DIY Fender Champ 6V6 Tube Sparking Lightning

[DaveMojo]

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 strange 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

There seems like a gas forming inside I am not a great Electronics expert, I built successfully couple 18 Watts and this is the first real strange issue,

I heard that can be normal to see that maybe I should leave the Amp longer on and see what happen, any procedure that I can follow up and test to isolate?

Unsure if actually is a real problem or if instead is a faulty tube

[pdf64]

I suggest not to proceed without your light bulb limiter in play. With a 60W bulb max.

[DaveMojo]

I suggest not to proceed without your light bulb limiter in play. With a 60W bulb max.

Sure done that but the bulb light is 220W I don't have bulb with filament that is that low in wattage, but let me see if I can find one

There seem however no shorts but not yet 100% sure

[tubeswell]

…
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, …

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

Unsure if actually is a real problem or if instead is a faulty tube

From the upside-down picture of the 6V6 tube socket, it’s a bit difficult to tell if you have it wired properly because I can’t see Pin 6 or 7, so I’m assuming you have the heaters wired properly at 2 and 7, so, …
Swap another 6V6 in there

[Latole]

[

Sure done that but the bulb light is 220W I don't have bulb with filament that is that low in wattage, but let me see if I can find one

 

I bought a stock of 60 and 100w filament bulb for the future. 220w is to big

[DaveMojo]

I have found out what is it wrong

The OT is blown and apparently was sent already blown since from the moment i finished the built it never worked properly.

Now vendor is claiming that could have been damaged by building it wrong but that is not true the built is correct nd I am 100% sure of that.

What could most commonly cause an OT to blow?

I know is correct because I returned the kit for vendor to check, they also confirmed the Amp is correctly built and they confirmed the tube is also fine and they also confirmed the issue is blown OT.

I am asking you here this question to self defense myself in case they came back to me saying I did something wrong, something that I couldn't maybe rebate due to possible limited knowledge even though so far I built few 18 Watts one 15 Watts Madam Amp which are far more complex

Thanks

[66Strat]

Where did the kit come from? A kit is only as good as the vendor that backs the product. As the vendor has already taken the position that it was operator error, you are not likely to get any satisfaction out of this transaction.

[DaveMojo]

Where did the kit come from? A kit is only as good as the vendor that backs the product. As the vendor has already taken the position that it was operator error, you are not likely to get any satisfaction out of this transaction.

It comes from tonefactory Netherlands

They didn’t really confirmed is operator fault but that most likely is.

I asked here to protect myself the amp was build correctly

I am guitar player even though I’m not an advanced tube amp knowledge I still have a decent experience and built also a lot of Hi FI Amps

Anyway thanks for your input

[acheld]

I think you did all you could do -- this is not your fault.  Whether the vendor will own up to the problem or not is another story altogether. 

I don't know anything about consumer rights in the EU, but one approach that might work is to start complaining on social media.

If that doesn't do the trick, you'll be sourcing a new OT from a company that stands behind their product.  We've all been there, trust me (LOL, no need for that  ).

[sluckey]

I asked here to protect myself the amp was build correctly

It's impossible for us to determine if you built the amp correctly based on the limited info you provided. It's very hard to see the wiring in a tweed style chassis. If we had the amp in hand we could give you a better answer. But, the vendor has already told you the amp was built correctly. That doesn't mean that you are not responsible for destroying the OT. It's very rare for a brand new OT to be faulty. And I doubt you could ever prove it was faulty.

A kind and generous vendor would probably just send you a replacement OT. Otherwise, just buy it yourself. It's not that expensive.
Definitely not worth getting upset about.

[pdf64]

I wonder how they tested to 6V6? Was its locating key still ok?
As I see it, if the OT was supplied with shorted primary to secondary or primary to frame, then mains fuse should have blown, or the light bulb limiter (even at 220W) should have been bright, when the build was initially tested without valves fitted?
It seems more likely to me that the valve was bad, and the OT was damaged by the lightning storm in it.
Thankfully a new OT should be fairly cheap.

[DaveMojo]

I wonder how they tested to 6V6? Was its locating key still ok?
As I see it, if the OT was supplied with shorted primary to secondary or primary to frame, then mains fuse should have blown, or the light bulb limiter (even at 220W) should have been bright, when the build was initially tested without valves fitted?
It seems more likely to me that the valve was bad, and the OT was damaged by the lightning storm in it.
Thankfully a new OT should be fairly cheap.

Well i didn’t test it without tubes but I was so sure there was nothing wrong that I just plugged and play. They said to have tried another 6V6 without resolving and then they find out some how the OT was faulty blown.

The only thing I possibly done wrong is to have swapped by by mistake the 6V6 with the 5AR4 tube and I remember there was no sign of life on the tubes once I realised immediately disconnected the amp swapped the tubes again using correct socket and this time the tubes glow but a light hiss with sparking lighting was noted.

I rechecked the layout and all connections 10 times and to the best of my knowledge it was all correct.

Once I sent it back vendor confirmed the circuit was built correctly but OT blown.

They didn’t yet mention is my fault and probably they will replace without charging costs

[pdf64]

…
The only thing I possibly done wrong is to have swapped by by mistake the 6V6 with the 5AR4 tube and I remember there was no sign of life on the tubes once I realised immediately disconnected the amp swapped the tubes again using correct socket and this time the tubes glow but a light hiss with sparking lighting was noted.
…

The OT connects to pin3 the output valve anode. A 5AR4 typically doesn’t have a pin3, so even if it got hot enough to conduct, how could the OT get damaged by that?

[DaveMojo]

…
The only thing I possibly done wrong is to have swapped by by mistake the 6V6 with the 5AR4 tube and I remember there was no sign of life on the tubes once I realised immediately disconnected the amp swapped the tubes again using correct socket and this time the tubes glow but a light hiss with sparking lighting was noted.
…

The OT connects to pin3 the output valve anode. A 5AR4 typically doesn’t have a pin3, so even if it got hot enough to conduct, how could the OT get damaged by that?

Indeed I don’t think it could and it was only for less than 20 seconds since I realised and pull the cord off the outlet. Anyway thanks for all the inputs