“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 10 years ago

“The Radiotechnique replaced a stock JJ ECC82 in the input of my Croft series 7r (normally there is an ECC83 there, but I needed less gain). The result was just as described in the web page of Upscale Audio: more extended and clear at the top, without any sign of hardness, clear and rythmic bass, natural voices. A very worthwhile purchase (despite the high transport costs and duties for getting the tube in Europe) and a tube upgrade that allowed the Croft to show all its strengths. I do not have much experience with tubes, but feel confident enough to recommend this tube.”

Helpful Report

Posted 10 years ago

“This is the first time I have replaced the tubes in my McIntosh c2200 preamp. Put me down as gob smacked. The smoothness and tone of the midrange were night and day. The soundstage was more vivid. I am stunned and amazed.”

1 Helpful Report

Posted 11 years ago

“Retubed my preamp with these. Wish I had done it years ago. Best bang for the audio buck since I went to stereo from mono. WOW!!!”

Helpful Report

Posted 11 years ago

“I recently bought a Belles 22a preamp that had Siemens tubes (not the crappy stock tubes). It is a fabulous preamp, regardless of price. My dealer suggested the RT tubes for a little more emphasis on both the low and high frequencies. I bought them and the difference was anything but subtle, from the first note of the music. The increased "slam" on the lower bass notes was immediately apparent as was the extension on the upper end. I have fiddled around with interconnects and cables off and on for years, most often with no discernible different in sound (to my 60-year old ears), but this bit of tube rolling was a sonic wonder. The Seimens perhaps have a bit more emphasis on the mid-range, so if you are a bit vocal lover, they may not be preferred for you. I listen 99% to jazz ensemble music with few vocals and I very highly recommend these tubes. I couldn't be happy with this purchase. In fact, I am going to buy a couple extra pairs in case I live to be 90 years old!!! Upscale Audio is the real deal for tubes, don't waste your time on ebay with sellers with potentially questionable-quality tubes to try to save a couple of bucks... life is too short. I judge Upscale's prices to be extremely competitive. You buy from Upscale, you need not worry about the quality of their products. I don't mean to sound like a shrill for these guys, but in this audio world of less-than-scrupulous dealers, these guys clearly deserve a huge "shout out".”

Helpful Report

Posted 11 years ago

“Replaced my Telefunken smooth plates in my Jolida JD100A Tubed CD player, and Wow! These Mullard's are much more dynamic. Bass is rounder, treble is smooth after burn-in. And the midrange is typical Mullard....very real without being forward. These are my favorite's!”

Helpful Report

Posted 11 years ago

“If I could keep only one 12au7 tube to use in my EE Minimax preamp this RT 12au7WA would be it. Excellent across the board- superior soundstage depth, nice punch and detail, mildly euphonic with nice tone reproduction across the entire frequency spectrum. Beautifully balanced with solid bass and clear high end and synergizes well in the Minimax with the classic 1950's era CV4001, EZ90 and U78 rectifiers, and with any 12au7 you pair it with- from the overly euphonic RCA black plates to the flat response of a Mullard M8136, and no noise or distortion evident at all.”

1 Helpful Report

Posted 11 years ago

Charlie Arachy

Unverified Reviewer

“Been using the stock Tungsram 12au7's in my Linestage section of my Spirit 3 and though I was quite pleased,I felt I needed a little more openness and pase..The RT for Upscale Audio made a huge difference in Openness and that " Air " we all search for..Excellent Bass too..Excellent tube...”

2 Helpful Report

Posted 11 years ago

Radiotechnique 12AU7 Platinum Grade / No Cryo Reviews