I-Tech Series
- How can I-Tech produce so much power with only a 20A plug?
- Isn't Class-I just like other amplifier classes?
- How does I-Tech recycle energy from the load?
- Why is the I-Tech 2 ohm power number smaller than the 4 ohm power number?
- How does Crown measure power?
- What are your 20Hz to 20kHz specs?
- I heard that PFC could cause the mains to sag and shut the amplifier down. Will I-Techs PFC do that?
- What kind of filters are available in I-Tech's DSP?
- How many filters are available in I-Tech's DSP?
- How much delay is available in I-Tech's DSP?
- What are the adjustment increments for I-Tech's delay setting?
- Will other signal processors work with I-Tech? I don't want to use the on board DSP.
- What is latency, and does I-Tech have a fixed latency?
- Is post-processed audio available on the analog audio XLR outputs/loop through?
- I cannot find 26dB gain in the sensitivity menu. Is it available in I-Tech?
- What is an attenuator limiter?
- How do I set the power limiters on an I-Tech?
- Why did you put an LCD on the front?
- Do I have to use the LCD?
- How can I keep unauthorized people from tampering with my settings?
- I don't know anything about networking. Can I get I-Tech's networking up and running quickly without reading a book or taking a class?
- What happens if the network breaks or goes down?
- What happens if the amp loses digital signal?
- Are there filters available for the air inlets?
- Are the air filters required? How often should I change them?
- Why is the screen on the I-Tech 4x3500HD no longer a touch-screen?
How can I-Tech produce so much power with only a 20A plug?
The combination of Class-I technology and an innovative PFC power supply enables I-Tech to very efficiently draw power from the A/C mains and deliver it to the speakers. This high efficiency, coupled with a significant amount of energy storage, allows I-Tech to deliver high power much more effectively than conventional designs, and thus reduces the demands on the power cord.
For more information, read this short "Tech Made Simple" article.
Also, to see real current draw numbers for I-Tech, refer to the AC Power Draw and Thermal Dissipation sheets here
Isn't Class-I just like other amplifier classes?
No, Class -I amplifiers are a fundamentally different design from all other amplifier classes on the market. Crown has patented the technology behind Class-I amplifiers and is the only manufacturer in the world building this design.
For more information about Class-I, read this technical paper.
How does I-Tech recycle energy from the load?
Why is the I-Tech 2 ohm power number smaller than the 4 ohm power number?
The question may be better stated, "Why is the 4 ohm number so large?" The 4 Ohm number is so large because Class-I is not fundamentally voltage limited, unlike ALL other amplifier designs available on the market. Competitive amplifier designs require complicated multi-level (Class-H) supplies, which limit the voltage available to the output under low impedance loads. This multiple step supply topology lends itself to the typical power matrix.
The down side of Class-H is that if the program material asks for a peak higher then the rail voltage limit the amplifier will distort. In other words, headroom is limited. Class-I does not exhibit this limitation. 200V is always available to all loads. As a result the amplifier is capable of producing very high music output peaks without distorting.
Some view I-Tech's unconventional power matrix to indicate that I-Tech is not "good" or is "unstable" when driving low impedance loads. Nothing could be further from the truth. A fundamental advantage of Class-I is that it cares little about the load impedance. Pile on the speakers. I-Tech isn't afraid.
How does Crown measure power?
What are your 20Hz to 20kHz specs?
I heard that PFC could cause the mains to sag and shut the amplifier down. Will I-Techs PFC do that?
What kind of filters are available in I-Tech's DSP?
There are 64 filters total within the I-Tech DSP and they can be placed anywhere within the system. In addition to filtering,each possesses up to +/-24dB of gain.
The following filters are available:
Lowpass::Bessel 2-4,Butterworth1-4,and Linkwitz-Riley 4
Highpass:Bessel 2-4,Butterworth1-4,and Linkwitz-Riley 4
Lowshelf::Low-frequency shelving EQ
Highshelf:High-frequency shelving EQ
Lowpass EQ:Variable Q from 0.1 to 35
Highpass EQ:Variable Q from 0.1 to 35
Parametric EQ:Variable Q from 0.1 to 35
All Pass:1st and 2nd order
All Pass filters provide no gain change to the output, but provide a phase change at the selected frequency. This corrects the phase relationship of the output without a gain reduction, such as is found in other filters.
How many filters are available in I-Tech's DSP?
How much delay is available in I-Tech's DSP?
What are the adjustment increments for I-Tech's delay setting?
Will other signal processors work with I-Tech? I don't want to use the on board DSP.
Yes, any outboard signal processing can be used with I-Tech. You must remember that all DSP has its own inherent latency and this must be considered when configuring delays.
Note: As in all cases with any amplifier, make sure you re-check the EQ for the room every time the system is setup in a different location.
What is latency, and does I-Tech have a fixed latency?
The latency of a device is the amount of time it takes a signal to travel from the device's input to its output.
When using the analog inputs, latency has been measured at 1.13ms. The latency of the input/DSP section is fixed, and does not change whether using no processing or maximum- available processing.
Latency with an AES/EBU input varies due to buffering of the signal that occurs before it is sent to the input/DSP stage, and is dependent upon the input AES/EBU data rate as shown below:
AES/EBU SAMPLE RATE | LATENCY |
32 KHz | 2.744 ms |
44.1 KHz | 2.358 ms |
48 KHz | 2.275 ms |
96 KHz | 1.807 ms |
In addition to these sources of delay through the amplifier, there is the possibility of some minimal delay due to the wiring of the AES/EBU signal. The AES/EBU standard 110Ω cable has a delay of 6ns/meter. In addition, the I-Tech amplifier has a delay of ~85ns in its active digital loop-thru. To put this in perspective, a system with 50 meters of cable and sixteen amplifiers all looped through each other would have a delay at the last amplifier of 1.575us. This is equivalent to a delay of less than one-quarter inch. This additional source of delay will be inconsequential in almost all systems and can be ignored.
Is post-processed audio available on the analog audio XLR outputs/loop through?
I cannot find 26dB gain in the sensitivity menu. Is it available in I-Tech?
Yes, many different sensitivities and gains are available depending on the setting of the max input level switch. Refer to the I-Tech Application Guide for a complete list of all 149 sensitivity / gain settings.
To set the I-Tech amp for 26dB gain, change the max input level switch to 20dBu using IQwic or the front panel display. Upon returning to the sensitivity menu you can set the gain to 26dB.
What is an attenuator limiter?
How do I set the power limiters on an I-Tech?
Why did you put an LCD on the front?
- To provide real-time diagnostics: thermal headroom, load monitoring, etc.
- To provide much of the IQ Network capabilities without the need to set up a network.
- To make monitoring all this information easy.
Do I have to use the LCD?
How can I keep unauthorized people from tampering with my settings?
I don't know anything about networking. Can I get I-Tech's networking up and running quickly without reading a book or taking a class?
What happens if the network breaks or goes down?
What happens if the amp loses digital signal?
Are there filters available for the air inlets?
Are the air filters required? How often should I change them?
Why is the screen on the I-Tech 4x3500HD no longer a touch-screen?
Due to supplier issues with quality and delivery, we have removed the touch-screen capability from the I-Tech 4x3500HD. Several of the display screens and menus have been updated to accommodate this change. Performance of the I-Tech 4x3500HD has not been impacted by this change in any way. If you have any questions regarding this issue, please contact our Technical Support team at support@crownaudio.com.