input tubes for 300b

[PhilippeS]

or mine :

An externally hosted image should be here but it was not working when we last tested it.

 

[ThorstenL]

Hi,

I am going to fish for more opinion here, regarding input tubes.

Also, what are opinions of what a 300b tube wants? High voltage swing, high current, low impedance, etc. and what might get us there.

Before we get bogged down in Bugleboys this, Telefunkens that and Valve postal tubes the other and so on, it may pay to consider fundamental topologies.

A while back I wrote a little wee little piece on that subject, you may find it beneficial to peruse.

http://www.fortunecity.com/rivendell/xentar/1179/theory/seamptheory/SEAmplifiertheory.html

You may also find this little set of Graphs of use, if you take them with the first part of the article.

http://www.fortunecity.com/rivendell/xentar/1179/theory/300bampdistortion/300BAmpDistortion.html

As this article is a bit long in the teeth (over 10 years old), so my latest variation (though covered in principle by the original article) is discussed here:

Audio Asylum Thread Printer

I hope this gives some pointers.

Ciao T

 

[jrenkin]

Thanks! That will give me a lot to chew on. At some point I will have to stop reading and actually build the dang amp...but I do really want to understand what i am doing, at least a little. Appreciate the help!

Oh, Phillip, can't open your picture.

 

[ThorstenL]

Hi,

Thanks! That will give me a lot to chew on. At some point I will have to stop reading and actually build the dang amp...but I do really want to understand what i am doing, at least a little. Appreciate the help!

My evil twin (King Kuei Yang Wang from Sazan Eyes) also posted this:

http://www.diyaudio.com/forums/tubes-valves/38278-line-tube-learning-newbies.html

He also posted a number of articles on calculating DC Coupled amplifiers, however they also include the answers to your other questions.

Ciao T

 

[rdf]

Interesting. Where are you running the tube ?

In a pre-amp with a topology of my own design. That actually measures well! 😉

 

[mach1]

In a pre-amp with a topology of my own design. That actually measures well!

Sorry, I should have been more explicit: what operating point are you using ?
Care to expound on your topology ?