F5 Turbo Builders Thread

Yes. I agree. With more fets, Yfs/gm increases, making for higher Df as well as helping offset the increases Miller capacitance. Thing is, it doesn't seem like Nelson ever does anything for the heck of it and I wonder if there was a lesson learned in the beast of a thousand fets that has been passed on to his commercial offerings. although the article is rather new, I think the amp is much older. Just wandering if anybody had any ideas. Oh well. Sorry. I am on vacation and have too much time.
 
I don't have a good enough understanding to explain it very well, but the F5T will pass more current at the large voltage swings because the diodes effectifly make the source resistors smaller. (fewer ohms) So with more current in general, not getting lost through the source resistors, the control over the lower impedance loads should be better... right?

Or am I just as confused as the rest of us? (probably...)
My take is same current more voltage . In effect raising the voltage swing that reaches the load on peaks overcoming the voltage loss normally in those resistors by conducting through the diode .This gives you a stable bias thru the resistor and peak flow through the diode like secondaries in the old carb.
 
My take is same current more voltage . In effect raising the voltage swing that reaches the load on peaks overcoming the voltage loss normally in those resistors by conducting through the diode .This gives you a stable bias thru the resistor and peak flow through the diode like secondaries in the old carb.
Yes, this lack of voltage drop is what we see as good current capability.
The amplifier output voltage droops less as the output current increases.

This is still CURRENT capability as used by Flg
I preffer to think in terms of load current demand.
 
Hi All,

If I have dead quiet finish 1 channel F5T V2 (Experimental Build using non-official DIY Store Board) and a stable output DC offset, do I still need to bother for measuring nor looking for any Oscillation?

These are following exact component value per schematic.

Do I expect same result with the DIY Official board? Visualize that the only difference is the board layout. Currently, my non-official board is concentrated on a single big heatsink. When I use the DIY Store Board, going to mono...P and N Channel board will have each separate heat sink where the gain stage will be in the middle similar with the commercial Pass Amp.

Cheers.