Vacuum Tube - 6L6GC, Tube Amp Doctor

Tube Amp Doctor (TAD)
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Customer image:<br/>"A Pair of TAD 6L6GCs installed in a vintage Ampeg VT-40"
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Customer Images:
Customer image: "A Pair of TAD 6L6GCs installed in a vintage Ampeg VT-40"

Vacuum Tube - 6L6GC, Tube Amp Doctor

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Quantity in stock: 2

Octal power tube (Max Plate Watts = 30W) TAD 6L6GC-STR RCA-Style black-plate

TAD has the remakes of the all time favorite 6L6 classics by RCA and GE. The TAD 6L6GC-STR is your perfect choice if you are up for the sound of the rock legends. It provides the low end with the right amount of pressure, as known from the famous RCA tubes. It has clear, transparent but unobstrusive highs and exactly the right bite to provide you with all those classic 6L6 sounds from big warm cleans to modern hard rock sounds.

This TAD 6L6GC-STR combines the famous reliability of the american made Philips/Sylvania STR series (also known as MESA 6L6GC-STR415) with the black-plate system of the highly regarded vintage RCA 6L6GC tubes. Silky top end, combined with deep bass response and lots of headroom make this tube a living classic.

Exclusive black-plate designs, gold gird wire, double getter construction, no-noise filaments and the 1.2mm thick heavy duty glass envelope.

RoHS Compliant
Item ID:
Tube Amp Doctor Part Number:
Tube Amp Doctor (TAD)
Product Measurements by Type
Body Height95 mm
Cathode to Heater Voltage≤ 200 V
D.C. Cathode Current, AF Power Amplifier100 mA
D.C. Plate Voltage, AF Power Amplifier550 V
Grid 1 (control) Voltage, Af Power Amplifier-37 V
Grid 1 Control Voltage, Class A1-18 V
Grid 1 to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 10 pF
Grid 1 to Plate Capacitance< 0.6 pF
Grid 2 Dc (screen) Dissipation, Af Power Amplifier5 W
Grid 2 Dc (screen) Voltage, Af Power Amplifier450 V
Grid 2 Screen Voltage, Class A1250 V
Heater Current0.9 A
Heater Voltage5.8 V - 6.8 V, 6.3 V nominal
Item Diameter38 mm
Item Height109 mm
Load Resistance, Class A14.2 kΩ
Output Power (POut) @ 5% Distortion, Class A18 W
Peak AF Grid 1 Control Voltage, Class A118 V
Plate Dissipation, AF power amplifier (Wa)30 W
Plate Voltage, class A1 (Ua)350 V
Plate to Cathode, Grid 3, Grid 2, Base Sleeve, Heater Capacitance< 6.5 pF
Signal Plate Current, Class A1, maximum66 mA
Transconductance, Class A1 (S)55 mA/V
Zero Signal Grid 2 Screen Current, Class A12.5 mA
Zero Signal Plate Current, Class A154 mA
Packaging Information
Packaging Dimensions2 in. × 2 in. × 4.6 in.
Weight (Packaging)0.2 lbs.

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Specifications, Files, and Documents

PDF: Specification Sheet Specification Sheet498.14 KB

Questions and Answers

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Asked by Anonymous on October 16th, 2018.
October 16th, 2018
Staff Member
The short answer to your question is yes, you can use the the Tube Amp Doctor 6L6GC in place of the GTs. To get a detailed description of all of the 6L6 (and variants) tubes we offer, please check out or 6L6 Comparison of Current Made Tubes chart:

Product Reviews

5.00 out of 5 based on 4 reviews
- May 20th, 2020
5 out of 5

I install a pair of these TAD 6L6GCs in a restored 70's Ampeg VT-40. They sound great, nice crisp clean tone with a slight warm break up about mid volume.

- January 2nd, 2019
5 out of 5

Definitely a step up in tone and clarity from the 5881 Tung-Sol re-issue pair that were in my Carr Rambler previously.

- October 27th, 2018
5 out of 5

Tubes do everything in my Carr Rambler that they claim to do which I guess isn't a surprise as Steve Carr puts them in his new production amps nowadays.

Nice even low end and bright but not fizzy top. Selecting the correct phase inverter/driver tube is critical. I got the best results with a NOS Jan/Philips 12AXTWA.

- December 11th, 2011
5 out of 5

I have a fender blues deluxe reissue that I have swapped many tubes out of, 6l6's and 6v6's. I must say that these tubes are the best sounding tubes I have heard yet. I have tried JJ 6l6 and 6v6 and Groove Tube 6l6 and these just blow them all away. Very big sounding, warm and the bass is round and fat. Doesn't get to boomy. I say give these a try and you will like what your ears are hearing.