So, I built this:
The voltages on my build are pretty close to the design.
I had to increase the screen droppers to get the screen voltages down a little lower.
The input pentode is working as expected.
I can't get the second pentode to "center" bias. I put a variable resistor in place of Rk to vary the bias and it just seems to want to go into "cutoff" very early over a pretty wide range of bias points.
I tried swapping the tubes...same result.
Any ideas?
Keuhnal Garage Amp
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Keuhnal Garage Amp
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Steve
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Stevem
- Posts: 5144
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Re: Keuhnal Garage Amp
How the heck that leg of the tone pot and that tubes input grid ( pin 9 ) have there needed ground reference with that cap there to ground?
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Re: Keuhnal Garage Amp
You do not have the required permissions to view the files attached to this post.
Steve
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Stevem
- Posts: 5144
- Joined: Fri Jan 24, 2014 3:01 pm
- Location: 1/3rd the way out one of the arms of the Milkyway.
Re: Keuhnal Garage Amp
Yup, I totally missed that!
Those upward running schematic grounds are totally contrary to the precived direction that physical ground is and I guess I will never get used to it!
Those upward running schematic grounds are totally contrary to the precived direction that physical ground is and I guess I will never get used to it!
When I die, I want to go like my Grandfather did, peacefully in his sleep.
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!
Not screaming like the passengers in his car!
Cutting out a man's tongue does not mean he’s a liar, but it does show that you fear the truth he might speak about you!