TAD 6550A-STR REDBASE, Premium Matched

Preview: RT881 Einzel (1 selektierte Röhre)

RT88 TAD 6550A-STR REDBASE, Premium Matched

From €73.95 *

*Prices incl. VAT, excl. shipping costs

In Stock, delivery time approx.1-4 working days (Within Germany)
The delivery times for shipping abroad can be found here.

Part Number: RT881
Packaging Size: 6x6x15 cm
Packaging Weight: 0.08 kg
UPC: 4251594901211

Remake of the Classical GE6550A - TAD 6550A-STR REDBASE - depth, power & detail in... more

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Product information "TAD 6550A-STR REDBASE, Premium Matched"

Remake of the Classical GE6550A - TAD 6550A-STR REDBASE - depth, power & detail in perfection

The breathtakingly large and precise sound as well as its straightforward appearance make the new TAD 6550A-STR REDBASE the first choice for high-end audio applications. The 6550A-STR REDBASE is also perfect for powerful bass guitar amplifiers. It delivers a natural and three-dimensional tone with exceptional depth, pleasant warmth and fine, subtle highs.

The TAD 6550A-STR REDBASE is a true remake of the classic American GE 6550A tube with a heavy, straight glass bulb, classic construction, metal base and excellent linearity.

It is characterised by an extremely balanced, natural tone throughout all frequencies and helps to create a very lively sound with an incredibly powerful bass range and fine brilliance in the relaxed treble range.

The TAD 6550A-STR REDBASE meets or exceeds the specifications of the classic 6550A tubes and can be used in any 6550 application with excellent performance.

The REDBASE series features gold-plated control grids for outstanding performance and reliable stability with an absolute low noise floor.

Tube Type:	6550
Selection:	Premium
Socket:	8 Pin(Octal)

Documents...

Available downloads:

Download TAD-Datasheet_6550A-STR-REDBASE-1.1

Safety information...

Responsible person for the EU

Economic operator established in the EU, who ensures that the product complies with the required regulations:

Tube Amp Doctor Musikhandels GmbH

Weinbrennerstr. 1

67551 Worms

shop@tubeampdoctor.com

www.tubeampdoctor.com

Danger:

Tubes are made of glass and are therefore fragile. Tubes can become very hot and are generally operated with high or very high voltages.

Improper installation, use and handling can lead to serious or life-threatening injuries and/or damage to the products.

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Customer evaluation for "TAD 6550A-STR REDBASE, Premium Matched"

From: Steve Whitson On: 23 Sep 2025

TAD 6550A-STR REDBASE - depth, power & detail in perfection. Oh yes. -

The the current power tubes in my Dialogue 7 Monoblocks are the superb TAD 6550A
Redbase I purchased. They now have 1950 Hours and I swear they keep improving. After I first tried TAD 6550A tubes I read that TAD considers their KT88 Redbase to be the superior in the 6550A, class of tubes I find this hard to parse. Better? guess I will have to purchase an Octet just to see.
TAD has got it going on. This is my third purchase of TAD power tubes and never a failure, never a problem always superb sound. -

From: Warren On: 6 Jun 2024

best new production 6550

I just replaced the Sovtek 6550WE which came with my ARC I/50. What an amazing step! I tried 6550C, 6550 Tung-Sol and NOS 6550A GE. These Redbase are superior right out of the box. Let's see if they open up even more during next a few weeks.

From: Rob On: 5 Jan 2024

Ampeg SVT is back alive with these TAD 6550A-STR REDBASE

Since years my SVT is eating 6550 tubes. I tried all 6550 made in last 20 years but with these Redbase 6550 first time I have back that magic tone it used to have way back in the 1990s when i was using General Electric 6550A which are unavailable since then. If you to beef up your Ampeg these 6550 are the real thing! Thanks TAD-Team for super fast and well packed shipping and special thanks for kind support from Stephan.

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Here you will find the most important information about the matching of our tubes more

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Information about TAD Matching

Here you will find the most important information about the matching of our tubes

When does a tube become a Premium Selected tube?

Power tubes

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

- Deep-Drive & Soak Test

Premium RT-Matching of Power Tubes

Our Premium Matching is an exact matching of power tubes with identical Plate Current (PC) and Transconductance (TC).

TAD Premium Selected tubes are guaranteed for a period of 12 months (according to terms of warranties)

for the quality criteria mentioned above.

Preamp tubes

All preamp tubes labeled Premium Selected have passed the following tests:

- Low Noise Test

- Microphonic Test

- Gain Test

- Sonic Tests

- Shock Tests

- Listening Tests

- Balance Output Test

Premium Selected

We call the tubes SELECTED which have passed above tests and thus qualify as reliable all-round tubes of their type.Typically this is around 30-60% from a batch that receives the SELECTED label from TAD.

For applications in particularly sensitive functions such as V1 or input stage with combo amps, V1 in high-gain amps, tube microphones and phono preamps, we recommend using the respective HIGHGRADE selection

HIGHGRADE SELECTION

But only those tubes which pass these tests best are labeled Highgrades.Typically this is approx. 3-10% from a production batch that qualifies for the HIGHGRADE rating from TAD.

Due to the very high selection requirements, this article is temporarily only available to a limited extent! Please note our shop-information on availability.

Matching and Selecting Options for Preamp Tubes

Matching in Pairs for preamp tubes means that two tubes show identical gain, hence, four characteristically identical systems.

This matching method includes our Balance-Selection. We highly recommend this matching method for hi-fi systems.

TAD Premium Selected/Highgrade tubes are guaranteed for a period of 12 months (according to terms of warranties)

for the quality criteria mentioned above.