Mullard CV4003 / M8136 / 12AU7
The NOS Mullard CV4003 (M8136) tube is a British military grade ECC82 / 12AU7 tube type. This 12AU7 tube has box plates which seem to improve resistance to microphonics and noise. They were produced in Mullard's Mitcham factory during the early 1980's.
The Mullard CV4003/M8136 tube has a deep and expansive soundstage, with overall fantastic definition. The lows are defined while the mids and highs are liquid smooth, just leaning to the warm side of neutral.
Other Mullard tubes12AU7 Tube Types
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Warranty Information and Return PolicyWarranty Period: 3 months
All 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
Best tube for Jazz enthusiasts.....
by Lalit -
Beautiful sounding tube. I end up preferring the Mullard over RCA clear top ( known for top high-end extn.) The Mullard’s were slightly laid back yet detailed with spot on tonality. These lean towards bit warm presentation. If you prefer a slightly laid back and relaxed sound, this is your tube. No listening fatigue here.
I bought 2 of these to put in my rouge audio sphinx v2. made a huge difference from the stock ecc802s JJ tubes, less forward and not as bright. Very big soundstage added a little warmth to the top end while still being quite detailed. Midrange is magic as many others have described on other forums