Bottlehead Forum
Bottlehead Kits => Kaiju Stereo 300B amp => Topic started by: Ravenshead on November 26, 2021, 07:57:34 PM
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Hi gang,
I bought my first kit (Kaiju) exactly one year ago, and have been loving it! I'm always telling people that the sound is great, which of course I'd kinda hoped for, but I also had way more fun with the actual build than I'd anticipated. Big thanks to all at BH for the clear and exhaustive instructions.
Anyway, my question is about hum. I don't get much hum coming through the speakers, but I do get a noticeable hum coming from the amplifier itself. It's definitely emanating from the rear, around the AC input. I've re-read the manual section about "buzzy hum," which advises to check grounds. Before I embark upon a fool's errand, I guess my question is: will a bad-ground-hum be audible through the speakers, or directly from the amp itself? Or even more basic: is some hum just normal?? In addition to my first kit/build, this is also my first piece of tube gear, so I guess I'm just not sure what to expect.
Perhaps relatedly, I'm looking forward to trying the filament upgrade, which I purchased at the same time but haven't installed yet. Following the instructions to hold off!
Thanks,
Ben Prima
Lodi, CA
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Transformers vibrate and can sometimes be heard. It may be best to tighten all hardware related to the power transformer.
As a matter of fact check all the hardware since it's been used for a year after assembly.
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We did get a batch of transformers some time back that had a little higher hum than normal. Though I think that was more than a year ago. If tightening the mounting hardware does not resolve the issue contact me.
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To add a little to what Doc mentioned, our winder altered the design of the Kaiju power transformer slightly and increased the time these transformers spend in the vacuum chamber to address these issues, and this was back in late 2018.
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Can you get put these transformers as an item we could buy if they would make a significant difference?
I still have issues with transformer hum with my several Kaiju amps that I have. I replaced 2 of the transformers for them with replacements from you some time ago and it helped 1 amplifier some, not the other and overall I dont like the transformer hum as I can hear it on all of the amps I have (3) which detracts. The oldest amplifier I have has the transformer the is the quietest.
Otherwise these are great amplifiers.
Thanks,
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The replacement units would have the updated keepers and longer soak time in the vacuum chamber. It's definitely important to tighten down those long screws till they are very tight, and I tend to consider them a one time use item, as they do stretch a bit and they can break.
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Thanks for that information. Are the general specifications for the transformer available?
Thanks,
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Thanks for that information. Are the general specifications for the transformer available?
Thanks,
There is no formal specification sheet, if that's what you mean - they are specific to the Kaiju. But I'm happy to dig up most winding parameters from my design notes if you have specific questions.