using only 1/2 of a dual triode

[gabriel611]

just want to ask you guys what to do with another half of a dual triode if i just want to use one side of it? do i still have to wire the other half of the heater, and if i do so should i ground the plate, grid and cathode of the unused half? thanks for any help.

gabriel

[kathodyne]

just refer everything of the unwanted half to ground, if possible do not connect the second heater.

[gabriel611]

thanks a lot!

[ErikdeBest]

Hi Gabriel

I have done this myself in a pair of monoblocks. Each required half a triode, so I wired one monoblock to use one half (pin 1, 2, 3 and according heater) and the other to use the other half (pin 6, 7, 8 and acoording heater). When they are tired I can swap them between amps, so that the other half will be used!.

Erik

[bibster]

Erik,

Now THAT's what I call brilliant... As my grandad would say: clever d*ck!

Paul

[ErikdeBest]

Hi Bibster

I just copied the idea from someone here at diyaudio

Erik

[sawreyrw]

I have no idea what your application is, but if you put the 2 devices in parallel you will double the mu.

[ErikdeBest]

Originally posted by sawreyrw
I have no idea what your application is, but if you put the 2 devices in parallel you will double the mu.

There have been so many discussions on this...mu stays constant...rp decreases by a half...and there was another thing, which escapes my memory.

You can try, lots of people don't like paralleled tubes...

[tubelab.com]

mu stays constant...rp decreases by a half...and there was another thing, which escapes my memory.

Because the two sections together draw twice the current for the same grid voltage is is said that the effective GM doubles. On many tubes the noise is reduced.

Since the two sections are never completely matched the current sharing between the two sections will not be exactly the same, and may change over the operating range of the tube. This can cause the "loss of definition" that some users talk about.

[gabriel611]

i've been busy the past few days so i was able to browse the net just now. thanks guys for the reply.

Originally posted by ErikdeBest
Hi Gabriel

I have done this myself in a pair of monoblocks. Each required half a triode, so I wired one monoblock to use one half (pin 1, 2, 3 and according heater) and the other to use the other half (pin 6, 7, 8 and acoording heater). When they are tired I can swap them between amps, so that the other half will be used!.

Erik

does this mean that i may not have to wire the other half (of the dual triode) at all? also, am i right that by doing so my main transformer will be less stressed because of less current required by the half triode operation?