Power Amplifier Reviews

Krell Chorus 7200 Amplifier Test Bench

Test Bench

Two channels driven continuously into 8-ohm loads:
0.1% distortion at 192.4 watts
1% distortion at 215.7 watts

Five channels driven continuously into 8-ohm loads: 0.1% distortion at 134.4 watts

1% distortion at 163.0 watts

Seven channels driven continuously into 8-ohm loads: 0.1% distortion at 133.9 watts

1% distortion at 162.4 watts

Frequency response RCA input: –0.03 dB at 10 Hz
+0.00 dB at 20 Hz

–0.12 dB at 20 kHz
–3.16 dB at 50 kHz

Frequency response XLR input: –0.02 dB at 10 Hz
+0.01 dB at 20 Hz
–0.14 dB at 20 kHz
–3.33 dB at 50 kHz.

This graph shows that the 7200’s amplifier channel 1, with two channels driving 8-ohm loads, reaches 0.1% distortion at 192.4 watts and 1% distortion at 215.7 watts. Into 4 ohms, the amplifier reaches 0.1% distortion at 319.6 watts and 1% distortion at 368.4 watts. An input level of 148.0 millivolts was required to produce an output of 2.83 volts into an 8-ohm load, indicating an overall gain of +25.66 decibels using the RCA input. When using the XLR input, a level of 147.7 millivolts was required to produce an output of 2.83 volts into an 8-ohm load, indicating an overall gain of +25.68 decibels.

THD+N from the amplifier was less than 0.008% at 1 kHz when driving 2.83 volts into an 8-ohm load using the RCA input. When using the XLR input under the same conditions, THD+N was less than 0.009%. Crosstalk at 1 kHz driving 2.83 volts into an 8-ohm load was –101.24 dB channel 1 to channel 7 and –104.44 dB channel 7 to channel 1 using the RCA inputs and –106.37 dB channel 1 to channel 7 and –104.85 dB channel 7 to channel 1 using the XLR inputs. The signal-to-noise ratio with an 8-ohm load from 10 Hz to 24 kHz with “A” weighting was –106.12 dBrA using the RCA input and –106.21 using the XLR input.—MJP

COMPANY INFO
Krell Industries, LLC
(203) 799-9954
krellonline.com
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COMMENTS
willieconway's picture
Submitted by willieconway on February 27, 2015 - 5:39pm

I'm genuinely curious so please don't take this as a trolling attempt:

To the best of my knowledge an amplifier's function is to take a weak (source) signal, amplify it, and pass it on. Now, if that's the case, how on earth can one amplifier improve (or even just impact) imaging better than any other amplifier in any other way than applying more or less power?

David Vaughn's picture
Submitted by David Vaughn on February 28, 2015 - 9:09am
Willie...thanks for the question. Every amplifier has its own signature sound, depending on the topology used in the electronic path. Some do it much better than others, that's for sure, but a "bad" amplifier will introduce noise and distortion into the signal that will get "amplified" with a higher output. Throw in a week power supply/transformer and you have a poor performer. If the design is done right, like this one here, you get a very clean rendition of the original signal. Does that make sense?
bootman's picture
Submitted by bootman on March 7, 2015 - 12:11pm

How can you give this unit 5 stars when it can't make its own rated spec of 200W per channel?
These honestly look more like AVR class amp benchmarks than those of a Krell.

David Vaughn's picture
Submitted by David Vaughn on March 7, 2015 - 7:17pm
Bootman,I don't see the benchmarks until you do. All of my evaluations are done without knowing how it measures. All I can tell you is despite it falling just short of its rated spec, the amp sounds outstanding. As for calling it an AVR class amp...I beg to differ. Try and find a local shop that can audition it for you and you'll hear what I mean.
bootman's picture
Submitted by bootman on March 16, 2015 - 1:24pm

Ok I'll admit the AVR comment is a bit harsh.
I guess I'm not used to seeing Krells measure so short on rated power.
When I hear Krell I envision KRS monoblocks driving Scintillas.
:)

Esoteric's picture
Submitted by Esoteric on March 17, 2015 - 9:54am

Thanks for your insight David. Since you have reviewed both this and the ATI AT-6005, how would you compare the two?

Tetto's picture
Submitted by Tetto on March 27, 2015 - 4:27pm

Any comments from Krell why this unit can't make its rated output? Is this an isolated case for this unit? Or is it true for the whole chorus line?

karlosTT's picture
Submitted by karlosTT on September 2, 2016 - 1:19pm

I think it is disappointing that Krell thought it necessary to play the same marketing game as the AVR manufacturers, ie quoted power through 1 channel only. A company of this stature shouldn't feel the need to play such "power games".
That said, it doesn't really impact on the 7200's value for money - as such. In total, it produces around 0.94kw of pure class A. In that respect it may well be absolutely unique. The high-end AVR's produce around 1kw (of class D) after you've cut through the marketing gumf, whilst the top-rated multi-channel power amps serve up around 1.4kw of class A/B.
So it depends what you're looking for and what your priorities are. I think we'd all appreciate greater honesty, but at the end of the day power and sound quality simply don't correlate.

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