“The Tube Tamer does exactly what it should – it allows me to crank my AC15 and get the wonderful chime and creamy drive sounds the amp is famous for…”
On Page 24 in this issue I looked at various ways to control the volume of valve guitar amplifiers without sacrificing tone. One of the methods discussed was using a speaker attenuator to cut down the power going to the speaker. Attenuators allow the amplifier to be turned up so that the power valves start distorting which is the widely accepted “true path to tone” while still keeping the volume turned down a few notches, thus making a larger amplifier more flexible by allowing it to be used in a smaller venue than it was designed for. They can even be used to tame a large amplifier down to the point where it can be used in a late night or bedroom practice situation although this can affect the tone.
Most attenuators are being imported so they are fairly expensive devices and often in limited supply. Most are also only rated for one speaker impedance, while amplifiers often come in 4, 8 or 16 Ohm ratings. So for those with more than one amplifier with different impedances, it usually means buying more than one attenuator, which can be a costly exercise.
Enter the Tube Tamer
Graeme Parfett is a Capetonian who runs GDP, a custom electrical and electronic design and repair service for musicians, hand-building custom devices for various power distribution, pedalboard switching and other audio applications. Ultimately this led to him building the Tube Tamer – an affordable attenuator for valve amplifiers.
The Tube Tamer is designed to handle the most common impedance ranges: 4, 8 and 16 Ohm at power ratings up to 120W RMS. It sports three controls: Impedance, Attenuation and Treble Boost on the front of the unit and a pair of 1/4″ sockets for input and output on the rear. It is larger than other attenuators, so is not ideal for tucking away in the back of an open backed amp, but the physical size helps keep the unit cool and the rubber feet are tall enough to make sure it stands comfortably above the strap handle when placed on top of an amp.
I tested the Tube Tamer on a Vox AC15 hand wired (15W at 16 Ohm) and a Blackface Fender Twin (85W at 4 Ohm). Connecting it couldn’t be simpler as the sockets are clearly labelled “From Amp” and “To Speaker”. The 3-way rotary switches for impedance and treble boost have a very solid, heavy feel to them, so there are few concerns that the switches can be knocked and the settings changed by accident. The Attenuation control also has a solid feel to it and works in reverse to a volume control turning the pot clockwise reduces the volume.
As a “torture test” I ran the 85W Twin with all controls at full and attenuated the volume right down to whisper levels and after an hour the Tube Tamer was barely warm, so it’s safe to say that the 120W power rating is a fairly conservative one.
I found the Tamer managed to stay fairly neutral down to about half the volume, beyond that the treble boost was needed ,and at extreme levels of attenuation the distortion became a little harsh and grainy all as I expected from experience with other attenuators.
The Tube Tamer does exactly what it should it allows me to crank my AC15 and get the wonderful chime and creamy drive sounds the amp is famous for, but still keep the volume down to more acceptable levels without affecting the tone adversely or blowing expensive speakers (the other thing Vox amps are famous for). It will work well on most amps, from the smallest amp to a 100 W Marshall and at a variety of impedance ratings, so obviates the need for more than one model for different amps.
Tube Tamers are available directly from www.tubetamer.co.za at R1,995.
Written By : Alan Ratcliffe