First, I'm genuinely impressed by your wealth of knowledge. I truly wish more people were as generous with their expertise. I come from an IT background, so some specifics fly over my head. Just a quick one - I've got this stock amp, and I'm considering replacing the original tubes to enhance its sound. Got a budget of around $1500. Suggestions? One of these days, I'll muster the courage to DIY this mod! Thank you!
Interesting, I've always heard that since the grid stopper is there to halt oscillations, it was the one that needs to be close to the pin. I do slip up a couple of times in the video and call the grid stopper "Grid leak" but I corrected it with a speech bubble. The grid stopper is the resistor in the signal path to create a low pass filter, the grid leak is there to reference the grid to ground for biasing. Hope this helps! www.aikenamps.com/index.php/grid-resistors-why-are-they-used
@@SkunkieDesignsElectronics in the final schematic posted on your website it shows the grid leak resistor tapped off the input before the grid stop resistor, in the video you wire it directly from the tube pin to ground, effectively putting it after the grid stop resistor? Is there a difference between your schematic and the way you actually wired it? Would it matter which comes first?
@@danielemorgani7459 It really doesn't matter. The grid stopper is there to stop oscillations that might be in the input signal. You are not going to have any oscillation from the ground, where the grid leak resistor is located.
I've completed all the mods and have the Mundorf paper in oil and Audio Note caps on order. 2 questions. I've used a small red led for bias, where can i get one like you've used. Also, with cascode there is a lot less gain. Is there a way round increasing the gain. Great work BTW, love your channel and excellent explanation.
Yes the gain is lower but before, the amp would go into clipping/distortion at less than 1/3 volume with normal sources. Yes, you will have to turn the knob more to get the same SPL, but the whole range is usable. You can get that LED at mouser HLMP-Q150
I noticed that you changed the B+ resistors, now using 8.2K ohm units. Unless there was a problem with your camera, you had 100 ohm resistors in place before.
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This A50 video has been my favorite to date, so much good info and DETAIL...one of the BEST!
Truly enjoy your wealth of knowledge. Keep the modifications coming 👍
Pretty cool to see you’re showing your soldering work.
First, I'm genuinely impressed by your wealth of knowledge. I truly wish more people were as generous with their expertise. I come from an IT background, so some specifics fly over my head. Just a quick one - I've got this stock amp, and I'm considering replacing the original tubes to enhance its sound. Got a budget of around $1500. Suggestions? One of these days, I'll muster the courage to DIY this mod! Thank you!
Love ur tips and tricks...
Hello, it seems to me better to connect the grid leak resistance just as close to the tube base than the stop resistance.
Interesting, I've always heard that since the grid stopper is there to halt oscillations, it was the one that needs to be close to the pin. I do slip up a couple of times in the video and call the grid stopper "Grid leak" but I corrected it with a speech bubble. The grid stopper is the resistor in the signal path to create a low pass filter, the grid leak is there to reference the grid to ground for biasing. Hope this helps! www.aikenamps.com/index.php/grid-resistors-why-are-they-used
@@SkunkieDesignsElectronics I generally mount the leakage resistor on the other side of the stop resistor
@@SkunkieDesignsElectronics in the final schematic posted on your website it shows the grid leak resistor tapped off the input before the grid stop resistor, in the video you wire it directly from the tube pin to ground, effectively putting it after the grid stop resistor? Is there a difference between your schematic and the way you actually wired it? Would it matter which comes first?
@@danielemorgani7459 It really doesn't matter. The grid stopper is there to stop oscillations that might be in the input signal. You are not going to have any oscillation from the ground, where the grid leak resistor is located.
I've completed all the mods and have the Mundorf paper in oil and Audio Note caps on order.
2 questions. I've used a small red led for bias, where can i get one like you've used.
Also, with cascode there is a lot less gain. Is there a way round increasing the gain.
Great work BTW, love your channel and excellent explanation.
Yes the gain is lower but before, the amp would go into clipping/distortion at less than 1/3 volume with normal sources. Yes, you will have to turn the knob more to get the same SPL, but the whole range is usable.
You can get that LED at mouser HLMP-Q150
Is there room for a motorised volume control?
not sure, I no longer have the amp here to check/measure.
I noticed that you changed the B+ resistors, now using 8.2K ohm units. Unless there was a problem with your camera, you had 100 ohm resistors in place before.
Unfortunately some of the video was shot out of order, the schematic is correct.
Is there no risk of the resistor overheating under the shrink tubing?
This resistor has almost no current running through it, only the AC/music signal.
you have plenty of cathodes on your finger nails !
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이해하기 어렵군요.
PCB기판을 쓰레기통에 버리고, 처음부터 새롭게 내부 배선을 다시 해야 옳습니다.