F4 power amplifier

[njepitt]

Look at the title page of your browser!!!

I think ZM was remarking on the labelling on the board you posted...

 

[cviller]

Ok, I see - ZM is just always making jokes so I have stopped taking him too seriously.

 

[cviller]

Thanks ZM for pointing out the error. I took the writing from the F5 board to make sure it looked the same. Should be corrected here.

 

[Zen Mod]

Look at the title page of your browser!!!

edit :
I didn't saw that you boyz typed in meantime ...... I'm working on some photoshoping ...... it's time consuming .....

 

[cviller]

You sure got me there. But I'm happy for getting those silly silk screen bugs removed before I order the boards!

 

[jacco vermeulen]

I'd keep both label versions, you can then always stick in a Toshiba IGBT GT20D101/GT20D201 pair on the exact same board and leave all other positions blank. (once the owner left the building)

 

[Zen Mod]

I'd keep both label versions, you can then always stick in a Toshiba IGBT GT20D101/GT20D201 pair on the exact same board and leave all other positions blank. (once the owner left the building)

YGFM , ya Dutchy Whale .....

 

[Zen Mod]

You sure got me there. But I'm happy for getting those silly silk screen bugs removed before I order the boards!

you owe me 2 boards for that .........

naah - make it 2 pairs of boards ........

 

[njepitt]

you owe me 2 boards for that .........

naah - make it 2 pairs of boards ........

Wait a minute!! You didn't even tell him what the problem was !! I think I deserve any free boards being handed out...

 

[Zen Mod]

Wait a minute!! You didn't even tell him what the problem was !! I think I deserve any free boards being handed out...

I'm always taking all boards !!

ask cviller , if ya don't believe me !!

 

[Blues]

I'm always taking all boards !!

ask cviller , if ya don't believe me !!

Choky, you have PM...

 

[fastvideo]

Has anyone tried driving F4 with OPA552 non inverting, gain X16 to 20?
How is the sound?

 

[generg]

Hi choky,

didn´t you only try this with your "last last F4":

"If you have a source which can drive 5 Kohm and a couple hundred pF,
you can dispense with the JFETs altogether and simply drive the Gates
of the Mosfets."

A little more work, and you can use a single pair of Mosfets and raise
the impedances of the bias circuit, and then it would be about 22K and 70 pF."
post #2913 from Nelson Pass

 

[Zen Mod]

I didn't tried it exactly as F4 , but that's pretty much boiled water ... especially here - in Papaland

 

[diyray]

Pre/Pro A/V

What is the amps out for the F4 at one volt in. Speaker is 97db, but one volt
probably won't work.

Ray

 

[jacco vermeulen]

97dB/W*m means you need 2W to reach 100dB.
1V at the input is just under a volt at the output, corresponds to less than 90dB SP from your LSP.

(current is not determined by the power amp, not this one, but by your loudspeaker)

 

[diyray]

97dB/W*m means you need 2W to reach 100dB.
1V at the input is just under a volt at the output, corresponds to less than 90dB SP from your LSP.

(current is not determined by the power amp, not this one, but by your loudspeaker)

Any ideas on what to put between the Pre/Pro A/V and the F4? Maybe something like Cans.

Ray

 

[cviller]

You need a preamp with some voltage gain.

 

[chrismercurio]

The Pre-Pro most likely has a whole lot of gain available. Can't you independently adjust levels for each one of your speakers?

 

[diyray]

I can't find any info. other than 1 volt .05 (pre-out). Maybe it does I don't know. They don't give enough info. in the manual to know.

Onkyo Europe - PR-SC5507