Headbone Guitar Amp Head Switcher Announced at NAMM
January 29, 2004
Radial Engineering has added the Tonebone Headbone guitar amplifier head switcher to its growing line of Tonebone guitar effect pedals at this year's Winter NAMM show.
The Radial Headbone is a guitar amplifier head switcher that allows the player to seamlessly transition between two amplifier heads such as a Mesa-Boogie Dual Rectifier and a Marshall JCM800 while using the same 4-12 cabinet. For tone aficionados, this provides the ultimate amp set-up whereby a rhythm setting can be set with one amp and soloing with the other, all the while using the same cabinet.
Although this seems easy to do, there are many engineering challenges that must be overcome to assure the safe performance of the switching. It is also important to note that because tube amplifiers are very different from solid-state amplifiers, two Headbones are offered: The Headbone VT for Valve/Tube amplifiers and the Headbone SS for solid-state amps.
Connection to the Headbone begins at the guitar input with a choice of direct or buffered 1/4" jacks. The direct input assumes that the guitar is pre-buffered, deriving its input from a series of pedals or a wireless system while the buffered input is for direct guitar connection. The Headbone directs the guitar to the two amplifiers using noiseless photocells that unlike relays, actually ramp up the input level without introducing an audible spike. The amplifier heads are then sent back to the Headbone which in-turn selects these using high-cycling, gold contact relays that direct the two amp signals to the speaker outlet.
To ensure safe and stable amplifier operation, these are controlled by a digital programmable interrupt that manages the head select and relay switching by providing a timed overlap. This ensures a constant load is applied to the amplifier, which, as any technician knows, is a major concern with tube amplifiers. As a further safety measure, the Headbone incorporates a power-off 'Safe Mode' that is automatically engaged should ever the power supply be disconnected or mistakenly turned off. In 'Safe Mode' the Headbone automatically diverts the input signal to head-1 and diverts the load to the speaker.
The introduction of the Headbone coincides with the introduction of a new remote controllable pedal interconnect system called 'the SlingShot'. The concept behind Radial's SlingShot is an easy to use, remote control system that allows a pedal such as the new Headbone to remotely switch the cabinet using a regular 1/4" to 1/4" guitar cable. To add versatility, SlingShot inputs may be controlled using either momentary or latching foot switches and standard 5VDC controller outputs as found on most MIDI controllers. The Headbone's SlingShot system also incorporates a remote output that can be used to remotely control a second stack should this be used in a concert system.
For more information, visit their web site at www.tonebone.com. | 
