The built-in Power Soak lets you enjoy the benefits of full-blown power amp saturation at low volume, and its silent recording capability captures genuine tube-driven tone even without having to drive speakers. But how does it work? And what is it good for?
The secret of many great guitar recodings lies in fully cranked up tube amp settings. But the resulting volume level is way too loud for most applications. It needs to be reduced. But how can this be done without sacrificing the tone? And why does it affect it at all?
Let`s compare it with cooking coffee: to cook a good coffee, the water has to be steaming hot, but you won´t drink it directly. It needs to cool down a bit. A proper coffee is served in a thick-walled ceramic cup – for good reason: The ceramic cup works like a “powersoak” and absorbes some of the heat. In this case a “mastervolume” would only reduce the temperature of the water itself. Now imagine, how a coffee will taste like, cooking it with lukewarm water? The energy has to be reduced afterwards, and that is exactly what a power soak does.
When it comes to silent recording, some tube amps only offer the preamp signal after switching the power amp in Stand By mode. Technically this works, but the power-amp saturation is completely missing. The Red Box of the GrandMeister (and TubeMeister) captures the signal in between power amp and power soak, so even in silent recording mode (power soak set to 0 watts), you can enjoy full-blown power amp saturation.
What`s the trick behind it?
The power soak transforms power into heat, you can see resistors and coils when you look at the bottom plate of the GrandMeister. But it is quite impossible to integrate a power soak into an amp that reduces more than 20 watts – it will just get way too hot. So how could the power be reduced without burning the amp?
TSC, the built-in Tube Safety Control, is not only able to switch off defective tubes but also shutting two of them down – anytime. So when you press the 18W button, TSC disables one pair of tubes to reduce the output power by half from 36 to 18 watts. That´s the trick! (By the way: In this case, TSC is simply indicating that two tubes are off, and not that it has detected a fault). When you press the 5W and 1W buttons, some of the power is converted into heat for further reduction, respectively.
Especially in silent recording mode the amp will get quite hot by turning up the master volume. But no worries: the metal case works as a heat sink feeling hotter than it actually is…
First published: April 15 2014. Most recent update: October 16 2015.