How to treat tube pres

[Ruphus]

Months ago I read a stereophile advice about how to treate a tube design headphone amp.
It sounded very restricting, basically saying that with sensible tube circuits nothing should ever be dispatched unless the unit was turned off, for it would otherwise generate spikes which could be damaging resistors or caps or thelike UFO in its guts.

I´m always turning off phantom power before plugging in or out a mic, however since having read that advice I´m wondering whether I should better turn down input gain too eventhough no feed to be expected on first sight.

However, sometimes it´s not really that handy to lose certain settings and I wonder whether turning off phantom power could be enough prevention already.

I suppose turning down output gain when patching to other gear to be advisable anyway. ...

Please fill me in.

Thanks,

Ruphus

Well your concerned about 48 V. What they were probably referring to in that article regarding the headphone amp was; do not unplug the headphones while the circuits are being driven, whether audio or supply voltage.

Tube amps big or small use output tx's. It is better to short the output of the tx when the signal is being driven full on than to disconnect it's load. Tubes don't like that, at all. It is always smart to turn off your phantom power when removing mics or plugging them in, even if your using a solid state pre.

Don't ever run your tube anything without a load on the other side of the output transformer. tutt

[Ruphus]

Originally Posted by WHITEAUDIOLABs

Don't ever run your tube anything without a load on the other side of the output transformer. tutt

So, just turning down output gain before wouldn´t help?

That would be meaning no patching around while the tube gear being turned on. Consequently, I suppose many users might be harming their pres while trying out different chain configurations. - As I assume the least would switch the pres on and off in between, right?

Having to turn them off for patching would make tube pres a bit unpractical when it is about trying different compressors etc. after them. Aside from having to wait each time until the tubes warm up again ( and possibly wait first with unplugging until the capacitors have discharged ), and considering that gear from what I think to know generally doesn´t like to be switched on and off too often.

Ruphus

Oh, no. You just don't want there to be any output present. Because once you turn your tube gear on in the morning or when ever, leave it on all day, or until you know you are not going to use it for a extended period of time.

Turn on or start up is the hardest or worse thing for a tube. Damn surge current.

Think of it this way, when does the light bulb in your bedroom always burn out.

When it's been on for 2 hours or when you come in all drunk in the middle of the night and turn it on. !!!!!!FLASH!!!!!!!

btw, by turning of your phantom power, you eliminate any input to the amplifier, or pre. So with no input there will be no output. So keep your settings, just remove input to the gear.

[Ruphus]

I think, I got it now.
Thanks a lot for the explanation!

Ruphus

[Empty Planet]

Though my understanding of these matters quite shallow, this is why Oliver Archut designed his V78m with a power supply that slowly ramps up the voltage, to save wear and tear. Makes it a little bit more idiot-proof.

Which is good news if I'm at the controls.

Cheers.

[Ruphus]

Originally Posted by Empty Planet

Though my understanding of these matters quite shallow, this is why Oliver Archut designed his V78m with a power supply that slowly ramps up the voltage, to save wear and tear. Makes it a little bit more idiot-proof.

Which is good news if I'm at the controls.

Cheers.

My Manley box has that feature too. Prolly generally a good idea, not only for confuses like us.

Ruphus

I want to add that in a ultra-linear power amplifier, always always have a speaker load on the output tx. Always.