What’s Wrong With Transformers?

Nothing, really. But they do impart coloration. More than any other electronic component, transformers must abide by the natural laws of physics as they pertain to magnetism. Hysteresis (magnet inertia and momentum) is the main hurtle an audio transformer designer has to clear gracefully. Any audio design engineer will tell you how difficult it is to make a transformer that will faithfully follow the edge of a musical transient and not want to keep going. That’s called “overshoot”. Transformers also tend to want to resonate at a particular frequency. This is called “ringing”. Designers try to keep this resonance out of the audio spectrum. The truth is that when this resonance combines with upper harmonics in the original program audio, a third “tone” can be produced well within the audio spectrum that is subtle, but definitely perceptible. Both overshoot and ringing are forms of distortion in that they are artifacts that were not present in the original signal.

How’s the Juice Box going to stand up to the demands of digital recording?

It already exceeds the present day capabilities of digital audio! The unit has wider dynamic range than is afforded by available digital storage mediums and is capable of much faster transient risetimes than present sampling rates will allow. Also, coupling a digital synthesizer with the Juice Box gives the benefit of tube warmth added to the digital environment. With its class A circuitry and impressive specs it is the ideal complement to the digital forum for now and many, many years to come.

Is the Juice Box XLR pin2 or pin 3 “hot”?

With the gain selector set to either “0” or “-20” the Juice Box produces a positive-going wave at pin 2 of the XLR in response to a positive-going input signal. With the gain selector set to “+20”, the signal inverts (an inherent result of adding a stage of tube gain) and the positive-going wave will be present at pin 3.

Can I use the Juice Box as a “re-amp” interface?

No. There are active electronics present between the input and output. A re-amp box is inherently passive.

Are replacement tubes special or difficult to find?

They are readily available on the open market. The unit was designed around the 12AX7 for the input and the 12BH7 tube for output, and its best performance is with that compliment of tubes (higher output; lower distortion and noise). Some of the older units used a 12FQ7 tubes for the output because, at the time (late 90’s), there was no reliable source of 12BH7s. Since then, the Russians have stepped in with a reasonable replacement. Both tubes, in use in the current production version, are of the Electro-Harmonix brand and are available from Antique Electronics or directly from Electro-Harmonix.

Where in my signal chain should I place the Juice Box?

The Juice Box has a very high input impedance . This feature is most beneficial when the instrument is plugged directly into the Juice Box input. Then, the instrument “sees” no significant load and will deliver a signal as full and uncolored as it is capable. The “to amp” jack is a buffered signal. Connections between this jack and the inputs of other devices (amps, effects boxes) will not effect the primary sound of the instrument. Also, the fact that the signal is buffered means that you can use a longer than normal (100 feet) instrument cord to connect to other devices.