F6 Illustrated Build Guide

[6L6]

Since you don't have the terminal blocks installed, you've got 6 holes on each side of ground. I'd choose one side and go for it.

 

[PDL]

Just to confirm:

1. Tie all of the center 0v pads together.

2. Land the left channel 0v, right channel 0v, and the thermistor lifted 0v on three adjacent pads.

Does this plan sound good?

 

[Full Range]

The one thing that stumped me on the M2 build was hum
After organising the earth to a star earth configuration, this resulted in a slight reduction in hum

This was suggested to me as a logical next step, and that was to romove the toroidal out of the chassis and hook it up via long wires
Doing this was a successful test as the hum vanished

So I ordered a different brand toroidal with an RF shield band an installed it
Now I have silence - a church mouse is louder

 

[PDL]

The toroid I used for this project has a shield.

 

[Full Range]

Then star earth is your next step
I started off with the drawing on the left first

The drawing on the right is the star earth scheme that I use now

Hope it helps

 

[6L6]

PDL - try Full Range's scheme on the left to begin. PSU 0v and speaker negatives together.

 

[PDL]

I'll get working on it.

Do you think I can leave the input shields as is?

 

[6L6]

Probably not... If you want to cover all bases, send the RCA grounds to the same place as the rest on the PSU board. Just run the signal wire to the amp PCB.

 

[alvinlim]

You are using shielded coax? How are you grounding the shield?


Sent from my iPad using Tapatalk

 

[PDL]

Alvin - The shield is landed on both ends, you can see it pretty clearly in one of the pictures I posted.

Jim - I tied all the center pads together and moved the right channel ground and the thermistor lifted ground to the pads next to the leftt channel ground. I powered up and the hum is gone! I think I'll leave the input shields as is.

Thanks to everyone for all your help, time to listen to the music!

Thanks Nelson for sharing with and supporting the community.

I've also attached a picture of where I started at yesterday morning. It's amazing what one can finish in a weekend when the wife is gone...

 

[Dennis Hui]

Congratulations PDL. Very nice build and I'm happy the hum has been resolved.

Now it's time to enjoy the music...

Cheers,
Dennis

 

[6L6]

Fantastic! If it's quiet, it's done!!!

Congratulations!

 

[Full Range]

Congrats @ PDL
Only one thing left to say - And that is

Enjoy The Music

 

[Bare]

Great! Now save up for some speakers that are worthy of the amp?

 

[PDL]

Great! Now save up for some speakers that are worthy of the amp?

The speakers are Madisound's BK-12m. They seem to pair very well with the amp. The speakers use Fostex FE126En full range drivers.

What are your suggestions for speakers that are worthy?

 

[ColinA123]

I use Jericho horn speakers (FE206 driver)
so possibly a big brother to your Madisound and they sound good to my ears.
They do however need a LOT of running in before they settle down.

 

[chede]

+1 for Jericho horns !

Mine have the original (vintage) FE208 Sigma.

Have not tried them with an F6, actually, but they work great with SE 2A3 tube amp, souped-up Aleph Mini, and vintage Sony VFET amp ...

At 100 dB/W sensitivity, not just loud, but delicate sounding as well ...

Best regards,
Claas

 

[ilikeit]

Why Nelson Pass do not use in his First Watt amplifer series, speaker protection circuts?
How he can not afraid that, in one moment amplifer can burn precious speakers.
Yes i do not have much skills to understand whole schematic, but someone can explain?

 

[Zen Mod]

these amps are reliable .

however , if you make your own , nothing stops you from including speaker protection modules

 

[ilikeit]

these amps are reliable .

however , if you make your own , nothing stops you from including speaker protection modules

So not need to worry that amplifer can burn my speaker coils? Can i sleep in peace of mind with my Diy F6? Thank you