If I tell you about an Idht similar to px4?

[IslandPink]

Actually I think I meant DA100 , but also there is the DA30 ....
Those would be Marconi I believe.

[steve s]

Nice paul, it very much has the look of the mullard aco44...

[Paul Barker]

Actually I think I meant DA100 , but also there is the DA30 ....
Those would be Marconi I believe.

I think Darren was able to get hold of some, I never did. They were expensive back then.

[steve s]

The cosser is a rebadged mullard, i have one the same

Nice pics paul..

Mark i think i have a da30, but only a single, i once turned down a few da something's which i regretted on they way home.. All where globes..

[Paul Barker]

Looking at the curves the cooking px4 with heavy use is on it's last legs but the 4xp which looks new is not much better. Odd. But the 4XP data (for example resistance 900 ohm) does show a valve which is not exactly a px4.



4XP Data Sheet

[pre65]

Actually I think I meant DA100 , but also there is the DA30 ....
Those would be Marconi I believe.

DA100 ?

There is one on e-bay for £900 (nine hundred pounds !! )

http://www.ebay.co.uk/itm/One-GEC-CV121 ... 2a301c1c4c

[steve s]

Looking at the curves the cooking px4 with heavy use is on it's last legs but the 4xp which looks new is not much better. Odd. But the 4XP data (for example resistance 900 ohm) does show a valve which is not exactly a px4.



4XP Data Sheet

Remember the valve you are testing is an aco44 and is not the one in the data sheet... it should be very similar to the px4

the original 4xp is a very different thing, like i said i will find some to show the differences...
Cheers

[Paul Barker]

You are going on outward appearance. Look at the characteristics.

[steve s]

Probaly paul..

Anyway an AD1 amp looks like a worthwhile project hope you get it sorted that one i would want to here, I spent amcouple of hours going through my side contact valves .. Only found one telefunken unfortunately it was a rectifier...