Vacuum Tube - ECC803 / 12AX7, JJ Electronics, Long Plate

JJ Electronics
Pictured: Regular
Pictured: Regular
Pictured: Gold
Pictured: Gold
Pictured: Regular
Pictured: Regular
Pictured: Gold
Pictured: Gold
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Vacuum Tube - ECC803 / 12AX7, JJ Electronics, Long Plate

Starting at: $13.95
In stock

The JJ Electronic ECC803 is a high performance, long plate version of the ECC83 / 12AX7. Like all JJ preamp tubes, these are built into a rugged package using the spiral filament and robust plate structure resulting in low microphonics and high reliability. The long plate version of this tube differs from the standard version with its stronger and fuller sound which offers a wider and more balanced frequency response. This tube ranges from deep rich lows to pristine highs covering a spectrum of harmonically dynamic mids along the way. This tube is an excellent choice for any guitar amp and perfect for studio and Hi-Fi equipment as well. This tube will work in any 12AX7 or ECC83 position.

RoHS Compliant
Item ID:
JJ Electronics
Part Numbers
Pin TypeOur Part NumberUPC/EANJJ Electronics Part Number
GoldT-ECC803-GLD-JJ609722123556 ECC803S - GOLD
RegularT-ECC803-S-JJ609722126533 ECC803S - GOLD
Product Measurements
Body Height51.2 mm
Cathode Current (Ik)≤ 9 mA
Filament Current (If)300 / 150 mA
Filament Voltage (Uf)6.3 / 12.6 V
Gain (μ)100
Grid Circuit Resistance (Rg)2,2 MΩ
Grid capacitance (cg1)1.6 pF
Grid to Plate Capacitance (ca/g)1.7 pF
Heater to cathode voltage (Uk/f)≤ 100 V
Internal Resistance (Ri)62.5 kΩ
Item Diameter22.2 mm
Item Height57.6 mm
Plate Capacitance (ca)0.46 pF
Plate Current (Ia)1.2 mA
Plate Dissipation (Wa)≤ 1.2 W
Plate Voltage (Ua)≤ 300 V, 250 V typical
Transconductance (S)1.6 mA/V
Packaging Information
Packaging Dimensions1 in. × 1 in. × 2.5 in.
Weight (Packaging)0.029 lbs.

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Specifications, Files, and Documents

PDF: Specification Sheet Specification Sheet435.17 KB

Questions and Answers

Click each question to see its answers.
Asked by Anonymous on October 13th, 2016.
Matt H
October 13th, 2016
Hi, preamp tubes are typically not matched but are balanced. Unfortunately, we do not match or balance preamp tubes.
Asked by Anonymous on October 13th, 2016.
Matt H
October 13th, 2016
Experimenting with preamp tubes is always a good idea if you dislike certain characteristics of your sound. Going with a tube lacking in lows would definitely help the situation.
Asked by Anonymous on March 30th, 2017.
Matt H
March 30th, 2017
Yes, if the S6 calls for 12AX7's these will be compatible.
Asked by knotscott on January 29th, 2020.
January 29th, 2020
Staff Member
Yes, that is correct. These are indeed made in Slovakia.

Product Reviews

5.00 out of 5 based on 5 reviews
- March 6th, 2015
5 out of 5

I bought this tube to test in my Blackstar HT-5R along with a few others to see what they would do to the tone. The HT-5R only has one pre-amp tube. This tube won out. I love this tube. Very nice smooth breakup and it keeps the clarity per notes ringing. Really good smooth 'Plexi' sounding tube in the Blackstar. Very happy.

- October 19th, 2011
5 out of 5

The JJ ECC803S (long plate. this is the wrong picture) is THE best new manufactured preamp tube available. They perform every bit as well as my late production Sylvania and GE tubes, and who could really ask for more than that. The attack, the detail and resolution which are so obviously absent from most mushy sounding new preamps are all here in the JJ. Overall tone and gain are better than with the more common ECC83 short plate tube and the overall soundstage genuinely compares very well to the old American tubes. This is the the standard that other manufacturers should be following.

- July 30th, 2010
5 out of 5

Fantastic, fast service; great bargain! Amplified Parts will be my starting point for any tube purchase/advice.

- July 13th, 2010
5 out of 5

I had a regular JJ ECC83 in my bass head that I replaced with the long plate version. There was a noticeable difference in my tone - it was less compressed and there was more headroom. I did not expect to hear such a difference. This is a great tube!

- June 30th, 2010
5 out of 5

This is my favorite preamp tube. Imagine if a NOS RCA 12ax7 and a Telefunken Smooth plate made love. This would be that love child. Totally smooth and rich sweet tone. Gain is full and robust but not overpowering. Highs are sweet and super dynamic, mids are strong, lows are deep and bassy. Like I said - Mother Of All 12ax7s!

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