Description
First version of the Valvo 6201 (ECC801S) made in 1958 in Hamburg Germany
Best sounding 6201 !
This is an extremely rare version of the Valvo 6201 tube. It is produced in 1958 in the Hamburg Valvo factories. The tube has a double post D-getter, a half box plate structure, triple micas, copper grid posts and gold pins, see pictures. The date code is, like some other tubes from the fifties, between the pins. Very healthy tube with NOS specs! The print has been lost over the years. Based on the appearance, the getter flash and the measurement results I assume that the tube has never been used. This is the longlife, tight tolerance version of the ECC81/12AT7. This tube was made exclusively for the army and manufacturers of high precision gear.
In fact, the 6201 is a military version of the 12AT7. Both tubes have similar specifications, but the 6201 is designed to be more robust and reliable, with a longer lifespan and better performance in harsh conditions. Overall, the 6201 tube is a significant step up from the standard 12AT7. And this very special first version of Valvo clearly stands out from that!
Sonics
Note from the WEB: This tube is characterized by an impressive open “air” at the top end. The soundstage is large. The midrange is flat, and the bass is Impressively tight and accurate. These tubes have a fine sense of dynamics, and most are impressively quiet. 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!
Test results*
The tubes test NOS. The internal balance between the triode sections is excellent. The measurement data below illustrate that the tube is in excellent condition.
| Valve
V104 |
Ia (plate current):
Transconductance (Gm): Gas test, Shorts test: |
10,2 / 10,3 mA
5,6 /5,8 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
| Tube type | 6201 |
| Quantity of Tubes | One tube |
| Brand | Valvo Hamburg |
| Manufactured in | Valvo factory, Hamburg Germany |
| Etch code | Both tubes Df1 D 8L3 (1958!) |
| Construction | Half box plates, triple micas, copper grid posts, gold pins |
| Getter Construction | Double post D-getter |
| Print Condition | No print; see pictures |
| Box included | Generic Valvo box |
| Equivalent tubes: | 12AT7, ECC81, 12AT7WA, ECC801S |
| General test results | NOS |
