Mullard

New Mullard CV4004 / 12AX7 Reissue Vacuum Tube

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SKU:
NP035-1
UPC:
696227971973
MPN:
CV4004
Shipping:
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Was: $25.67

Description

New Gain Tested Mullard CV4004 / 12AX7 Vacuum Tube

Out of the two variations of Mullard's 12AX7 model, this tube (CV4004) is particularly great for guitar amplifiers. The CV4004 is the military designation for the 12AX7 and is its ruggedized counterpart which is modeled directly after the British military's 12AX7. Its short plate design cuts down on noise and microphonics which is especially important for this tube as these skew higher on their gain rating. With a sweet sound, they rival their originals.

Will work in place of: CV4004, 12AX7 Short Plate, 12AX7, ECC83, 12AX7A, 7025, 12AX7WA, 12AX7WC, 12AX7WB, ECC803S, CV4004, CV492

Testing and/or Matching

At VIVA TUBES, all of our customers get the same high standard of testing and matching. Some sellers charge more for premium matches but we believe all of our customers should get the same level of quality and service. 

Tubes are tested and/or matched at full operating voltage with regulated power supply on a Maxi Matcher tester for general mutual transconductance (Gm). In addition, power tubes are tested/matched by plate current (Ip) and preamp tubes are tested/matched by gain. Rectifier tubes will be tested for emissions on a calibrated military grade tube tester. 

Our goal is to match within 5% with an upper limit of 15% (15% is the industry limit to consider a set).

Hand written test data included.

Note that we do offer a few models which are tested & matched at the factory. They will be matched by the same parameters (Ip & Gm) but to the manufacturer's standards. Factory testing will be indicated in the item title and description. 

Guarantee

We offer a minimum 90 day guarantee covering functional defects - including noise unless otherwise stated. The guarantee period begins the day you receive your order.

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Additional Information

reverb_offer:
offreverb_condition=Brand New"
reverb_shipping_profile:
$12.99
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on
Item Type:
Vacuum Tubes
Production Era:
New/Current Production
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1 Review

  • 5

    Great tube

    Posted by Stewart on 7th Feb 2026

    I'm sharing this review because I haven't seen enough about this tube out there. I'm quite a fan of the New Sensor tubes as I don't have endless dollars to experiment with NOS, although I have on occasion. I have found the TungSol re-issues to be highly reliable and very musical. I also have used the long plate Mullard 12AX7/ECC83 tubes happily, especially when I want a more gainy sound. The sonic spectrum of these CV4004 tubes is pretty darn close to the long plate version, but they almost dead quiet comparitively. To me, that's gold. I think it's a taste issue of which tube you would use where, but I rotated several tubes through the phase inverter section of my 6V6 amp (also using Tung-Sol reissue tubes there) and these are a perfect sonic match for the 6V6 tubes. These are a short plate tube, so fine to use in a combo amp, and I don't think I'm hallucinating that the bottle seems a bit more stout, as it should in what is supposed to be a repro of the military spec tubes. Oh yeah, working with Viva tubes is also seemless, but you all already know that....

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