Home Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

RE: triode wired KT88




Please explain how a tube used in a PP circuit magically becomes linear when the tube itself is not?

The output of a PP amp can be more linear than the output of a SE amp when using non-linear tubes but each tube remains non-linear.

Or, to turn it around the other way....

Please explain how a linear tube magically becomes non-linear when used single ended?

We have only been talking about the output stage of a system.

What about a preamp stage or the input stage of an amplifier.

If it is single ended, using extremely linear tubes like a 6sn7, does the output of a SE preamp magically become non-linear (asymmetrical)?

If you believe that then you need to show me.

Take a look at the plate curves of a 6sn7 above.

I've plotted a horizontal load line (CCS loading) at about 14ma, 200vdc plate.

Can you show how the output of the 6sn7 becomes asymmetrical just because the circuit that it's used in is SE.

In a PP or SE amplifier circuit any asymmetry in the output waveform has to start with asymmetry of the tubes used.

With PP most of the asymmetry of tube #1 is canceled by the asymmetry of tube #2 but that is not the same as saying that in the absences of a PP circuit the tube itself becomes anymore asymmetrical than it is to start with.

Here's what I'm trying to explain to you that I don't think you understand,

A SE circuit doesn't cause asymmetry, it just allows the asymmetry of the tube being used to show up at the output while a PP circuit hides that asymmetry.

So if you're going to use a SE circuit, you need to use very linear (symmetrical) tubes.


Tre'
Have Fun and Enjoy the Music
"Still Working the Problem"



Edits: 06/25/17

This post is made possible by the generous support of people like you and our sponsors:
  Signature Sound   [ Signature Sound Lounge ]


Follow Ups Full Thread
Follow Ups

FAQ

Post a Message!

Forgot Password?
Moniker (Username):
Password (Optional):
  Remember my Moniker & Password  (What's this?)    Eat Me
E-Mail (Optional):
Subject:
Message:   (Posts are subject to Content Rules)
Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:  Automagically notify you when someone responds.