No output from new amp build

[Bootsman]

I have the bias v wire and I have a bias common wire from th pt

[Stevem]

There are 3 main wires that comprise the bias circuit.

1) the AC bias tap feed from the power transformer to the input dropping resistor that then feeds the diode.

2) as I posted before the ground wire off of the positive end of the two bias filter caps.

3) the negative DC bias feed from the right hand side of the 1K resistor to the junction of the two 220K resistors.

I will ask again what do you have for a negative voltage on pin 5 of the output tubes with these output tubes not in there sockets?

[Bootsman]

-22v

[Bootsman]

This is the pt I have

[Stevem]

Do not put your output tubes back in until that -22 volts is increased to -30 to -32!

Is the what that Hammond chart calls the common wire on that bias tap grounded like it should be?

[Bootsman]

Ok. I just wanna make sure where that green wire goes to

[Bootsman]

With the standby switch on
or turned off?

[sluckey]

Ok. I just wanna make sure where that green wire goes to

Green wire goes to chassis ground.

[Bootsman]

Thanks

[Colossal]

also pins 6/7/8 all being 108 volts seems really odd... Without a schematic, though I'm just guessing, but they should be similar to V1.

~Phil

Cathode follower

So a cathode follower has the anode and cathode voltages identical? that definitely seems odd to me... there's zero voltage drop across the entire triode?

I know that the cathode voltages on one half of the cathode follower can be higher, but I didn't think the anode and cathode were at the same potential? And the grid of the same triode?

~Phil

No, the grid and cathode of the follower will be at the same voltage as the previous, adjoined gain stage plate (direct coupled).

[pompeiisneaks]

Cathode follower

So a cathode follower has the anode and cathode voltages identical? that definitely seems odd to me... there's zero voltage drop across the entire triode?

I know that the cathode voltages on one half of the cathode follower can be higher, but I didn't think the anode and cathode were at the same potential? And the grid of the same triode?

~Phil

No, the grid and cathode of the follower will be at the same voltage as the previous, adjoined gain stage plate (direct coupled).

Maybe I misunderstood your point, but my point was that these three triode components all being at the same voltage seemed bad... (just reread my original content and I indicated I didn't know 'why' the voltages might be how they are, due to not having a schematic, and likely you were clarifying that for me.. makes sense that the anode should be the same as the cathode of the previous stage, but the anode should definitely have a voltage drop... seems very odd to me.)
Edit: forgot trailing parenthesis

~Phil

[sluckey]

A typical cathode follower has the plate connected directly to a B+ node. The plate must be more positive than the cathode. Otherwise, there's no way to attract those electrons that are boiling off the cathode.

[blackeye]

A typical cathode follower has the plate connected directly to a B+ node. The plate must be more positive than the cathode. Otherwise, there's no way to attract those electrons that are boiling off the cathode.

Well said. And the grid must still be kept negative relative to the cathode. None of the voltages should be identical at idle.

[pompeiisneaks]

A typical cathode follower has the plate connected directly to a B+ node. The plate must be more positive than the cathode. Otherwise, there's no way to attract those electrons that are boiling off the cathode.

Yeah that's right, I'm tired today, and I couldn't visualize it to explain it... it's the grid that's coupled to the cathode of the previous phase... ugh, I'm at coffee cup 3 and still not braining things...

~Phil

[Stevem]

You may need plane old water to rehydrate with !