Tube warm up

[jesus69lol]

I bought my first 5150 back in 1994 and I used to play through it for scratch tracks on recordings (direct) with no cabinet plugged into it. This was way before I knew anything about tube amps....it was my first tube amp after all. Nothing bad ever happened however, and I used it for several more years and eventually sold it on Ebay. I had no idea if it was damaged because of what I did but it never died and always sounded good.

I do exactly this with my xxx but I won't anymore. I don't exactly understand how its bad for the amp tho?

 

[Wolfeman]

I do exactly this with my xxx but I won't anymore. I don't exactly understand how its bad for the amp tho?

It really isn't 'bad' per say.... You are not going to damage anything in the long run, don't be scared. But good quality instrument cables to the amp, and good quality speaker cable to the cab will make your tone better/fuller. Don't believe me? Buy some, a/b recordings with both, you will hear a difference.

 

[jesus69lol]

It really isn't 'bad' per say.... You are not going to damage anything in the long run, don't be scared. But good quality instrument cables to the amp, and good quality speaker cable to the cab will make your tone better/fuller. Don't believe me? Buy some, a/b recordings with both, you will hear a difference.

I was talking about recording my head direct without a cab plugged in. I had no idea you weren't supposed to do that and yet that awful sound it made should've been a clue.

 

[006]

It's the fact that if there isn't a cabinet plugged into the amplifier, the power just basically circulates over and over inside the amp's circuitry. Not good in the long run. Like Jeff said, it takes a while, but it will definitely fuck your shit up eventually. Output transformers are typically on the expensive side to get repaired/replaced. Those are usually the things to go first. Then anything else is fair game. You have something that isn't intended to circulate 100-120w continuously, but rather disperse it into the speaker output, eventually something has to give. It's common sense...to me anyway.

Using an instrument cable vs. a speaker cable is really debateable...however the argument that a speaker cable is more suited in the interest of tone is definitely a strong one. An instrument cable will surely work, but it'll get hot, malfunction, make your tone different, and cost you more in the long run due to them wearing out a lot faster. A speaker cable will last longer, carry the load a hell of a lot better, and benefit the tone a lot more.

Basically, an inst. cable will work, but if you care you should use a speaker cable.

*Disclaimer: I'm drunk right now. Yes.*

!~e,.a

 

[JeffTD]

You are not going to damage anything in the long run, don't be scared.

No, you ARE going to damage something in the long run.

The amplifier needs to see a 'load' - some resistance from the speakers, an attenuator, a dummy box, etc...

 

[everybody's x]

tha's right, tube amps need an ohm load. newer designs have resisters strapped across the tranny so they'll fry before the tranny does but still. don't do it.

 

[Radd]

Man, I don't even want to turn my amp on now until I have a speaker cable.

 

[MetalWorks]

Honestly, the amp will be fine if it's on for a bit without a cabinet plugged in.

The damn things were designed and tested to be able to withstand the rigors of touring... they're not going to take a shit on you because you had them on for a few seconds without a cabinet, you know?

The first thing that would go would be the output tranny, and it'll take a lot of neglect to screw that thing up. I've heard of guys running their amps as preamps and using the fx out (AKA no load on the poweramp, what we're trying to avoid here) for a month or so before the output tranny finally died.

When I first got my Ampeg VL-1002 Head and didn't have a cab available I turned it on with the Direct out hooked up to a nother combo amp return jack so I could here it and the EL34 Power tubes started glowing bright red like light bulbs.

I switched it off and remembered I needed to have a cab hooked up. Duh....

Never happend with a cab hooked up. But it only took a few minutes for the Power Tubes to nearly fry themselves.

Guess it might depend on the amp itself to say how harmfull it is but definately would stick to keeping it on Bypass or connected to some sort of cab or cab emulator/dummy load device.

 

[Vit]

Just occured to me while reading this thread - I am not 100% sure - need to check some typical schematics first - but it seems it makes a difference whether you plug the cab connector cable into the power amp's out and at te same time don't plug the other end into the cab - then the output tranny should be at risk. I presume as long you plug the connector into the power amp the high wattage load (the resistor that should be there) would be disengaged and stop "substituting" for the speaker cab. If not plugged, the high wattage load (the resistor that should be there) would be supposed to do its job protecting the output tranny and in turn the power tubes.

Please don't take my word for it - seek techs' advice.

 

[Loren Littlejohn]

Thats it I am calling FJA tomarrow. If you want I will call voodoo as well.