F5 Turbo Builders Thread

[6L6]

One 48 volt secondary with center-tap will work.

 

[henryve]

I assume that the sign-up sheet for the Fairchild MOSFETs are still active. After adding my name, what would I need to do. Pay buzz via Paypal?

 

[AudioSan]

One 48 volt secondary with center-tap will work.

yes. that will work

 

[Blink_PT]

what?
and one 24VAC secondary??? you need 2x24VAC

This source is not symmetrical, have + and - there is no point 0.

Where I turn on 2x24VAC in PSU...

I must be confused or to do evil thing!!!

An externally hosted image should be here but it was not working when we last tested it.

 

[AudioSan]

here is the 0 point.

 

[Blink_PT]

here is the 0 point.

You are absolutely right, I apologize for my inexcusable stupidity, and I did an F5, brbrbrbrb. Rectification common to 2 channels completely confused me.brbrbrbr

 

[a.wayne]

some nice lights allways make the sound good

Have you built a 4 Pr version yet ..... ?

 

[noSmoking]

hi AudioSan,
I changed R 5,6 to 2.2K at 25 volt rails on F5v2 turbo yields 10 volts at Q5 and 6 emitters,just right for cascode for input fet's. At 32 volt rails about 18 v,still good value!
Thanks,
NS

 

[Renron]

You are absolutely right, I apologize for my inexcusable stupidity, and I did an F5, brbrbrbrb. Rectification common to 2 channels completely confused me.brbrbrbr

one channel, P&N rails

 

[buzzforb]

hi AudioSan,
I changed R 5,6 to 2.2K at 25 volt rails on F5v2 turbo yields 10 volts at Q5 and 6 emitters,just right for cascode for input fet's. At 32 volt rails about 18 v,still good value!
Thanks,
NS

May be misreading, but V across R5 and R6 is the gate voltage your fets will see.

 

[AudioSan]

Have you built a 4 Pr version yet ..... ?

no. not yet. i need a new M3 tap

 

[AudioSan]

hi AudioSan,
I changed R 5,6 to 2.2K at 25 volt rails on F5v2 turbo yields 10 volts at Q5 and 6 emitters,just right for cascode for input fet's. At 32 volt rails about 18 v,still good value!
Thanks,
NS

the change of R5/6 is to get the bias of the outputs up.

 

[buzzforb]

The curse of V3 strikes again.

 

[a.wayne]

There's cursing going on alright ...

 

[buzzforb]

I bet you got more to listen to than you need. You thinkin about building on?

 

[AudioSan]

no curse. but cursing. well. that is ment to be

 

[AudioSan]

I bet you got more to listen to than you need. You thinkin about building on?

and you don*t?

 

[buzzforb]

 

[AudioSan]

exatly

 

[AudioSan]

a little update regarding F5 turbo. and other F5's for that matter:
after a confirmation from nelson. R3/R4 do NOT need to be 3W. you guys can use whatever you like. 0.6W is just fine.
just as i was thinking. regardless what someone said/tried to calculate.
if R3/R4 needed to be 3W, then the P3 pot would need to be 3W too.