[dogfish]

I just picked up a 3rd-hand MINT amp, with a 12VDC wall wart. When I connect my MacBook Pro's output to the MINT, turn it on, set the volume at 12:00, and plug in my Altec Lansing im716 (68 ohm impedance), the volume goes down relative to plugging the headphones directly into the MacBook.

I.e.:

MacBook Pro -> phones = loud
MacBook Pro -> MINT at 12:00 -> phones = soft

Possibilities that occur to me are

(a) bad MacBook -> MINT cord (measured to be 0.5 ohms)
(b) bad match between headphones and amp (seems unlikely)
(c) broken amp
(d) not enough voltage
(e) ?

Any ideas (including "don't use a MINT, get a MINI^3/cMoy/E7/...") would be appreciated.

 

[ShinyFalcon]

Is your MBP's volume maxed?

 

[dogfish]

No, the MacBook is at 12:00 as well. My thought was that the amp would add boost relative to the MacBook's output if the amp was at 12:00.

But I might put this up for sale anyway -- I splurged and bought one of these for $36 yesterday. I'll have to see how it sounds.

 

[ShinyFalcon]

For all sources, the volume will have to be at max for proper amplification and to have "bit-perfect" output. I'll assume 12:00 means 50%, and you should only lower the volume if your Mint's gain is too high for your headphones.

On my machine, when I had a USB DAC that is volume controllable with Windows, it would always default to 50%. I would almost have to max out my amplifier (gain 3x) to get decent volume. I'm sure this is what you're seeing as well.

That seems like an interesting amp. Hope you enjoy it.

Edit: Just remember that 3x GAIN does not equate to 3x the loudness. 3x gain for example will boost the gain by 20 * log (gain) decibels. In this example, 3x gain is a 9.54dB boost.