Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: DenverDude on May 16, 2020, 09:33:53 AM

Title: Buzz after adding new Tung Sol 5998 tube to Crack
Post by: DenverDude on May 16, 2020, 09:33:53 AM

Hello all - I built a Crack w/ Speedball about 8 years ago, and in recent months it has developed a little buzz in the output, mostly in the left channel. However, the situation is resolved if I slightly prop the left side of the unit up with a small board, which I have been doing the last few months.

I also noticed I was sometimes getting harmonics and I could get it to stop or lessen when I tap on the metal top of the unit.

I was wondering if this was a tube issue, so I replaced the stock RCA CRC-6080 tube with a NOS Tung Sol 5998. I also have a Valvo ECC82 tube that I rolled into this unit about 5 years ago which is still in the unit.

Now, when I turn on the unit, I get a much louder buzzing noise (which is much more pronounced in the left channel) and this lasts about 20-30 minutes. Once it dissipates, there is no buzzing, the background is pitch dark and the music has never sounded better.

So do I have a tube problem, a circuitry problem, or both? Your expert help is much appreciated. :)

Title: Re: Buzz after adding new Tung Sol 5998 tube to Crack
Post by: Tom-s on May 16, 2020, 09:39:32 AM

It's probably a solder connection that's not perfect. Try reheating all solder joints on the 8 pin socket and connecting wires.

Title: Re: Buzz after adding new Tung Sol 5998 tube to Crack
Post by: Doc B. on May 16, 2020, 10:52:59 AM

Clean your tube pins and the socket contacts too.