Bottlehead Forum
Bottlehead Kits => Kaiju Stereo 300B amp => Topic started by: Alby0521 on August 14, 2020, 03:43:25 PM
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Hello
Is it worth to upgrade the 0.1uf caps on the 2 pc boards? Anyone had good experiences on this upgrade? If so what good brands can be used which don’t brake the bank?
I already got the 10uf, 100uf and 0.1uf(the one attached to the terminal strips) for a future upgrade but I see that some people upgraded the 0.1uf caps on the boards too so I was interested in any experience.
Thanks in advance.
AB
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Hello,
No one had success with the spoken upgrade?
Best
AB
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The questions that you might want to ask yourself is: why is swapping one capacitor for another always an upgrade? What is the function of that capacitor in the circuit?
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I’m not completely sure what that cap does that’s why I’m asking here as I saw some people changing caps in that position.
Thanks
AB
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I haven't heard huge differences in caps there. I have had to do some repairs where huge 0.1uF caps have destroyed the PC board because they are too heavy.
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The 0.1uF cap on the shunt regulator, along with it's associated resistor, stabilizes the feedback loop to prevent oscillation and/or ringing. Don't change the values! It's been a long time since I did the analysis, but if I recall correctly the instability happens at around a megaherz, which would lead sometimes to very hard-to-trace, unpredictable effects.
If you do change the cap, use something physically smaller to minimize RF sensitivity. Don't use Mylar without re-doing the stability analysis because Mylar develops a significant ESR at radio frequencies. Maybe something like mica, or NPO (C0G) ceramic.
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Hello Paul and Paul
Very clear thank a lot.
I’ll let the caps be on that position.
Best
AB