Made a mistake with my amp, help!

[Birdman642]

Hi everyone,
I finally got a chance to play today after the long holiday. I got my pedal board set up, guitar out and plugged into the amp. I turned my amp on and it wasn’t making sound. I thought it just needed to warm up. After about 30 seconds to a minute, I realized that I didn’t connect the amp to the cab. After a mild heart attack, I turned the amp off and connected the speaker cable from the head to the cab. When I turned the amp back on, everything was fine and worked as normal. I proceeded to play for a couple hours solid. Still no problems. The amp has been acting fine ever since. However, I’m concerned because I’ve heard horror stories about people running their amps with no load and destroying them. My question is, did I wreck something, or will it be alright?
The amp in question is a Marshall DSL100H.

TL;DR: Turned on amp without connection to cab. Immediately turned off, plugged into cab and proceeded to play away. Amp worked fine. Did I wreck something?

[Mincer]

If it is working fine, then I'll bet it is fine. I've done the same thing for a minute or so until I realized what I did, and it never suffered. It certainly depends on the amp and transformer, but I'll bet you are OK.

[Birdman642]

If it is working fine, then I'll bet it is fine. I've done the same thing for a minute or so until I realized what I did, and it never suffered. It certainly depends on the amp and transformer, but I'll bet you are OK.

Thanks Mincer. I think I was just so excited to play that I forgot to hook it up haha. I’ve definitely learned my lesson though

[80's_Thrash_Metal]

I've done that same thing a few times before, never had any issues with any of the amps I did it to. But I always caught it very quickly as well. I also think it is fine if it's working.

[Securb]

I would not worry. Amps are a lot more resilient than most think. Most damage in my experience, is done in transport when things are being rattled around. That is why when I get to a gig the first thing I do is to make sure my tubes are still seated properly.

[NegativeEase]

You are good. it should be fine.

[beaubrummels]

If you didn't play or send signal through the amp without a load connected, it should be fine.

[Birdman642]

If you didn't play or send signal through the amp without a load connected, it should be fine.

I did play lightly. The amp volume was set to less than one though

[Birdman642]

Thank you all. You’ve taken a lot of worry off of me. It sounds like if something did go wrong with it, I would’ve known immediately

[devastone]

You probably need to burn it just to be sure.

Nah, it's fine, happens more than people acknowledge. What happens when you do that is that all the power destined for the speakers has to be absorbed by the output transformer. SInce you didn't turn it up and didn't play for long it's fine, as Securb said, amps are generally pretty resilient, contrary to all the "experts' on the interwebs. Where this is more of a problem is when the amp is cranked to 10 and people keep playing trying to figure out what is wrong. That can end in nasty smelling smoke, but usually what happens first is you hear the transformer singing, and it one has any sense, they quit playing and plug it in, and generally it is fine, ask me how I know.

[Birdman642]

You probably need to burn it just to be sure.

That can end in nasty smelling smoke, but usually what happens first is you hear the transformer singing, and it one has any sense, they quit playing and plug it in, and generally it is fine, ask me how I know.

I think the first piece of advice is the most obvious answer haha.
As for how you know, is it from personal experience? Haha

[Demanic]

Thank you all. You’ve taken a lot of worry off of me. It sounds like if something did go wrong with it, I would’ve known immediately

This.

Sent from my SM-A115A using Tapatalk

[Ewizard]

Most amps will tolerate this sort of thing for a bit. The exception is having the amp cranked to ten and trying to play it for a prolonged period of time, or simply leaving it on for way toooooo long with that condition.

The transformer is what takes the brunt of the situation. The power tubes are trying to dump energy into the transformer which has an open loop condition ( no energy is transferring from the primary to the secondary ). The primary side of the OT then simply charges up until it breaks its dielectric limit and then it will arc internally across the coils winds. This arcing can burn off the protective enamel coating until the winds can physically short to each other ( no protective coating anymore ). This shorting of the winds in the coil causes the output transformer to fail in function for the tubes, which then begins their path to destruction. The tubes now have a build up of electrons on their plate and the resistance keeps raising and raising ( more heat, and less efficiency at doing their job of amplification ) until the tubes start to simply burn up. Depending on where the OT shorts out, it could short the tubes to each half of the primary together ( no center tap for current to go through ) and the tubes go into dramatic and instantaneous death by electron overload.

Many modern CE, UL, or RoHS approved amps will have some form of protection from open loop conditions. Not all, but some, will have some circuit designed to mitigate output failures. A simple example of this is a switching jack that places a low ohm resistor across the secondary leads when no speaker is connected. This resistor acts as a static load that will turn the OT's output into heat and providing enough of a load and lasting long enough for you to realize your mistake.

[Birdman642]

This resistor acts as a static load that will turn the OT's output into heat and providing enough of a load and lasting long enough for you to realize your mistake.

Is this a pretty standard feature on most modern amps? I’m tempted to fire it up again tomorrow just to make sure everything works

[Demanic]

Most amps will tolerate this sort of thing for a bit. The exception is having the amp cranked to ten and trying to play it for a prolonged period of time, or simply leaving it on for way toooooo long with that condition.

The transformer is what takes the brunt of the situation. The power tubes are trying to dump energy into the transformer which has an open loop condition ( no energy is transferring from the primary to the secondary ). The primary side of the OT then simply charges up until it breaks its dielectric limit and then it will arc internally across the coils winds. This arcing can burn off the protective enamel coating until the winds can physically short to each other ( no protective coating anymore ). This shorting of the winds in the coil causes the output transformer to fail in function for the tubes, which then begins their path to destruction. The tubes now have a build up of electrons on their plate and the resistance keeps raising and raising ( more heat, and less efficiency at doing their job of amplification ) until the tubes start to simply burn up. Depending on where the OT shorts out, it could short the tubes to each half of the primary together ( no center tap for current to go through ) and the tubes go into dramatic and instantaneous death by electron overload.

Many modern CE, UL, or RoHS approved amps will have some form of protection from open loop conditions. Not all, but some, will have some circuit designed to mitigate output failures. A simple example of this is a switching jack that places a low ohm resistor across the secondary leads when no speaker is connected. This resistor acts as a static load that will turn the OT's output into heat and providing enough of a load and lasting long enough for you to realize your mistake.

Such a poetic way of putting it.

Simple terms, you let the smoke out of the wires.

Sent from my SM-A115A using Tapatalk