If you are a fan of “tube rolling,” you know the struggle. It is a relentless pursuit of a sonic perfection that stock tubes rarely provide—a shimmering mirage on the audiophile horizon. However, the Westinghouse 12AU7 Carbon Plate might actually be the oasis you’ve been looking for.
I stumbled upon this gem in a “junk” eBay lot—six anonymous tubes for five bucks. But once I plugged this specific tube in, I was floored. The soundstage transformed into pure sonic bliss. We’re talking about a full, extended bass response paired with a luscious midrange and crystal-clear high frequencies. It captures the incredible depth of an RCA 12AX7 D-getter and mixes it with the sheer musicality of a Sylvania Gold Brand 5751. It doesn’t just play music; it doubles the realism of the artist standing in your room.
The reason these aren’t more famous? They are fairly rare and easy to mistake for lesser RCA-made versions. If you are hunting for the “real deal” original Westinghouse production, look for these specific hallmarks:
The “Grey Dots”: Small, grayish dots around the “12AU7” etching (distinct from the larger GE-style dots). The Copper Post: The getter must be raised on a copper post above the plate, featuring a large “D” shape with two support wires. Heavy Flashing: An extensive silver top cover that makes it nearly impossible to see the getter from above. Carbon Plates: These aren’t shiny like RCA plates; they have a unique, charcoal-like matte finish that sits somewhere between black and dark gray. Yellow Labeling: Look for yellow silk-screening and the 337 manufacturer code (often rebranded as Conn).
Final Verdict: The Westinghouse Carbon Plate is a hidden heavyweight in the vacuum tube world. It is a rare, “catch-it-if-you-can” component that offers a balanced, holographic performance that puts most legendary Mullards and RCAs to shame. If you find one with yellow letters and charcoal plates, do not hesitate—buy it.
Received the first of two matched quad’s yesterday morning and went through Nick’s checklist to make sure they are legit (yup, legit on all fronts). Took out the Psvane’s and in went the Westinghouse Carbon Plates. Been playing them for most of the day, letting the system run when I’m not around to let them break in faster.
First, they make the Psvane’s sound harsh and one-dimensional. I’m not sure how to best describe the westinghouse tubes because they’re pretty solid in every category. It’s like a team working together with each playing its part to make the total package super awesome. Balanced, clear, sweet, and very MUSICAL. They let you sit back and enjoy the music without distraction, over-thinking or fatigue. Great tempo and great sound. Love them..
Continuing to listen to these…they have excellent soundstage and depth, with the music extending far out in front of the speakers. The tone is very sweet and present. The bass is just awesome. The separation of instruments playing simultaneously is the best I’ve heard. These things are like crack.
I was all about the CV491 Mullard Short Plates for a few days, but the Westinghouse tubes just came in and smoked them.
Agreed, BEST 12AU7 EVER PRODUCED. Same as 1st poster, had 1 I got in estate sale bargin, makes me want to sell all my others in order to buy more of these. No matter what preamp circuit, what system/speakers/headphones, this tube delivers.
I cover everything in my listening from classical to Tony Mottola, electric blues/blues, classic rock, electronica/new age, jazz, country, big band, rock and metal, this tube does them all with such perfection it as if god himself created this tube. Can’t say that about any other tube, not even about my previously preferred Mullards. The others all seemed to have strengths and weaknesses depending on what and where your listening, not this tube, there is no weakness.
It drops you right in front of musicians/vocalists/orchestras as if they are there playing for you in person. Highlights every string whisper, vibrato, snare/cymbal hit, bass slap and adds that tube goodness but without overdoing anything. Never fatiguing, always in perfect balance.
1st song I tried with was Deep Purple’s LAZY, one of my favs for many years. It’s was like I had never really heard this song before even though i’ve heard it 100’s times over the years. Billy Joe Walker Jr.’s Painting Music CD, Queen’s We Will Rock You, you will here little details that never really stood out before.
If you are a fan of “tube rolling,” you know the struggle. It is a relentless pursuit of a sonic perfection that stock tubes rarely provide—a shimmering mirage on the audiophile horizon. However, the Westinghouse 12AU7 Carbon Plate might actually be the oasis you’ve been looking for.
I stumbled upon this gem in a “junk” eBay lot—six anonymous tubes for five bucks. But once I plugged this specific tube in, I was floored. The soundstage transformed into pure sonic bliss. We’re talking about a full, extended bass response paired with a luscious midrange and crystal-clear high frequencies. It captures the incredible depth of an RCA 12AX7 D-getter and mixes it with the sheer musicality of a Sylvania Gold Brand 5751. It doesn’t just play music; it doubles the realism of the artist standing in your room.
The reason these aren’t more famous? They are fairly rare and easy to mistake for lesser RCA-made versions. If you are hunting for the “real deal” original Westinghouse production, look for these specific hallmarks:
The “Grey Dots”: Small, grayish dots around the “12AU7” etching (distinct from the larger GE-style dots).
The Copper Post: The getter must be raised on a copper post above the plate, featuring a large “D” shape with two support wires.
Heavy Flashing: An extensive silver top cover that makes it nearly impossible to see the getter from above.
Carbon Plates: These aren’t shiny like RCA plates; they have a unique, charcoal-like matte finish that sits somewhere between black and dark gray.
Yellow Labeling: Look for yellow silk-screening and the 337 manufacturer code (often rebranded as Conn).
Final Verdict: The Westinghouse Carbon Plate is a hidden heavyweight in the vacuum tube world. It is a rare, “catch-it-if-you-can” component that offers a balanced, holographic performance that puts most legendary Mullards and RCAs to shame. If you find one with yellow letters and charcoal plates, do not hesitate—buy it.
Received the first of two matched quad’s yesterday morning and went through Nick’s checklist to make sure they are legit (yup, legit on all fronts). Took out the Psvane’s and in went the Westinghouse Carbon Plates. Been playing them for most of the day, letting the system run when I’m not around to let them break in faster.
First, they make the Psvane’s sound harsh and one-dimensional. I’m not sure how to best describe the westinghouse tubes because they’re pretty solid in every category. It’s like a team working together with each playing its part to make the total package super awesome. Balanced, clear, sweet, and very MUSICAL. They let you sit back and enjoy the music without distraction, over-thinking or fatigue. Great tempo and great sound. Love them..
Westinghouse 12au7 Carbon plates – 5 Stars
Continuing to listen to these…they have excellent soundstage and depth, with the music extending far out in front of the speakers. The tone is very sweet and present. The bass is just awesome. The separation of instruments playing simultaneously is the best I’ve heard. These things are like crack.
I was all about the CV491 Mullard Short Plates for a few days, but the Westinghouse tubes just came in and smoked them.
Agreed, BEST 12AU7 EVER PRODUCED. Same as 1st poster, had 1 I got in estate sale bargin, makes me want to sell all my others in order to buy more of these. No matter what preamp circuit, what system/speakers/headphones, this tube delivers.
I cover everything in my listening from classical to Tony Mottola, electric blues/blues, classic rock, electronica/new age, jazz, country, big band, rock and metal, this tube does them all with such perfection it as if god himself created this tube. Can’t say that about any other tube, not even about my previously preferred Mullards. The others all seemed to have strengths and weaknesses depending on what and where your listening, not this tube, there is no weakness.
It drops you right in front of musicians/vocalists/orchestras as if they are there playing for you in person. Highlights every string whisper, vibrato, snare/cymbal hit, bass slap and adds that tube goodness but without overdoing anything. Never fatiguing, always in perfect balance.
1st song I tried with was Deep Purple’s LAZY, one of my favs for many years. It’s was like I had never really heard this song before even though i’ve heard it 100’s times over the years. Billy Joe Walker Jr.’s Painting Music CD, Queen’s We Will Rock You, you will here little details that never really stood out before.
THE PERFECT TUBE