ECC81 pair Valvo Hamburg, 6201SQ-like pin reinforcement 1960 / 1961 V67/68)

Description

Pair Valvo ECC81 made by Valvo in 1960 & 1961

This is an early pair ECC81 produced by Valvo in april 1960 & 1961 in the Hamburg Valvo factories. The pair has a halo getter, a half box plate structure without holes, see pictures. Healthy tubes with NOS specs! Tubes with matching triode systems; see test results. The halo getter is placed or a reinforcement pin like the 6201 SQ version!

Sonics

Note from the WEB: These tubes are characterized by an impressive open “air” at the top end. The soundstage is large. The midrange is flat, and the bass is tight and accurate. These tubes have a fine sense of dynamics, and most are impressively quiet. These are not “very warm sounding” tubes, and to some ears their lower of midrange warmth may be interpreted as transparent/bright. I tend to think of them as accurate, and their clean, focused sonic image is astonishing.  They are absolutely incredible tubes that will never be made again!

Valvo’s Hamburg production has a good reputation among tube enthusiasts. Experiences with this 6201 SQ mainly point to:

• • A very open and detailed high.
  • A nice layered sound image.
  • A natural representation of voices.
  • A tight layer without excessive thickness.
  • An excellent placement of instruments.

This is typically a tube for someone who loves detail, spaciousness and a natural rendering, without excessive heat or coloring. The Valvo is described by some listeners as a middle ground between the fast, lively Siemens and the somewhat smoother, warmer Mullard

Test results

The tubes have been tested carefully with the official factory test set-up and our sophisticated test equipment. Please read our tube testing page for the ECC81 tube family. The measurement data below show that these tubes are perfectly matched to each other and are internally balanced. And meet the factory specifications of a new/NOS tube very wel. Tube to tube match and internal balance for all tubes is good.

Valve V67

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

9,8 / 10,0 mA 6,0 /6,1 mA/V OK

=  NOS / NOS =  NOS / NOS

Valve V68

Ia (plate current): Transconductance (Gm): Gas test, Shorts test:

10,5 / 9,5 mA 6,1 /5,5 mA/V OK

=  NOS / NOS =  NOS / NOS

Where NOS is : Ia = 7 to 14 mA, Gm= 4,5 to 6,5 mA/V. 

  *  For test methods and factory specification read the tube testing page.

 

Short description