I was out playing music at a friend’s house and took Little One along to show it to the other guitarists that were there. They loved it, which was reassuring (it sounds great with a boost pedal in front of it), but what sticks in my mind most is that it wasn’t drowned out by the drummer. Okay, we were playing in a kitchen and the drummer wasn’t hitting the skins as hard as he could but the fact remains; one watt is louder than you might think. In fact, one Watt is half as loud as 10 Watts which is half as loud as 100 Watts so one Watt is pretty damn loud.
It’s easy to miss that something is unacceptably loud when you’re playing on your own; your ears quickly become accustomed to the volume but the neighbours don’t! Guitar amps designed specifically for home use should be as quiet as possible without sacrificing tone. How quiet can the turned-up-to-eleven tone be? That’s what I’ve got to find out.
Off the top of my head there are three ways to attenuate the output:
- Attenuate the signal after the output transformer making sure that the amp always sees the required load. The Vox AC4 has an in-built resister network to drop the output from 5W to 1W to 0.25W. Using resistors will change the tone of the out put stage so is not the best appoach but there is a hint that 0.25W is a useful amount of power. Denis Cornell’s Romany amp goes one step further by delivering 0.05W (50mW).
- Drop the HT (B+) Voltage using a Zener Diode which will reduce the power of the amp as a whole. To half the power output would require a drop of 75V which is quite a lot but achievable because it’s a low-powered amp.
- Drop the HT (B+) Voltage using a VVR circuit which will allow increased flexibility which may be required given what Vox, Cornell and others are doing.
Food for thought.