Carroll Watts

“Put the two 'new' tubes in my PrimaLuna amp and was surprised at the difference they made. Clear improvement in sound stage, greater clarity overall. Pricey but worth it to me! Thanks!”

Helpful Report

Posted 4 years ago

Timothy Shultz

Verified Reviewer

“I added these to my Primaluna400 in the center front two slots. Wow, what a nice pair of tubes. Very airy in the highs. Couldn't be more pleased. Upscale was also quick to ship and packed them very well.”

Helpful Report

Posted 4 years ago

“Thanks Kevin, You have 100% credibility in my world! Tried several types of 12AU7s in my Rogue Sphinx 2 including NOS Mullard 4003s and some Tung Sols from Kevin. Good sound and revelatory experiences learning how tubes alter the sound of my gear. . The Radiotechnique 1AU7s have completely changed my understanding of what my gear is capable of. Worried when the first pair I received were fizzy at start up. I stuck with them and now that they have settled in, wow what beautiful sound. Thank you Keven and co. what an enlightening experience. If it is helpful, The system I'm listening on is: Rogue Sphinx 2, Audioquest Type 4 cables Kef LS 50 Black (on Kef stands) Source: Cambridge CD transport, Pro Ject S2 DAC Audioquest Carbon interconnects, alternate source Qobuz Studio (24 bit when available) via Audirvana App on MacBook Pro (wonderful App easy. to hear improvement as it overrides OS X audio path) , Audioquest Carbon USB. This is the best gear I have ever owned, assembled over the past 3 years. Sure, entry level into true audiophile quality but I love the sound so much, especially with these Radiotechniques. (what in heaven's name are you all experiencing with more subtle high end gear? I cannot imagine!) Thanks Kevin, You have 100% credibility in my world!”

1 Helpful Report

Posted 5 years ago

“I purchased the Radiotechnique / 6189s on the advice from Evan and also one of the statements from one of the other reviewers saying he almost fell out of his chair. Evan's descriptors were not only spot on and met expectations but far exceeded them. All the cliches ring true here. Broader sound stage, more oomph and presence in the vocals, more dynamic and articulate bass, just an all around grander presentation. Playing this through a Rogue Sphinx and a Hana EL cartridge, it's like I tripled the value of the Hana. My only regret is not having done so sooner.”

1 Helpful Report

Posted 6 years ago

“I currently have these in my Rogue Audio Ares phono preamp in the 12AU7 slot, replacing the Siemens 12AU7 I had in there. These are incredible tubes. Three dimensional and extension on both ends. Very dynamic. I have them paired with some Mullard 12AX7 (which I didn't like at first) based on what others have said in the reviews below and I agree--it is a good match.”

Helpful Report

Posted 7 years ago

“Leave it to Kevin to run down the killer tubes! I put this tube up against my treasured Sylvania 6SN7WGT brown base chrome domes in the input stage of my 845 amps and they held there ground with the Sylvania 6SN7!! That's saying a lot about just how good these tubes are. It's great buying tubes from Kevin because he does such a great job matching the tubes and he weeds out any that don't test exactly the way they should. I know I'm in great hands with Upscale Audio. I've been doing business with Kevin and his team for over 25 years!!!”

1 Helpful Report

Posted 9 years ago

JosÃ© Morales

Unverified Reviewer

“My impression of the RT 12AU7 platinum cryo treated is after around 70 hours of use in a Decware ZP3 Phono preamp accompanied with a rectifier, 2 12ax7's and a voltage regulator tube. I cannot secure the improvement is totally the responsibility of the RT because at same time I changed all four Sovteks 6922 for Amperex NOS 7306 PLATINUM cryo treated too in my ARC LS16. Whoever is the culprit, I can testify to the improvement in the sound of all LP's: mostly original used vynil and a few newer 180 gm records. The improvement to me has being progressive and gradual and given my limited experience with tubes, is a humble questioning if I can perceive all the criteria of sound mentioned by audiophiles. But, if is the RT or the Amperex 7308 or their synergy, the words I can use to describe this new sound could be: shimmer, frontal presence, percussive layers, female vocal realism, bass forests, great timing, not fatiguing, revealing but not brutally. I have not done comparisons nor will do between the old tubes and the new ones to decipher the precise contributions of each type of tube. My LPs are jazz, latÃn salsa, afrocuban drumming, classics (haven't play a lot of them so far), 60-70 rock and folk and 50's crooners, and even the old scratch ones sound better with this RT Tube in the phono preamp. After 100 hours people say it will finally reveal all their potential so if I get the "wow" moment of jump in performance by then, i will add my comment. But until now... good buy... al though the complaints of wife neglect also have increased proportionally to the performance of these tubes and the "sistema de sonido"!”

1 Helpful Report

Posted 9 years ago

“Bought these along with the KT88 Gold Lions. They make a great combo back up with the brimar 12ax7 c4004. I have in 6sn7 raytheons, RCA bottom getter and Sylvania gtb found that I like the russian and gold lion to be the combo that I am most pleased with.Thank you Upscale audio for selling me Quality tubes. It is just to bad that I am the type of person who thinks there might be something else out there that I might be missing, so I experiment, not a bad thing if you share your results.”

Helpful Report

Posted 10 years ago

Radiotechnique 12AU7 / 6189 Platinum Grade / No Cryo Reviews