[PaulBoy]

Hi - Head-Fi made me do it! I was happy with my cans & then I got sent over here from another forum & look what's happened

...

Anyway I ordered a PA2V2 (less than a week to get to UK & Gary's such a nice helpful guy) - I wanted this mainly for mobile use with 2 x mp3 sources and a pair of Senn PX100's - the sound with the amp is superb 10/10

I had heard that the sound of my home cans (HD600's) would be improved too (usually listen through Rotel RA-01 stereo amp - though could just listen directly from the CDP) So I connected the CDP directly to the PA2V2 and the sound was improved (not as noticeably as with the PX100's) but only at low > medium volume - as soon as you add more volume there is noticeable distortion

- I asked Gary about this and he suggested this might occur due to the difference in impedance of the two sets of cans ...

My question here is whether I was right to take the Rotel stereo amp out of the picture when using the PA2V2 with the HD600's ? or if not how should I be connecting to the HD600's when using my home setup?

Paul

 

[hciman77]

Quote:

Originally Posted by PaulBoy So I connected the CDP directly to the PA2V2 and the sound was improved (not as noticeably as with the PX100's) but only at low > medium volume - as soon as you add more volume there is noticeable distortion

I dont know the 600s but I have the very similar 580s and have no distortion issues with them at higher volumes.

a) You *are* using rechargeable batteries with the amp ? - there are known issues with alkaline batteries.

b) When you say connect directly to the CDP you do mean via the line level outputs not a headphone out


If (a) and (b) above apply then three possibilities exist...

1) The amp is defective, send it back, Gary has an excellent support policy.

2) You are using it at insane and ear damaging listening volumes, the PA2V2 is a 2.4V amp and whilst it is atypically powerful for a low voltage amp under a difficult load in extreme conditions it will obey certain laws and will probably clip

3) Something else...


Quote:

Originally Posted by PaulBoy My question here is whether I was right to take the Rotel stereo amp out of the picture when using the PA2V2

Yes there is no point in applying two levels of amplification to a line level signal you are just multiplying the distortion

 

[PaulBoy]

Quote:

I dont know the 600s but I have the very similar 580s and have no distortion issues with them at higher volumes. a) You *are* using rechargeable batteries with the amp ? - there are known issues with alkaline batteries. b) When you say connect directly to the CDP you do mean via the line level outputs not a headphone out If (a) and (b) above apply then three possibilities exist... 1) The amp is defective, send it back, Gary has an excellent support policy. 2) You are using it at insane and ear damaging listening volumes, the PA2V2 is a 2.4V amp and whilst it is atypically powerful for a low voltage amp under a difficult load in extreme conditions it will obey certain laws and will probably clip 3) Something else...

hciman777 - thanks for taking the time to answer (typical ex pat

)
In answer to your questions ...
a) Yes 1.2v NiMh rechargeables as suggested by Gary
b) From CDP to PA2V2 via 2x phono - 1x 3.5mm jack lead (not the headphone out on CDP)

1) Gary told me I could send it back but suggested the reason why I was getting distortion at higher volumes was the impedance of the cans
2) Insane volume levels do not appeal to me so that is not the issue here

My son has lower impedance Senns HD555's so I plan to try the PA2V2 with them & then consider sending back the amp if there is distortion with them

Paul

 

[AdamWill]

I believe PA2V2 is a low-voltage, high-current amp and so not best suited to the high-impedence HD580/600/650 series. I'm guessing you're in PaulBoy's scenario #2, but 2.4 volts into 300 ohms isn't that much power, so it may be that you aren't really at "insane" levels.

 

[redrich2000]

I had a similar problem using the pa2v2 with DT-880s, which I think are considered similar to the HD-600s in terms of difficulty to drive.

As well as the distortion the phones sounded thin and distant, it really sounds like the cans are starving for more juice. The amp was fine using e3cs, it just couldn't drive the DT-880s.

 

[hciman77]

Interesting comments - I had no problems with the Senn 580s or Beyer 990-Pros but I did not get a good result with the AKG K501s.

 

[mrarroyo]

Another factor to consider is the how "powerful" is the line leve out of your cd player. I have had no problem driving HD600 with the PAV2 out of an iPod. Maybe it is because I do not listen to music very loud.

 

[PaulBoy]

Thanks for the input everyone

Like I said above Quote:

I wanted this mainly for mobile use with 2 x mp3 sources and a pair of Senn PX100's - the sound with the amp is superb 10/10

So in the finest traditions of "Head-Fi Made Me Do It" I guess I need a dedicated headphone amp for home use & keep the PA2V2 for use on the go

Paul