[csg]

Today my Darkvoice 336SE finally arrived!
First few hours and it sounded great. Although some humming on the left channel but it seemed to disappear more and more.
But all of a sudden it stopped working

The big tube doesn't glow at all now.
Can it possibly be just a broken tube?
Noticed the bottom part of the glass has turned into a black or almost silver colour. Is that normal?

 

[atbglenn]

According to a 6AS7 spec sheet, the heater (the part that makes the tube glow)is pins 7 and 8. If you have a multimeter, you should get continuity (probably a couple of ohms) between those pins. If not, the tube is bad.

 

[csg]

Quote:

Originally Posted by atbglenn /img/forum/go_quote.gif According to a 6AS7 spec sheet, the heater (the part that makes the tube glow)is pins 7 and 8. If you have a multimeter, you should get continuity (probably a couple of ohms) between those pins. If not, the tube is bad.

Thanks! Don't have one but can hopefully borrow one tomorrow.
But if it's just the tube isn't weird a new one dies just after a few hours?

 

[atbglenn]

It's not so weird, it happens sometimes. Hopefully it's just a bad tube and not some issue with your amp. I have my fingers crossed for you.

 

[Skylab]

The stock 6AS7 is not a good tube anyway. Get a vintage RCA 6AS7G and try that out - you can get these for $10 or less - 6AS7G Tubes - eBay (item 370371920031 end time May-27-10 10:28:58 PDT)

 

[atbglenn]

I would take Skylab's advice. He knows his tubes

 

[Skylab]

It seems unlikely that there was a catastrophic failure in the amp, since the driver tube still lit up. So since 6AS7G's are cheap, it seems worth a try. You'll want the RCA tube anyway, even if you end up having to get the amp repaired. Good luck!

 

[csg]

Thanks for your answers.
Checked it with a multimeter now and it seems to be broken.
And ordered the tube Skylab recommended

 

[Frank I]

Quote:

Originally Posted by csg /img/forum/go_quote.gif Thanks for your answers. Checked it with a multimeter now and it seems to be broken. And ordered the tube Skylab recommended

Is it the DarkVoice or the Lafigaro amp. I suggest you notify the manufacturer and let him know what happened. Hopefully its only the tube and hopefully it did not take out a resistor. Keep the forum updated as I have been thinking about one of these amps.

 

[csg]

It's the Darkvoice.
Contacted the ebay seller and will see what he says.

Do anyone know if the 6080WC Philips ECG will work instead?
I want to listen noooow

It was the only tube I was able to find here in Stockholm, and shipping from ebay will probably take a while...

 

[Skylab]

Quote:

Originally Posted by csg /img/forum/go_quote.gif Do anyone know if the 6080WC Philips ECG will work instead? I want to listen noooow It was the only tube I was able to find here in Stockholm, and shipping from ebay will probably take a while...

Yes - absolutely will work.

 

[csg]

Quote:

Originally Posted by Skylab /img/forum/go_quote.gif Yes - absolutely will work.

And possibly better than the ones you recommended?

They want almost 40usd for one...

 

[Skylab]

Well, not in my opinion. I like the 6AS7G better than the 6080, almost universally. 40USD is a lot of money for a 6080. They should cost $10 USD, like this one, which at least is a UK seller: 6080 NATIONAL VALVE TUBE - eBay (item 190348917748 end time May-11-10 04:02:56 PDT)

In the US you can easily get 6080's for very cheap:

6080WC

 

[csg]

Thanks for your answer. I guess I'll just hope for quick delivery on the RCA's then

Wasn't really planning to start with the tube rolling already, but if I have to change one why not change the other too?

Any recommendations of one that will go well with the RCA's?
UK seller would be super!
Thanks in advance.

 

[Skylab]

Well, the 6SN7 is even more important to change in terms of sound quality, but it will cost much more. 6SN7's have gotten expensive. The good news is you only need one.

This UK seller who I have used before has Mullard 6080's for 10 GBP, and Sylvania 6SN7GT's for 25 GBP - that would be a nice tube set.

Sales, Langrex