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Bottlehead Kits => Kaiju Stereo 300B amp => Topic started by: Lowercase on April 23, 2023, 04:28:20 PM

Title: Failed second test of high voltage power supply with tubes?
Post by: Lowercase on April 23, 2023, 04:28:20 PM: Passed the first stage of the test with flying colors on 10U, 14U and 15U. Proceeded to the second part of the test. Placed the tubes in the correct orientation, larger pins in the back. Then back over and plugged everything in. Did not get a reading on 53U or 65U, noticed a slight electronics/warm smell then subtle smoke around 13 appeared. Unplugged quickly, discharge took about the same time as first go around. Once that was done I removed the tubes, checked for anything amiss and conducted the first part of the test again. Passed again on the same terminals with no issues. Any ideas on what to check next? No signs of any burnt components and no blown fuse. Didnâ€™t want to directly proceed again with tubes without a second opinion.
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Paul Birkeland on April 24, 2023, 04:46:10 AM: I would post some build photos just in case, but you might have had some debris shorting something out.
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Lowercase on April 24, 2023, 07:12:44 AM: Didnâ€™t see any rogue leads or debris in the area, but maybe something fell out when i flipped it back over. Images of the overall build and the area in question.
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Paul Birkeland on April 24, 2023, 07:30:22 AM: Things look pretty tidy in there, I would be inclined to think there was a tiny piece of debris that cooked itself away.
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Lowercase on April 24, 2023, 07:32:29 AM: Quote from: Paul Birkeland on April 24, 2023, 07:30:22 AM
Things look pretty tidy in there, I would be inclined to think there was a tiny piece of debris that cooked itself away.

Thatâ€™s good to hear! I will proceed with the second part of the test and report back.
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Lowercase on April 24, 2023, 07:45:42 AM: Same result, but no smoke. Transformer hummed quite a bit too. :(
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Paul Birkeland on April 24, 2023, 07:49:00 AM: How are the voltages? Are the transformer screws nice and tight?
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Lowercase on April 24, 2023, 07:53:04 AM: Iâ€™m getting 0VDC on terminals 53 and 65. The transformer is tight. I made sure to get it extra secure when assembling after reading others report humming when not tightening it down enough. I also didnâ€™t get any humming when doing the first part of the test. Want me to test voltages on 10, 14 and 15 with tubes in? Afraid Iâ€™m going to damage something, but maybe Iâ€™m being overly cautious?

Iâ€™ve triple checked the wiring on both the B and C sockets and see nothing amiss. Something up with the tubes themselves since the first part of the test is passing?
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Paul Birkeland on April 24, 2023, 11:41:21 AM: The white wires you have going to the rear terminal strips are not wired properly and will cause these issues.
Title: Re: Failed second test of high voltage power supply with tubes?
Post by: Lowercase on April 24, 2023, 12:24:38 PM: Itâ€™s always good to be humbled from time to time! :) I think I stared at every connection for a good minute or two.

Fixed the error(s) and perfect measurements!

Thank you Paul!