Totally Tubular: The Tube Thread

Welp, I think some of my 6550 power tubes may have bit the dust. Was listening and there was a pop and the amplifier turned off. Happened again as soon as I tried to power it up a second time. The V6 and V7 tubes flashed and the whole thing again turned off. I think I’ve got some spare fuses, but I have noticed that the bias on these two tubes has needed adjustment a number of times, so I would not be surprised if they were originals and just reached the end of their life.

Anyone here have advice concerning how I would confirm this?

update: based on my reading, blue flash is definitely a bad tube. I’ve powered the unit down and am ordering some replacements.
 
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kvetcha said:
Welp, I think some of my 6550 power tubes may have bit the dust. Was listening and there was a pop and the amplifier turned off. Happened again as soon as I tried to power it up a second time. The V6 and V7 tubes flashed and the whole thing again turned off. I think I’ve got some spare fuses, but I have noticed that the bias on these two tubes has needed adjustment a number of times, so I would not be surprised if they were originals and just reached the end of their life.

Anyone here have advice concerning how I would confirm this?

update: based on my reading, blue flash is definitely a bad tube. I’ve powered the unit down and am ordering some replacements.
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And now you’ve learned the beauty that is JoLida. They are designed very smartly. Replace the tubes and fuse and rock on for another year or two.

Had this been a Rogue, you’d be sending it off for service.

What tubes did you order?
 
HiFi Guy said:
And now you’ve learned the beauty that is JoLida. They are designed very smartly. Replace the tubes and fuse and rock on for another year or two.

Had this been a Rogue, you’d be sending it off for service.

What tubes did you order?
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It had Tung-Sol 6550s and I quite liked them, so I ordered another quad from Upscale.
 
New tubes are installed! Just letting things warm up for 30 minutes or so before I adjust the bias.

@HiFi Guy The fuse looked good as new, so I did not bother to replace it. I assume that shouldn't be a problem.
 
How are these fuses wired up, and is this something I should consider for my Bottlehead before it blows a tube? It currently only has a fuse on the power socket.
 
apholden said:
How are these fuses wired up, and is this something I should consider for my Bottlehead before it blows a tube? It currently only has a fuse on the power socket.
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The JoLida just has a slo-blo fuse on the power socket. I thought maybe it had blown when the tube went, but it appears fine.
 
I just experienced a bit of an issue on my Jolida as well - I went to power it on just a bit ago and put on a record and was only getting sound out of the right channel. I thought it might be the speaker initially but I changed speaker wires, which didn't do anything and then changed the left/right connection so the opposite speaker wasn't producing sound.

The tubes themselves look good and I haven't heard any real "pop" come from them yet. Any idea what it could be or troubleshooting that can be done?
 
apholden said:
Try swapping the tubes between the channels. If you have more than 2 tubes, do one pair at a time.
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I gave that a shot thinking that could help resolve or at least pinpoint that it’s the tubes. I’m still only getting sound out of the right channel but now noticed a hum come from the left channel. Seems like it may be something internal at this point perhaps with wiring? I’m going to reach out to Jolida/Black Ice tomorrow to see their take since I’d love to not have to ship this beast.
 
DoubleM said:
I gave that a shot thinking that could help resolve or at least pinpoint that it’s the tubes. I’m still only getting sound out of the right channel but now noticed a hum come from the left channel. Seems like it may be something internal at this point perhaps with wiring? I’m going to reach out to Jolida/Black Ice tomorrow to see their take since I’d love to not have to ship this beast.
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Really hope you get it straightened out. A local place might be able to open it up and check the connections.
 
kvetcha said:
Really hope you get it straightened out. A local place might be able to open it up and check the connections.
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I actually talked to the nice people at Black Ice this morning and they think its the 12ax7 that went bad since that connects to both channels. They're sending me out a new one to try that first but at least heard they have a local warranty person who can service it in case that doesn't solve the case.
 
DoubleM said:
I actually talked to the nice people at Black Ice this morning and they think its the 12ax7 that went bad since that connects to both channels. They're sending me out a new one to try that first but at least heard they have a local warranty person who can service it in case that doesn't solve the case.
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That would certainly make more sense as a failure mode than any of your wiring going bad.
 
Update: after trying a new 12ax7 and still running into the same issues with the bad left channel I took my Jolida to the local certified tech they use for their warranty repairs. Turns out a resistor went out that caused the channel to hum and cease. He said in his 25 years working on Jolidas he’s never seen that particular resistor go out so I guess it was just my luck. I did manage to luck out and score a set of Gold Lion KT88s for the trouble that are now in with the amp back home and in business.
 
DoubleM said:
Update: after trying a new 12ax7 and still running into the same issues with the bad left channel I took my Jolida to the local certified tech they use for their warranty repairs. Turns out a resistor went out that caused the channel to hum and cease. He said in his 25 years working on Jolidas he’s never seen that particular resistor go out so I guess it was just my luck. I did manage to luck out and score a set of Gold Lion KT88s for the trouble that are now in with the amp back home and in business.
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I’m glad it worked out. With JoLida, every issue I’ve ever seen was solved by replacement of an output tube and a fuse. Man, I’m getting old. I just realized that my JoLida experience is somewhere around 20 years.
 
Ginormousthumbs said:
How long do tubes tend to last before you need to replace them?
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It depends hugely on the amp and the type of tubes you’re using. Even within a tube type or manufacturer you can get a bad one that needs replacing. Mine advertises 5,000 hours (so roughly 5 years) for the output tubes and 10,000 hours for the small input and rectifier tubes but then 2 power tubes went bad after 1 year and needed replacing whilst the other 2 are still fine after 2 years use...
 
Joe Mac said:
It depends hugely on the amp and the type of tubes you’re using. Even within a tube type or manufacturer you can get a bad one that needs replacing. Mine advertises 5,000 hours (so roughly 5 years) for the output tubes and 10,000 hours for the small input and rectifier tubes but then 2 power tubes went bad after 1 year and needed replacing whilst the other 2 are still fine after 2 years use...
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As @Joe Mac says, it’s amp dependent. When I ran a Jolida amp, I had to replace output tubes annually. With the PL, they specify 2500 hours, which I see as 2.5 years.
 
What are the pros and cons with tube amps vs solid state? Besides the Black Ice Audio F22, what other models are available for around that price to the $2k level, if any?
 
Tube and solid state amps have a different sound. There are people who prefer both, so it's impossible to say, with authority, that one sounds better. Solid state has several concrete benefits:
  • Longer lifespan. There are no tubes to replace.
  • Potentially lower power consumption. This depends heavily on the amp. YMMV
  • Higher power output. Most tube amps I have seen only have a few watts, meaning they need high-efficiency speakers. On the other hand, I've seen 2,000 watt solid state amplifiers (although, I can't imagine a living room that would need such a thing). That said, many people report that the watts on tube amps seem to be worth more than equivilent watts on a solid state amp. I'm not sure exactly what's happening here, but I've heard enough reports to conclude that something is.
The main advantage of tube amps is a phenomenon called "tube rolling." You can alter the sonic character of a tube amp by replacing its tubes with different brands. If the idea of tweaking your system appeals to you, then this gives you more parts to tweak.
 
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