Ultimately, to settle this SNR measurement kerfuffle, how do we go about getting Gene to measure a Benchmark AHB2? Seriously...I would like to see that.
Email him if you know the address.
The 128.5 dB I quoted was Stereophile's measurement not Benchmarks. According to JA he also used 100mV.
Where did you get that? Below is the link to where I read about the 128.5 dB you probably are referring to.
https://www.stereophile.com/content/benchmark-media-systems-ahb2-power-amplifier-measurements#KKllmKc7ofmgfhiA.99
The wideband S/N ratio, measured in the high-gain, stereo condition with the input shorted to ground and ref. 1W into 8 ohms, was very high, at 89.3dB. Reducing the measurement bandwidth to 22Hz–22kHz increased the ratio to 106dB, while switching an A-weighting filter into circuit increased it further, to 108.5dB. Referenced to the AHB2's clipping power of 100W, this is equivalent to a dynamic range of 128.5dB
So as ADTG pointed out before, that was dynamic range, not SNR. SNR, as measured by JA was 106 dB unweighted, and 108.5 dB A weighted, at 1W.
I know Irv doesn't believe in S&V's measurements but if we give S&V the benefit of doubt, at least we can say JA's A weighted numbers measured at clipping power of 100W are based on the same methodology as S&V, at least on paper.
Please also note that we cannot compare with JA's figures directly with S&V's on the AV8802A because once again, the Benchmark AHB2 is a power amp, not a prepro.
I was not the one trying to compare them.
Fair enough if you say so now, but in your post#205, you did say:
Here's another amp that Audioholics measured at a SNR of 90db but @ 1watt. Which I believe translates into an SNR that is markedly better than the AVR-3300." right?
The answer is, no, we
don't know that, because Gene measured the pre-out of the Denon, and the power amp out of the Yamaha at 1W. I would guess the Yamaha is better but unlikely "markedly" better. My guess is based on Gene's measurements of other gear's pre-out, such as the $7500 Denon AVP and other expensive prepros and AVRs. Even compared to the results of those so called high end gear, the Denon AVR looks pretty good, within a few dB.
I was illustrating a point. The view I had (which you again confirmed) is that you cannot compare them because they are not equivalent. It was ACDT Guy that originally compared the two disparate specs (Benchmark @1watt and Denon 3300 @Dynamic range). The point of me bringing the Yamaha into the mix was because it was measured @1 watt like JA did the Benchmark.
Agree, I told him the same, that he shouldn't compare the SNR of preamp and power amp directly. I agree you can compare JA's unweighted SNR of the Benchmark to that of the Yamaha and the two appeared to be very comparable, both low enough to be inaudible by normal people.
As noted above, I think that JA confirmed that Benchmark's published specs are accurate.
Well, 128.5 vs 132 dB, that seems pretty close, accurate or not is sort of subjective though. Regardless, those numbers are still considered excellent.
