Power Amplifiers Lexicon ZX-7 Multi-Channel (300 watts x 7) Power Amplifier
| Lexicon ZX-7 Multi-Channel (300 watts x 7) Power Amplifier |
| Written by John E. Johnson, Jr. | ||||
| Monday, 21 January 2008 07:52 | ||||
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On the Bench  At 20 volts, THD+N was 0.004%. This is 50 watts of power, which probably covers 99% of the signals we listen to.  At 10 kHz and 5 volts, THD+N rose to about 0.01%.  And at 20 volts, distortion was 0.144%. Having more distortion at higher frequencies is the way most amplifiers perform.  IMD at 5 volts into 8 ohms was less than 0.04%.  And at 20 volts, IMD was actually less, at 0.014%. If you look at the peaks around the 2 kHz fundamental, they are higher than the ones in the 5 volts graph. The reason the distortion number is less is because the fundamental is higher in relation to the distortion peaks than in the 5 volts test. Note also that there are more IM peaks around the 4 kHz, 6 kHz, 8 kHz regions (multiples of 2 kHz) than in the 5 volt test, but IM measurements only take into account the peaks at ± 250 Hz around the fundamental (2 kHz), so this is why showing the actual graph is important, rather than just giving a number.  For THD+N vs. Frequency into 8 ohms (1 kHz set to 5 volts or 20 volts output), distortion for both voltages stayed below 0.05% from 10 Hz to 4 kHz, then rose.  At 4 ohms, the distortion at 20 volts and 20 kHz was at 0.5%.  The THD+N vs. Power Output measurement shows that the ZX-7 delivered 400 watts into 8 ohms before clipping (defined as 1% THD+N), and 600 watts into 4 ohms. At the spec of 300 watts into 8 ohms, distortion is 0.01%.  The measured Frequency Response was 10 Hz – 50 kHz, - 1 dB. Depending on the output voltage, the response rolled off. Notice that at 20 volts, it drops suddenly at about 72 kHz. Apparently, as voltage rises, the ZX-7 is designed to limit the frequencies out of the audible band.   Conclusions Comments (18)
Lets see a head to head shoot out with the Lexicon and the Outlaw Model 7900
written by Rudy , January 22, 2008 Is 3x the price really worth it???
Lexicon zx-7
written by dholaday , January 22, 2008 Or a head-to-head with the ATI-3007. Wouldn't surprise me if ATI were making all three amps
I AGREE
written by RANDY , January 22, 2008 I AGREE WITH THE OTHER POST. HEAD TO HEAD WITH OUTLAW 7900 WILL GET MY ATTENTION.
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written by JEJ , January 23, 2008 We will request the Outlaw 7900 and see how it performs in comparison.
Lexicon ZX-7
written by Jaime , January 24, 2008 My recollection is that Lexicon amps were built by Bryston. I have no idea if this is still true. I last heard one before Bryston came out with the ST circuit many years ago and it sounded similar to my Aragon 4004 Mk.II (but not as dark on top).
Sunfire vs. Lexicon
written by ed , January 24, 2008 Would also like to see a comparison between the Sunfire 7400 and Tex.
Looks like Outlaw 7900 to me
written by JOsh , January 24, 2008 Looking at the specs on both, it looks like the same amp rebadged...Same power and IMD specs, same weight, very similar measurements.
Lexicon/Bryston
written by tonygeno , February 03, 2008 Bryston stopped making Lexicon amps two generations ago. The last generation of Bryston amps was made by Crown (a Harman company). This new amp is definitely not made by Crown.
Some Helpful Info for You All
written by Adam , February 09, 2008 The amp is manufactured by ATI but is based solely on Lexicon's design. Its also NOT $10k retail as advertised. Its $7,999. Still not inexpensive, but this is truly a reference piece that will be the last amp the buyer will ever want or need.
How long before a heaqd to head shoot out would happen?
written by Bernie , February 18, 2008 Just wondering if it will happen at all, some companies don't like comparisons...
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written by JEJ , February 18, 2008 We are requesting the Outlaw amplifier, but it takes time for the request to be processed, for it to get here, and then be tested.
Zx 7
written by This e-mail address is being protected from spambots. You need JavaScript enabled to view it , February 25, 2008 I don't have a review but a question. I just bought the amp (Zx 7). Could someone suggest a tuner, DVD/CD, subwoofer and cable wires? My processeor is the MC 8 by Lexicon. Did I do the right combinations?
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written by JEJ , February 28, 2008 Peter Tribeman, President of Outlaw, called me this morning (February 29) and said that Outlaw respectfully declines to send the model 7900 for review.
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written by JEJ , February 28, 2008 To aachampong: Certainly, I would suggest the Oppo DV-983H when it becomes available on March 10.
Misses Specs
written by JS , March 06, 2008 This very expensive amplifier misses its specifications by a wide margin. While specs may or may not be really important the distortion of this device is really excessive for a solid state product - plus if a company gives a spec they should meet it. Look at almost any other amplifier reviews here or other places and you won't see solid state amps with this much distortion at higher frequencies. I wish someone would post an interior shot of the amp. My guess is that it is exactly the same as an Outlaw unit which is unfortunate since Outlaw has generally provided much better products. You can see an interior shot of Outlaws 300 watt amp on their website. Write comment
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