Practical Devices XM5 - Page 18

Oops, I was trying to quote you when I said that too.

No idea, i got my BUF634 with the XM5.

HeadphoneAddict: I think LME49710 would be a low cost option over OPA134 to upgrade w/o increasing cost.

I am enjoying some new U2 music through my new HD650 using the XM5's USB DAC ... yeah it's my birthday!

My 4th gen ipod 20GB sounds very flat when driving the HD650 with headphone out, the need for a headphone amp is obvious. My 2nd gen ipod shuffle does a pretty good job driving the HD650 with headphone out but the improvement the XM5 creates can be noticed with careful listening, especially with the punch of deep bass. The XM5 is also a noticeable improvement over the old sound-blaster live audio card in my PC, mainly in the bass area. So, it's good I studied up on the posts here at head-fi and got the XM5 in preparation for the HD650

I think my HD485 sounds very good no matter what I drive it with. I really don't need the XM5 if I was only going to use the HD485, except maybe for the crossfeed. I was curious to hear what a higher end headphone sounds like and that's why the XM5 and HD650 are here. I think they are both keepers!

My XM5 has the OPA134 + BUF634. I got lucky and found the BUF634 at Newark but they are out of stock now. It's not an easy chip to find. I'm still resisting the AD8065, I do have limits on how fast I can absorb new toys ... or do I?

The AD8065 improve performance by maybe 5% or a little more, so one could be perfectly happy with the stock opamps, But for those of us looking to squeeze every little bit out of it the AD8065 are a welcome addition.

HeadphoneAddict, should I wait until you start your "REVIEW 13 Op-Amps for the XM5" thread before I decide which one to buy?

I think the AD8065 improves performance more than that just by the elimination of distortion. The Stock opamps clip and distort even during normal volume and it was starting to get quite distracting for me.

No. I've tried the stock OP134, AD743, AD8397 and AD8065 and picked the 8065 as my favorite. For me the AD743 distort more easily than the stock opamps. AD8397 have loads of power but sound best with my HD600 and not my IEM.

With the op-amps you tested, do you notice any distortion with your HD600 or is this more of a problem with IEMs which probably have much lower impedance? Is switching in the extra 75 ohms something that is supposed to help with lower impedance IEMs/headphones in some way?

I only get distortion with HD600 at very high volume levels, but not with all opamps, the AD743 were the most likely to clip, and the AD8397 and AD8065 are the least likely to clip at high volumes. Lower impedance phones are quite difficult to drive to distortion before permanent hearing damage.

The 75 ohm may help some low impedance phones but not all. My 50+ ohm ES3X don't like it and don't sound right with it on. It's supposed to be like a P-to-S adapter for Etymotic ER4P to act/sound like ER4S.

That's what I'm thinking to, The extra price is worth it and it really improves this amp to another class while not increasing the price all that much.

They should offer this setup as default and let you strip it away if you HAD to save a few bucks now.

...well look what finally showed up after 2 weeks. --->



...getting ready to do some pre-swap listening then pop in the 8065.

I still want to do a comparison to Pico with the BUF634 & AD8065 but that will have to wait.

I first used my Phonaks and did notice a smoother sound as the most noticeable difference. I didn't notice any increase in bass but I'm not saying it isn't there. I've mostly listened to my favorite female vocalists for the past 3 hours so that of course is no test for bass or max available power. I switched to HD 650 and have been listening for over an hour and continue to notice a smoother, sweeter sound with very nice detail. I do use the treble boost & 10 dB. gain with HD 650.

I don't plan to roll back to stock op-amps to further compare but I am convinced that the AD8065 is a worthwhile cost for this amp.

This is mostly Phonak related but I have been trying the 75 Ohm feature with the PFE for music that has forward mids or when I want to listen at high volumes. I noticed this as a "tweak" a couple weeks ago but yesterday realized this was very useful when listening to several Hayley Westenra tracks where her voice is very prominent and somewhat peaky at high volumes which was very much reduced with +75 Ohms & + 10 dB enabled.

does xm5 good paired with dt770/250 or dt880???

I was curious about that, too, and I may upgrade tp the DT880's one day.
I talked to James at PD about it, and decided to get the AD8397 chip, but the BUF634 and your choice of driver chip may do as well.

For HD600 the AD8397 with busbars in the buffer socket is a good combo.

But with all my IEM I like the stock OPA134/BUF634 or better the AD8065/BUF634 as they are smoother with IEM and can still drive the big phones well (but with just a little less power than AD8397).