RCA 5751 'Command Series' , black plate matched pair

In stock

RCA 5751 NOS 'Command Series' black plate, matched pair

One of the best NOS tubes from the RCA ‘Command Series’ for both guitar and audio applications.

This item is in stock;
Ordered before 16 PM will be shipped the same workday;
All prices are including VAT;
Need help? Please contact us.

More Information
Tube type 5751
Manufacturer/Brand RCA
Production NOS
Tube kind Signaltube
Construction Dual Triode
Pin Layout Noval 9 pins
Country of Manufacture United States

RCA 5751 NOS 'Command Series' black plate, matched pair

This RCA 5751 NOS is one of the most popular 5751's from the so-called 'Command Series' of RCA a counterpart of the 'Five Star' series of GE. These were the 'top of the bill' tubes from RCA.

The 5751 is a double triode with medium gain. Popular in guitar and audio amplifiers as input tube respectively for more headroom and line amplifier stage.

RCA or Radio Corporation of America was founded in 1919 by General Electric (GE) and Westinghouse with the aim of providing communication between shipping traffic. The tubes that came on the market under the name RCA Radiotron were made by GE and Westinghouse until 1931.
The best known tube of RCA Radiotron is the Beamtetrode 6L6. This was initially produced under the license of Marconi-Osram as the American version of the KT66. The first 6L6 tubes were provided with a black coated metal casing which was replaced by glass from the 6L6G (G stands for Glass).

TubeDirect aims to be able to offer RCA NOS tubes in its product range. This NOS (New Old Stock, not second-hand) tubes are used by reliable suppliers from the USA and tested for delivery by us and provided with an individual test report. Multiple tubes of the same type are matched as much as possible. See also our articles about testing and matching tubes.

Matched tubes 
This set of tubes is matched. This means that the measured values of the tubes fall within the same range and thus perform equally.
This is important for two reasons:
1. To obtain the same gain factor per tube.
2. For the same amount of quiescent current per tube.
The first requirement speaks for itself and the second requirement prevents the one tube where a higher quiescent current or bias is needed to make it work in the linear region will also be worn out earlier. Both new tubes and our NOS tubes can be ordered separately.