F6 Illustrated Build Guide

[Spe@kerBox]

Of course the pots normally default to center.

 

[2 picoDumbs]

He messed around with the pots.
He didn't leave them in the mid-position.

 

[Super_BQ]

Can someone elaborate why the input JFets in the following photo are zip tied?

https://www.diyaudio.com/forums/gallery/data/500/4080017.jpg

 

[bkdog]

Can someone elaborate why the input JFets in the following photo are zip tied?

https://www.diyaudio.com/forums/gallery/data/500/4080017.jpg

Thermal tracking.

 

[Yaho]

Bias and Led

Hello,

My F6 is behaving so far. No firework since the 4th of July. And I am about to close my enclosure. I have 3 questions please.
My speakers consist of LF of 16 ohm and HF of 8 ohm. So basically a 16 ohm speaker?

Q1. Should I leave my bias at .5 or should i raise to .6 ish? Or does it
matter. Or what has been your experience in terms of optimum biasV?
Q2. For LED chassis mount: Can I extend wire from the LED to the
chassis?
Q3. How did you mount the LED to the chassis? I am thinking about
either super glue or Gorilla glue.

thank you!

 

[2 picoDumbs]

Set one channel at 0.6 and the other at 0.5, and compare for yourself

Listen to one channel at a time

 

[ItsAllInMyHead]

Q2 - Yes
Q3 - Friction mounting and/or a teeny bit of silicon to hold in place seems to be a common practice and has worked for me. If you use glue, and need to remove it, it could be more challenging.

 

[Yaho]

Bias and Led

Set one channel at 0.6 and the other at 0.5, and compare for yourself

A brilliant idea! Thank you!

Q2 - Yes
Q3 - Friction mounting and/or a teeny bit of silicon to hold in place seems to be a common practice and has worked for me. If you use glue, and need to remove it, it could be more challenging.

Wonderful! I do have silicon handy. Why didn't I think of that!
Thanks so much!

 

[6L6]

1) Higher bias is better as long as you do not get the heatsinks too hot.

2) Yes.

3) That will work nicely.

 

[glenv6]

Antek 400a AS-4220

Hi F6 Builders,

I couldn't find a transformer with 18v secondaries so I went with 20v secondaries (Antek AS-4220) as tbrooke said he did in post #2096. Will the higher voltage change the way the F6 sounds in any significant way?

Also, I take it that the purple wire coming off the AS-4220 is an RF shield, so I plan to run that to the chassis right next to the transformer. Is that correct?

Thanks in advance!

 

[Spe@kerBox]

Mine uses the 2x 4220 in dual mono and sounds fantastic. Rails sit at +-25v with no issues. Have never heard one with 4218 so can't comment. Yes, purple is the shield.

 

[glenv6]

Mine uses the 2x 4220 in dual mono and sounds fantastic. Rails sit at +-25v with no issues. Have never heard one with 4218 so can't comment. Yes, purple is the shield.

Good to know - Thank you!

 

[Yaho]

Got it

@6l6

1) Higher bias is better as long as you do not get the heatsinks too hot.

2) Yes.

3) That will work nicely.

My goal is to keep it at 48-50C.

thanks

 

[meanie]

You can easily achieve these temps with the F6, i ran mine at 55DegC.

 

[Yaho]

meanie,

i ran mine at 55DegC.

Thanks for sharing...it's really encouraging. What voltage did you set for your bias?

Thanks again,

 

[meanie]

My F6 is modded as per 2picodumb and TA recommendations.
Currently at 1.4A ie 0.65v.

You may run at stock bias first and then slowing increase up, to your listening requirement. track your HS temp along the way, coz we may be using diff size of HS.
I am using Conrad's 350x151

I like how it sounds at 1.65A, but HS temp is too high, may switch to a bigger HS in the future.

 

[2 picoDumbs]

Nice one.

 

[TungstenAudio]

Crank the bias 'till it starts to melt, then back off a little.

 

[Yaho]

track your HS temp along the way, coz we may be using diff size of HS.

Excellent point! My is 40x300. So, I need be much more conservative than your approach.

Crank the bias 'till it starts to melt, then back off a little.

This is my first SS amp build (put together) ever. I am so excited!

 

[zman01]

Excellent point! My is 40x300. So, I need be much more conservative than your approach.

You mean 140 mm x 300 mm?