Where can I get RAM super low noise tubes?

My advice is to forget about the RAM SLN tubes. You'd be much better off, seeking out some low noise vintage tubes.You would end up, with a better sounding, much longer lasting, and just as quiet, if not quieter tube. But if you must have them, check out Welbourne Labs.

RAM does not make tubes, they buy tubes and put them through extensive testing and grading. So when you buy a SLN, LN, or SG tube; while the SLN will be the better types, you may also find the same brand at different grades; because some do not test out as well as others.

Thanks to those of you who understand and appreciate what we do at RAM TUBES. We started computer testing in 1981. We are the only premium tube source that tests for real-world conditions. We are the only source that gives you all the data for that particular tube after it has passed out stringent grading system. More importantly, we are the only tube source run by a designer of tube amplifiers and, therefore, know what matters and what does not matter in tubes for amplifiers. The thinking user can see that FFT testing to 100 MHZ is meaningless, cryogenic treatment is foolish, and sandblasting the glass is just plain silly.

On the subject of NOS tubes: We have them, we test them, we can provide them, and they are expensive. As they generally yield no more quiet samples than the modern tubes we can buy (at reasonable prices), I caution potential users from buying them untested (for noise) on the open market. Even if these tubes "sound" better, how can you enjoy them if the ones you get are noisy and microphonic? You will likely pay the same price for a Telefunken of unknown performance, have a 2% chance of finding a SLN quality (within 1 dB of theoretical noise limit) and little or no recourse with the seller who couldn't measure the noise in the first place. We have tested 100,000's of tubes since 1981, including nice looking Telefunken gold pin E88CC's and E83CC's. They yield about the same mix of SLN, LN and SG that I find from the new stock that I carefully select from good factories. Since we buy in large batches, we can consistently supply tubes you like. We just sold a customer a replacement 12AX7 Smooth plate Yugo from the same batch he purchased 8 years ago. We stock 5 types (Yugo, Tungsram, Chinese, Sovtek, RCA) + some NOS Telefunken, Bugleboy and whatever else comes our way.

We also have matched power tubes, again matched at real world, not Hickok test condition. You cannot match output tubes on a Hickok as the voltages and currents are too far from typical amplifier operating conditions. I am happy to respond to that issue later if there is interest.

Please visit our website: ramlabs-musicreference.com for further info. We are updating it in an effort help you with your tube needs and questions. As Audio Advisor and Electron Valve have recently chosen to get out of the tube business, we are offering tubes direct to you and through selected retail stores. Please call 805-687-2236 m-f, 7am-noon, or email: ramlabs@silcom.com.

Thanks,

Roger A. Modjeski

Roger, thanks for dropping in. It is a pleasure having someone of your caliber joining the conversation. I hope you don't mind me asking you a few questions and throwing a few comments / observations your way while we have your attention.

Even with checking tubes for noise levels, gain matching, etc... how do you account for variables in sonics from tube to tube and brand to brand ? Obviously, not every tube, even though they might have come out of the same batch and production run, will sound or measure the same. That is why i stated that tubes "almost offer TOO many variables", even amongst the same brand.

I know that people that work on / design gear for a living tend to look at things like this as kind of a science. I also know that the many years of experience have taught you a LOT of the "in's and out's" of what to look for. None the less, i still think that it is almost impossible to know exactly what tube will work best in a component in a specific system without actually trying them out. Obviously, the work that you do somewhat "pre-qualifies" the tubes in that they are not "junk" or "noisy", but that does not specifically tell anyone what sonics they might possess in a specific piece of gear.

As you know, changing just a few of the operating points within the curve can DRASTICALLY alter both the readings and sonics that you get out of a device. This is true of either tube or solid state devices. As such, how do you select the specific settings that you choose to use when testing tubes ? How applicable are those results on a somewhat "universal" basis ? Sean
>

http://www.electron-valve.com/reading/amplifier/tubechange.html

Don't know if you've seen this article by Roger, or if it answers your question, but it is very interesting...