[MatthewK]

Ordered a Practical Devices XM5 amp this morning. I'm very excited to get it.

It will be my first portable amp.

I'll be using it with an iPod (6G) 160GB, ZyCable Zn7 iPod LOD (from head-direct.com), and either the Denon D2000 or Sennheiser HD25-1 'phones.

Do you own one? What are your thoughts on it?

Anyone have recommendations for opamp rolling? It'll have the BUF634P chips installed when they come in the mail (sadly, it might take a few weeks). I'm considering the OPA627 and LME49710 opamps, maybe the AD8610. I'm not really interested in dual-channel opamps, I want to keep the monoblock configuration.

 

[RAQemUP]

I think it just came out recently. You probably may be the first with a impression/review thread when you get it.

 

[MatthewK]

I think this is one of the very few portable amps out there that has both a bass and a treble boost. Something I don't like about the other amps is that they don't have an easily user-replaceable battery, the XM5 does (9V). Even rechargeable batteries wear out after a while. There's a lot of other features that are nice too. I'd say my only gripe about the specs (this is before actually testing it though) is the DAC, it's a Cirrus-Logic chip and 24/96 would have been better. But they did pack quite a bit into such a small package. It would have been good even without the DAC thrown in.

My initial review may not be as good as it could be since I won't have the BUF634P chips right away. The Denon D2000 'phones need a lot of current (rating at 1,800mW), so the BUF634P should help quite a bit in that regard.

Even those who don't have it, can you recommend some opamps? What do you think of the ones I mentioned in my original post?

 

[basman]

I really like the amp implementation of XM5 draw back only is the DAC chip used.

 

[Drag0n]

Sounds like something im going to keep my eye on to see what others say to decide whether to pull the trigger and add it to my growing collection of portable amps

 

[MatthewK]

Wow, am I really the first one to buy it on Head-Fi??

 

[egoo33]

well im using the xm5 with my akg 701s and all i can say is wow, absolutely worth its price in gold and got it with in 2 days counting the weekend

 

[MatthewK]

I'm hoping mine will come in the mail before the weekend, I ordered it on Monday. I'm in Minnesota which borders Canada, so you'd think it wouldn't take too long...

Have you done any opamp rolling? I've got an LME49710 and OPA627 in the mail. I didn't get the BUF634P with it because I found someone who offered them to me for a great price (but I won't get it for a few weeks, dangit), so I'll be stuck with the copper bars for a little while. Are you using the BUF634P buffers?

 

[MatthewK]

Still waiting for it to come in. Hopefully it'll be here early next week.

There's one thing I'm not happy about though. I emailed P.D. and asked their advice on opamp rolling. They've never replied back and it's been several days. Now it's possible their spam catcher deleted my email, or perhaps they are just too busy, but it would be nice if they sent back at least some kind of reply. Even a "sorry, can't help you" would be better than nothing at all. I really hate it when people ignore emails..

 

[Fungi]

It might be a case of lost email or something; when the knob on my XM4 went bad I emailed them, and they replied quickly and sent a replacement right away.

 

[brotherlen]

I've owned the xm4 (and lost an xm4). Its a solid little device. I'll probably add the xm5 for my portable, can't decide black or silver?

 

[walls]

Ive been waiting for reviews of this amp since I first read it was coming out. I am thinking that this may be my first portable amp!

Looking forward to some reviews!!

 

[bobloblaw]

Quote:

Originally Posted by MatthewK /img/forum/go_quote.gif I emailed P.D. and asked their advice on opamp rolling. They've never replied back and it's been several days.

Here's what they told me:

Quote:

There are 3 options we currently offer. 1) OPA134 only 2) OPA134 with BUF634 buffering 3) AD8397 amp/buffers Aside from this we aren't currently offering any other options. However, there are many other chips you can use other than the OPA134's. OPA627, for example, seems to be a favorite (we don't have it in-stock; however, it is readily available from digi-key.com and others). The OPA134's (and OPA627) pinout is "semi-standard"; _most_ single-channel opamps in a DIP8 package will work.

I'm interested in this, too. I got the BUF634 upgrade, and am looking into options for opamp rolling. A lot of the recommended options seem to only be available in dual-channel configurations (at least from Digikey). Anyone know of some solid single-channel options for this amp? I'm pairing with HD650's, if that makes a difference.

 

[MatthewK]

Thanks bobloblaw. They did answer some of my emails, so I think it may have just been a case of going into their spambox or something.

Someone is sending me some BUF634P chips, but it's probably going to take another week or two to get here.

Because the Denon D2000 has an input rating of 1,800mW the BUF634P chips should increase the current quite a bit. It'll be interesting to see what kind of difference that makes.

I'm currently using the OPA627. It seems a little better than the OPA134 (which is supposed to be very similar). I think the bass is slightly better. Was it worth the high price of the OPA627? Probably not, but I'm going to wait and see what happens with the BUF634P chips.

I've also tried the LME49710NA chips. I'm not sure if I like them or not. I think I'll wait until I get the BUF634P chips to make a final judgment. Actually, the only reason I haven't written a review yet is because I'm waiting for those darn buffer chips...

 

[basman]

How do you compare XM5 to other amps? Please post some pics of your XM5!

Thanks!