Studio Projects SP828 User Manual

S P 8 2 8 M I C R O P H O N E P R E A M P L I F I E R

v i s i t o u r w e b s i t e a t s t u d i o p r o j e c t s . c o m

Place

Stamp

Here

STUDIO PROJECTS

D I S T R I B U T E D BY PM I A U D I O G R O U P

1845 W. 169th Street

Gardena, California 90247 USA

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INSTRUCTION BOOK CONTENTS

What is Studio Projects............................................................................................2

Front Panel Controls – Individual Channel Controls.............................................3

Front Panel Controls – Master & Monitoring Controls............................................5

Rear Panel Connections – Individual Channel Jacks...........................................6

Rear Panel Connections – Master Jacks................................................................7

Block Diagrams ........................................................................................................8

Specifications........................................................................................................10

Problems..............................................................................................................11

Troubleshooting......................................................................................................11

Origins and manufacture.........................................................................................11

Declarations of conformity........................................................................................11

WHAT IS STUDIO PROJECTS?

Studio Projects is a technology company committed to designing and bringing to market

high quality pro audio products at an affordable price. As a small sized company with lower

expenses than many of our competitors, we pass along the savings to our end users.

When we introduced our “C” Series microphones in 2001, both end users and reviewers

acclaimed the build and sound quality as nothing short of amazing. Pushing the “Price Vs.

Performance” envelope even further, we brought out the “B” Series mics in 2002. As part of

the “B” series we introduced our first electronics product, the highly acclaimed VTB1 Mic Pre/

Direct Box.

Now we offer our second release in what will be a series of electronics products, the SP828.

This unique product offers the best possible quality and feature set in its price class.

We hope you enjoy using it as much as we enjoyed making it for you!

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Studio Projects is manufactured and

marketed under the direction of:

PMI AUDIO GROUP

USA: 1845 W. 169th Street

Gardena, California 90247

toll free: 877-563-6335

fax: [phone]

UK: P.O. Box 358

Torquay, Devon TQ2 5XS

tel: [phone]

email: [e-mail]

FRONT PANEL CONTROLS - INDIVIDUAL CHANNEL CONTROLS

1) Mix Level to L/R bus

Controls the amount of the channel signal that is sent to the L/R mix buses. Use these individual channel level controls to create a mix of all the channels

within the SP-828. NOTE: This control does not affect the level at the rear-panel Channel Output jack (#16).

2) PAN to L/R bus

Positions the channel in the L/R mix. CCW is full Left, CW is full Right. The channel signal will be 3dB down to both buses in the center-detent position.

Create a stereo blend of the 8 channels within the SP-828 with the PAN controls.

3) SOLO switch & LED

When depressed, the LED illuminates and the channel’s signal is sent to the SOLO mix bus. This signal is independent of the Mix Level, only the Preamp

controls (#6, #7, #8) will affect this signal. Use the SOLO system to set the Preamp gain (#8) for proper signal level.

4) Signal & Peak LED

This LED will vary in Green intensity with the signal level of the channel. It will turn Red when the channel level is within 3dB of clipping. Used with the

Solo system and Preamp Gain to properly set the channel level.

5) +48v Phantom Power

This switch applies +48 volts to Pins 2 & 3 of the channel XLR connector. This Phantom power (as it’s called) is used to power condenser microphones

and direct boxes. It is not needed for Dynamic microphones and should be avoided with Ribbon mics.

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FRONT PANEL CONTROLS - INDIVIDUAL CHANNEL CONTROLS

6) Line select / Mic Pad

This switch selects between the XLR and TRS connectors on the rear panel. When UP, the XLR connector is selected, when depressed the TRS jack is

selected. The two jacks are “normalled” together in that the XLR signal is available at the TRS jack if nothing is plugged into the TRS jack. This allows the

switch to do double-duty as a Line-select switch (if a plug is inserted into the TRS jack), or as a -20dB PAD switch for the XLR jack if nothing is plugged

into the TRS Line jack.

7) Polarity reverse

This switch reverses the balanced connections to the preamp circuit and therefore reverses the polarity of the input signal. This switch is sometimes called

“Phase”, or marked as “Ø” on other products, but the function is the same. It is used to change the overall polarity of the signal. This matters most when

the signal is being mixed with other signals. The overall sound of the mixed signals may change depending on the position of the switch. Try both positions

when mixing channels together (through the L/R mix controls)

8) Preamp Gain

This rotary control varies the circuit gain of the preamp. The minimum gain of the preamp is approximately 15dB, the maximum is 65dB. By using the

Line/PAD switch, a wide-range of input signals can be accommodated. This control should be used in conjunction with the Solo switch and Sig/Peak LED

to properly set the channel gain: adjust the Gain control so that the Sig LED is a strong Green intensity, occasional Red peaks are OK. By using the Solo

switch (#3), the channel can be monitored on the Level meters (#9) and heard in the headphones.

FRONT PANEL CONTROLS - MASTER & MONITORING CONTROLS

9) Level Meters

These meters allow the user to monitor the main L/R mix output, or individual channels by using the channel Solo switches. Normally, the meters are show-

ing the output level of the L/R mix (controlled by #11). When any channel Solo switch is pressed, that channel’s signal level is displayed on both meters

and the Pwr/Solo LED (#10) turns Red indicating that the meters are monitoring the Solo mix bus. The Solo mix is made up of all channels that have their

Solo switch pressed, so individual channels, or a mixture of channels can be monitored. The meters have a VU-response, and will show the average level

of the signal. The headphone system follows these meters, so anything that shows on the meters can be heard in the phones.

10) Power/Solo Indicator

This LED normally is Green, indicating that the unit is being supplied power (via the rear AC power jack). The LED will turn Red when any channel Solo

switch is pressed. This lets the user know that the meters are now showing the Solo mix level instead of the L/R mix output.

11) L/R Master Level

This rotary control sets the overall level of the L/R mix output to the rear-panel output jacks. The L/R mix is the sum of all of the channels, controlled by

their individual Mix and Pan controls (#1 and #2).

12) Headphone Level

This rotary control sets the overall level of the headphones. The headphones follow the Level Meters and normally monitor the L/R mix. If a Solo switch

is depressed, the phones then monitor the Solo mix bus.

13) Phone jack

This 1/4” TRS jack is used to connect headphones to the unit. The phones normally monitor the L/R mix, switching over to the Solo bus when a channel

Solo switch is pressed. Best results are obtained with studio-quality phones with an impedance of 30 to 75 ohms.

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