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Mullard CV4004 / 12AX7 British New Old Stock

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Price:
$125.00

 



Product Description

Mullard CV4004/12AX7 boxed-plate, made in Great Britain. The most sought after 12AX7 we have. It was sad that we were down to our last box, but Uncle Kevin did the deal and found some that were stocks from the Australian Royal Navy. Dig those Aussies!!! These are bulk packed and as perfect as it gets. Price is for a single tube.

Platinum grade - The best of the best. Lowest noise and microphony with the tightest triode balance we have available. This is typically 10% or tighter, but may be higher depending on available stock.

Gold grade - Low noise and microphonics with a triode balance typically between 15% and 20%, but may be higher depending on available stock.

Driver grade - Lowest noise but not the lowest in microphony. Triode balance will be similar to Gold grade.
This grade is only suitable for use in the driver stage of an amplifier, or the output/buffer stage of a DAC or CD Player.

If you have a preamp or phonostage, you need at least Gold grade.

Click here for a more in depth discussion on how we grade tubes.

Box may vary from picture above, as tubes may come in the military box or generic white boxes depending on available stocks. Price includes matching in any quantity you need at no extra charge.

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Product Reviews

  1. Great tube worth twice the price

    Posted by -

    I have a Jadis JPL pre-amp and I think the simplicity of the design is one of the greatest strengths (sounds amazingly natural) and weaknesses (live and die by the tubes you use). The CD input is buffered, veiled, and ought to be avoided (it uses a 12AU7), with all the other gain tubes being 12AX7. After using 1960s ECC803S in place of the 12AX7s for a number of years (same tooling as the Telefunken) I tried the Mazda Chrome Plate 12AX7, but the preamp overloaded with large signals so I had to give up on that one though what was there sounded very nice (my friend loves them in his MAC C2300 preamp). I then tried the Mullard CV4004 and was impressed at how much more vibrant the system sounded; not distortion, but greater harmonic depth, structure, and dynamics. Highly recommended!


  2. A Sublime Dimension

    Posted by Ed in Orlando, FL

    Just added a Platinum rated pair of these tubes to a Jolida JL9 phono preamplifier: Wow! With a new Ortofon 2M Black, what an upgrade to my vinyl playback capability! The bloom for vocals and jazz is perfect! Thought about a phono preamp upgrade and thought this addition was worth a shot before I spent over $2K on a new one; indeed it is. Keeping the JL9 with the NOS Mullard 12AX7s. Don't even think about the price: do it and you will be delighted. Every purchase I have made from Upscale Audio in graded tubes has exceeded my expectation.


  3. Outstanding tube used in the right place

    Posted by Bill K

    I have a pair in the line stage of a VTL TL5.5 and they have an outstanding mid range adding just the right amount of warmth. Very wide and deep sound stage. Much better than both NOS Amprex and Telefunkin in the line stage.
    I also tried them in the VTL's MM phono stage but found them to be a little syrupy. Maybe a little too much of a good thing? I found NOS Telefunkin tubes to be much better there.
    I also have a Cal Audio Alpha that I bought from Kevin that had the original (Russian?) tubes installed and a pair of 4004s were packed with it. I also have a Sigma II with a NOS Mullard 12AX7 in it. The Alpha with the original tubes sounded dry and lifeless compared to the Sigma. After swapping the 4004s into the Alpha I was blown away by the sound. Big sound stage, instrument timber was much more natural, Very extended highs without grain or edge.
    One of the very best AX7 types I've heard when used in the right spots!


  4. major audiophile tweak

    Posted by George O.

    There’s resolution and presence combined with an atmospheric sound-stage that makes for a totally immersive experience. This valve synergizes quite well with my rig.


  5. Beautiful!

    Posted by David

    Just plugged these into my Mac C22 a few days ago to replace the Telefunken smooth-plate 12AX7s that were in there for YEARS. I've never heard such a beautiful mid-range in my life. WOW! Went through every Ella Fitzgerald and Carmen McRare LP and CD I own and still can't believe my ears!


  6. none

    Posted by Les Lammers

    This tube is excellent in the MA2275 McIntosh integrated and would be great in the new MC275 IV.


  7. Best 12AX7 I've ever used

    Posted by Robert H. Levi

    I am gob smacked by this perfect 12AX7 tube. As the key tube in my EAR 834L line stage it clearly communicates musical versamilitude! Best 12AX7 I''ve ever used, clean and clear from 20-20k hertz. Marvelous and worth its weight in gold coin.


  8. Serious upgrade!

    Posted by Rieck Staehle

    I am totally pleased with this 12AX7, I have it in a Zman Audio Signal Enhancer, and this is an UPGRADE! Thanks, Kevin for all your help and fine products! Your info, on the tubes and testing, was very helpful. Keep up the good work!!


CRYOGENICALLY TREATED VACUUM TUBES. DONE TO UPSCALE AUDIO STANDARDS!


cryotubessmall.jpgMost of you already know that Upscale Audio is the premier destination for expertise and availability of vacuum tubes for high-end audio equipment. So when we offer servies and options, you can be guaranteed that it represents a significant investment of research and capital, and that the end result will greatly enhance your listening experience.

Upscale has contracted with the foremost company involved in this technology, 300 Below, to treat our most popular tubes.  Other tubes will be added as time allows, but it is a time consuming proccess.  Our intention is to have most stocks Cryogenically treated before we even test them.  

 

Of course, your first question is – and should be – why?  In a nutshell, reducing an object’s temperature to -300ºF re-arranges its molecular structure, creating greater uniformity that results in longer life and better performance than when the product was initially designed.With vacuum tubes, this process has a profound impact on a tube’s ability to endure thermal shock. Therefore, tubes can last longer and their sound can been enhanced in ways that are simply exquisite.

After thoughtful and thorough research, Upscale Audio chose 300 Below because of their extensive experience in working with musical instruments as well as auto racing, metal tooling, and high-end sporting goods from rifle barrels to golf clubs.  Expect nothing but the best from Upscale Audio.

Our charge for Cryogenically treating tubes is a fraction of what others charge, though we use the premier company.  Count on Upscale to do the best job and not price gouge .  Also available is cryogenic treatment for cables, along with our well-known Nordost Vidar cable treatment system.  Call for details. Pricing is listed on each tube and cable page. 


Warranty Information

Vacuum tubes are warranted for 90 days against defects, except in cases of abuse, and replaced with like-item only.

  • Tubes being sent in for warranty must have a return authorization number from Upscale Audio. This RA number must be written on the outside of the box. Please also include a note in the box that has your name and telephone number, and please explain the issues with the tube. If this information is missing it will delay the shipment of your replacement tube.
  • Vacuum tubes being sent to Upscale Audio for warranty replacement must be shipped in a box with appropriate packaging to keep them from being damaged. Vacuum tubes returned to Upscale Audio using inadequate packing will have a voided warranty and will be refused at the customer's expense.


Exceptions to our warranty policy are as follows:

  • Upscale Audio reserves the right to refuse warranty at our disgretion based on the equipment being re-tubed. You will be notified of any change prior to your order being processed.
  • Using a tube in an application in which it was not meant to be used. If your amp calls for a 6550, and you decide you want to plug in a 6V6GT, Upscale Audio is not liable if the tube fails, and will not honor any warranty in such a situation.

Upscale Audio is not liable for any damage or injury caused by the improper use of its tubes or the use of an incorrect/incompatible tube type. If you are unsure of what tube or tubes your equipment uses, consult the manufacturer before making a purchase. Using an incompatible tube type may cause severe damage to your equipment and will void your tube's warranty.


vacuum tube returns for refund:

Vacuum tubes are electronic parts and are not refundable under any circumstances.

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