The Lavry DA11: For your ears only

[Dan Lavry]

Originally Posted by Anders

Thanks for the answer about voltage but I also wonder about output impedance. Is it the same output impedance on the headphone output and the XLR outputs when configured as single-ended? And I assume that the impedance is different when using the rear outputs as balanced compared to SE.

The relevance of the output impedance is that it affects the frequency response of the headphone (if the headphone impedance is frequency dependent and that is common).

The output impedance of the real panel XLR's is 75 Ohm resistive (not inductive or capacitive), for each pin (pin 2 and pin 3).

You are correct to state that the impedance of the source, driving a signal into a non resistive load (headphone), does alter the flatness response. If a headphone were purely resistive load, then a resistive source will only cause attenuation, and the impact would be the same across the audible frequency range. But headphones are not a pure resistive load.

As a "rule of thumb", a lower load impedance and a higher headphone impedance tend to minimize the flatness response issue. Also, as a rule, a resistive source is better then inductive or capacitive.

The XLR outputs heave a limited current drive. They offer a lot of voltage. They are not meant to drive low impedance loads (they can drive 300 Ohms OK, but not much lower). The 75 Ohms is a pretty standard thing to do - the purpose is to enable driving long lines that end up looking like capacitive loads at audio frequencies. The series resistance "buffers" that capacitive load to prevent oscillations.

For a headphone output, the issue is not about oscillation prevention. The cables are not very long to start with, and different headphone introduce a very wide range of load impedances. Indeed, with a very low headphone impedance, a 75 ohms in series is not the way to go. Close to zero Ohms provides a near flat response...

Regards
Dan Lavry

[Speederlander]

*edit: removed*

[reverendo]

I've just recently heard about the DA11. It seems to fit in a very small niche of product I've been looking for: a dac with pre-amp with remote control and balanced outputs that I could use to drive an amp directly, preferably with balance control. I am not interested in the Benchmark HDR and initially would tend to classify the DA11 in the same league, but for different target group. I will refrain from doing that and try to get a hold of one. Can anybody tell me if I can listen to one here in Brazil?
I've been looking at the PS Audio PerfectWave DAC, the Audio Aero Prima DAC (discontinued; actually the DAC of the Capitole); the Cyrus XP DAC and a few others. Has anyone who knows the Lavry DA11 had experience with one of these that I just mentioned?
I would be very curious about knowing how it would compare to my North Star 192MkII DAC sonically. Has anybody here heard both?
Thanks a lot in advance
best regards
André