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REAR PANEL CONNECTIONS AND CONTROLS continued

8

Note: 

If the controller’s trigger output is a + and - terminal, you can cut the 2.5mm plug off one 

end of the included trigger wire and attach the bare wires to these terminals. The lead with 
the white stripe on it corresponds to the plug’s tip and the unmarked lead corresponds to the 
sleeve of the plug.

Note: 

If the trigger voltage source is DC, the trigger plug tip must be + (positive) and its 

sleeve - (negative). 

12V Out Jack

The Trigger Out jack lets you loop or “daisy-chain” the incoming trigger voltage to an additional 
Model 275 or other component.

Note: 

The Model 275 trigger circuit draws a negligible 15 mA from the controller. The total load 

on your controller’s trigger output(s) is the sum of the trigger current drawn by each of the com-
ponents you’ve looped together. Controllers can typically supply 150 mA at their trigger outputs.

Audio Trigger Sens (Sensitivity) Knob

The Auto Turn On Audio Sensitivity knob adjusts the incoming audio level or the “threshold” 
required to turn on the Model 275. Its 12 o’clock position will be suitable in most cases. To increase 
sensitivity for response to lower level audio signals, turn the knob counter-clockwise .
Turn the knob clockwise toward - to decrease its sensitivity. This will prevent spurious noise 
and switching transients in your system from false-triggering the Model 275.

Note: 

Plugging in the 275’s AC cord for the first time will usually create an internal power surge 

that “false triggers” its Audio auto turn on, even if there’s no audio signal at its input jacks, and 
it will remain on for 10-15 minutes after you switch it off. This is normal.

Ground Switch

Ground is the normal position for this switch. If you hear background hum in the speakers 
connected to the Model 275, try setting the Ground Lift Switch to its Lift position. The Ground 
Switch disconnects or “lifts” the audio circuit ground from the chassis ground. This often helps 
to eliminate audible hum that results from ground loops. Ground loops are multiple ground 
paths such as the metal-to-metal contact with the panels or chassis of other components 
combined with the ground connections of the audio cables or even the ground wires of the 
various AC cords.

AC Power Connections and AC Grounding

If possible, plug your Model 275 into the same AC outlet that your accompanying audio com-
ponents (especially then preamp or system controller) are plugged into. The ground potential 
between different AC outlets may be higher or lower, resulting in audible hum.

WARNING: To Prevent Fire Or Shock Hazard,

Do Not Expose This Unit To Rain Or Moisture.

AC      115V/60Hz

AC      230V/50Hz

Speaker Pair A

L

R

Mono

Manual

Audio Sens

Max Min

12V Trigger

Ground

Lift Norm

Mono

Stereo

4-8

Ohms

2-3 

Ohms

230V

50Hz

115V

60Hz

20Hz 40Hz

Flat

Audio

Auto Turn On

Loop

Level

Bridging

In

12V

In

Loop

R

Mono

+

+

AC      115V/60Hz

AC      230V/50Hz

Power Consumption: 300W

AC

Voltage

Load

Impedance

275 Two Channel Amplifier

Parasound Products, Inc.

San Francisco, CA    U S A

CAUTION: To Prevent Electric Shock, Do Not Remove Cover. No 

User-Serviceable Parts Inside. Refer Servicing To Qualified Service Personnel.

L

High Pass Filter

Speaker Pair B

L

R

Mono

WARNING: To Prevent Fire Or Shock Hazard,

Do Not Expose This Unit To Rain Or Moisture.

AC      115V/60Hz

AC      230V/50Hz

Speaker Pair A

L

R

Mono

Manual

Audio Sens

Max Min

12V Trigger

Ground

Lift Norm

Mono

Stereo

4-8

Ohms

2-3 

Ohms

230V

50Hz

115V

60Hz

20Hz 40Hz

Flat

Audio

Auto Turn On

Loop

Level

Bridging

In

12V

In

Loop

R

Mono

+

+

AC      115V/60Hz

AC      230V/50Hz

Power Consumption: 300W

AC

Voltage

Load

Impedance

275 Two Channel Amplifier

Parasound Products, Inc.

San Francisco, CA    U S A

CAUTION: To Prevent Electric Shock, Do Not Remove Cover. No 

User-Serviceable Parts Inside. Refer Servicing To Qualified Service Personnel.

L

High Pass Filter

Speaker Pair B

L

R

Mono

Summary of Contents for 275

Page 1: ...Model 275 Two Channel Power Amplifier OWNER S GUIDE Model 275 Two Channel Amplifier A B Power M o d e l 2 7 5 T w o C h a n n e l A m p l i f i e r Protect Hi Temp L R...

Page 2: ...will only fit into a grounding power outlet If you are unable to insert the plug into the outlet contact your electrician to replace your obsolete outlet Do not defeat the safety purpose of the ground...

Page 3: ...High Pass Filter Switch 4 Speaker Connections 5 Bridging Switch Stereo Mono 5 Mono Input 6 Speaker Connections 6 Load Impedance Switch 6 Auto Turn On 6 Sensitivity Adjust Knob 8 Ground Switch 8 Front...

Page 4: ...thoroughly before you begin installation Unpacking Carefully unpack your Model 275 and these accessories Detachable AC power cord Trigger wire with a 2 5 mm sub mini plug at both ends Trigger wire ad...

Page 5: ...till develop around any heat producing equipment Therefore a ventilation fan is high ly recommended Allow a few inches of empty space on each side and above the unit and try to avoid crowding or stack...

Page 6: ...certified amplifier might play a bit louder because of its higher power output We recommend setting the 275 s R and L level controls to 3 o clock if you are driving it from a THX surround controller...

Page 7: ...peakers is another way the 275 will run cooler Note Autoformer type passive volume controls are highly reactive loads that are known to cause amplifier malfunction The 20 Hz or 40 Hz filter settings e...

Page 8: ...the mono power output is much higher than the sum of the L and R channel outputs for stereo operation Mono Input and Speaker Connections 1 Turn the unit off and remove the AC cord 2 Connect the single...

Page 9: ...s set to its 12V position the Model 275 is turned on and off with an external 9V to 12V voltage from your preamp or controller When the external volt age ceases the Model 275 will turn off immediately...

Page 10: ...gging in the 275 s AC cord for the first time will usually create an internal power surge that false triggers its Audio auto turn on even if there s no audio signal at its input jacks and it will rema...

Page 11: ...right away You can also turn it off by unplugging its AC power cord Auto Turn On switch in the Audio position turn off the preamplifier surround controller or system controller that drives your 275 Y...

Page 12: ...ires are secure at both ends Make sure the control preamp receiver is switched to the correct input If using Auto turn on increase the sensitivity of the audio trigger Is the Hi Temp or Protect or bot...

Page 13: ...Dealer or Parasound Authorized Reseller Units Will Be Refused by Parasound Under the Following Conditions 1 Unit was sent without the Parasound assigned RA number marked on the carton 2 Unit was sent...

Page 14: ...at 2 828 V output IHF A weighted 84 dB at 2 828 V output unweighted Input Impedance 33 k Input Sensitivity 800 mV for full rated output Inter Channel Crosstalk 80 dB 1 kHz 72 dB 10 kHz 65 dB 20 kHz D...

Page 15: ...Notes CONNECTION AND SETUP NOTES 13...

Page 16: ...why Parasound has been a quality and value favorite of magazine reviewers sound professionals and listeners like you since we were founded in 1981 rev 0 91 2005 Parasound Products Inc Parasound Produ...

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