JJ ECC803S / 12AX7

16 Reviews
Out of Stock
USD $‎19.95
A premium quality ECC803 tube that replaces any 12AX7 / ECC83 tube type. The JJ ECC803-S is a warm, full sounding tube, with high-gain. It's great sounding in hifi amps and guitar amps (guitar players see note below).

Note: Because this tube has a long plate structure it is susceptible to excessive microphonics and is therefore not recommended for use in combo amps or high gain stages. For these amps the JJ ECC83-S is a better choice.

Other JJ Electronics tubes12AX7 Types

Additional Information and Downloads

12AX7 Tube Review

Tube Matching Information:
Matched Sections Service

JJ ECC803S / 12AX7 Datasheet (PDF)

Download Adobe Acrobat PDF reader

Warranty Information and Return Policy

Warranty 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

16 reviews

  • 3 stars
  • 0 reviews
  • 2 stars
  • 0 reviews
  • 1 star
  • 0 reviews

An NOS sound without an NOS pricetag


I bought a pair of these to replace some NOS Sylvania 12AX7 tubes that were in my EAR 534 amp. The Sylvania tubes were flat and non-involving. At the price of the JJ tubes I figured if they too were non-involving I was not anything. Wow! I could not have been more wrong! After about a 12-20 hour break-in period these tubes just got better! They give me nice detail in the music, are warm and inviting when the music calls for it plus they give a nice large impression of the music. I think these are better than some NOS tubes I have tried and the best thing yet, they are quiet! No tube rush like many NOS tubes and no NOS price tag. If you have a piece of equipment that needs a 12AX7 tube, I would look to these. Great price, great sound and so far they have been reliable performers.

One of the greatest JJ tube for phase inverter for Mesa rectifiers


I really love the way this ECC803s tightens the sound of Mesa rectifier in Phase inverter V5 position. NEVER heard that amp sound so good and I’m not just talking about little subtle changes
Unbelievable 😳 no more boomy bass especially on palm muting
It’s a really AWESOMENESS to play my amp now 😃
These JJ ECC803s should be already installed in all Mesa recto’s from Petaluma Mesa factory
Thanks for the very quick shipping

Good value, great sound.


I have two SWR Grand Prix bass preamps I use in my stereo extended range bass rig, which also is full range enough for reproducing pre-recorded full ensemble music. I have been using the gold pin version of these tubes. Wonderful sound. They last about a year before degrading and exhibiting audible changes. I decided to try the standard pin version. Very balanced reproduction when new at a 50% reduction in cost. Even if the replacement interval is the same, a cost effective way to save money and get the sound you want.

Great tube for harsh Fenders

by -

For 20 years I have been unhappy with the way my strat sounded through my favorite amp. Very shrill and harsh. After reading the reviews, I decided to give these a try. Wow, exactly as advertised. Full smooth clear top end without the cringe. Thank you !!

This will wake up your Marshall Plexi


this is actually a pretty good sounding tube. i find them sonically clearer than Tungsol or Mullard reissue. I use ECC803S on all preamp tube slots in my Fargen Super Lead/Bass. Slightly a hair less gain than the Tungsol or Shuguang 12ax7b, but the clarity of the notes sounded better to my ears. I find the high and low end almost “even” with a singing midrange which is great for soloing. They crunch up well without that “hazy” undertones of the regular JJ ecc83. Dime the gain/preamp volume, the saturation is there without the fuzziness.