S D 8 P O W E R E D MIXER OWNERS MANUAL ®
Produced by On The Right Wavelength for Samson Technologies Corp. Copyright 1997, Samson Technologies Corp. Printed March 1997 Samson Technologies Corp. 575 Underhill Blvd. P.O.
Introduction 1 SD8 Features 2 Guided Tour 4 Overview 4 Channel 5 Main Section 7 Rear Panel 9 Connecting The SD8 - General Suggestions 11 Setting Up and Using the SD8 12 Setting the Correct Gain Structure 13 Suggested Performance Application 15 Grounding Techniques 16 Using Equalization 17 Using The Aux Sends and Returns and Monitor Output 19 Using the Internal Digital Signal Processor (DSP) 20 Table of SD8 Effects 21 Specifications 22
Introduction Congratulations—you’ve made an excellent choice in your purchase of the Samson SD8 Stereo Mixer Amplifier! In this manual, we’ll take you on a guided tour through all the features of this powerful and flexible device, and we’ll tell you how to get the most out of the SD8. Although designed for easy operation, we suggest you take some time out first to go through these pages so you can fully understand how we’ve implemented a number of unique features.
SD8 Features The Samson SD8 utilizes state-of-the-art technology in integrated mixer/amplifier design. Here are some of its main features: • Convenient carrying handle and supplied standard 19" rack ears (the SD8 takes just four rack spaces) allows easy integration into any setup. • Eight independent channels, with both mic and line inputs for each channel. This allows you to blend together a variety of source signals, including dynamic or condenser microphones, keyboards, CD/tape players, etc.
SD8 Features • Protection relay circuitry prevents “thumps” when powering on or off. This means that you can use the SD8 with a single power strip into which other audio devices are connected, without danger of damage to connected speakers. • A rear-panel amplifier input allows you to bring external signals from other mixers or audio devices into the SD8 power amplifier.
Guided Tour - Overview The following illustration shows an overview of the front panel of the SD8: CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNEL 6 CHANNEL 5 CHANNEL 4 CHANNEL 7 CHANNEL 8 SAMSON PEAK PEAK O PEAK O ∞LEVEL+10 O ∞LEVEL+10 O ∞LEVEL+10 ∞LEVEL+10 O O -15 -9 -6 -3 0 +3 +6 -15 -9 -6 -3 0 +3 +6 L O O O O O O O O O SD8 STEREO MIXER AMPLIFIER PEAK O ∞LEVEL+10 ∞LEVEL+10 ∞LEVEL+10 O O PEAK O O O ∞LEVEL+10 O O PEAK PEAK PEAK R O PHANTOM ∞ +10 -15
Guided Tour - Channel CHANNEL 1 PEAK O 1 5 ∞LEVEL+10 O O 2 ∞ +10 -15 +15 HIGH AUX1/MON O 3 -12 +12 MID DSP AUX2 6 O -20 4 -6 -50 TRIM -15 +15 LOW 8 7 L LINE R PAN 9 MIC 1: Level (white) - This knob determines the final signal level being sent by a channel to the main speaker outputs. In practice, this will be used to adjust the levels of the various signals being blended together by the SD8. The “0” position indicates unity gain (no level attenuation or boost).
Guided Tour - Channel 6: Equalizer (blue) - These knobs determine the amount of boost or attenuation in each of three frequency areas. The high and low frequency knobs provide 15 dB of cut or boost at 10 kHz and 80 Hz, respectively, with shelving-type control. The mid frequency knob provides 12 dB of cut or boost at 800 Hz, with a bell (peaking) curve. A center detent in each knob (at the 12 o’clock position) indicates no boost or attenuation (that is, flat response).
Guided Tour - Main Section 1 -15 -9 -6 -3 0 -15 -9 -6 -3 0 +3 +6 +3 +6 L R 2 PROTECT PHANTOM POWER 8 CHANNEL STEREO MIXER 250 WATT AMPLIFIER 32Hz 64Hz 125Hz 250Hz 500Hz 1K 4K 2K 8K 16K +12dB 3 0dB -12dB 32Hz 64Hz 125Hz 250Hz 500Hz 1K 4K 2K 8K 16K 5 6 O 4 ∞ ∞ +10 MAIN LEVEL MIX O 5 4 3 ∞ DSP+10 10 D S P ∞ +10 RETURN 1-2 8 9 10 7 11 6 12 9 O 13 5 14 4 3 15 2 1 16 PRESET +10 MONITOR 8 9 10 7 11 6 12 13 14 15 2 1 16 EFFECT O ∞ 7 +10 HEADPH
Guided Tour - Main Section 4: Main Level (white) - This knob determines the final signal level sent to the speaker output jacks on the rear panel. You can think of this as being the “master fader”—and we made this knob extra big so you won’t miss it even under low-light performance conditions. At its fully counterclockwise (“∞”) position, the signal is infinitely attenuated—that is, there is no sound.
Guided Tour - Rear Panel 3 4 6 5 SD8 STEREO MIXER AMPLIFIER PHANTOM POWER SAMSON AUX RETURN 2 (+4dBu 10KΩ) 1 AUX SEND 1 (+4dBu <75Ω) PRE OUT R (+4dBu <75Ω) L AUX SEND 2 (+4dBu <75Ω) +48V POWER O ON 1 MON OUT (+4dBu <75Ω) AMP IN R (+4dBu 10KΩ) L OFF 7 SPEAKER OUT R MINIMUM 4Ω L TAPE/CD IN CAUTION RISK OF ELECTRIC SHOCK DO NOT OPEN ! CH8 2 CH7 SERIAL NUMBER AC INPUT 115V 50/60Hz 9 10 8 11 12 1: Power switch - As you may have guessed, this is what you use to turn the SD8 on and off.
Guided Tour - Rear Panel 5: Aux Sends 1 - 2 - These unbalanced outputs allow you to route signal from each of the two discrete Effects Sends to external devices such as effects processors. Aux Send 1 is pre-fade and pre-EQ, while Aux Send 2 is post-fade and post-EQ. See the “Using the Aux Sends and Returns” section on page 19 in this manual for more information.
Connecting The SD8 - General Suggestions The actual connections you’ll make to and from the SD8 will vary according to the environment you use it in and the particular equipment you have. However, here are a few basic rules concerning connections that will apply in pretty much all situations: • In general, it’s best to make all connections with the SD8 turned off—this particularly applies to speaker connections.
Setting Up and Using the SD8 Setting up your SD8 is a simple procedure which takes only a few minutes: 1. Remove all packing materials (save them in case of need for future service) and decide where the SD8 is to be physically placed—if desired, remove the carrying handle and install the supplied rack ears so that it can be mounted in any standard 19" rack (it requires four rack spaces). Be careful when handling the SD8—the rear heat sink fins and side rack panels have sharp edges.
Setting the Correct Gain Structure You’re now ready to establish the correct gain structure—the key to getting the best performance from the SD8, or from any mixer, for that matter. This is a simple procedure that ensures optimum input and output levels so that no unnecessary noise (caused by too low a signal) or overload distortion (caused by too high a signal) is created. Here’s a step-by-step description of how to do so: a.
Setting the Correct Gain Structure j. The procedure for setting optimum microphone levels is virtually identical; sing or speak into the mic at the level you expect to use in performance while slowly raising the Level control for that channel to its “0” position. Then adjust the input Trim control for that channel while watching the segment meter and Peak LED. You should expect that microphone inputs will require rather more in the way of input Trim boost than line inputs. k.
Suggested Performance Application The following illustration shows the basic interconnections between an SD8 and external equipment when used in a typical live performance application: CHANNEL 1 CHANNEL 2 CHANNEL 3 CHANNEL 6 CHANNEL 5 CHANNEL 4 CHANNEL 7 CHANNEL 8 SAMSON PEAK PEAK PEAK PEAK PEAK PEAK PEAK O O O O O O O ∞LEVEL+10 ∞LEVEL+10 ∞LEVEL+10 ∞LEVEL+10 ∞LEVEL+10 ∞LEVEL+10 ∞LEVEL+10 O O O O O O O O O O O -15 -9 -6 -3 0 -15 -9 -6 -3 0 +10 -15 ∞ +15
Grounding Techniques Hum and buzz are the biggest enemies you face when interconnecting a large number of different pieces of equipment to a central audio mixer.
Using Equalization One of the most exciting aspects to using a mixer such as the SD8 is having the ability to shape a sound, using a process called equalization. But there are few areas of audio engineering more misunderstood than equalization, and, just as good EQ can really help a sound, bad EQ can really hurt it, so read on... O -15 +15 HIGH Every naturally occurring sound consists of a broad range of pitches, or frequencies, combined together in a unique way.
Using Equalization In most instances, the best way to approach equalization is to think in terms of which frequency areas you need to attenuate, as opposed to which ones you need to boost.
Using The Aux Sends and Returns and Monitor Output The two Aux sends provided by the SD8 allow you to combine the signal from multiple channels and send the resulting mix to the rear panel Monitor output jack, to the internal Zoom Digital Signal Processor (DSP), or to external devices such as effects processors.
Using the Internal Digital Signal Processor (DSP) There’s probably no better way to enhance audio than with the judicious use of effects such as reverb and echo. The SD8 has its own built-in Digital Signal Processor (DSP) chip which provides some of the best effects around. These are some of the same effects, in fact, that you’ll find in the highly acclaimed Zoom Studio 1202 signal processor.
Table of SD8 Effects Preset # Description Effect settings 1 Hall reverb - simulates a medium-sized concert hall Alter the reverb time. Effect 1 (standard) is 2.2 seconds. Larger Effect values increase the reverb time, from 1.0 second (Effect 2) to 3.8 seconds (Effect 16). 2 Room reverb - simulates an acoustically dead space such as a rehearsal studio Alter the reverb time. Effect 1 (standard) is 0.7 seconds. Larger Effect values increase the reverb time, from 0.5 seconds (Effect 2) to 3.
Specifications Mixer / Pre Amp Section: Frequency Response (± 3 dB) Mic to Pre Out Line to Pre Out Aux Return to Pre Out Normal Limit DC ~ 65 kHz DC ~ 58 kHz DC ~ 70 kHz 20 Hz - 50 kHz 20 Hz - 50 kHz 20 Hz - 50 kHz Total Harmonic Distortion (20 Hz to 20 kHz, with 30 kHz LPF, trim center) Mic to Pre Out (Trim Max) 0.060% Line to Pre Out (Trim Min) 0.015% Aux Return to Pre Out 0.008% 0.10% Max 0.03% Max 0.
Specifications Power Amp Section: Normal Limit Rated Output Power (per channel) (1% THD @ 1 kHz stereo, 4 ohm) 275 watt 250 watt Min Maximum Voltage Gain Amp In to Speaker Out (@ 1 kHz) 27.5 dB 28 dB ± Total Harmonic Distortion (20 Hz to 20 kHz with 30 kHz LPF) 0.02% 0.
