6AM6S is this tube usable for our purposes ? (datasheet here)

[kagliostro]

A friend give me some of this military grade tubes

The datasheet is in french, I can read it but I understand it not 100%

Reading the datasheet seems that the tube is usable for HF and BF (I translate it as Audio Frequency)

The part of the datasheet I understand is the part related to class A amplification

Anode = 250V
G2 = 250v
Rk = 160ohm
Amplification = 74 (it is strange, usually I read this data only on triode datasheet)
S = 7.6mA/V
Ia = 9.8mA
IG2 = 2.6mA

but I'm still not able to read curves (they confuse me)

Someone knows of audio applications that uses this pentode ?

Or, someone, looking to the curves, can say if this tube is usable like an EF86 or a 5879 tube ?

https://frank.pocnet.net/sheets/181/6/6AM6S.pdf

Thanks

Franco

[Tony Bones]

It's a beefier tube than the EF86 (higher max plate dissipation and current capabilities) but the characteristics are in the same neighborhood. By that I mean that for a given screen voltage you can bias the two tubes with similar grid voltages and obtain plate currents that are roughly similar.

You'll just need to experiment with plate, screen and cathode resistors to see what works well.

Can't predict how quiet it will be as an input stage.

[darryl]

For those of us who are Anglophones:

https://frank.pocnet.net/sheets/184/6/6AM6.pdf

These datasheets also include information on using the 6AM6 as a resistance coupled amplifier.

[DummyLoad]

use it triode connected - it is similar to a 12AT7 with a anode rating of 250V vs. 300V of 12AT7. has about 20% more gain with typical 100k/1.5k bias set.

as a pentode, you may be disappointed as the slope is pretty steep for an audio pre-amplifier. you could play with Rg2 (smaller) and shoot for less gain as RC charts show example with Av of 195 or more.

--pete

[PRR]

http://www.r-type.org/exhib/aaa0248.htm

As pentode, it is liable to be way too much gain.

As triode, it lays between 12AX7 and 12AT7 (but only one section per bottle), and will do much higher current. So I think you could get 12AX7 gain with 1/4 the resistances (and 4X the current) for driving low-Z networks.

[kagliostro]

Many Thanks Tony Bones - Darryl - DummyLoad - PRR

Thanks also for the english versions of the datasheet

As triode, it lays between 12AX7 and 12AT7 (but only one section per bottle), and will do much higher current. So I think you could get 12AX7 gain with 1/4 the resistances (and 4X the current) for driving low-Z networks.

So, connected as triode is possible to get a gain similar to 12ax7 with 4x the current, good for driving low-Z

this will be if connected as Anode Follower, correct ? (or the configuration for low-Z refers to Cathode Follower ?)

Thanks

Franco

[PRR]

I mean run with say 27K plate resistor, set the cathode resistor to maybe 300r-500r bypassed so plate voltage is 60%-70% of B+. Just like standard Fender except smaller resistor values. Probably ~~10K output impedance at gain of 40-50.

[kagliostro]

Grazie


Franco