ZM what I meant is how does this circuit produce the approx 4Vish ?
I understand that the voltage across the 5k pot is the same as the zener voltage and that the current thru the pot is 1.36ma as per your example but how does this translate into getting the desired Vgs?
thanks again.
Nash
The trimmer is the voltage divider for the Zener voltage.
You take the gate voltage for the mosfets from the trimmer viper.
OK but it goes thru R9/10 and R11/12 before reaching the gate. So how does one calculate the Vgs ?
thanks. nash
just do it
it's pretty obvious .... from pot viper to gate there is no significant current , so voltage at wiper is practicaly same at gate
it's pretty obvious .... from pot viper to gate there is no significant current , so voltage at wiper is practicaly same at gate
Lu1014d is depletion mode mosfet. You would also need to cascode to dissipate power.
You would need to completely change the circuit to make it work
You would need to completely change the circuit to make it work
look at latest two Papa amps with Sony outputs
they're depletion devices too , differing in that that LU needs much lower placed cascode (lower Uds)
as pico said - check Zen 8 for recipe
they're depletion devices too , differing in that that LU needs much lower placed cascode (lower Uds)
as pico said - check Zen 8 for recipe
Postage Only
I have a pair of line transformers from an HP 353C patch panel -- should work in the F6 -- you can see the schematic on page 26 of the manual from Agilent's website. I measured them and they are flat from 20Hz to 200kHz. Will send them out, US only, for the price of postage. (Should be $6 w PP fee).
I have a pair of line transformers from an HP 353C patch panel -- should work in the F6 -- you can see the schematic on page 26 of the manual from Agilent's website. I measured them and they are flat from 20Hz to 200kHz. Will send them out, US only, for the price of postage. (Should be $6 w PP fee).
Attachments
Folks:
Am I right in assuming the bias and offset trimmers should be bottomed out (set to 0R) before installing on the F6 boards?
Thanks,
Scott
Am I right in assuming the bias and offset trimmers should be bottomed out (set to 0R) before installing on the F6 boards?
Thanks,
Scott
Just finished a F6, on one of the amp channels the LED is not lighting. It is installed in the correct polarity. Any thoughts why this could be?
I just set initial 0.1v bias and zeroed dc offset with light bulb in place on both channels.
I just set initial 0.1v bias and zeroed dc offset with light bulb in place on both channels.
What's the DC voltage across the resistor that feeds the LED? Are you sure the resistor is the right value
and not 10x or 100x too large?
Occam's Razor says that you probably installed it backwards. (Or the silk is backwards...?)
