Experience with CV181, anybody?

Tubes Asylum

Questions about tubes and gear that glows. FAQ

131.176.183.182

Good morning!
I have a question for 6SN7 valve family experts:
Recently I found two Mullard CV181s in a box of old valves.
Databooks suggest that the CV181 is a version of the 6SN7.
Observation says: The CV181 I found have bottle-shaped bulbs rather than the cylindrical shape I am used to with 6SN7s. As well, they measure distinctly different to the average 6SN7/12SN7 I have tested on my VCM-163. All four have very close data, showing gm of 2.5 mS at 9 mA, but require a grid voltage of - 5.5 V instead of the -8V nominal for the 6SN7 at Ua=250V and Ia=9mA. The variance between the four systems tested is less than 2 %.
Here are my questions:
(1) Is the deviation in grid voltage at bias point a common thing for the CV181 - and therefore is it in actual fact significantly different from the 6SN7 - or is this a peculiarity of my valves.
(2) How does it compare - in your opinion - to other 6SN7s w. r. t. the sonics - just to get an idea on how to interpret certain pattern I think to have found.
Many thanks!
---mb---
======
PS: I did search the AA for older articles on the subject, but did not find a suitable posting.

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable

Topic - Experience with CV181, anybody? - mb-de 04:29:46 02/22/01 (9)

Re: Experience with CV181, anybody? - Lew 18:18:32 02/23/01 (0)

Re: Experience with CV181, anybody? - robert 09:13:09 02/22/01 (7)

Question for Robert: Do you have real data on the CV181? - mb-de 09:21:02 02/22/01 (6)

Here is some data - Ken S 19:55:39 02/22/01 (1)

Thanks - this is pretty much in line with my measurements... - mb-de 09:42:43 02/23/01 (0)

search for ECC32 data (nt) - PÃ¤r 09:52:47 02/22/01 (3)

or ECC31 which has seperate cathodes like 6SN7 (nt) - shane 18:04:49 02/22/01 (1)

hey, that IS an ECC32, sorry for waisting your timt (nt) - shane 16:56:39 02/23/01 (0)

Thanks!!!(nt) - mb-de 11:10:28 02/22/01 (0)

You can not post to an archived thread.