Vacuum Tube - EL84, Tube Amp Doctor

Vacuum Tube - EL84, Tube Amp Doctor

Tube Amp Doctor (TAD)
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Customer image:<br/>"TAD EL84STR"
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Customer Images:
Customer image: "TAD EL84STR"
Starting at: $18.90
In Stock

Tube Amp Doctor opted for the thickest glass possible and the heaviest construction available, just like the Russian EL84M, and combined these features with the sonically most promising cathode plate options, in order to meet and exceed the tonal quality of the EL84-Cz. Finally, Tube Amp Doctor added the gold grid wire in order to improve overall reliability. The sound can be described as very harmonic in the middle and treble frequencies, without adding too much power to the bass. The result is the best EL84 in current production.

No Compromise!

Q: When does a power tube become a Premium Selected power tube?
A: All power tubes labeled Premium Selected have passed the following tests:
- Plate Current (PC) and Amplification (TC)
- Low Noise Test
- Microphonic Test
- Sonic Tests
- Shock Tests
- Listening Tests
- Shorts & Leakage Tests

SKU:
T-EL84-TAD-X
Item ID:
004858
Brand:
Tube Amp Doctor (TAD)
Type:
Part Numbers
Single or MatchedOur Part NumberUPC/EANTube Amp Doctor Part Number
Matched PairT-EL84-TAD-MP609722123457
Matched QuadT-EL84-TAD-MQ609722123464
SingleT-EL84-TAD609722123440 RT871
Product Measurements by Type
Body Height71 mm
Cathode to Heater Voltage≤ 100 V
D.C. Cathode Current, AF Power Amplifier65 mA
D.C. Plate Voltage, AF Power Amplifier420 V
Grid 1 (control) Voltage, Af Power Amplifier-100 V
Grid 1 Control Voltage, Class A1-4.8 V
Grid 1 to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 10.8 pF
Grid 1 to Plate Capacitance< 0.5 pF
Grid 2 Dc (screen) Dissipation, Af Power Amplifier2 W
Grid 2 Dc (screen) Voltage, Af Power Amplifier300 V
Grid 2 Screen Voltage, Class A1250 V
Heater Current0.76 A
Heater Voltage5.8 V - 6.8 V, 6.3 V nominal
Item Diameter22.5 mm
Item Height77 mm
Load Resistance, Class A15.2 kΩ
Output Power (POut) @ 5% Distortion, Class A15.7 W
Peak AF Grid 1 Control Voltage, Class A114 V
Plate Dissipation, AF power amplifier (Wa)12 W
Plate Voltage, class A1 (Ua)250 V
Plate to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 6.5 pF
Signal Plate Current, Class A1, maximum80 mA
Transconductance, Class A1 (S)9 mA/V
Zero Signal Grid 2 Screen Current, Class A110.8 mA
Zero Signal Plate Current, Class A149.5 mA
Packaging Information
Packaging DimensionsMatched Pair versionT-EL84-TAD-MP1 in. × 2 in. × 3.3 in.
Matched Quad versionT-EL84-TAD-MQ1 in. × 4 in. × 3.3 in.
Single versionT-EL84-TAD3.25 in. × 1 in. × 1 in.
Weight (Packaging)Matched Pair versionT-EL84-TAD-MP0.1 lbs.
Matched Quad versionT-EL84-TAD-MQ0.2 lbs.
Single versionT-EL84-TAD0.05 lbs.
Product Measurements by Item
T-EL84-TAD - Single versionBody Height71 mm
Cathode to Heater Voltage≤ 100 V
D.C. Cathode Current, AF Power Amplifier65 mA
D.C. Plate Voltage, AF Power Amplifier420 V
Grid 1 (control) Voltage, Af Power Amplifier-100 V
Grid 1 Control Voltage, Class A1-4.8 V
Grid 1 to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 10.8 pF
Grid 1 to Plate Capacitance< 0.5 pF
Grid 2 Dc (screen) Dissipation, Af Power Amplifier2 W
Grid 2 Dc (screen) Voltage, Af Power Amplifier300 V
Grid 2 Screen Voltage, Class A1250 V
Heater Current0.76 A
Heater Voltage5.8 V - 6.8 V, 6.3 V nominal
Item Diameter22.5 mm
Item Height77 mm
Load Resistance, Class A15.2 kΩ
Output Power (POut) @ 5% Distortion, Class A15.7 W
Peak AF Grid 1 Control Voltage, Class A114 V
Plate Dissipation, AF power amplifier (Wa)12 W
Plate Voltage, class A1 (Ua)250 V
Plate to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 6.5 pF
Signal Plate Current, Class A1, maximum80 mA
Transconductance, Class A1 (S)9 mA/V
Zero Signal Grid 2 Screen Current, Class A110.8 mA
Zero Signal Plate Current, Class A149.5 mA
T-EL84-TAD-MP - Matched Pair versionBody Height71 mm
Cathode to Heater Voltage≤ 100 V
D.C. Cathode Current, AF Power Amplifier65 mA
D.C. Plate Voltage, AF Power Amplifier420 V
Grid 1 (control) Voltage, Af Power Amplifier-100 V
Grid 1 Control Voltage, Class A1-4.8 V
Grid 1 to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 10.8 pF
Grid 1 to Plate Capacitance< 0.5 pF
Grid 2 Dc (screen) Dissipation, Af Power Amplifier2 W
Grid 2 Dc (screen) Voltage, Af Power Amplifier300 V
Grid 2 Screen Voltage, Class A1250 V
Heater Current0.76 A
Heater Voltage5.8 V - 6.8 V, 6.3 V nominal
Item Diameter22.5 mm
Item Height77 mm
Load Resistance, Class A15.2 kΩ
Output Power (POut) @ 5% Distortion, Class A15.7 W
Peak AF Grid 1 Control Voltage, Class A114 V
Plate Dissipation, AF power amplifier (Wa)12 W
Plate Voltage, class A1 (Ua)250 V
Plate to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 6.5 pF
Signal Plate Current, Class A1, maximum80 mA
Transconductance, Class A1 (S)9 mA/V
Zero Signal Grid 2 Screen Current, Class A110.8 mA
Zero Signal Plate Current, Class A149.5 mA
T-EL84-TAD-MQ - Matched Quad versionBody Height71 mm
Cathode to Heater Voltage≤ 100 V
D.C. Cathode Current, AF Power Amplifier65 mA
D.C. Plate Voltage, AF Power Amplifier420 V
Grid 1 (control) Voltage, Af Power Amplifier-100 V
Grid 1 Control Voltage, Class A1-4.8 V
Grid 1 to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 10.8 pF
Grid 1 to Plate Capacitance< 0.5 pF
Grid 2 Dc (screen) Dissipation, Af Power Amplifier2 W
Grid 2 Dc (screen) Voltage, Af Power Amplifier300 V
Grid 2 Screen Voltage, Class A1250 V
Heater Current0.76 A
Heater Voltage5.8 V - 6.8 V, 6.3 V nominal
Item Diameter22.5 mm
Item Height77 mm
Load Resistance, Class A15.2 kΩ
Output Power (POut) @ 5% Distortion, Class A15.7 W
Peak AF Grid 1 Control Voltage, Class A114 V
Plate Dissipation, AF power amplifier (Wa)12 W
Plate Voltage, class A1 (Ua)250 V
Plate to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 6.5 pF
Signal Plate Current, Class A1, maximum80 mA
Transconductance, Class A1 (S)9 mA/V
Zero Signal Grid 2 Screen Current, Class A110.8 mA
Zero Signal Plate Current, Class A149.5 mA

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Specifications, Files, and Documents

PDF: Specification Sheet Specification Sheet485.22 KB

Questions and Answers

Click each question to see its answers.
Asked by Anonymous on February 10th, 2019.
BradWbr
February 11th, 2019
Staff Member
These tubes are made in China, then sent to Germany for thorough testing.
Asked by Anonymous on May 29th, 2020.
BradWbr
June 1st, 2020
Staff Member
We are indeed shipping internationally, yes.

Product Reviews

4.79 out of 5 based on 14 reviews
- February 1st, 2021
5 out of 5

I really like these tubes so far in my studio guitar amp. They seem a little deeper, clearer and tighter than the jj’s it came with. It’s not a high fidelity stereo amp but they sound great for what I need!

- March 10th, 2020
5 out of 5

Tubes sound great!

- August 4th, 2018
3 out of 5

Installed a matched pair of these TAD EL84-STR's in my Vox Night Train 15H and got a loud hum after taking the amp off standby, after a warm up for 3-4 minutes. Gain and volume all the way down, the amp is self biasing. The hum would disappear after 2-3 minutes. But this is occurring less though, the more the tubes are being broken in and used. These tubes break up a lot earlier than the Preferred Series 7189 I had in before. I have to dial back the gain a lot on my amp. It's an aggressive tube, with a wide fat tone. It's great for rock or crunch. Lots of bass and good midrange, but less headroom compared to what I had in before.

- October 14th, 2017
5 out of 5

Excellent...! These TAD EL84 STRs add a 6V6 flavor muscle to the already *very* good EL84 sound. I'll definitely be staying with these - the best new production EL84s I've heard (hear that Ruby/JJs...?). If only TAD improved new production 12AX7s like this...!

- October 14th, 2017
5 out of 5

Excellent...! These TAD EL84 STRs add a 6V6 flavor muscle to the already *very* good EL84 sound. I'll definitely be staying with these - the best new production EL84s I've heard (hear that Ruby/JJs...?). If only TAD improved new production 12AX7s like this...!

- March 22nd, 2017
5 out of 5

I have been using these TAD EL84str power tubes for quite some time now and I have tried them all in my Soldano amp. These have the best of all worlds for lows, mids and highs. The bass response from my amp is absolutely fantastic. I play classic rock and blues guitar and these tubes really are the best I have ever found so far. Way better then Sovt, JJ, Mull, you name it I tried it. Been playing for 45 yrs, 63 and still rocking on the weekends. Love these tubes so much I don't have any others on hand anymore. Sold everything else I had. I might add I use Sylvania 12ax7's for the pre-amp tubes. Best I have found in 12ax7's. NOS Sylvania's with the green lettering.

- April 20th, 2016
4 out of 5

Application: Heathkit UA-2 amplifiers. These are competent tubes with no bad qualities that I could hear. Perhaps nearly the equal of the Sovtek tubes I generally use. As such, they're not worth the extra cost.

- February 20th, 2016
5 out of 5

The TAD EL 84 STRs have about 35 hours of play time on them and continue to improve. Best characteristic of the tube is the impression that my amp has additional power. These tubes are great!

- January 31st, 2016
5 out of 5

Replace power tubes in Vox AC15C1X. Nice sounding tubes!

- December 31st, 2015
5 out of 5

Quick delivery. And it sure was nice getting a phone call to clarify what I was going to receive. The Tubes I was replacing were about twenty years old (EL84 TAD-str's)so bottle length was longer than the old tubes. A little tweaking of the hangers solved that problem. They're a little crisp sounding. I'm running them in class A so it shouldn't be long before the mellow out a bit. All and all I'd say a good re-tube for my '94 Laney VC30 112. Thank you.