Measurements Advance Paris A12
Contents
We drive the power amplifier analog from the Prism. So we have a 100% analog loop through the Advance A12 in this measurement.
The strength of the Advance Paris is in the amplifier. It is just exceptionally well designed. The noise floor is relatively low at -110dB. We estimate that the tubes push it up slightly. But that’s a guess. We can see from the spectrum that Advance Paris uses relatively high feedback (few harmonics visible). In short: a clean image (0.012% THD+N at 1 watt / 8 Ohms). At 10 watts, the noise floor drops slightly, but the THD+N is the same. At 50 watts, the noise drops some more, but we see that the harmonics rise considerably. The THD+N rises to 0.09%.
Frequency response is quite neat. We estimate that the bandwidth is wider than we can measure with the Prism (which stops around 90 kHz). The bass end drops off slightly from 30 Hz. With most speakers, this is not audible. If we measure harmonics up to 500 kHz on the spectral analyzer we don’t see anything crazy either. So the output is pretty clean.
Looking at the power measurements, we see around 255 watts into 4 ohms before the distortion shoots up. At 1%, that would come to 280 watts approximately. In 8 Ohms, we measure 173 watts at the tipping point and almost 200 watts at 1%.
The residual measurements show a neat result (no harsh / jagged distortion) for an amplifier in this class. We’ve certainly seen worse. By the way, what is striking is that we do not see a difference between high- and low-bias in any of the measurements. We wonder if it’s our sample (we have a very early model) or if it’s just not measurable.
Measurements DAC board
We measured the dac board in various ways. We tried coax, aes and optical and measured through the pre-out, rec-out and speaker out.
There is no big difference in the results, which in itself is positive, were it not for the fact that we believe the amplifier is of a higher level than the dac in this Advance Paris A12. This is especially visible in the harmonics and channel separation.
We find the results of the dac measurements frankly not really impressive. Crosstalk is just high at -69dB through the speaker out. An average dac sits at almost double that: 110 to 120 dB. So there’s something going on there… we asked Advance for feedback and they shared their measurements. They almost match our measurements. So they are correct. The linearity measurement shows it’s fine from -110dB. There is nothing wrong with that.
A dynamic range of 96 dB is not shockingly good, but not bad either (about 16 bits). In this class, however, there are models that measure better than that. THD is average; around -90dB and interface jitter sits at 91ps. That, in turn, is above average in this class.
What troubles us a little is that a dac around €1000 measures significantly better than this in really all areas. Advance has obviously invested in the amplifier. Which therefore performs excellently. Both sound-wise and measurement-wise.
It seems that Advance Paris has opted for lots of connectivity on the digital level, but not necessarily for a high-quality solution. What we suspect is that the power supply for the digital board has been an afterthought (lots of 50 Hz harmonics).
