Single 6N6P stereo pre-amp

[Brit01]

Hi guys,

I'm going to have a shot at a very simple cathode follower pre-amp but using both sides of double triode like the 6N6P for the left and right channels.

I have attached a photo (don't have any software to design these yet; if anyone knows of a good freeware please advise).

How does this look?

[leadbelly]

Originally posted by Brit01
How does this look?

It looks nothing like a cathode follower

[Brit01]

It looks nothing like a cathode follower

Just a rather minor embarrassing mistake!!

Quickly brushing my error aside what I was trying to achieve was using a single double triode for a stereo pre-amp. I've read that there shouldn't be any crosstalk between the channels.

This was basically a design taken from a DecaWare driver stage.

[Cauhtemoc]

What is the purpose of C1? If it's meant to be a cathode bypass, that's not the way to do it.

[leadbelly]

The circuit has other problems besides C1. The output caps are too small if you ever want to drive a power amp with 100K or lower input impedance for example. I think you should either look for a published preamp project or work through a book like Morgan Jones on learning to design one.

[Brit01]

I think you should either look for a published preamp project or work through a book like Morgan Jones on learning to design one.

Looks like I need to go back to the books.

I've got my Aikido up and running on the breadboard right now. Very nice .

What is the purpose of C1? If it's meant to be a cathode bypass, that's not the way to do it.

I guess I should have drawn 2 caps there. One bypassing each Cathode resistor.

[adamus]

dont worry about it, most of us have done far worse.

As others have suggested, read morgan jones "valve amplifiers". this is a section on cathode followers that will answer all your questions. its a lot of learning in one book.

[Brit01]

thks guys.

In the meantime JB's journals are great. Got some other pdf files from some other members.

What I was trying to achieve was using both sides of the triode, for both channels.

This is one channel of a very simple design that I'd like to modify using the same triode for both channels.

How would I apply this concept to this design?

[wakibaki]

It's a common cathode with cathode bias and bypass, not a cathode follower.

You really need a bit tighter definition than just 'preamp'. What exactly is it intended to do?

w

[Brit01]

You really need a bit tighter definition than just 'preamp'. What exactly is it intended to do?

Source: Standard 2V CD players

Planning to use it as a versatile linestage, either with SS amps or tube amps. Maybe too much gain for a SS amp but the 6N6P is one of the tubes with a low gain, 16-24.