18Watt.com

Hi All,

This is a self built 5F1, very simple build.
Unfortunately there seems an issue that I am not sure if is faulty Tube
The 6V6 Tube after turning on the Amp at the bottom between the Glass and the Socket but I think is inside the glass tube I see sparks and some sort of noise, difficult to explain is not really a hiss but it feels like something could possibly explode that is the feeling

From the moment I switch the Amp on it takes 6 to 10 secs for the noise and the sparks to appear.

I have checked the soldering all visible parts, I have checked the connections, and there seems to be no mistakes the circuit is simple and I have made some photos and attachment.

Now since I hear that strage noise I unplug the device immediately there is no smoke on components, or on caps not even a bad smell or anything burned but probably because I don't allow the time for anything to happen.

I can see during the 10 secs the Amp is on and the 12AX7 the 6V6 and 5AR4 are glowing I am afraid to leave the amp on in case I burn the whole thing or the tubes.

Regarding the noise that seems to be coming from the tube 6V6, but the sparks lighting are definitely from that tube glass, I would define the noise as bleeding noise, or like a I am not sure if that is the correct English expression. It seem like a vent air with light hiss

Get the electrolytic off the chassis wall. Then swap the tube with a different one and see if the problem persists.

JMPGuitars wrote: ↑

Thu 12/16/21 11:21 am

Get the electrolytic off the chassis wall. Then swap the tube with a different one and see if the problem persists.

Thanks let me ask the vendor to send another tube I have not another of the same type immediately available I would have tried.

The question is could a tube spark inside and be that normal? I heard that can be normal but I am not sure.

davemojo wrote: ↑

Thu 12/16/21 11:35 am

Thanks let me ask the vendor to send another tube I have not another of the same type immediately available I would have tried.

The question is could a tube spark inside and be that normal? I heard that can be normal but I am not sure.

Seems bad to me.

Here's more opinions: https://www.thegearpage.net/board/index ... d.2132033/

Looks like some good tips in there.

JMPGuitars wrote: ↑

Thu 12/16/21 11:49 am

davemojo wrote: ↑

Thu 12/16/21 11:35 am

Thanks let me ask the vendor to send another tube I have not another of the same type immediately available I would have tried.

The question is could a tube spark inside and be that normal? I heard that can be normal but I am not sure.

Seems bad to me.

Here's more opinions: https://www.thegearpage.net/board/index ... d.2132033/

Looks like some good tips in there.

Resolved was a defective tube replaced and worked immediately, first time I experienced that. Thanks

Hey All,

I have resolved forgot to post but basically the issue was one simple problem, the connection wire that goes from underneath the board to 6V6 tube socket was not properly soldered and that was the only one after rechecking all soldering points one by one I found out

Amp is up and running and great sound out of it

davemojo wrote: ↑

Wed 01/12/22 9:41 am

Hey All,

I have resolved forgot to post but basically the issue was one simple problem, the connection wire that goes from underneath the board to 6V6 tube socket was not properly soldered and that was the only one after rechecking all soldering points one by one I found out

Amp is up and running and great sound out of it

Congrats Davide !!!