Fostex HP-P1 Portable Amplifier and DAC for iPod/iPhone (Short REVIEW and Impressions Thread) - Page 7

Those are good points and i look forward to your impressions. My only hesitation regarding the HP-P1's amp section is the power rating at 80mW which seems a bit low...

 

Has anyone tried the HP-P1 with higher quality interconnects?  Wondering if it makes a difference in the SQ.

 

Any trustworthy jitter- or impedance measurements? Did the Fostex have an async USB or a re-clocker? 

 

I couldn't care two flying poopers about the dac chip. In the end, it's a very small part of the equation. Power supply and clock matter more. 

 

Edit: Found the info. Going to pass on this. Way over-expensive. 

 

CLAS is starting to look good, though it's simply too much hassle and size. Have found some of the <100eur usb re-clockers to work quite good and have determined the clock is an important factor. Hah, though I could in no way lay that one out in technical terms :)

Edited by electropop - 9/6/11 at 7:31am

I connected the line out at the back of the HP-P1 to a Fiio E7 via mini to mini cable. I was able to hear music come out out of the E7's headphone out.

Does anyone know if someone has the hp-p1 in stock in the US? someone wants to sell it?

Sorry to keep everyone waiting for my impressions but, unfortunately, I had to return my HP-P1 to Moon Audio due to a couple of problems I was having.  I think the problems are unique to me and not the HP-P1 specifically, but in any event, it was not a good fit for me.

 

First, I discovered that my iPhone 4 apparently does not deliver a clean digital signal to the HP-P1 as I was hearing pops and crackles consistently while playing Apple Lossless files.  As an alternative source, I have an iPod Nano 6G that I tested and it worked fine; hence my conclusion that my iPhone was to blame.  I tried several things (resetting, airplane mode, different types of files (ALAC, AAC, MP3)) but could not make the problem go away.  Again, this is a problem I could have overcome by using a different iDevice, but chose not to as I prefer to use my iPhone for the vast majority of my portable listening.

 

Second, my portable listening habits utilize iTunes smart playlists almost exclusively.  I run my music library (currently about 8,000 songs) through a maze of smart playlists to achieve what I refer to as a "Daily Mix" of new releases and old favorites that I sync to my iPhone.  Because I am mixing and matching new and old recordings, I rely heavily on Sound Check (I use the modified iVolume, which seems to work much better) to balance out the gain on my playlist.  While auditioning the HP-P1, I came to realize that it disables Sound Check completely.  Apparently, the iPhone (and the iPod Nano I tested) apply Sound Check after the digital-to-analog conversion, because it just doesn't work when you route the digital signal to the HP-P1.

 

These were deal-breakers for me, but like I said, they are really personal preferences and not indictments of the HP-P1 (unless the "crackling" issue becomes widespread).

 

As for my very brief time spent with the HP-P1, I was impressed with the build quality and sound.  I only listened with my Edition 8's, so I can't give any opinion on harder-to-drive headphones,  but the HP-P1 drove the Ed.8's with authority and accentuated the traits that the Ed.8's excel in:  a very clean and highly articulated sound with tight and authoritative bass.  Again, while I did not listen with any higher impedence headphones, I got the feeling that the HP-P1 is not power shy and should be able to adequately drive many full-size cans.  Unfortunately, the HP-P1 was not a good fit for my portable listening habits, so I won't be able to opine any further.  Others, I am sure, will find it fits their needs perfectly as the ultimate "all-in-one" audiophile portable DAC/amp.  Their opinions of the performance of the HP-P1 will certainly be of more import to interested Head-Fier's.

Edited by NewMexiCat - 9/15/11 at 8:59am

I had a custom LOD to USB made using Mundorf silver/gold cables for my HP-P1. Compared to the stock Fostex LOD to USB cable, the Mundorf cable gave a much cleaner and smoother sound overall. Separation was much improved. The only negative I found was that the stock Fostex cable had more bass quantity but a bit murky.

Hope this helps.

Yes, I'm running the latest iOS on my iPhone and I did try a restart, all to no avail.  I spoke to Drew Baird at Moon Audio about it and he said his iPhone worked flawlessly with the HP-P1, so for whatever reason it seems to be an issue with my iPhone and not the HP-P1.

 

Again, I don't want to sour anybody on the HP-P1.  It is cutting edge gear for sure, and despite my issues I could certainly detect that it has a rock solid build and sounds great.  It just wasn't the best fit for my needs.

I don't know how many times I have to share this advice... although I guess it is too late for you.

 

Your problem would have been solved by rebooting the iPhone. (Restart is not enough.) Hold the Power and Home keys simultaneously until the screen goes black and then the Apple icon appears. Let go and do this again immediately, i.e. holding the buttons until the screen goes dark and the icon comes on. Then let go and allow the iPhone to reboot. Problem solved.

I don't really understand the mechanics of the issue. I think that it is something in the iPhone and iPod OS that gets polluted and then doesn't deliver a clean bit stream to the CLAS/HP-P1 etc. The solution then is to reinstall the OS from firmware via a reboot.

 

I don't think that there is any rule as to how often it is needed. Rarely in my experience.

Hi NewMexiCat and all I am looking at the Fostex and have Edition 8 phones, I have been amazed at the quality from my iPhone 4 with these headphones but am looking to get the best out of them. How much of an improvement was the Fostex with your Edition 8s? I won't be able to try here in the Uk without hearing first so your experience would be invaluable!! My main player is a Naim CDX 2 and I want to get as close to that as possible in a portable rig. Thanks for your help in advance David

Does anybody know if it possible to use the DAC in the Fostex HP-P1 with a computer? Using an USB cable.

Or does it only work with iDevices?

 

 

The HP-P1 (and CLAS too..) only works with iDevices...