[rodbac]

This is related to a previous post where I asked for predictions, so sorry if the info is redundant (I didn't get a solid answer, though):

I am listening to some HD-600s on my Corda HA-1 with my PC (Audigy) as the source.

They sound great through it, but I find it odd that I have to put the volume knob at about 80%+ to get the music to a point that I would consider loud, and it remains listenable even when it's maxed out.

Is this normal considering the impedance of the 600s? If so, why would my SuperMini drive both the 600s (high imp) and my A900s (low imp) similarly? I've been told it may have something to do with "gain", so I'm trying to educate myself on exactly what that is and how it impacts this scenario.

Thanks for any insight. -rodbac

 

[slindeman]

If you have access to a digital multimeter then you could measure the voltage of the signal the soundcard is putting out, and the signal coming out of the HA-1. You would use a 0db 1khz test tone. Then you could know for sure what is happening.

Do you have all of your volume controls set to max on your computer? I mean both in the system volume control and in the volume control of your media playing software. If not then the signal coming out of the soundcard could be way to low for a low gain amp like the Corda. The Corda HA-1 has a gain around 3. Both soundcards I have put out around 1V RMS when I max the volume controls, so the Corda could then amplify that to 3V RMS. I listen well below 1V RMS with HD600, and consider 2V RMS almost unbearable. So my guess is either 1 - You listen very loud, 2 - You haven't got the volume control turned up enough on your computer, 3 - Your soundcard has a very low output.

Hope this helps!

 

[rodbac]

Good thoughts. Thanks.

I did have all volumes maxed. I also don't normally listen to my music that loud, but once in a long while I like to crank it up a bit and that would require me to max the Corda's volume (almost), which surprised me.

Also, while I'm sure the Audigy's output is nothing to be impressed with, I also ran both phones off my Xin SuperMini and the volumes are virtually identical.

I'm baffled, but I'm sure there's an explanation. Thanks again for the info. -r

 

[lini]

As mentioned above, the HA-1 is indeed not particularly high-gain. But personally, I've only reached the max volume setting with portable sources (which usually only shell out ~ 300 - 700 mV) and high impedance headphones or especially "quiet" aad cds together - so I'm also a bit puzzled that it's an issue with the Audigy...

Greetings from Munich!

Manfred / lini

 

[rodbac]

I guess it's not so surprising by itself, but when I consider that the SuperMini drives both the A900s (40 ohm) and the HD-600s (300? ohm) at the same (or very similar) levels, I can't explain it with my level of knowledge...

 

[slindeman]

OK, I see what you are getting at now, how on the Super-mini you get the same volume from A900 and HD600 at nearly the same position on the volume knob, whereas on the Corda you have to turn it up much higher for the HD600 as compared to the A900. Is that right? I can think of 2 things off the top of my head that would account for that:

1 - Gain is much higher on the super-mini

My guess is that super-mini has a very high gain, probably 10-20. This is because it is designed for low-powered portable sources. The Corda has a gain of about 3. So what this means is that the super-mini is cramming a lot more db of gain in the same rotational distance of the volume knob. Thus a 6 db change on the super-mini may be a very slight rotation of the knob, whereas on the Corda it could very well be 1/4 of the rotation. So what you are experiencing would be perfectly normal.

Less gain is better since it is best to have the whole rotation of the volume knob at your disposal for better fine tuning of volume level, and better tracking between channels. That is why, I imagine, Jan uses a small gain for the Corda HA-1. And in most home systems such a gain is fine, because the standard CD player is 2V. In your system it appears that you need more gain than the Corda offers.

2 - Volume control taper is different on the two amplifiers

This could also account for what you are seeing. These volume controls we use are logrythmic (I can't spell that word!), and there are different tapers out there that determine how quickly the voltage ramps up as you turn the knob. So a different taper could account for the effect you are experiencing.

Hope this helps!

BTW I never needed more than a gain of 3 with HD600 and my soudcards and portable sources, so I think you are listening too loud.

 

[rodbac]

You're spot on about the situation I was trying to explain. Those explanations make perfect sense, too- thanks for the information.

Your discussion of the gain would still be true considering both phones sound *virtually* the same at the same volume setting, right? You see, it isn't that I don't have to turn the volume on the Super Mini up much- it's that I don't have to adjust it at all when switching between the two phones (they both sound like they're at the same volume with no adjustment required).

Not being entirely familiar with gain, I'm not sure if this invalidates your explanation at all (I suspect it does not), but I thought I'd just get clarification.

Thanks again!

PS- I'd also like to note that I don't really want to crank it up to full volume. It just surprised me that I could (I listen to the 600s at about half to 2/3 volume most of the time

)