[GTanaka]

Hey hey Head-fi folk! I haven't posted here in a really long time, but a question just came to mind dealing with my mini-amp/can combo and it got me thinking...The DT770Pro 80s have a power handling capacity up to 100 mW, but the PA2V2 is capable of up to 200 mW RMS (?)

I've heard that these cans and this amp make a pretty good budget combo, but does this power difference mean that if I turn my music up too high my cans will start deteriorating heavily or even blow out? The reason I ask this is that I swear my bass isn't as solid as it once was, but that could just be them burning in as I did leave the combo playing for a good 6 hours or so one day. On that same day, however, I found out one of my mp3s was severely unbalanced in volume and was blasting the cans so loud I could hear them while they were on the ground and I was watching a movie about 8 ft away with some cheap headphones on my computer. I was just wondering if I should be worried or not...

EDIT: I just did a quick tone test (by ear) through the amp and phones, and I can't hear 5 Hz, but I can hear 10Hz through 15,000Hz, and then I can't hear anything again. odds are, my ears just can't pick up anything past that, but if this helps at all let it be.

PS: I am 18 years old, and frequent concerts about once every other month. Otherwise I do not live in a loud area or visit loud places in particular.

 

[AudioCats]

you probably want to try another amp and see if the same thing happens. Just use a stereo receiver's headphone jack will be fine for quick comparison.

PA2Va uses only two AA batteries and if they are the rechargable type, only 2.4V total, which means it won't do much to the higher impedence phones....

 

[GTanaka]

By "higher impedance," do you mean phones like the 250 Ohm model?

 

[AudioCats]

I meant like 100 ohm and such. The chip used in PA2VA was probably originally intended for the standard 16 or 32 ohm phones (most mass market phones are like that). With 2.4V supply, the highest output swing is probably +/- 0.7V before sound quality starts to get bad. That is 1.4v peak to peak, which is like what, 1VRMS? that will only drive about 10mW into a 100 ohm phone. The chip can produce higher output voltage but the distortion level will go higher really quick.
Now for a normal 32 ohm phone the power will be more like 30mW so will be adaquate. I think the 200mW output rating is for using really low impedance speaks and at a distortion level of 10% or so.

 

[GTanaka]

Sorry to be n00bish, but I only understood about half of that ^^;. Put simply, though, I'm in safe water?

 

[AudioCats]

what I was trying to show is that it is Not very likely the PA2v2 have damaged your 770. Even if the output is 2.4V straight from the batteries, the power into a 100 ohm phone is till less than 100mW, so the phone should be save.
possibilities left: your ears got burnt out? or the amp got burnt out because you tend to drive it too hard for too long?

that is why you need to find another amp to do a comparison. If both amps do the same thing, it could be your ear....

 

[GTanaka]

Ah, if only I had the cash but thanks for the techie help and reassurance! I rarely turn my amp up anything past half nob, so it's probably just my hearing going. Everyone I know thinks I blast my music in my car, but I think it's just enough to drown out the traffic . Anyways, I bought this combo at the recommendation of of head-fi folk about 6 months ago, and I can't say I'm unhappy in the slightest! Thanks!