“These French tubes work beautifully with my open, airy Focal Diablo Utopia speakers and Rogue Audio amplification. They reveal the delicate colors and subtleties of Debussy or Ravel, but can also do wonders with the dense orchestrations of Wagner and Bruckner. An excellent choice for lovers of great music.”

1 Helpful Report

Posted 8 years ago

“This is my first NOS tube. I am using two of them as the pre-amp tubes in a push-pull integrated amplifier. I was skeptical at first about NOS tubes because of their high price. However after buying this tube and trying it out, I can tell you it is worth every penny I paid for it, and more. This tube sounds absolutely fantastic in my amp. I am so happy I bought a them.”

Helpful Report

Posted 8 years ago

“Uncle Kevvy is the man, he know his tubes, slowly my system lost it's mojo, was thinking didn't it used to sound better??? Dropped a couple of these in my Klimo Merlin preamp and WOW, the biggest improvement I ever heard in my system. Improved in every way, and these tubes are not overly warm, they are wonderful. Thanks Uncle Kevvy!!!”

Helpful Report

Posted 9 years ago

“The English have a certain way with words and gobsmacked is a particularly good word to describe my gut reaction. I purchased the Mullard CV4004 along with the Radiotechnique 12au7 for my Cayin HA1A headphone/speaker amp. Others have more eloquently described their experience with this combo so I will just say I agree with everything you will read in these reviews. I am a casual audiophile with a relatively modest system cobbled together over the years. If you are like me, you have champagne ears on a beer budget, and when you upgrade you cannot afford expensive trial and error. You need to get it right the first time. Spending $300 bucks on 2 tubes seems like self indulgent lunacy... and it is! BUT, for less than the price of my best power cord (and I am VERY pleased with my best PC) The improvement to my system is nothing short of incredible. The cool thing is that all my sources sound better because everything goes through this amp. Talk about bang for the buck! So if you are into self indulgent lunacy (as in you are an audiophile) then you should try these tubes.”

Helpful Report

Posted 9 years ago

“What glorious tubes these are. I was expected the wonderful warm midrange but not the detail and the amount of presence displayed. Paired with MULLARD 12AU7 the sound was warm but the treble lacked a little sparkle and the lower tones just a bit too warm. Paired with RADIOTECHNIQUE 12AU7 rectified this the highs now extended with just enough sparkle and bite and the base now was tight deep with lots of drive. Rhythm and timing now excellent. In my system this is a marriage made in heaven. I had thought the RADIOTECNIQUE was very good but this combo showed I had underestimated its talents. What are we going to do when these wonderful old tubes disappear.”

Helpful Report

Posted 9 years ago

“Tube produces very clear, detailed sound. Has good mids, excellent highs. Was a bit disappointed in the low performance, but depending on the type of music you're listening to this may not matter. I used this in a bottlehead crack tube amp with DT 990 pro headphones.”

Helpful Report

Posted 9 years ago

“After a couple weeks in a Marshall Custom Offset (JTM1) amp the Radiotechnique 12AU7 proves killer as a low wattage power tube. As with the JCM1, the difference was instantly noticeable. Dead quiet even at full volume with guitar pot off. This model of Marshall has the least preamp gain, most of the growl comes from the power tube. The tubes provided by Marshall were an upgrade from normal stock and had good response and tone. Upgrade with a UA GL platinum in V1, Northern Electric in V2, and the Radiotechnique 12AU7 Cryo for power - the amps tone is so rich and controllable even with only 1 tone knob and 1 "loudness" knob. Tried other vintage strong 12au7s including Mullard and RT stood out. Cryo treatment should provide longer life over other running in the hard use as a Marshall power tube. Given the difference in preamp of the JTM1 over JCM1, feel the RT shows even more tonal character in the JTM circuit. More headroom and richer addictive power tube OD. What is most surprising is the tone keeps getting better as the tube is breaking in. More hours on the JCM1 has had same result, but the RT really shows it's superiority in the simpler JTM circuit.”

Helpful Report

Posted 9 years ago

“The stock tubes in the Marshall 1w amps are better than most MFG stock, but don't do the amp justice. upgrading V1 with UA's platinum GL B759, a Northern Electric in V2, and was running a NOS Mullard 12au7 for power section. Have few strong vintage 12au7 and the Mullard was the best of my bunch. The new tubes greatly enhanced the tonal spectrum, depth, and even more available volume. Tone controls on the JCM1 are more responsive as well. The Mullard sounded pretty good but would get 'swirly' at 85%+ on volume. Also Mullard have reputation for going microphonic in guitar combos. Wanted to see if could find a more robust alternative that would sound at least as good as the Mullard. Given the quality of the amp's build to chance on UA's highly rated Radiotechnique 12au7wa Cryo (to make more robust for power tube duty. Only risk could see was that reviews were not for guitar amps, which hit all the tubes harder than an audio tube amp. This tube is awesome, has even more range, solid low end, smooth cutting highs, and the Marshall power tube overdrive is amazing, close to my JCM800 4103, especially given its the JCM1 is not an el34 amp. Been running at different levels, as well as full out, and tone has sweetened and not hint of hiss or tube stress. Given the performance and tone. have ordered 2 more, one for a Marshal custom shop 1w Offset and one as spare (they are rare and may not be around too long). If you have a low watt tube amp that uses 12au7 for power section, this tube will help bring the best out of the power section of the amp. Cryo treatment puts it over most NOS you can find, by toughening the tube's internals for hard duty. Marshall's are not known for being easy on tubes!”

Helpful Report

Posted 9 years ago

Radiotechnique 12AU7 Platinum Grade / No Cryo Reviews