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Jim Root Tiny Terror sudden static / hum overnight

Posted: Fri Nov 10, 2017 6:20 am
by Rattlesnakepete0853
I bought a new Jim Root Tiny Terror head early summer 2017. I work a lot, so it probably gets played about 10 hours a week tops. After a day of recording, I noticed that the amp was in standby for about 6-8 hours. I thought nothing of it, and turned it off. The next day, I turned it on, let the tubes warm up, and then switched it to the 7 w setting with the volume at about 10%, gain at 100% (as usual). I noticed that I was getting a very loud hum, which hadn’t happened before this.
I tried a new cable, same problem. Different guitar, same problem. Plugged the amp into a different circuit, same problem. The hum reduces as I dial back the gain, but the style I play requires high gain. Switching to 15w has no effect. The sound completely goes away when I remove the cable from the input. All tubes glow, and haven’t been used that much, so they should be fine.
Any suggestions?

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Fri Nov 10, 2017 11:25 am
by bclaire
Probably a tube. Tubes start to wear out as soon as you put them in an amp and turn it on and they can go at any point.

With a tube amp, the first thing to suspect when something isn't right is always tubes. Once you have ruled that out, then you look for other things.

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Sat Nov 11, 2017 3:30 pm
by Rattlesnakepete0853
bclaire wrote:
Fri Nov 10, 2017 11:25 am
Probably a tube. Tubes start to wear out as soon as you put them in an amp and turn it on and they can go at any point.

With a tube amp, the first thing to suspect when something isn't right is always tubes. Once you have ruled that out, then you look for other things.
Is there any way that I can test this without buying new tubes online and trying them? I (live 5-6 hours away from the closest guitar shop unfortunately)

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Sat Nov 11, 2017 7:02 pm
by Rlw59
To test it, at the bare minimum you need two known-good tubes. One 12ax7 and one El84.

Swap each tube one at a time with a known-good tube (turn the amp off each time). For the test you can use a 12ax7 temporarily in place of the 12at7.

But there's no point in buying one EL84. If one is bad you should replace both at the same time. (Guaranteed that sooner or later you'll need to replace the power tubes so you might as well order a pair now.)

It's highly unlikely all your preamp tubes went bad at the same time. So you could probably just buy one 12ax7 and one 12at7.

But it's a very good idea to always have spare tubes on hand. Power tubes typically last a couple of years, preamp tubes much longer -- sometimes decades. But all tubes eventually die, and sometimes they die suddenly way earlier than they should.

For future reference, you should get spare tubes while your amp is working correctly and test them in your amp to make sure the new tubes work. Rough handling during shipping can kill a tube, so even if your tube vendor tests them before shipping, they may be DOA when you get them.

Terrors are cathode biased so power tubes are plug & play. You don't need to check and adjust the bias when replacing the power tubes.

Edited to add: I suggested buying both a 12ax7 and 12at7 just in case one gets damaged in shipping. You can safely try either in all the preamp tube sockets so even if you get a duff new tube you'll be able to check which old tube is causing the hum.

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Sat Nov 11, 2017 7:10 pm
by Rlw59
Oh, before buying tubes, try sticking a cable from the effects send to the effects return jack.
Sometimes those jacks build up a little corrosion when unused which can cause either no signal or rarely hum.

Not likely to be the problem, but it's a simple, quick, and free thing to check.

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Sat Nov 11, 2017 7:28 pm
by Rlw59
Tube amps are weird, mysterious, magical things. Tom Morello says he's been using the same Marshall JCM800 for 25 years, since the beginning of Rage Against the Machine. 25 years of around the world tours and tens of thousands of hours of full volume mayhem.

And he swears it's never had the back panel removed. Still running on the factory tubes and filter caps. And that he and his tech are baffled about how that's even possible, but they aren't going to work on it unless it breaks.

The rest of us aren't so blessed. It's not a question of "if" a tube will fail, just a question of when.

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Sat Nov 18, 2017 5:47 am
by Rattlesnakepete0853
I just ordered a full set. Thanks for your help. I should get them on Monday, but I work 2 back shifts, So I should be able to test them out some time next week after Wednesday.
I took it apart the other day, and I noticed that my 12at7 effects loop tube is very brown/black at the top on that little nub thing. I’m guessing it’s that one, but I’m going to try them all 1 at a time, starting with that one. I’ll post what was wrong when I find out.
Thanks everyone!
Rlw59 wrote:
Sat Nov 11, 2017 7:02 pm
To test it, at the bare minimum you need two known-good tubes. One 12ax7 and one El84.

Swap each tube one at a time with a known-good tube (turn the amp off each time). For the test you can use a 12ax7 temporarily in place of the 12at7.

But there's no point in buying one EL84. If one is bad you should replace both at the same time. (Guaranteed that sooner or later you'll need to replace the power tubes so you might as well order a pair now.)

It's highly unlikely all your preamp tubes went bad at the same time. So you could probably just buy one 12ax7 and one 12at7.

But it's a very good idea to always have spare tubes on hand. Power tubes typically last a couple of years, preamp tubes much longer -- sometimes decades. But all tubes eventually die, and sometimes they die suddenly way earlier than they should.

For future reference, you should get spare tubes while your amp is working correctly and test them in your amp to make sure the new tubes work. Rough handling during shipping can kill a tube, so even if your tube vendor tests them before shipping, they may be DOA when you get them.

Terrors are cathode biased so power tubes are plug & play. You don't need to check and adjust the bias when replacing the power tubes.

Edited to add: I suggested buying both a 12ax7 and 12at7 just in case one gets damaged in shipping. You can safely try either in all the preamp tube sockets so even if you get a duff new tube you'll be able to check which old tube is causing the hum.

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Thu Nov 23, 2017 12:27 am
by Rattlesnakepete0853
So I changed out every tube with known working tubes, and I’m having the exact same problem... any suggestions?

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Thu Nov 23, 2017 1:26 am
by bclaire
Rlw59 wrote:
Sat Nov 11, 2017 7:28 pm
Tube amps are weird, mysterious, magical things. Tom Morello says he's been using the same Marshall JCM800 for 25 years, since the beginning of Rage Against the Machine. 25 years of around the world tours and tens of thousands of hours of full volume mayhem.

And he swears it's never had the back panel removed. Still running on the factory tubes and filter caps. And that he and his tech are baffled about how that's even possible, but they aren't going to work on it unless it breaks.

The rest of us aren't so blessed. It's not a question of "if" a tube will fail, just a question of when.
Yeah, a friend of mine had a early 70's Superlead that he had never changed the tubes - he was running it full out and it was only about as loud as a 30 watter! I was like "You really need to retube that and take it to a tech..." He only did when it finally died. Never asked him what happened after that...

Re: Jim Root Tiny Terror sudden static / hum overnight

Posted: Thu Nov 23, 2017 1:27 am
by Rlw59
The good news is that since you bought it new in the summer of 2017, it's covered under warranty.

Since it's not tube related, it's most likely a failed capacitor or a solder joint that's gone bad.

There's a thread on this page about how to obtain warranty service in the USA. If you're in another country, check Orange's website.

Sorry the new tubes didn't fix it, and sorry for delaying you from seeking warranty service.

But it's always good to have spare tubes, and as Billy said, with tube amps the first thing to check is always the tubes.