THE ALFABET.
Hi,
e)better still,use a separate supply for in- and output tubes.
f)better still,regulate the anode supplies for both tubes.
g)better still,up the anode supply for the 12AX7A to at least 300VDC
h)hey,and what about a volpot at the input?
Okay you got 18 characters left...
Cheers,
Hi,
e)better still,use a separate supply for in- and output tubes.
f)better still,regulate the anode supplies for both tubes.
g)better still,up the anode supply for the 12AX7A to at least 300VDC
h)hey,and what about a volpot at the input?
Okay you got 18 characters left...
Cheers,
g)
Then it won't be triode.add a 100 ohm, 5W resistor inbetween screen and plate
Well it was a quoteg) was used already.
Damn, I must have started up in modulo 7 this morning
z)
I don't really want to run this in triode mode
Well it's drawn in triode mode.
If you want pentode mode, you'll need some NFB to make it sound reasonable IMO.
What is the impedance of the iron?
I'm not experienced in pentode mode operation, but that sounds reasonable to me. I've seen them running into 3K triode mode.The primary z is 5K.
Perhaps someone with more experience than me can comment.
No, I meant seperate 250 ohm resistor for each cathode.
I think 150 will leave you underbiased, no?
It depends where you want to operate them I guess, but a 6BQ5 in triode mode will draw somewhere around 40mA. E=(250)(.040)
=-10V bias. Seems about right.
And if you run them in triode mode, you will get just under 2W per channel. Switching to pentode will get you over 5, but will be more like a guitar amp!
I think 150 will leave you underbiased, no?
It depends where you want to operate them I guess, but a 6BQ5 in triode mode will draw somewhere around 40mA. E=(250)(.040)
=-10V bias. Seems about right.
And if you run them in triode mode, you will get just under 2W per channel. Switching to pentode will get you over 5, but will be more like a guitar amp!
FALSE MODESTY?
Hi,
For penthode mode that is the Z to go.
So now it is confirmed.
Cheers,
Hi,
I'm not experienced in pentode mode operation, but that sounds reasonable to me.
For penthode mode that is the Z to go.
So now it is confirmed.
Cheers,
G said:[BAt 250 volts biased at 48 mA with -7.3 on the grid the bias resistor would be 7.3/.048= 152 ohms.[/B]
Except it will not draw 48mA in triode mode. That's the figure for pentode. So your actual bias with 150 ohms will be closer to -5V... too low. Try it!
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