VAC 160i, any experiences

I've owned two Avatar's Dave, they were dead quiet and extremely musical. VAC must not have paid Stereophile enough $$$. Who cares what some glossy review says?

Stereophile's John Atkinson loved Mark Levinson gear, which I thought sounded dreadful. It's MY money, I'll buy what I want, not what some glossy rag tool tells me to want.

Fair enough....go with your ears. I geuss it was the S/N of 69db that stood out to me...really old school, high noise design. Good luck!

I do understand that some folks let pictures or specifications or ideology determine what they think will sound best. Many companies will even employ 'tricks', like using negative feedback loops, to make specs more attractive for their spec buyers. That's never been Kevin's game. He is much more interested in how it sounds to human ears then how it's sound as measured by test instruments.

I just looked at my VAC preamps specs, and it also has listed residual noise at 69 dB. I've owned preamps from BAT, CJ, ARC, Krell, ML, Jeff Rowland, Cary, etc. And while I won't say that this is the quietest preamp I've ever heard, it's noise is a none issue in the real world. I have owned preamps that were dead quiet with the volume knob turned all the way up and no music playing, unfortunately, they did not sound as good when music was playing.

So should we buy equipment for how good it sounds when music is NOT playing? I think not.
Of course, YMMV.

Several things should be realized about that 69 db spec, which is presented a bit more clearly in the Avatar manual, on page 12.

1)It applies to the amplifier output when the built-in phono stage is being used. The number would be about 6 db better if a line-level input were being used.

2)It can be calculated from the numbers shown that the 69 db is referenced to an output level of about 10 watts into 8 ohms. Many manufacturers reference signal-to-noise performance to maximum rated output power. Referencing the number to the amp's 60W rating in UL mode would add another 8 db of improvement.

3)There is no mention of the numbers being weighted in any manner, such as with A-weighting. The corresponding specs that most manufacturers supply are based on that or other weighting techniques which de-emphasize noise components at high and low frequencies, to which our ears are relatively insensitive. A-weighting will commonly make S/N numbers look something like 10 or 15 db better.

It can be calculated that the VAC numbers and the unweighted line-level S/N numbers presented by TJN in the Stereophile review are approximately consistent, when adjusted to reflect the fact that the output reference level used by TJN was only 1W, rather than 10W. That would seem to confirm that the VAC numbers are unweighted. And in fact TJN's measured numbers (shown in the fourth paragraph of the measurements section of the review), are somewhat better than spec'd. Based on a worst case assumption that the 1.5 mv residual noise spec'd for the power amp section sums together with the 0.1 mv spec'd as being contributed to output noise by the line stage, and referencing to 1W into 8 ohms, calculates to an S/N of 65 db. All of TJN's numbers are better than that.

Is it the quietest amp ever made? Certainly not. But as stated in the review:

The background noise grew louder as I advanced the control past midnight toward full power, sounding in CD mode like a grounding hum, and in phono mode like hashy surf. However, given the Avatar's high voltage gain—TJN measured a maximum of 35dB—11 o'clock was the loudest I ever cranked the system, and that was plenty loud, plenty clear, and safely below the audible noise range.

Regards,
-- Al

I've owned a Ref 5 and the krell KCT and 202Evo plus a BAT 5SE and well....a whole lot of preamps. One should have low noise and hum as a fundemental design principal and then build upon that for musicality. Ya don't need bad numbers to get great sound. But it's all subjective at some point anyway, so grab a beer and sit back to enjoy what you have:)

IS sigma 160i class A or B?

Guys,

Just wondering if any of you are using ceramic tube dampers and on which tube?

Thanks,

The key to VACs is their Lundahl output transformers. None better.

Anyone know what the vac phono mc load is ....100 ohms or 200 ohms