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Upscale Certified Tubes

Brimar CV4003 / 12AU7

Brimar CV4003 / 12AU7

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Regular price $140 In stock now!
Regular price Sale price $140 In stock now!
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Cryogenic Treatment

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This product is limited to a quantity of 6 at this time. Any additional quantity will be removed at checkout.

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Brimar CV4003/12AU7

The Tube Gods have BLESSED US!!! There won't be many reviews of this tube because I have not had them FOREVER, and just found a small stash. But you gotta listen - those in the know will tell you Brimar and their sister companies like Ediswan made BAD ASS stuff!


OK kiddies….I had some of these years ago, and we blew through them really fast. This is the classic Brimar 12AU7 made in England in the 60’s . If you want to know how these sound, they are like the Ediswan CV2492/6922: Incredibly pleasant, wonderful, pleasing mids with zero harshness. When I listen to these, it reminds me of a girl I knew once that would touch the back of my neck. They are that nice. I have to say something here. I’ve seen a flying lead version being sold with an adaptor on the bottom. It’s the exact same tube. But uses an adaptor soldered on to the bottom. I had some offered to me but passed. Soldering those leads isn’t exactly the cleanest way to do things. Why would you want an adaptor on the tube leads? That’s fine to use later after these dissapear from the market, but not now while you can get the real deal.

Each tube is graded carefully on both an Amplitrex AT-1000 and a Triplett 3444a. After that we grade for noise and microphony by ear with headphones in a single-tube moving coil phono stage circuit where the tube is really under a microscope and listed to with headphones.

Price is for a single tube. Tubes come in generic white boxes, not the ones pictured. Price includes matching in any quantity you need at no extra charge.

ATTENTION! These tubes are packaged with black plastic pin protectors covering the pins. This was a very common method of packaging tubes for the British military. The pin protector just slides off.

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.

Special CJ Test - For guys with Conrad Johnson or Rogue preamps, you want this grade. The absolute tightest triode balance, with the lowest noise and microphony. Then we put these tubes through another special test to ensure they stay low in microphony.

Driver/Buffer 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.