Coustic GBE 600 user manual

Summary of the content on the page No. 1

600
SIX HUNDRED
GBE
TECHNICAL MANUAL
DESIGN PHILOSOPHY

With many years of experience designing and manufacturing both bass guitar speaker cabinets and am-
plifiers, it became obvious that there is a large market for a bass amplifier line that reproduces the natu-
ral tone of the instrument itself, while allowing for personalization of tonal texture.

As with our speakers, Genz Benz amplifiers strive to maximize your instrument’s natural tone and feeling
without imparting additional c

Summary of the content on the page No. 2

TECHNICAL INFORMATION The first stage of the GBE-600 preamp uses a low noise bi-fet linear scaling amplifier with a 2 pole low cut point at 23 Hz to prevent excessive speaker cone excursion and intermodulation distortion. Addi- tional bandwidth roll-off is provided at 20 kHz for RFI suppression. The variable gain stages are a feed- back-divider type control, one of which is all solid state and the other utilizing a cathode follower (tube), each providing a maximum gain of about 30 dB. On t

Summary of the content on the page No. 3

With the switch in the active position, the preamp presents a lower gain and input impedance which is tailored to active pickups. An active pickup is, for all practical discussions, any pickup that uses pre- amplification between the pickup element and the amplifier input. The purpose of this pre-amplifier is to buffer the high impedance signal from the pickup element (magnetic, piezo-ceramic, piezo-film etc) and convert it to a higher level, lower impedance form. It is common for a bass with

Summary of the content on the page No. 4

Tuner Output Jack — The “tuner output jack” is provided to allow a tuner to remain plugged into the amplifier while playing. This output remains active when the “mute switch” is pressed, allowing for tuning your instrument while not sending signal to either the “direct output” or the speaker. Signal level of -30dB (typical hot bass level) will drive all known tuners. Effects Insert Jacks — The “effects insert jacks” are provided to allow access to the pre-equalization signal for the purpo

Summary of the content on the page No. 5

Fan Switch — The GBE-600 is a fan cooled high powered rack mount device. A 2 speed rear panel mounted “fan switch” is provided to allow the reduction of fan speed and corresponding fan noise during recording and low power playing. Operating the fan at high speed is recommended anytime the amplifier is driving 2 ohms, 4 ohms at high levels, high ambient temperatures and when the “thermal” LED illumi- nates, indicating a reduction of thermal headroom. Direct Output — The GBE-600 includes a

Summary of the content on the page No. 6

CAUTIONS • Never set an amplifier on anything that will tip over or collapse under its weight. • These amplifiers are capable of producing sound pressure levels that may cause permanent hearing loss. • There are no user serviceable parts inside these units. Always consult a qualified service repair fa- cility for service. THE HEATSINK MAY BECOME VERY HOT!!! WARNING!! DO NOT TOUCH The use and operation of this device constitutes an agreement of full release of any and all liability c