AVP-A1HDCI Measurements and Analysis

Frequency Response & Distortion

Denon AVP-A1HDCI Preamp Frequency Response

I measured a ruler flat frequency response with a -3dB point around 200kHz in all 2CH stereo modes (ie. Pure direct, Stereo direct). The AVR-5308CI measured similar bandwidth as well.

Denon AVP-A1HDCI Preamp FFT Distortion Analysis

With 200mVin, I set the master volume until I reached 1Vrms out of the preamp. The FFT plot was so clean that I couldn’t measure any appreciable distortion products until I ramped up the signal level to drive the output to nearly 6Vrms. At that point, I measured (15.268+ 80.424)dBv = 95.69dB or 100*alog^-1(-95.69/20) = .0002% THD + N which is among the lowest distortion I’ve ever measured in a preamp regardless of price. The AVR-5308CI didn’t compete here as the measurable harmonics were about 6dB worse driving an output of 1Vrms than they were on the AVP-A1HDCI outputting nearly 6Vrms.

I measured about 15.5dB of gain via the balanced and unbalanced outputs of the AVP-A1HDCI preamp (with source level set to 0dB on the particular input and channel trims set to 0dB). The preamp has plenty of output capability as evident by the following measurements all taken @ < 0.1% THD +N:

Balanced:

• Vmax out = 14Vrms
• Vmax In = 15.5Vrms

Ubalanced:

• Vmax out = 7.2V (3.8Vrms was the limit on the AVR-5308CI)
• Vmax in = 8V

Though this is more than enough output to drive any power amplifier to maximum capability (THX amps require about 2Vrms to reach full power) the gain is structured a bit low requiring the input signal to be larger than normal to reach high output levels. This explains why I always had to peg the volume near max on low compression sources. I personally wished Denon would have followed a more common gain structure in this processor like I’ve seen on other A/V products as follows:

• Unbalanced: Av = 17dB
  
• Balanced: AV = 23dB (6 dB higher than unbalanced)

SNR

With 200mVin and 1Vout, SNR = 95dB (unweighted) in pure direct mode. This is an excellent measurement, and with its ample drive capability proves the AVP-A1HDCI is a top notch preamplifier that will satisfy even the most critical audiophile.

Crosstalk

Denon AVP-A1HDCI Crosstalk Measurement at Full Rated Power vs Frequency

Running a full range frequency sweep from the preamp, it displayed superb crosstalk measurements between the front left and right channels of over 108dB @ 1kHz with a slight rise with increasing frequency due to capacitive coupling and actually no increase at low frequencies indicating no magnetic coupling was present. The separated power supplies Denon boasts in this design truly show off their benefit via this measurement as evident when I measured about 20dB worse crosstalk on the AVR-5308CI under similar test conditions. I did note that when I engaged the bass management circuitry, the crosstalk measurement level went up about 10dB which is likely because of the added trace paths and associated circuitry but at these low levels it’s more academic than a concern of audibility.

Measurement Wrap Up

Every measurement I made of the AVP-A1HDCI was benchmark. This processor has one of the cleanest preamp sections I've seen and certainly has a top notch DAC section that few products regardless of price can compete with. Whether you're listening to redbook CD's, DVD-A, SACD or the latest hidef formats such as Dolby TrueHD and DTS HD, you can be assured that the AVP-A1HDCI will process those formats with the highest resolution possible.