Costly rookie mistake?

[L1V1D_0n3]

Hello all, first post here.

First of all, my compliments on a very informative forum!


Now, for my embarrassing question....

Earlier today, I received my first ever tube/valve guitar amp.

I've been playing guitar for awhile, but have been using POD's and software emulation for a few years for recording. I don't play live, I just enjoy writing and recording. However, I was never quite able to achieve a truly exciting guitar mix.

So I decided to get an amp, a Bugera 6262 ( 5150 clone ). I intend to record direct out of the preamp out or FX send to my DAW, where I will use convolution cab impulses and maybe get a cab and mic it proper down the road.

You vets can probably guess where I'm going with this at this point.....


So I received it today. Immediately tore the box open and hooked up the head to my DAW. NO CAB.

I jammed with it for awhile through the PC and at some point I noticed that I could hear a faint sound coming from the head. I turned my studio monitors off and played some more...sure enough I could hear a mild preamp distortion tone coming from the head as I played...as in I could hear the guitar notes...sounded like a weak direct out sound.

I became worried at this point and looked up manuals etc. Of course, then I learned that I could damage the head by powering it on at all without a load on the outputs or a cab.


So, to summarize, I want to know is this sound a sign of damage? I played through the amp without a cab for maybe an hour.


Thanks in advance.

[Chuck H]

The fact that you can hear a sound could be a good sign. What your hearing is probably the power tubes becoming mechanically noisy. If they weren't noisy right away then there is at least that much damage already done. If you want to find out what all is wrong you should plug the amp into a cab and see. Running into an open load is quick death for tubes and output transformers. If the MFG of that amp used a shorting jack for the output, that is very hard on the tubes but the amp probably survived.

Chuck

[Enzo]

Yeah you probably got away with it, but only way to know is with a speaker.

A new type thing but didn;t scan the instructions, eh?

I agree, that you can hear it holds out hope. It could be the tubes themselves singing, or the laminations of the output transformer could as well.

The output jacks on that are NOT shorting jacks, but the flyback diodes by the power tubes offer some protection.

[Steve Conner]

Output transformers often "sing" when working, I've heard this when running into a dummy load many times. It very probably isn't a sign of damage, since the transformers I've heard it from were good and are still working years later. It's just the same effect that makes the power transformer hum.

I've never heard power tubes make any sound whatsoever: if running without a load does anything, it makes the screen grids light up like lamps, and ultimately melt, flyback diodes or not. I have a ruined GEC KT66 here that looks like a previous owner did that to it

The fact that it still makes that noise and isn't belching smoke or popping fuses means that you probably got away with it. If you want to keep doing it, you should invest in a dummy load. Devices like the THD Hotplate are great, but you'll pay more for a Hotplate than you did for your Behringugerthing, and if you're going to use cabinet impulses, you won't need the cabinet modelling part of the Hotplate anyway.

If you know a little about electronics, you can buy some resistors and make your own load cheaply. I use a big variable resistor that I found on Ebay for $30. If I take the output from this into an Alesis parametric EQ and a reverb box, it actually makes quite a decent ghetto cabinet simulator. I just fiddled with the EQ until it stopped sucking.

Or, if you want to be really ghetto, maybe the amp's preamp out will keep delivering signal to your DAW with the master volume turned to zero. Under this condition, the power amp is doing absolutely nothing and you may get away with leaving the speaker output open; though I wouldn't care to do that myself.

Of course, if you had plugged the speaker output into your DAW, you win a complimentary fire extinguisher.

[Gtr_tech]

Mic up a speaker cab.....other wise you may as well be using a POD. Speakers are a part of the equasion as well as the interaction between them and your guitar. Start moving some air.....things get interesting.

[Gtr_tech]

Output transformers often "sing" when working, I've heard this when running into a dummy load many times. It very probably isn't a sign of damage, since the transformers I've heard it from were good and are still working years later. It's just the same effect that makes the power transformer hum.

.

I've heard PI tubes ring with a signal on them.

[L1V1D_0n3]

Thank you all very much for the timely responses and valuable information. ( And also thank you for refraining from any "RTFM!" type comments though I probably would've deserved it.

I've ordered a Weber MASS to use as a dummy load for now and an attenuator when a cab is added at a later date.

Hopefully, you all are right and no damage has been done yet.

On that note, if I were to use the line out of the powersoak into the DAW would I be able to trouble shoot for damage to the output? or would the damage only be audibly appreciable through a cab?

Any symptoms to look out for would be helpful.

Thanks again.

[Chuck H]

Provided you have a good way to monitor whats happening with the MASS unit, it should work fine to see if you've damaged your amp. There are different MAS units for different power ratings, so it must be able to take the power of your mp.

It is plugged into the final output. So if there's anything wrong at that end, you'll know.

Chuck