Sonnyhad,
You said: the cascade mod.
For most of these kits and assembled amplifiers, the input tube and driver tube are already in cascade.
Perhaps you meant the cascode mod (o, not a).
You said: the cascade mod.
For most of these kits and assembled amplifiers, the input tube and driver tube are already in cascade.
Perhaps you meant the cascode mod (o, not a).
In the video I just did one channel and then tested the difference. You want to do both the same.
Yes, you are definitely right, I misspoke. Cascade, that's the mod we are talking about.
Cascade triodes are one triode stage after another.
The input signal drives tube 1's grid.
Tube 1's plate, drives tube 2's grid. This is Cascade.
The output is taken from tube 2's plate.
Cascode triodes:
The input signal drives tube 1's grid.
Tube 1's plate, drives tube 2's cathode. This is the difference that makes it a Cascode circuit.
The output is taken from tube 2's plate.
Most, if not all, of Stephe's input stage mods start with the original Cascade, and modify it to Cascode.
I hope that makes the differences, and the similarities clear.
The input signal drives tube 1's grid.
Tube 1's plate, drives tube 2's grid. This is Cascade.
The output is taken from tube 2's plate.
Cascode triodes:
The input signal drives tube 1's grid.
Tube 1's plate, drives tube 2's cathode. This is the difference that makes it a Cascode circuit.
The output is taken from tube 2's plate.
Most, if not all, of Stephe's input stage mods start with the original Cascade, and modify it to Cascode.
I hope that makes the differences, and the similarities clear.
Well, I finished and I had to shut it down. It got very hot. The 300b tubes got red hot. Any ideas? I did have a pair of 1w 100m resistors left over.
I did the second socket just like the first. Using the same number 1 pin.
I did the second socket just like the first. Using the same number 1 pin.
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That 100 ohms is likely the grid stopper for the grid of the 300B tube. If either of the 300b tubes red plated, make sure the grid of the tube is connected to ground through the grid stopper + grid leak resistor. You should measure ~ 270K ohms between the grid pin and ground on both 300B tubes.
Thank you. But I have the one in the yellow grid stopper with the shrink wrap. I have 7 resisters in the front end mod.
Grid stopper for the 300B tube. Somehow I think you have lost the grid to ground on the output tubes, that will make them red plate for sure. It also looks like you melted the outside of at least one of the coupling caps. make sure they aren't damaged/shorted. There shouldn't be ANY voltage on the grid of the 300B tube.
Yes that might help, I'll go through it 1 by1 and see where the mess is
Thanks a bunch. I did both side the exact same. Pin one is the same on both sides.
Thanks a bunch. I did both side the exact same. Pin one is the same on both sides.
Thank you Steph, yeah I had a heck of a time with temp settings on the new solder station. I m sorry but I still can't find where the 1w 100ohm resistor goes. I'm probably a pain in your rear. This is new for an old man.
Is there another way that 100r 1w is called out on the schematic
The package says 100ohm.
Thanks in advance, I'm confused. And is it OK if it is wired the same using same pins?
The package says 100ohm.
Thanks in advance, I'm confused. And is it OK if it is wired the same using same pins?