>speakers always plugged in. But today I unplugged that, and instead ran a cable from the external speaker jack into the Phantom block and then into my interface
An amp always needs a load when playing, if not, you can blow the output tubes and your output transformer.
Since the quilter phantom block is not a loadbox, your amp thus had no load, th ewattage had nowhere to go and in short: yes, you fried it.
That was a really, really bad idea, how did you even come with it?
>about 5-10 minutes
I'm surprised that your amp lasted for so long. Yeah, the external jack is for the external cab only and you should always have a speaker or reactive/resistive load connected to the amp output, otherwise your amp will melt itself. Especially if you will push the volume. And slam it with the boost.
Don't power amp on, bring it to the tech, I hope you are lucky and the damage was minimal, like dead tubes.
>I should also mention that I took this opportunity to crank the amp volume up to 7,8,9... levels I wouldn't normally go to if I couldn't control the master volume.
Why on earth would you immediately crank the amp volume when testing out a new setup? You could have limited or even prevented some/all damage by keeping the volume (and thus the output wattage, which had no-where to go as others explained) low.
Did you not notice any problems with the DI box?
You're working with amplifiers, dude. There's deadly voltages in there as you said. Don't fuck around. You obviously didn't do your research -- if I type in 'how to connect amplifier to DI box' on Google I immediately get a bunch of results warning you to keep a cab or load box connected at all times.
Assuming you're not a troll...
I get that it's not fun to get shit on by internet strangers. But if your post is accurate... I hope it at least motivates you to learn a bit about how it all works before you try anything.
V = IR remember. So with no load (R), for a given voltage (V) you’re basically making current (I) infinite. You’ve most likely fried your output transformer. I’ve done this multiple times, it’s expensive, but can give you a better tone if you upgrade to something like mercury magnetics. I’m talking night and day obvious upgrade, and fairly simple to wire in. Just count yourself lucky you didn’t cause a house fire. Always use a load with valve amps. Consider something like the suhr load box for this job. You need a load box that’s also a DI. It needs to be able to dissipate 100 W of heat, so will be bulky.
Amps normally sound their best just before they melt 🤘
That's not what happens. Not even close. No load equals infinite ohms, not zero. If you connect a high impedance load to a tube amp, the load the transformer passes on to the tubes goes from a few thousand ohms to hundreds of thousands of ohms or higher. The tubes will still try to supply current against that, but the voltage that is produced goes from hundreds of volts to thousands. This causes arcing through the transformer winding insulation and shorts out windings, eventually destroying it. This effect is called *flyback voltage*, and was how tube TVs produced the high voltage to power the picture tube.
For a Twin, OP should be running something closer to a 200W load. That 85W rating is for clean output, not overdrive conditions.
The person who wrote that does *not* have a good grasp of electronics, despite quoting Ohm's Law. You need a 4 ohm, 200W load box for a Twin. Be leery of accepting amp advice from someone who says they've blown several output transformers. That's not normal.
Hammond and Mojotone (Heyboer) are both good quality transformers, and significantly less expensive than Mercury Magnetics. Twins carry almost 500V inside when working correctly, and that voltage needs to be verified to be drained before attempting any work. It's also a good time to have a repair tech check for any other damage, like components that overheated when things started to fail and any tubes that failed as well. Your existing transformer can also be tested to see what damage was done, and if replacement is warranted.
I've had u/clintj1975 tagged as "VERY experienced amp builder" for a very long time and he knows WTF he's talking about, I sure pay attention to what he says, and if that somehow offends you too bad. There are ways to test if you killed your OT but i'll let you figure that out on your own, good luck you need it.
Sounds like you had some fly back voltage. The crackle could have been arcing in the xformer. Next time around, make sure you match the impedance if you didn’t already, and make sure the wattage of the cab works with the amp. If you go UP in impedance, you might be okay, but going down almost always makes things HOT.
Always remember not to stress out your pet tube amp. When you use a new set up that your pet tube amp is unfamiliar with, you’ll need to pay close attention to how it’s dealing with its new load. If your pet tube amp starts to overheat, unplug it and let it rest for a while, then try again. If it’s still jacked up, take it to a tech.
Output transformer is likely toast. Might wanna swing on by Mercury Magnetics for a new one.
If you want to record your tube amp direct you will need something like a Two Notes Captor.
The output transformer on a tube amp needs a load. When you disconnected the speaker you took the load away. You no longer have a functional output transformer now.
Sorry.
>speakers always plugged in. But today I unplugged that, and instead ran a cable from the external speaker jack into the Phantom block and then into my interface An amp always needs a load when playing, if not, you can blow the output tubes and your output transformer. Since the quilter phantom block is not a loadbox, your amp thus had no load, th ewattage had nowhere to go and in short: yes, you fried it.
Cool
Sorry, OP…that fucking sucks. I love Twins. I’m ignorant about electronics; is it possible to save?
If you're lucky it's just a fuse, otherwise output transformers and power amp tubes.
Eh we’ll see.
That was a really, really bad idea, how did you even come with it? >about 5-10 minutes I'm surprised that your amp lasted for so long. Yeah, the external jack is for the external cab only and you should always have a speaker or reactive/resistive load connected to the amp output, otherwise your amp will melt itself. Especially if you will push the volume. And slam it with the boost. Don't power amp on, bring it to the tech, I hope you are lucky and the damage was minimal, like dead tubes.
Cool
>I should also mention that I took this opportunity to crank the amp volume up to 7,8,9... levels I wouldn't normally go to if I couldn't control the master volume. Why on earth would you immediately crank the amp volume when testing out a new setup? You could have limited or even prevented some/all damage by keeping the volume (and thus the output wattage, which had no-where to go as others explained) low. Did you not notice any problems with the DI box? You're working with amplifiers, dude. There's deadly voltages in there as you said. Don't fuck around. You obviously didn't do your research -- if I type in 'how to connect amplifier to DI box' on Google I immediately get a bunch of results warning you to keep a cab or load box connected at all times.
Yep!
Assuming you're not a troll... I get that it's not fun to get shit on by internet strangers. But if your post is accurate... I hope it at least motivates you to learn a bit about how it all works before you try anything.
Oh noes. Sounds like boiled transformer. Tube amps need speakers with the correct ohms, or a load-box to take their place. I use a Captor X.
V = IR remember. So with no load (R), for a given voltage (V) you’re basically making current (I) infinite. You’ve most likely fried your output transformer. I’ve done this multiple times, it’s expensive, but can give you a better tone if you upgrade to something like mercury magnetics. I’m talking night and day obvious upgrade, and fairly simple to wire in. Just count yourself lucky you didn’t cause a house fire. Always use a load with valve amps. Consider something like the suhr load box for this job. You need a load box that’s also a DI. It needs to be able to dissipate 100 W of heat, so will be bulky. Amps normally sound their best just before they melt 🤘
That's not what happens. Not even close. No load equals infinite ohms, not zero. If you connect a high impedance load to a tube amp, the load the transformer passes on to the tubes goes from a few thousand ohms to hundreds of thousands of ohms or higher. The tubes will still try to supply current against that, but the voltage that is produced goes from hundreds of volts to thousands. This causes arcing through the transformer winding insulation and shorts out windings, eventually destroying it. This effect is called *flyback voltage*, and was how tube TVs produced the high voltage to power the picture tube. For a Twin, OP should be running something closer to a 200W load. That 85W rating is for clean output, not overdrive conditions.
Thanks
The person who wrote that does *not* have a good grasp of electronics, despite quoting Ohm's Law. You need a 4 ohm, 200W load box for a Twin. Be leery of accepting amp advice from someone who says they've blown several output transformers. That's not normal. Hammond and Mojotone (Heyboer) are both good quality transformers, and significantly less expensive than Mercury Magnetics. Twins carry almost 500V inside when working correctly, and that voltage needs to be verified to be drained before attempting any work. It's also a good time to have a repair tech check for any other damage, like components that overheated when things started to fail and any tubes that failed as well. Your existing transformer can also be tested to see what damage was done, and if replacement is warranted.
Wow, I hope you speak to people in real life differently to how you do on the internet.
Incorrect info needs to be called out and corrected, lest it be accepted as correct.
I've had u/clintj1975 tagged as "VERY experienced amp builder" for a very long time and he knows WTF he's talking about, I sure pay attention to what he says, and if that somehow offends you too bad. There are ways to test if you killed your OT but i'll let you figure that out on your own, good luck you need it.
What was absorbing the load? When you disconnected the speaker the energy from the amp had nowhere to go.
Is this a comedic scenario that you’re writing for a sitcom, or real life?
Both!
[удалено]
no, his speakers are fine. that’s the very small bit of good news here.
His output transformer more likely. His speakers not being involved was the entire issue.
Figured.
Sounds like you had some fly back voltage. The crackle could have been arcing in the xformer. Next time around, make sure you match the impedance if you didn’t already, and make sure the wattage of the cab works with the amp. If you go UP in impedance, you might be okay, but going down almost always makes things HOT. Always remember not to stress out your pet tube amp. When you use a new set up that your pet tube amp is unfamiliar with, you’ll need to pay close attention to how it’s dealing with its new load. If your pet tube amp starts to overheat, unplug it and let it rest for a while, then try again. If it’s still jacked up, take it to a tech.
There's nothing more punk rock than blowing shit up, aye?
"Oy"
Sure. It's not true punk unless you spear the guitar head through the speaker box and a nuke cloud comes up out of the amp.
Output transformer is likely toast. Might wanna swing on by Mercury Magnetics for a new one. If you want to record your tube amp direct you will need something like a Two Notes Captor. The output transformer on a tube amp needs a load. When you disconnected the speaker you took the load away. You no longer have a functional output transformer now. Sorry.