The OC-04 produces three different signals one and two octaves below and one octave above the original note (synthetically). Especially while playing single-note (only one note the same time) using the OC-04 many attractive effects can be achieved. The completely independent volume adjustment possibilities allow playing with only one additional octave or mixing all signals together at any level.

Most guitarists know that True Bypass switching is needed to prevent tone sucking when an effect is not in use; but most True Bypass systems create as many problems as they solve. The Exar Silent True Bypass perfects the art of effect switching. Standard True Bypass systems are based around the mechanical switch. This is a simple and low cost method, but poor reliability, clicking and popping during switching, low quality signal transfer can all be a significant problem. The Exar Silent True Bypass substitutes the unreliable mechanical switch with a jointless magnetic switch, microprocessor and relay, which is practically indestructible. Clicking and popping during switching is eliminated using an innovative microprocessor controlled circuit design. In the space of just a few milliseconds, the signal is short-circuited, the micro-relay contacts are switched, and then the signal is re-connected again. This process is unnoticeable and provides you with noiseless switching of every single effect. Switching is done by a special micro-relay with 24 carat gold-plated contacts providing much better signal transfer. This micro-relay uses very little current and only while switching, so it has almost no effect on battery life. All the benefits of standard True Bypass without any of the problems; the Exar Silent True Bypass sets the new standard.

Input Impedance1 Mohm
Output Impedance10 kOhm
Power Supply9V DC
Current Draw23,5 mA
Size60x110x50 mm
Weight400 g
oct+1: Volume of the signal one octave above the original note.
oct-1: Volume of the signal one octave below the original note.
oct-2: Volume of the signal two octaves below the original note.
direct: Volume of the original signal.
tone-1: Tone control of OCT-1.
tone-2: Tone control of OCT-2.


I decided to get acquainted with other Exar Electronix products. I started using the Octavium, a typical octaver pedal which produces one or two octaves lower sound even at the same time. Of course you can regulate the volume control and the octaves tones added without changing the base sound. I am using a subwoofer on stage, so all together it makes a great impression.


The Little Egoists group was established by Marek Styszowski on the 30th May in 1986 when he parted with a legendary group Laboratorium after 16 years of existing and collaborating together as the co-leader. During that time he succeeded not only on the domestic market, but also on the international one. Laboratorium received the 2nd prize at the Jazz Music Festival on the Odra in 1972 and one year later the 1st prize. Since that moment it was known as the most popular jazz-rock group in Europe. Thanks to the Grand Prix prize received in Lublin in 1975 they were invited to perform at the Jazz Yatra World Festival in Bombay and then in the festival concerts in Calcutta and Poona in India. Marek Stryszowski was not only famous for the fact that he is a jazz singer and an instrumentalist (he played the alto and soprano sax), but also that he is a song composer. Thanks to his works Laboratorium could enjoy the sweet smell of success having quite a good musical oeuvre with more than 10 albums.