First Watt website update

[Nelson Pass]

Today my spreadsheet told me that I have to update the First Watt
website, and so I did.

Two articles you may or may not have seen, also the DIY Biamp 6-24 and

First Watt F8



FIRST WATT

 

[twitchie]

Let the speculative discussion begin!

Thank you once again for keeping us pigeons well fed Papa!

 

[Soundhappy]

Ethernal entusiasm for Papa DIY updates a good time on the bench source

 

[Blk Dynamite]

Gonna have to read the square law article

 

[codyt]

When it rains, it pours - I’ve got some reading to do!

 

[codyt]

No degen on the F8 SS output - nice! I’m still trying to understand where the tab for that lunch is being paid.

 

[Zen Mod]

well, F8 is nothing special

half handful of parts, entire amp

 

[Nelson Pass]

Just think of all the money I'm saving with only one Toshiba Jfet on input
instead of six.

 

[woofertester]

Very generous of you to share the fruit of your labor with DIY junkies.

 

[zman01]

Thanks for sharing Mr. Pass!

 

[Michael Rothacher]

My brain exploded.

 

[EUVL]

So all the J2 builder can now stop and change plans.
You are a evil man.




Many thanks for the articles,
Patrick

 

[2 picoDumbs]

Cool

 

[2 picoDumbs]

Just think of all the money I'm saving with only one Toshiba Jfet on input
instead of six.

Hahahaha

That means I save money too.

Thank you for thinking of us cheap bastards.

 

[twitchie]

Why is this one named F8 instead of J3? Is there any rhyme or reason behind it? Isn't it closer to the J2 than the F7?

 

[2 picoDumbs]

It's not all Jfets.
Papa cheaped out and used an irfp device on the current source.
F8 sounds cool, and 8 is a lucky number to quite a few cultures.

F3 is nothing like F4 etc etc.

 

[EUVL]

The challenge is not to copy, but to improve upon.
For example, (at least) DC coupled at the output.


Patrick

 

[bajjisw]

Hmmm. Did I get lucky ? I ordered 4 instead of 2 SS devices. 2 for babelfish 2j .....

 

[Antoinel]

A masterpiece.

 

[EUVL]

DC Coupled

> The challenge is not to copy, but to improve upon.
> For example, (at least) DC coupled at the output.

Quick attempt. Seems to work.
By no means optimised.
THD 0.016% 1W into 8R.
No coupling caps input and output.
Output stage identical to previously published at the J2 thread.

Disclaimer :
I don't have a F8. I have not seen one.
I have no idea of the original component values.
I don't have a schematics.
This is pure speculation in Spice.
I have not built, only simulated.


Have fun simulating further,
Patrick

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