Practical Devices XM5 - Page 19

That would be an excellent thread topic. Please make that idea a reality.

It can't be a reality unless we agree on which 13 headphones he has to audition all 13 opamps on.
I switched to closed headphones and my former LME49710 favorites with Audio-Technica AD700, do not make me happy with Denon AH-D1001, on those it's a toss up between the sparkle of the AD8610 and the darker yet detailed OPA627.

Since i also run the XM5 through a tripath amp to drive my speakers, i favor the OPA627 right now, since it works for both the Denons and the speakers, while the AD8610 is fine with the Denons, it is reaching "bright" with the speakers.

So 13 opamps on 13 headphones at the very least.

What, only 169 possible combinations?

I have posted and picked my opamps, and shared it here - that is all.

(I did do something like a 9 amp 9 IEM synergy review with 81 ways to screw it up).

Hmmmm...my XM-5 came with the AD 8397 chip, and I also tried the OPA134's and my present LM6171's. I've not noticed any clipping or distortion with any, using my AKG 240S headphones and an assortment of low cost earbuds, but my ears have lost that golden tinge many years ago

All three chips were subject to a burn in of at least 24 hrs. Perhaps the 134's needed more, as I prefer the sound of the other two over it. One day I'll try some of the other chips, and maybe the BUF634's if I can find then at a reasonable price.
Oneday I'll spring for a better set of phones, or a good set of IEM's or buds.

I think the link morfic provided has some very good opamp info.

I noticed some interesting headphone/IEM impedance, voltage & current info here: headb.com: Support
The maximum voltage swing numbers (Vp-p) for many headphones/IEMs are shown as measured by C&C Studio lab. For example, they show the max voltage swing for the HD650 as 6.0Vp-p (or 2.12Vrms). 1Vrms = (1.414 * 2)Vp-p

I think this data might help match headphone/IEM characteristics to opamp characteristics. I'm using it to compare the OPA134 and AD8065 when driving high impedance headphones. The author of the opamp notes says in the AD8065 section "As you can see from the clipping numbers, the chip is running rail-to-rail in the 330 Ω test: 2Vrms is 5.656V peak-to-peak. You can't get better than that." This is an experiment where the power supply voltage is dropped until the opamp starts to clip, in this case it could be dropped as low as 5.7 volts before clipping occurred. The author reports the OPA134 starts to clip when the voltage drops below 8.4 volts in the same 330 Ω test. This experiment, where the headphone receives 2Vrms, would be driving the HD650 close to the maximum voltage swing number reported by C&C Studio lab, which I think would be very loud.

Yup, noodling with numbers is a poor substitute for the 169 combination "golden ear" report we're wishing for

I finally got my XM5 after some waiting and I can say that it was worth the wait. The build quality left a bit to be desired, especially for the price, but I guess thats the case with most portable amps. I am speaking about the internals, as I immediately opened it up to check out the opamps buffers. Also the way everything fit together was a bit simplistic.

The sound is however, the main reason I chose it and it did deliver, in spades. Bass was tight and clean, sound stage much wider than my old extigy. All the features are great and not gimmicky. I really do like the crossfeed, as it helps alot with some older music, that separate instruments completely between channels. It really does help, though the pot doesnt seem very sensitive.

I love how well it works with the dt 880s that I have, though at this point I'm not very sure whether the distortion that I am hearing at higher volumes is from the xm5, with the opa134 opamps or the beyers, the treble is definitely brite, siblance is under control but present. I'm getting the 8065s to see if it can control the distortions and hopefully tone down the siblance. Overall I am happy with the sound, and Im sure everything will even out with some more burn in. One thing I've noticed is that it definitely beats the headphone out on my onkyo receiver, amp wise at least. The headamps in receivers are most definitely after thoughts, sad really, so for anyone like me that thought receivers do movies justice through headphones, well, no.

Oh and one more note, I have sennheiser cx500s plugged in, though, I tend to think that the XM5 just outpaces it, coming from the recabled 880s that I have there is just so much that the XM5, beyer combination reveals in the source, I have high bitrate mp3s but exclusively test with flacs. Lol I guess the sennheisers arent very good. My wallet's running scared.

audiophonicshz,

I'm still happy with my XM5 and the 8065 was a boost in SQ. I hope your 880's agree with the 8065, from my experience they might reduce sibilance and give a smoother sound.

Are your comments based on using the DAC?

Thanks GreatDane, I hope I get the chips faster than the XM5, took a month! Yes I play flacs off my laptop and use the DAC. I realize the dac isnt the best, but it is better than my extigy. I will do more tests with my receiver as the source, running an optical cable from my computer to the receiver. It uses the BB 1796 dac so that should be a step up. I do have a question, when I use the headphone out on my receiver to the input on the XM5, wouldn't the headamp on the receiver affect the sound going to the XM5? Is this a good setup or would it be flawed?

What stand alone dac would everyone recommend? I've read many of the threads on the dac forum, I'm looking at the zero dac, as its pretty inexpensive, but I don't mind putting up the money for a Benchmark DAC1. Just don't know if the zero, from ebay, would be of low build quality.

If you're using the DAC in the receiver, use a line-out(RCA) instead of the HP out. You would need a stereo RCA to 1/8" TRS cable of course.

I don't have any recommendations for DACs. I'm content using my Pico DAC for my HP rig. For listening to my Denon/Rotel/B&W speaker system I use an Apple Airport Express with computer as source using an optical cable to send the digital signal from the Airport to my receiver's DAC.

I tried out using the pre outs from my receiver, but I can't find a way to shut off my speakers so I guess its pointless. So I just use the headphone jack, its not bad. Reason I bring this topic up is that I use a WD TV and I use that now to listen to flacs.

One more note to everyone, I'm having great success with Sony 888s with bass boost and 75ohm on the XM5. Quite amazing.

What is the Onkyo model? Strange that it doesn't have a button to switch speakers...A & B ??

Even with no speaker switch you should be able to still use a line-level out(tape/VCR,etc) and just turn the speaker/main volume down to zero and still have that line-level output.

Simple yes?

How do different XM5 opamps affect the crossfeed? I'm interested to know if there are adverse effects...

Never noticed any difference in how crossfeed works with different opamps.

x2

I don't think it should, or could effect the crossfeed performance.