How good and powerful is the internal headphone amp on Benchmark DAC1? - Page 2

Errr, the guys at Benchmark probably knows better than be but I don't know where the the sales rep pulled out those figures.

According to the spec sheet, the Benchmark current limit is 250 mA, not 800 mA and there's no way you can get 20 Vrms out of 18 V rails, at max you get 12 Vrms.

Still, I stand by my earlier calcs which where confirmed by Elias Gwinn from Benchmark, with the jumper set on 0 dB, you can get 113.5 dB musical peaks with the HE-6, which should already be an ear splitting level.

I just checked the spec sheet of the original DAC1: http://www.benchmarkmedia.com/sites/default/files/documents/DAC1%20Manual%20RevN_0.pdf

Yes, it's set the its equivalent to the 0 dB setting on the HDR,

It means that with a 0 dBFS signal being fed from the DAC, the amp will output 21 dBu = 8.7 Vrms = 24.6 Vp-p.

It would be make sense to publish that spec when there is a situation where the amp section will be fed that signal, maybe I'm reading too much in the spec, but I don't think so.

Also, engineering something for more current and voltage capacity ie. extra headroom to then saddle it with a 10 dB attenuation (and make that extra headroom unavailable) simply doesn't make sense, over-engineering costs money, they would have designed a less powerful amp in the first place. Besides, as far as I remember, the -10/20 db jumpers where added after some people complained that there was too much gain with high sensitivity headphones for the original DAC1, not the other way around.

No damage, the M50 is a very easy load to drive.

Quote:

Originally Posted by cactus_farmer 

The specs say that the internal headphone amp of the Benchmark drives headphones upwards of 60ohms.

 

If I plug in an Audio Technica M50 to it (this is only 32ohms) - will I damage either the amp/dac or the headphones?

 

(Assuming I keep the volume reasonable, of course!!)

You will not damage the headphone amp, and if you keep the volume reasonable, you will not damage your headphones either.   The DAC1 is designed to drive two pairs of 60-Ohm headphones or one pair of 30-Ohm headphones.

Best,

Elias

Quote:

Originally Posted by cactus_farmer 

Basically, we know the headphone amp in both the original DAC1 and the DAC1 HDR are exactly the same (Benchmark's HPA2 headphone amplifier).

 

But if there are two headphone amps that are exactly the same, and one version of it has adjustable gain and one doesn't, do you assume that the one without adjustable gain has its built-in non-adjustable gain set equal to the highest gain selection of the version with adjustable gain (in this case '0dB'), equal to the lowest gain selection of the version with adjustable gain (in this case '-20dB) - or somewhere in the middle?

 

Or you just can't make any assumptions?

This is correct.  The HPA2 in the original DAC1 has the same gain range as the highest range in the other models.

Best,

Elias

How good does the amp match up with Denon D7000 or HD650?

Quote:

Originally Posted by dukeskd 

How good does the amp match up with Denon D7000 or HD650?

you can turn the volume pretty loud but i dont know if i really like the sound quality, sounds too digital? i cant explain

i have grado rs1 and er4s

for me personally i like the sound whole alot better though asgard or some other headphone amplifier

Thats strange because of the really low impedance output on the DAC1, it should be marvellous with low impedance headphones. I mean, that is, technically, however sometimes ears prefer whatever they want.

I’ve been using the DAC1 headphone out occasionally with a modified Grado 225, GR10 IEM and Sennheiser HD600. Honestly, it sounds very good to me. strong bass, clean highs, lots of detail. It doesn’t provide any sort of “lush” EQ that boosts lower midrange but the midrange headphones I have sound great out of it. 

Unfortunately, I no longer have any high end dynamic headphones (HD800, D7000, RS1, etc) to test on it (sold them all) but I’m getting a GS1000 next week and will be trying it out on the DAC1 - gotta see if my ears scream out for a separate amp or not.

i just found out something

i think i much preferred the sound of my headphones on asgard because i connected it via dac1 xlr outputs

i just tried er4s and rs1 directly on xlr outputs with an xlr to 1/4 adapter instead of headphone out and it actually sounds almost as good as asgard

it sounds much clearer. probably because less circuit?

but thats about it. i mean it sounds clearer but i still like listening through asgard better

its like it adds more dimensions to the sound

so when you listen to headphones on dac1 directly i would recommend xlr outputs instead of headphone out