Mullard CV4004 / 12AX7 Preamp Vacuum Tube
From our review: "The smaller plates reduce noise. They are dead quiet both electrically and mechanically. Nice thick bottles and well aligned internals also help. If you currently like the Tung-Sol 12AX7 preamp tube you will love this tube. The gain is similar but overall it is quieter and a bit warmer to my ears."
From the manufacturer: "The CV4004/12AX7 is a high gain, low noise valve with a short plate structure for reduced microphonics. Excellent for use in high gain Marshall pre-amplifier circuits where noise and microphonics can be a problem. Best for guitar amps."
The Mullard name and trademark have been acquired by the New Sensor Corporation. This new production Mullard CV4004 tube is manufactured at their Xpo-Pul factory (also known as Reflektor) in Saratov, Russia. New Sensor is an American corporation and since taking ownership of this factory has been steadily improving the quality of current production tubes.
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Warranty Information and Return Policy
Warranty Period: 3 monthsAll our tubes are guaranteed for 3 months from the date of purchase. (Any exceptions will be noted on that tube's Warranty tab)
If you receive a tube that does not perform to the manufacturer's specifications, please do the following:
- contact us to get a return authorization
- return it via regular mail within 90 days from when we shipped it, and we will provide an exchange or refund of the full purchase price of the tube.
Returns not related to warranty or defect will be considered at our discretion, and are subject to a 15% restocking fee.
We can not accept returns that don't have an authorization, are past 3 month, or are returned improperly.
These guidelines may be updated without notice.
Ratings & Reviews
16 reviews
Mullard CV4004 / 12AX7 | Perfect for V1 socket in highgain amps
by Bashar -
I contacted the folks at TheTubeStore for a recommendation for a 12AX7 tube to put in the V1 of my Egnater Armageddon to help tighten the amp up but at the same time give it some punch, smooth out the gain and take away the harshness. They recommended the Mullard MU-CV4004-12AX7.
Their recommendation was bang on. Cranked in the amp tonight and what a world of difference compared to the JJ ECC83S that was in the V1. the harshness is gone. The sound is more open and wide, yet punchy and tight. Smoothed the gain out without taking away gain... if anything, these tubes added a bit more useful gain to the amp.
Highly recommended..
Mullard CV4004 / 12AX7 | The Goldilocks Zone for a VOX NT15H Finally Achieved
by Frank Lee -
I've gone down the rabbit hole with a Vox NT15H (v1), checking out just about every tube, every speaker that's easily accessible, and I finally feel as though I have this amp dialed in. (Contrary to what many might say, no matter what tubes or speaker used, it is very much like an AC15; and in its bright mode, it does wonderfully Voxish clean chime and top-boost crunch. In its thick mode, it also does a pretty good crunchy tweed-like thing -- with the wrong speaker, wrong tubes, it only gets about 75-85% of the way there, though -- with the wrong stuff, you can also achieve ice-pick highs and honky, cocked-wah-like mids, so I understand the mixed views on this amp). But with these MU-CV4004-12AX7s, Mullard's EL84s and an Alnico Blue or Weber Bluedog, I've finally found this amp's right stuff. She's finally in the proper Goldilocks zone. (For those curious, JJ's EL84s and 803S large-plate preamp valves were very close, coming in second place for me.)
Mullard CV4004 / 12AX7 | Marshall + Mullard = Melodious
by Joseph Weldinger -
I purchased a matched pair of these MU-CV4004-12AX7 along with a matched and balanced quad set of Mullard CV4004/12AX7 tubes for my Marshall JCM602 combo, and after slightly adjusting the bias back to the referenced -42V I am very pleased. The clean channel sounds much better, i.e. the bass response is punchy and tight while the mids are well balanced, and the highs are sharp and crisp. In relation to the stock Svetlana tubes, the overdrive channel does lose just a tad of that trademark Marshall tone to my ears, but overall I consider the tradeoff to be well worth it.
Mullard CV4004 / 12AX7 | Excellent in Orange Rockerverb MKIII
by John
Wow! Absolutely perfect 12AX7 tubes for this amp (clean and both dirty channel positions) and they sound fantastic! I'll be using these from now on. They are exactly the sound I have been looking for - smoother and much more full sounding than Tung-Sol's in these positions, without question.
Nice Valve
by Tin
Used this as a replacement for a AVT 275. A whole lot less noise. Made for even nicer clean ranging from tweedy to voxy. A hair less gain on OD1&2= cutting down on the muddy OD 2. Which made for some sweet ZZ-tone with the treble cut out.