HELP- Monoblock F6 amplifier

[dallas21]

We completed a premium parts build of the F6 AMPLIFIER.
That bring said in my larger room thev50wpc into 4ohms is boarder line.
In my build it uses 2 -300va Plitron torroid, snd 240k Nichicon Fine Gold Audyn Copper .1 bypass caps. Besides that standard build.

We ard looking for Help staying in pure class A upping the wpc to,
50wpc-8ohms, 100 wpc-4 ohms. Since these will be in seperate chassis it Is time.
I have looked and see Nowhere a 1st Watt F6 higher power amplifier.

Your knowledge and creativity will allow this Great design ,Thank you NP for sharing
We all give you thanks. I am late to the party, Happy Birthday Nelson 😎👍

 

[Zen Mod]

50W is doable , with elevated rails to ,say, +/-35Vdc
besides that , cascoding input buffer JFets (covered in F5 thread) , doubling outputs (to 2 pairs/ch) , setting Iq to ,say, 2A
take care ...... dissipation goes up to 140W/channel

100W/4R ....... that's uncharted territory , where problems can arise from need to drive multiple output pairs with same xformer ....... so you'll be on your own

possible way is to use input buffer with severely lower Rout , but xformer capabilities need to be tested

 

[MASantos]

What about an F4/BA3 output stage which can easily provide this power with 30-35V rails, and then build an F6 with 2sk2013/2sj313 to act as preamp?

So it would be a low power F6 acting as preamp and then a power buffer.

 

[KatieandDad]

The Aleph 4 was 100W/Ch, have a look at that.

 

[poseidonsvoice]

Or be smart and buy/build/design a higher sensitivity loudspeaker.

These designs are called "First Watt" for a reason 😉

Best,
Anand.

 

[ColinA]

Or be smart and buy/build/design a higher sensitivity loudspeaker.
These designs are called "First Watt" for a reason 😉
Best, Anand.

Aggree
The FirstWatt designs and particularly the F6 are low power high quality amps for reasonably sensitive speakers.

If you have insensitive speakers, or a concert hall to fill, or you want 120db.
Then pick an amplifiers design to suit.
Please don't ruin this design.

 

[KevinHeem]

How about an F5T?

 

[6L6]

BA-3

 

[vdi_nenna]

Build two F6 amps and bi-amp or go active crossover. Will give about as much perceived power as 100w, or maybe closer to 75w-80w. Not losing much between 75w and 100w.

Just saying, if you like the F6 and know how to build it... 😉

(Bi-amp technical info above taken from Speaker Builder Special Edition issue, in case you're thinking I pulled that out of my rear.)

 

[vdi_nenna]

I'll be using two F6 amps, one mosfets and one jfet, in the near future.
At the moment using mosfets F6 and 60w T-amp. Sounds good, but it gets fatiguing after an hour. I'm going to blame that on the T-amp 3rd harmonic distortion. 😀

Speakers are around 86-87db efficient.

This is my second system in the photo, testing new speakers.

 

[KevinHeem]

This is my second system in the photo, testing new speakers.

What effect does the lantern have on the sound. Is that a worthy addition to a system. Please advise.

 

[vdi_nenna]

Helps me see.

 

[Bare]

Lantern ? I was too busy staring at the IKEA salad bowl speakers 🙂.

 

[vdi_nenna]

Don't have to stare at them because they pretty much disappear when playing. That was the idea with this design. 😉

Anyway, build two F6 amps...

 

[Nelson Pass]

This is my second system in the photo, testing new speakers.

That's what I like, amplifiers that are bigger than the speakers.

😎

 

[Zen Mod]

me too

under condition that speakers are at least 15" in diameter

 

[vdi_nenna]

The T amp is behind the F6. 😀

 

[vdi_nenna]

Two F6s kicking ***! 😛

Midrange cleared up. More resolve in decaying notes.
Bigger sound stage.

Could do worse than two F6 amps.

 

[MASantos]

Does the salad taste better when listening to salad bowl speakers?

 

[vdi_nenna]

Does the salad taste better when listening to salad bowl speakers?

Everyone's a comic. You don't deserve an answer.