#bx25

AKG - BX25 spring reverb

“1981 ... Made in Austria * RARER THAN MERMAID TEARS *

The father of all springs, "The AKG BX25". This model was an improvement on the AKG BX20. They were able to increase the spring length by 25% while reducing the size by 1/3 ...

AKG BX-25 was the next step in true studio and transportable two-channel reverberation. Replacing the BX-20, the BX-25 continues to provide both the quality and operating features required in studio applications. The BX-25 is based on the patented and extremely successful Tortional Transmission Line principle used in all AKG reverb units. The TTL-SYSTEM has been improved by extending the overall length of the spring by about 25% over the BX-20 yet at the same time reducing the overall size of the BX25 dramatically by about one-third. The two Tortional Spring Systems are physically separated and isolated providing a dramatic increase in channel separation resulting in greater than 60 dB crosstalk. Independent decay-time adjustment (via R25 remote control, included). High and low frequency equalization, external input and output level adjustments and dry/reverb signal mixing are provided for each of the two electronically and acoustically separate channels. Decay time is adjusted silently through the use of motional feedback. In addition to the shelving type frequency equalization, AKG has incorporated a high-cut filter at the input/reverb drive amplifier. This enables the selection of a bright, more aggressive sound or a more mellow natural reverberation sound. Plug-in PC boards are used for the electronics within the control module. This module may be removed from the main housing and operated remotely via an optional extension cable up to 30 feet away from the reverb section. The exciting news is the new M-250 Digital Delay module that may be added to a BX-25 at any later time or ordered within the BX-25. As a complete unit (reverb and delay). The BX-25ED incorporates all the reverb features mentioned above plus digital delay. The new digital delay module provides: remote mix control between reverb signal and reverb plus individual reflections. Individually adjustable level for each of the discrete reflections in 2dB steps from original level down to 20dB below the original level, descrete reflections are available as reflections only or mixed with reverb; initial delay for the reverb signal is switchable to 0, +30ms and +60ms; two discrete reflections for each channel may be adjusted in 6ms steps from 6ms to 60ms; bandwidth reflections: 12kHz. At the rear of the digital delay module are six XLRconnectors - two input and four output. Two of the output connections allow for fixed echoes only. The second set of output connections allows for mixing between reverb only and reverb plus echoes (using R25 remote). REVERB SECTION: • Decay time: 1.5 to 3.5 seconds continuously and in ­dependently adjustable for each channel on remote control • Nominal input level: adjustable to -22, -6, 0, +6 and + 12 dBm (0 dBm ~0 775 volts) • Maximum permissible input level: 35 dB above selected input level • Input limiters: Threshold = 6 dB above selected nominal level Range = approx. 30 dB • Input impedance: ~ 10 k ohms per channel, transformer balanced • Nominal output level: adjustable to -6, +6 and +12 dBm • Maximum output level: Associated equipment should have input headroom of at least 20 dB over selected nominal output level to accommodate instantaneous peaks in reverb signal • Output impedance: 300 ohms (+12 dBm); 100 ohms (+6 dBm) transformer; 15 ohms (-6 dBm) balanced • Recommended load impedance: 600 ohms (+12 dBm); 200 ohms (+6 dBm); 50 ohms (-6 dBm) • Frequency range: 50-4,000 Hz in position 50-8,000 Hz in position • Signal to noise ratio: ~ 76 dB r. m. s. weighted ~ 75 dB r. m. s. unweighted • Bass control range: +/-10dB at 150 Hz • Treble control range: +/-5 dB at 5,000 Hz • Crosstalk between channels: ~ 60 dB • Level difference between the channels: adjustable compensation • Acoustical feedback safety: ~ 120 dB • Operating temperature range: - 10° to +60° C • Power requirements: 115/230 volts, 50-60 Hz, 80 VA • Max permissible inclination during operation: 10° (20%)“