Bottlehead Forum

Bottlehead Kits => Crack => Topic started by: luczamic on October 26, 2021, 04:44:27 PM

Title: Crack not working after downgrade from Speadball [resolved]
Post by: luczamic on October 26, 2021, 04:44:27 PM: Hi guys,

I've built the crack a couple of months ago with speedball upgread. While building it I manage to have a chance to listen to it for a bit without the upgrade. I liked it a lot. In fact, I liked it more than with the upgrade, so I decided to remove the speedball. First I removed the small board. It was working fine and then I removed the big board. And now it's broken :)

I can't even do a voltage check, the thing is getting so hot that the 5W resistors (the white ones) started to melt my cables and desolder themselves. I ended up replacing almost all of the capacitors with the closest ones I could find in Australia, and I replaced the resistor as the old one simply fell apart.

All the tubes are glowing, and the LED's are coming on for a second right after I turn the thing on, but go dark after that.

Any ideas what I've done? :/
Title: Re: Crack not working after downgrade from Speadball
Post by: Paul Birkeland on October 26, 2021, 07:15:58 PM: Try running the amp with no 6080 and let us know if the PSU resistors get hot. If they do, try running it with no tube at all and report back.

The LEDs coming on immediately after you power up the amp is not at all normal.

If running the amp with no tubes still results in super hot power supply resistors, I would suggest removing the 3K resistors and posting photos of the amp without them, as something would need to be shorted to ground after the last node in the power supply in order to make both resistors get really hot like that.
Title: Re: Crack not working after downgrade from Speadball
Post by: luczamic on October 26, 2021, 07:41:02 PM: Hi Paul,

Thanks for the replay.
I didn't say that correctly, the LED come up after a few seconds gradually, and then they were going off after a few seconds.

In any case, without 6080, the LEd's are staying on and the PSU resistors aren't getting even warm to the touch.

Does it mean that the Tube is faulty?

Thanks
Title: Re: Crack not working after downgrade from Speadball
Post by: Paul Birkeland on October 27, 2021, 05:22:23 AM: You're quite good at taking/posting pictures, so it probably wouldn't hurt to see some more images around the octal socket.

I suspect something is touching that shouldn't touch, and as the 6080 is warming up it's being forced to conduct excessive current.
Title: Re: Crack not working after downgrade from Speadball
Post by: Thermioniclife on October 27, 2021, 07:41:35 AM: Having 3 ohm 10 w resistors in that position will let a ton of current to flow. You need 3k ohm in that position.
Title: Re: Crack not working after downgrade from Speadball
Post by: Paul Birkeland on October 27, 2021, 07:49:03 AM: Quote from: Thermioniclife on October 27, 2021, 07:41:35 AM
Having 3 ohm 10 w resistors in that position will let a ton of current to flow. You need 3k ohm in that position.
Good catch!
Title: Re: Crack not working after downgrade from Speadball
Post by: luczamic on October 27, 2021, 08:45:36 AM: Of Course!!!
Thanks! Guys!
Title: Re: Crack not working after downgrade from Speadball
Post by: luczamic on October 27, 2021, 08:58:41 AM: quick follow-up question.

I'm having trouble finding the exact same resistor that is available to ship. I would have to wait till January.
I found these, will they work?
Title: Re: Crack not working after downgrade from Speadball
Post by: Paul Birkeland on October 27, 2021, 08:59:52 AM: Those will likely fit the space.
Title: Re: Crack not working after downgrade from Speadball
Post by: luczamic on October 27, 2021, 09:04:28 AM: Thank you very much for your help!
Title: Re: Crack not working after downgrade from Speadball
Post by: luczamic on October 27, 2021, 09:32:07 AM: Ok, I managed to salvage the one that came originally with the kit. Didn't cut them close enough ;D

Happy to report that all is good!!

Thanks again, guys!