Single Rectifier problem

[Acesofbelkan]

So I was jamming on my Single Recto v2 monday night with no hiccups at all. Then the next night as I fired it up I took off the standby and started on the clean channel and all was good and chimey. But when I clicked on the dirty channel with the footswitch, the volume went from normal to completely dropped off in about 2 seconds.

-I could only hear anything from the dirty channel only if I maxed the output and channel volumes.
-The clean channel was unaffected until I started switching preamp tubes then I got both channels working fine.
-but then the new issue became that both channels started to sound like crap and heavily distorted.
-The powertubes started to get a blue haze tint. The powertubes were still orange but there was like this blue tint whenever I took the standby off.

I ****** LOVE this amp, this amp single handedly cured my G.A.S. for tone.
The help is greatly appreciated.

 

[mikey383]

The blue tint is normal. Most tubes do that when taken off standby.

What preamp tubes did you swap?

V1 controls both channels.
V2 and V3 control channel 2.
V4 is the effects loop
V5 is the phase inverter.

Sounds like you need to replace V1 if it's affecting both channels. It's the closest to the input.

 

[Acesofbelkan]

Thanks for the reply, I'll bring spare preamp tubes and swap out the v1 and see if that solves the issue. As for the blue haze in the powertubes, is that normal?

 

[94Tremoverb]

V2 is also shared between both channels (one half on each channel), but it's possible that it could have failed only in the Ch2 half. But, far more likely is that V3 failed - this is used as a cathode-follower which is responsible for a lot of failures in some (mostly Russian) tube types. If you mean you swapped the tubes around (not swapped in a known good spare), the chances are that you put the dead - maybe intermittent, they don't always die completely - V3 tube into a position used by both channels (which is all of them *apart* from V3), which is why the amp sounded bad.

 

[erectifier]

as for the glow i heard dark blue is bad, light purple is normal. its to do with the gasses inside the tube, have another look and if the luminescence is really blue then you should swap them soon because oxygen is making its way into the tube and will corrode the filament resulting in a dead tube. you dont want that to happen on stage!

 

[boss4]

Yes, it looks like a tube problem. Ask a friend with a tube amp to try his tubes and confirm that before you have to buy a fuse, or worst, a transformer.

 

[Acesofbelkan]

Hey so today I went in and swapped some tubes around. I think more than 1 tube is faulty. Swapping tubes around gave me different symptoms. Like certain tubes in one position gave me this helicopter sounding steady bumping sound that also caused the powertubes' blue haze to follow the rhythm.
I think most of the tubes went out cuz I came in with 4 extra tubes that I had laying around for a while. At this point I dont know if MOST of the tubes that I have are messed up. The only solution I see right now is to just buy a whole new set since I need to.
If it makes a difference on the diagnosis on what going on, the set that went bad on me was a set of JJtubes I bought from Eurotubes. Dont get me wrong tho, I LOVED the way these sounded. A lot better than the chinese tubes that came originally.

My next move I plan to either get the cocktail from DougsTubes, Or just make my own little cocktail with a Tung-sol in V1.

 

[94Tremoverb]

as for the glow i heard dark blue is bad, light purple is normal.

No, exactly the other way round!

its to do with the gasses inside the tube, have another look and if the luminescence is really blue then you should swap them soon because oxygen is making its way into the tube and will corrode the filament resulting in a dead tube.

No. What matters is *where* the glow is, not the color - although dark purple/blue is good, and bright pinkish/purple is bad - which will tell you what the cause is and whether it's a risk to the tube or amp.

1 - blue glow (usually royal blue or purple-ish blue on the inside of the glass) is always safe and is actually the sign of a good tube working properly. It's caused by stray electrons bombarding fluorescent minerals in the glass and indicates a good vacuum. This one is the most common and has probably led to more good tubes being trashed than I care to imagine... particularly as it's very common in high-quality old-production US power tubes, due to the type of glass used and the very high vacuum.

2 - blue glow (usually lighter blue or slighty green-ish, although it can be very slightly purple-ish as well) inside the plate structure - visible only if you look carefully through the slots at a particular angle normally - is also normal and almost always safe, unless it's really extreme, when it usually means the tube is running too hot but not quite hot enough to red-plate. It's caused by gas in the tube, but only the tiniest quantity and isn't a problem.

3 - bright glow that is distributed throughout the tube - any color, but it's usually bright purple or pink - is bad and a sign of imminent or already occurred failure. It is caused by large amounts of gas in the tube - but not just oxygen, it's mostly nitrogen since that's what air is made of . It will cause the tube to fail simply because ionized gas conducts electricity and it will short the tube.

Google image search "blue tube glow" and you can see some great examples - especially of the intense pink glow.

I really wish more people would learn about this. It is absolutely the biggest myth about tubes, and no matter how many times it gets debunked it always seems to keep coming back! Worse than the Terminator, it just won't lie down and die .