Pictured: Regular
Pictured: Gold
Pictured: Regular
Pictured: Gold
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Vacuum Tube - 12AX7 / ECC83, JJ Electronics
The JJ Electronic 12AX7 / ECC83 has quickly become a modern classic in preamp tubes. Its rugged design and rich harmonics make this tube an obvious choice for musicians who need a reliable and high quality tube at a reasonable price.
The balanced tone of the JJ 12AX7 works well in any amp. This versatile tube sounds excellent in clean amps offering an amazing dynamic response while also proving itself in high gain amps with its low noise and noticeably less microphonic issues than other tubes. The warm highs and transparent lows make it a great choice for any position in a tube amp. The JJ 12AX7 is the go-to tube of many amp builders and touring musicians.
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Accessory Items:
| Pin Type | Our Part Number | UPC/EAN | JJ Electronics Part Number |
|---|---|---|---|
| Gold | T-12AX7-GOLD-JJ | 797734820959 | ECC83S / 12AX7, 7025 - GOLD |
| Regular | T-12AX7-S-JJ | 844632022081 | ECC83S - 12AX7, 7025 |
| Body Height | 49.2 mm | |
| Cathode Current (Ik) | ≤ 8 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 Voltage (Ug) | ≥ -50 V, -2 V typical | |
| Heater to cathode resistance (Rk/f) | 150 kΩ | |
| Heater to cathode voltage (Uk/f) | ≤ 180 V | |
| Internal Resistance (Ri) | 62.5 kΩ | |
| Item Diameter | 22 mm | |
| Item Height | 56.3 mm | |
| Plate Current (Ia) | 1.2 mA | |
| Plate Dissipation (Wa) | ≤ 1 W | |
| Plate Voltage (Ua) | ≤ 300 V, 250 V typical | |
| Transconductance (S) | 1.6 mA/V |
| Packaging Dimensions | 1 in. × 1 in. × 2.5 in. | |
| Weight (Packaging) | 0.032 lbs. |
| T-12AX7-S-JJ - Regular version | Body Height | 49.2 mm |
| Cathode Current (Ik) | ≤ 8 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 Voltage (Ug) | ≥ -50 V, -2 V typical | |
| Heater to cathode resistance (Rk/f) | 150 kΩ | |
| Heater to cathode voltage (Uk/f) | ≤ 180 V | |
| Internal Resistance (Ri) | 62.5 kΩ | |
| Item Diameter | 22 mm | |
| Item Height | 56.3 mm | |
| Plate Current (Ia) | 1.2 mA | |
| Plate Dissipation (Wa) | ≤ 1 W | |
| Plate Voltage (Ua) | ≤ 300 V, 250 V typical | |
| Transconductance (S) | 1.6 mA/V | |
| T-12AX7-GOLD-JJ - Gold version | Body Height | 49.2 mm |
| Cathode Current (Ik) | ≤ 8 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 Voltage (Ug) | ≥ -50 V, -2 V typical | |
| Heater to cathode resistance (Rk/f) | 150 kΩ | |
| Heater to cathode voltage (Uk/f) | ≤ 180 V | |
| Internal Resistance (Ri) | 62.5 kΩ | |
| Item Diameter | 22 mm | |
| Item Height | 56.3 mm | |
| Plate Current (Ia) | 1.2 mA | |
| Plate Dissipation (Wa) | ≤ 1 W | |
| Plate Voltage (Ua) | ≤ 300 V, 250 V typical | |
| Transconductance (S) | 1.6 mA/V |
 Specification Sheet for Regular | T-12AX7-S-JJ |
| Specification Sheet for Gold | T-12AX7-GOLD-JJ |
My Project Lists
Specifications, Files, and Documents
Questions and Answers
Click each question to see its answers.
3 answers
Will I have to rebias my Mesa Boogie Dual Rectifier 100watt amp head once I put these in. Also how well do they work in a Mesa Boogie Dual Rectifier 100 watt amp head.
Thank you for your time and effort.
Asked by Anonymous on November 11th, 2016.
No, the only time you might need to rebias is when you are replacing power tubes.
Will I have to rebias my EVH 5150 III amp if I put these in
No, the only time you might need to rebias is when you are replacing power tubes.
1 answers
I need to retune a Tweed Blues Jr. It currently has JJ pre amp and power amp tubes. I'd like to put the TAD EL-84's in. What preamp tubes would you recommend? (12ax7). I'd like to have a crunch to the tone and natural breakup when on the edge of a clear tone, if that helps. More depth to the tone also, that the JJs seem to currently lack.
Thanks,
Matt
Asked by Anonymous on May 27th, 2016.
June 1st, 2016
Staff MemberTop Contributor
I would suggest checking out our tech corner article comparing preamp tubes. Personally I have Tung Sol 12AX7's in mine and I think they are great for the Blues Jr. You also couldn't go wrong with the TAD premium selected 12AX7's.
1 answers
Are these matched or balanced?
Asked by Anonymous on August 24th, 2016.
Hi, we only match power tubes and do not balance preamp tubes.
1 answers
The numbers seem to match up, but will these work in my Orange BT500 Bass Terror Amp?
Asked by Anonymous on May 2nd, 2017.
Yes, according to the Orange website you amp takes two of these tubes.
1 answers
Hi, I haven't been able to find anywhere in the web a straight answer about the actual technical difference between regular and gold versions of these great tubes. I don't mean the difference on how they compare soundwise, but on the technical paper: Is it just the gold coated pins and the rest is the same? are gold pins maybe factory selected under another criterion before gold coating? etc... Thank you very much! Your tube comparison chart is awesome!
Asked by Anonymous on May 16th, 2017.
The pins are gold and this helps to prevent corrosion and buildup on the tubes pins. Other than the pins, they are the same tube as compared to the regular pin version.
1 answers
Will this fit in the space of a Traynor dynabass 400T?
Asked by Anonymous on May 24th, 2017.
When plugged in this tube has the following dimensions: 1.94" (49.2mm) x 0.87" (22mm). You will want to measure your existing tubes to insure a proper fit.
1 answers
Is this the ecc83-s or the ecc83? the image shows its the ecc83-s but the title reads ecc83.
Asked by Anonymous on August 25th, 2017.
The S stand for spiral filament and refers to the internal construction. This will work in any situation where an ECC83/12AX7 is needed.
1 answers
I bought my first tube amp, will these tubes help my vht special 6 sound less boxey/muddy so i can get more tone?
Asked by Anonymous on October 6th, 2017.
Tube characteristics can be different from brand to brand, and because the tone of tubes can be highly subjective, we can not verify if these tubes will get you your desired tone. You can visit the "Tech Corner" of our website for a 12AX7 comparison of current made tubes. This has a wealth of information to help you make a decision.
1 answers
What is the difference between the 12ax7 and the 12ax7-s ?
Asked by Anonymous on February 16th, 2018.
The plate design on these is slightly more compact but function just like any other 12AX7.
1 answers
I have Bedrock 600 amp with 415v plate voltage. What power tubes would you recommend?
Asked by Anonymous on June 25th, 2018.
June 26th, 2018
Staff Member
All information we were able to find on a Bedrock 600 stated that it uses EL84 power tubes.
1 answers
I have an older 80's Dean Markley amps signature series 60 that needs new tubes need to go high gain pre amp tubes & loud clean power amp tubes... what you suggest??
Asked by Anonymous on July 20th, 2018.
July 20th, 2018
Staff Member
Please see our 12AX7 comparison chart that has current production 12AX7's listed by gain rating found here https://www.amplifiedparts.com/tech-corner/12ax7-comparison-current-made-tubes
Substitute Products
The following items can be substituted for this product. While not necessarily exactly the same, they will function as replacement items in your project.
12AX7 - TAD Tubes, Premium Selected (T-12AX7-PS-TAD)
Product Reviews
Installed the tubes...............Work/sound great!!!!!!!!!!!!
JJ Tubes are always well made and deliver great tone. Both my amp (vox ac30) and the korg sv1 needed new 12AX7's so I ordered 4 (one as a spare as well.) The stock tubes that were replaced had seen their time come and go with the tube in the pre-amp of the korg blown. While getting into the guts of the keyboard was ridiculous (bad design flaw on Korg's part considering there is a "cute" window to see the tube glowing - you cannot access the tube from the front for an easy fix (enough of that gripe,) once the new JJ tube was installed and the keyboard reassembled, the difference was incredible immediately! With the vox, not so much because I already had JJ's in there for the pre-amp drive. All in all, JJ tubes are fantastic - clean pure tones and powerful delivery! Amplified Parts is a big part of this equation - their tube comparison charts, customer service and product lineup are top notch. Shippng was fast (we needed these in place in 3 days so I opted for 2 day shipping) and we were back up in running right on schedule. Thanks to everyone at Amplified Parts for a job well done!
The jj83s is an excellent 12ax7 preamp tube, low microphonics, high gain with compression. Use in my Bogner 101b and Fuchs custom Wildcard 100 D style amp in gain channel. Highly recommend this tube.
Great tubes for Blackstar amp. The gold connectors make a big difference.
Great tube replacement for my Jolida 1501 BRC integrated amp. The gain is lower than the Tung Sols that were there before, and that's what I was trying to achieve. The tubes sound very good right of the bat, then improve with the break in.
Highly recommend these tubes if you're looking to lower your gain.
Solid, economical and consistent. Love their tone in my Peavey 5150II amp.
Spare replacement tube, arrived in good shape!
Purchased to re-tube a block letter 5150. Tubes arrived next day and were extreme well packaged! The amp sounds absolutely incredible!
I put this in my 50 year old Harmony 410A amplifier. This was a drop in replacement for the tube that was originally in the amp. Now my first amplifier from childhood that ended back in my hands after many many years is functioning perfectly.
Really happy with the service from Amplified Parts. This was my first order with them, and I got an order confirmation very quickly, and their site was very good at providing updates. My tubes were shipped the same day I ordered them and they arrived faster than I expected. Thanks!
I was previously running Groove Tube 12AX7's in my amp but see the JJ's highly recommended across various guitar forums I visit. I bought a complete set of 12AX7's and EL84's. I really didn't expect much of a difference, but boy was I surprised. After I plugged these in, my tone was night and day difference over the groove tubes. My amp has never sounded so good, and I didn't want to stop playing. It sounded much more alive, bright, and with a better mid-range punch. These were the gold pin JJ's and I have not compared them to their standard 12AX7's, so I'm not sure how much, if any, a difference the gold pins make. I might try the standard tubes next time just to see if the additional cost is worth it. Bottom line, you won't be disappointed with either JJ tubes or the service from Amplified Parts.