Bogen GS-150 Gold Seal Series 150W Commercial Mixer Amplifier w/ Aphex Aural Exciter

Bogen GS-150, the 150-watt model in the Gold Seal Series of commercial mixer amplifiers. Bogen built the line for sound contractors, giving every model from 35W to 250W the identical feature set so you did not have to buy a bigger amp just to get more routing options. This is a lot of amplifier and a lot of preamp in a single 2U chassis.

This example carries the earlier faceplate with the licensed APHEX AURAL EXCITER legend printed on the front. Later manual revisions rename the same circuit “Audio Enhancement,” described as regenerating upper harmonics to restore presence and clarity lost in amplification, so the Aphex-branded panel is the more collectible variant. The depth of the effect is set by the AE trim on the rear panel.

Inputs

Six low-impedance balanced mic inputs: four on rear XLR connectors, two on screw terminals. Two high-impedance AUX inputs on RCA. One 600-ohm telephone page input on screw terminals. MIC 5 shares its channel with TEL and MIC 6 shares with AUX 1, each selected by a rear slide switch. Sensitivity is 0.35 mV at 200 ohms on mic, 0.085V at 10k on aux, and 0.07V at 600 ohms on the telephone input.

Outputs

Transformer-coupled 8-ohm, 25V, 25VCT and 70V taps on the barrier strip, plus a 4-ohm direct output. Transformer output runs 65 Hz to 20 kHz at +0/-2 dB; the direct output runs 20 Hz to 20 kHz at +0/-1 dB with 0.3% typical distortion. Also on the rear: Tape Out, To Power Amp, and a WMT1A line-matching jack.

Processing and control

• Dual-function 10-band graphic EQ. Acoustic mode gives full-range shaping on one-octave centers starting at 62.5 Hz with 12 dB of boost or cut. Feedback Control mode moves the bands to 2/3-octave centers between 125 Hz and 8 kHz, same 12 dB range, for ringing out a room.

• Switchable 15V DC phantom power, with individual rear slide switches for MIC 1 through 4.

• Lo-cut filter giving 3 dB of attenuation at 65 Hz across all mic inputs.

• True loudness contour on the AUX inputs, +8 dB at 100 Hz and +4 dB at 10 kHz.

• Pre Out and Power In jacks with a LINK switch, so you can patch outboard processing between the mixer and power sections, or use either section on its own.

• Precedence terminals for contact-closure muting on every input, remote master volume terminals for the GSRVC, ALC and VOX trims for paging, and a four-position variable mute at -60, -21, -10 and 0 dB.

• Resettable circuit breaker rather than a fuse.

Practical uses: 70V distributed audio for a café, restaurant, shop, warehouse or church; a rehearsal-room or practice-space head; a self-contained small-venue system where you need mic channels, real EQ and speaker power in one box. The Pre Out and Tape Out also make it usable purely as a seven-channel mic mixer feeding something else.

Dimensions are 16-1/2” W x 3-1/2” H x 12” D. Bogen lists shipping weight at 31 lb. Made in Korea. It is a 2RU rack-mountable package, though the GSRPK rack kit is a separate accessory and is not included here.

CONDITION

Working and fully functional. Powers up, all channels pass audio, EQ and Aphex sections engage, and the amplifier drives a load.

Front panel: Very clean for the age. All gold legends are crisp and fully legible with no rubbing or fade. All seven input knobs plus the master knob are present with original caps. All ten EQ slider caps present. Contour, EQ mode and Aphex Aural Exciter switches all present and operating. Red power rocker present and functioning.

Top cover: Vent slots are open and unobstructed.

Sides: One side panel has a long diagonal scratch through the paint, roughly 6 inches, photographed. The opposite side has lighter scuffing and handling marks. No dents, no bends, no rack-ear rash. Chassis is square and all cover screws are present.

Rear panel: All legends legible. All four XLR connectors present and tight. All RCA jacks present. Every barrier strip terminal and screw accounted for on both strips. All slide switches present and moving: Lo Cut, AUX1/MIC6, MIC5/TEL, Var Mute and the four phantom switches. AE, ALC and VOX trimmers present. Circuit breaker button intact. Both factory safety labels are complete and readable.

Power cord: Factory captive cord, jacket intact, no cuts, splices or repairs.

Feet: All four rubber feet present.

What’s included: Amplifier only. No manual, no rack kit, no tamper-resistant cover, no original box. Ships double-boxed and well padded.

No modifications, no repairs, no non-factory holes. Smoke-free environment.