F6 Amplifier

[necplusultra]

Thanks ZM

Your process is flawless. I always use this method except that I set the pot voltages to about .8V to start.

In this case, I started with 0and got to a max of .2

If the fets are fried. that sucks.

I'll swap out and add a led to try it out with IRFs.

BF: noted. Learn from mistakes

Don't know what went wrong. The other channel is fine.

 

[Zen Mod]

you can test that presumed broken one with simple mosfet test (FW site , articles) taking in account difference in Ugs , vs. mosfet

 

[R-K Rønningstad]

Don't you dodo the ancient VFETs:
https://www.youtube.com/watch?v=TXauEmBOjxQ

 

[necplusultra]

before I start the biasing process,

is the bias for the IRF 1.6A?

 

[buzzforb]

hot as your sinks can take

 

[necplusultra]

well, BF and ZM were correct.

the semis have gone the way of the dodo. I would like members to observe a moment of silence in respect for these fine pieces of fet. If anybody can recommend a museum somewhere where I can donate, preferably next to a stuffed dodo.

I am in bereavement

 

[marconi118]

could someone tell me where to find the last F6 schema? too long to read 500 pages of this Thread...

 

[6L6]

Marconi - It's all in here;

6moons audio reviews: FirstWatt F6

 

[jugi63]

I have a wierd thing with my F6 fuses... When I place ceramic tubed fuses in they burn every time I turn the amp off. Every time. Glass tubed fuses work fine. Both 1,25 A.

Can there be some variance in different production patchies? The ones in the local store seem to be the same touchy type.

If I used a 1,6 A fuse, would that possibly do harm to the amp before blowing out in the case of a problem..?

 

[Zen Mod]

more details

xformer VA , uF in cap bank per rail , arrangement of cap bank , any sort of soft start or not etc.

exact schmtc would be perfect

 

[jugi63]

Sysmatics exactly as Nesson suggests. Dual mono 240V. Nothing extra.
Caps are 15 000uF and arranged as in sysmatics.

 

[Zen Mod]

Xformer VA ?

common fuse for both xformers or one per xformer ?

 

[jugi63]

Like Nelssons: 300VA per side (mono amp). Both transformers with their own fuse. Fuse between switch and AC input. Switch on the live wire.

(And I repeat: 1,25A ceramic blows, 1,25A glass does not.)

 

[Zen Mod]

1A6T per xformer will do the job

considering you're in 220/240Vac area

 

[jugi63]

Ok, thanks!

 

[rolandong]

Pardon me for novice question, will R125 work with F6?

 

[buzzforb]

just fine.

 

[Zen Mod]

more then fine

in fact ........ it will not work !

send all those non-adequate R125s to OPLDF

 

[Tea-Bag]

What Buzz said, not ZEN MOD!!!

 

[necplusultra]

Zen Mod,

I have 2 burnt r125s if you want them.

as long as you have a stuffed dodo lying around, they're yours.