan to clean the pins of the RCA's this weekend, should I use Silclear on it (silver enhancer)?

I just listened to my system tonight (well rested and everything)and it sounds amazing. This is my second night with the Eklipse and I'd have to say I'm very happy. This pre is very quiet, sweet, slightly forward in the midrange which bring out vocals perfectly for rock albums such as Dire Straits Brothers in Arms, SuperTramp, etc.
You can't go wrong with RAM Labs Super Low Noise grade. These are very quiet and transparent and only 2% of tested tubes are graded Super Low Noise. The 12AU7 is difficult to find with low microphonics, especially with NOS tubes. I use Super Low Noise RAM tubes in all of my input and power tubes on my VTL and CAT electronics. Here is the website tubeaudiostore.com and I am not affiliated with them other than as a consumer with 30 years in this hobby.
You will have NO problem finding low noise/non-microphonic NOS tubes. You just have to shop with sellers that know how to test for such things. Kevin Deal is one of those that is most fastidious with his testing and grading (http://www.upscaleaudio.com/view_category.asp?cat=44). If, by stating, "transparency", you are saying, "no colorations": then you don't want anything British. They will impart an unnatural warmth to your presentation. Siemens and Telefunken are the most transparent, of which the ECC802S would be the ultimate. They were ECC82's, specially selected for low microphonics/noise, linearity, and triode balance(and cost accordingly). There are no new production tubes that can come close to the reproduction accuracy of a properly selected pair of NOS tubes. The exception to that rule in 9 pin miniatures are the EAT tubes (http://www.musicdirect.com/product/73403). There again- You WILL pay for the quality. They don't manufacture a 12AU7 unfortunately.
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It's been my experience, over the years, that any equipment with nine pin Mullard or Brimar tubes installed had an added warmth, sugary glaze or "tubey sound"(as the originator of this thread put it) that simply does not exist in live music. Said coloration was easily eliminated when the tubes were replaced with those of German manufacture. What others may prefer/enjoy/seek in their sound does not concern me, as Scar972 asked about "transparent", "detailed" and "resolving" tubes. I replied based on what I know to be true. Scar972- Kevin Deal at Upscale has a great amount of experience with the tubes that he sells, in a wide variety of components. Call, and ask him for suggestions regarding the presentation you'e seeking.