51 (edited by N00b 2019-07-22 17:28:58)

Re: ADI-2 DAC: settings with power amp

sq143 wrote:

Can someone please recommend how to ideally set input gain level of Benchmark amplifier AHB2 for (balanced) connection to ADI-2 DAC?

The AHB2 has three gain levels Low-Gain = 22 dBu (9.8 Vrms), Mid-Gain = 14.2 dBu (4 Vrms), High-Gain = 8.2 dBu (2 Vrms). Benchmark recommends to use the lowest gain level possible.

However, with the low-gain setting the max volume achieved with ADI-2 near 0 dbFS is a little bit low. With the AHB2 set to mid-gain volume is ample, but with auto ref on the 19 dBu output level of the ADI-2 exceeds the 14.2 dBu input level of the AHB2.

Thank you,
Sebastian

Hi Sebastian,

From what you say, I would put it at mid-gain. You will have headroom for the tracks who are recorded low: even if the volume pot of the ADI is set to 0 dB fs, the actual output will only be at 19 dBu when the tracks are recorded high and reach 0 dB fs.

I have old classic CD's or some music online whom levels never reach the 0 dB fs... You'll need headroom for those. smile

ADI-2 DAC - Neumann KH 310 A monitors

52

Re: ADI-2 DAC: settings with power amp

sq143 wrote:

Can someone please recommend how to ideally set input gain level of Benchmark amplifier AHB2 for (balanced) connection to ADI-2 DAC?

The AHB2 has three gain levels Low-Gain = 22 dBu (9.8 Vrms), Mid-Gain = 14.2 dBu (4 Vrms), High-Gain = 8.2 dBu (2 Vrms). Benchmark recommends to use the lowest gain level possible.

However, with the low-gain setting the max volume achieved with ADI-2 near 0 dbFS is a little bit low. With the AHB2 set to mid-gain volume is ample, but with auto ref on the 19 dBu output level of the ADI-2 exceeds the 14.2 dBu input level of the AHB2.

Thank you,
Sebastian

The "gain levels" are not the gain but the input level corresponding to nominal power at the specified gain. The AHB2's output level at nominal power is about 31 dBu for stereo and 37 dBu for bridged mono. For stereo, low gain is 9 dB, mid gain is 17 dB and high gain is 23 dB.

The ADI-2 DAC's 19 dBu at 0 dBFS correspond to half of nominal power for the AHB2 at low gain. If that is not loud enough for you, you would most likely be better off with a more powerful amplifier rather than overdriving the AHB2.

More under "specifications" here: https://benchmarkmedia.com/products/ben … -amplifier

Re: ADI-2 DAC: settings with power amp

The "gain levels" are not the gain but the input level corresponding to nominal power at the specified gain. The AHB2's output level at nominal power is about 31 dBu for stereo and 37 dBu for bridged mono. For stereo, low gain is 9 dB, mid gain is 17 dB and high gain is 23 dB.

The ADI-2 DAC's 19 dBu at 0 dBFS correspond to half of nominal power for the AHB2 at low gain. If that is not loud enough for you, you would most likely be better off with a more powerful amplifier rather than overdriving the AHB2.

More under "specifications" here: https://benchmarkmedia.com/products/ben … -amplifier

Thank you N00b and jiw for your opinion.

@jiw: Soundwise I am very happy with the AHB2 and the last thing I want is a different amp :) On the other hand, I do not intend to overdrive the amp. As long as the output level of the adi-2 does not exceed the 14.2 dBu I will be fine with the mid-gain setting of the AHB2, don’t you think? I could even fix the output level of the adi-2 to 13 dBu, but I’d rather use the auto reference function.

54 (edited by jiw 2019-07-22 19:40:18)

Re: ADI-2 DAC: settings with power amp

Yes. The AHB2 also has integrated protection circuitry. As long as the centre LEDs stay off, your levels should be fine.

Unless you have already done so, you could also get another AHB2 and run each of them in bridged mono. That would likely quadruple the power and gain you 6 dB of SPL while mid-gain on your (presumed) single AHB2 gains you about 3 dB of SPL.