F6 Amplifier

[Russellc]

For me "good" mean : able to give the very best from what you'r testing , pc sound card is way way far from that



.

Download MusicBee ( it's free) and set it for the WASAPI output, which will by pass your sound card and microsoft "sound stack" and feed that into a DAC. Even with the Audioquest Dragonfly/Jitterbug combo, your sound quality will surprise you big time...Musicbee will rip your CDs and organize them, or you can use you CDs in the laptop's cd slot. This combo is surprising and very cheap to try. OK, back on topic...

Russellc

 

[Bksabath]

How totaly bonkers would it be to drive the opposite side of a balanced configuration from the same coil ?

mean output of coil 1 drive + side of A amp and - side of B amp

Double current at half voltage yes ?

 

[Zen Mod]

do you mind posting some sketch of idea ?

it sounds impossible right now , but one never know , with Talians

 

[Bksabath]

it is bonkers idea and pretty poor sketch bias circuit covered by other piece of paper most probably is still needed

just the coil pin 5 connected on other half pin 8
and pin 8 connected to other half pin 5

but then I could not use my pumpkin balanced out to drive it

 

[Bksabath]

this may be clearer

 

[triode_al]

it is bonkers idea and pretty poor sketch bias circuit covered by other piece of paper most probably is still needed

just the coil pin 5 connected on other half pin 8
and pin 8 connected to other half pin 5

but then I could not use my pumpkin balanced out to drive it

looks to me like you have to pay attention to galvanical isolation . i.e. the coil in the left bottom has a different potential than the one at the right top, so to say.

 

[Zen Mod]

no way Jose

you can put your foot wherever you wish , but it's molto importante where you're going to put other foot , when step is approaching finish .......

 

[Bksabath]

agree

2 traffos at imput as sch zen posted look much betterer

Just got my hands of over 20 Kg of copper heat sink as it was used to cool down same 250Kw JGBT

Looks perfect for 2 F6 vanilla versions

 

[Zen Mod]

pics , or I'm nonbeliever

 

[Soundhappy]

pics , or I'm nonbeliever

 

[Bksabath]

for now believe that it came out of a Danfoss VTL 250 Kw inverter

The picture was taken 3 months before the drive blow up and show the aluminium one used for the rectifiers
The copper one is just behind it
and now sitting in my locker at work but not for long

Hey another bonkers idea.
Any Place where they repair drives near ancient Batsch
one may be able to scrounge same pretty stuff maybe in exchange for services

 

[ColinA]

I wonder if someone would answer this without the maths as I am lost when it gets past fingers and toes.

Using a Marantz 6005 cd as source and a standard F6
I am just using a 10k stepped attenuator which works and sounds fine (to me.)

Is there an "ideal" value for this combination?

 

[Zen Mod]

you're good to go

however , 50K after CD and nice buffer after pot is way to go

 

[Bare]

Additional buffer to the "inbuilt' one inna F6?

 

[Zen Mod]

if you have easy interconnects between pot and F6 , then buffer is redundant

however , ppl are mostly using coax cables , which I'm finding not so easy on ear

 

[ColinA]

Thank you.
Interconnects are "Starquad" homemade.

 

[Bare]

if you have easy interconnects between pot and F6 , then buffer is redundant

however , ppl are mostly using coax cables , which I'm finding not so easy on ear

Ahhh thank you .
Wasn't aware Coax was still popular / in wide usage.
Sounds effects are fairly obvious when using that stuff

 

[Bksabath]

pics , or I'm nonbeliever

There you go

a couple of days in a coca cola bath and it will be all sparkling like the day it was born

Then chop in half and hand lapping whit baking powder
It was designed whit fan cooling in mind for a 250 Kw drive

Can't remember who's sedz "amazing what a litle forced air cooling can do"
Moss Fet's and thermistor for fan controller 2 120 mm fans at quarter speed should be pretty silent.

The F5's have been running for years now at 34 V and 2.6 A bias on TO 220 FQP19N20 pairs (see my F5 )

So one wonder given the size of this sink how far up can I push the trafo specks for vanilla F6 (Just one duda for rail)
24 V ac secondary seems to add up

Only worry is current clipping whit the Polk LSi15

 

[Zen Mod]

 

[jacco vermeulen]

There you go

Looks like a 30 year stash of ciggies went through it.
Amazing what a little thar she blows can do.