Owner's manual
I-Tech HD Series Power Amplifiers I-Tech HD Series Power Amplifiers
page 34
page 35
Operation ManualOperation Manual
Optimized system gain structure maximizes signal to noise within the sys tem. Adjusting your amplifier to fit
within an optimized system gain struc ture is accomplished by properly setting both the sensitivity and attenuation
controls within the amplifier. I-Tech amplifiers offer 149 sensi tivity and gain settings allowing very fine adjustment
of the amplifier’s gain and voltage sensitivity. The Appendix section of the I-Tech Application guide (online at
www.crownaudio.com) provides charts with sensitivity in volts and gain in dB for each sensitivity/gain setting.
With other amplifiers, it is often necessary to apply attenuation in order to achieve the desired sound pressure
level. Large amounts of attenuation are not necessary with I-Tech amplifiers and can, in fact, degrade
performance. The attenuation adjustment should only be used for small (3 dB) or tempo rary adjustments in
amplifier gain. Instead, set the sensitivity/gain of your I-Tech amplifier so that you can achieve the desired output
with the attenu ators at or near 0 dB.
Example: Suppose that you are using an I-T9000HD with the sensitivity/gain set at 1.4V/37.1 dB. After optimizing
the gain structure of the rest of your system you find that attenuating the amplifier by 10 dB produces the desired
loudness. The same output level, with improved signal-to-noise ratio and headroom, can be achieved by using 0
dB of attenuation and by setting the amplifier sensitivity/gain to 5.81V/27.0 dB (37 dB – 10 dB = 27 dB).
Note: as indicated in the online appendix, the list of possible sensitivity settings is different for each position of
the max input setting. If, while adjusting sensitivity/gain in your amplifier, you do not find the setting you need, try
changing the status of the max input setting and search again.
Setting Sensitivity for Best Gain Staging
Crown amplifiers are quality units that rarely require ser vicing. Before returning your unit for service, please con-
tact Crown Technical Support to verify the need for servicing.
This unit has very sophisticated circuitry which should only be serviced by a fully trained technician. This is one
reason why each unit bears the following label:
CAUTION: To prevent electric shock, do not remove covers. No user serviceable parts inside.
Refer servicing to a qualified technician.
Complete the Crown Audio Factory Service Information form, in the back of this manual, when returning a Crown
product to the factory or authorized service center. The form must be included with your product inside the box
or in a packing slip envelope securely attached to the outside of the shipping carton. Do not send this form
separately.
Warranty is only valid within the country in which the product was purchased.
Service
International and Canada Service
Service may be obtained from an authorized service cen ter. (Contact your local Crown/Amcron representative
or our office for a list of authorized service centers.) To obtain service, simply present the bill of sale as proof of
purchase along with the defective unit to an authorized service center. They will handle the necessary paperwork
and repair.
Remember to transport your unit in the original factory pack.
US Service
Service may be obtained in one of two ways: from an authorized service center or from the factory. You may
choose either. It is important that you have your copy of the bill of sale as your proof of purchase.
Service at a US Service Center
This method usually saves the most time and effort. Sim ply present your bill of sale along with the defective unit
to an authorized service center to obtain service. They will handle the necessary paperwork and repair. Remem ber
to transport the unit in the original factory pack. A list of authorized service centers in your area can be obtained
from Crown Factory Service, or online from
http://www.crownaudio.com/support/servcent.htm.
Factory Service
Crown accepts no responsibility for non-serviceable product that is sent to us for factory repair. It is the owner’s
responsibility to ensure that their product is ser viceable prior to sending it to the factory. Serviceable product list
is available at
http://crownweb.crownintl.com/crownrma/.
For more information, please contact us direct.
A Service Return Authorization (SRA) is required for product being sent to the factory for repair. An SRA can be
completed online at www.crownaudio.com/support/factserv.htm. If you do not have access to the web, please call
Crown’s Customer Service at 574.294.8200 or 800.342.6939 extension 8205.
For warranty service, we will pay for ground shipping both ways in the United States. Contact Crown Customer
Service to obtain prepaid shipping labels prior to send ing the unit.