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Fostex HP-P1 Portable Amplifier and DAC for iPod/iPhone (Short REVIEW and Impressions Thread) - Page 79

post #1171 of 1305

Nice bridge softbunlet, Purple Magic!

post #1172 of 1305
Quote:
Originally Posted by ExpatinJapan View Post

what is your firmware of your Fostex hp_p1.....................

 

sorry about that, i honestly have no idea what my unit's firmware is. i checked their website and there seems to be no update on their firmware.

 

Quote:
Originally Posted by FatmanSize48 View Post


Please do not take this as criticism, as I sincerely would like to know the following: why purchase the HP-P1 instead of the CLAS? The HP-P1 was meant to be a one brick solution--it seems you are negating the entire point of such a device. Would it not be easier to carry around a CLAS and a similarly slim amp, as opposed to the rather bulky and cumbersome HP-P1 with yet another amp? Of course, if you are using this as your home source, please disregard what I've said.

none taken. i got my hp_p1 from a trade and i already had a lisa3 and i find that better to match my current setup rather than using the headphone out. i also do not travel with amps as i find it a bit cumbersome. i go for portable though so i can transport it easier from my home to my office. and i also use it with my speaker amps when at home. :)

post #1173 of 1305
Quote:
Originally Posted by jcruiz View Post

 

sorry about that, i honestly have no idea what my unit's firmware is. i checked their website and there seems to be no update on their firmware.

 

none taken. i got my hp_p1 from a trade and i already had a lisa3 and i find that better to match my current setup rather than using the headphone out. i also do not travel with amps as i find it a bit cumbersome. i go for portable though so i can transport it easier from my home to my office. and i also use it with my speaker amps when at home. :)

 

confused_face(1).gif Gotcha....I think.... 

Quote:

Originally Posted by jcruiz View Post

 

sorry about that, i honestly have no idea what my unit's firmware is. i checked their website and there seems to be no update on their firmware.

 

Expat wanted to know what your HP-P1's firmware is. To find out, make sure your HP-P1 is running and connected to the iPod, then go Settings->General->About. Scroll down and check the HP-P1 setting. 

post #1174 of 1305
Quote:
Originally Posted by FatmanSize48 View Post

 

Expat wanted to know what your HP-P1's firmware is. To find out, make sure your HP-P1 is running and connected to the iPod, then go Settings->General->About. Scroll down and check the HP-P1 setting. 

 

I think I read here that older firmware versions had battery life issues that were corrected in later releases. I have the latest version (1.1.2? I don't have it with me to verify) because I purchased it less than a month ago. If your version is older that could be part of the reason for your issue. Fostex will update the firmware, but based on your situation you may be charged for that in addition to shipping charges. Maybe not though. wink_face.gif

post #1175 of 1305
What Fatman an Silver said +1
post #1176 of 1305

I recently got an HP-P1 and have been enjoying it so far using it with the 3GS (32GB) and FLAC Player, although I do have some minor issues that have been bugging me that I haven't quite yet resolved. The software version is 1.1.1, the hardware version is 1.1.2, and it doesn't display the serial number (for ex. the whole "betaxxx" stuff.)

 

The main issue is if FLAC Player outputs bitperfect to the HP-P1 on the 3GS for 24/88.2, 24/96, and 24/192 files or if it downsamples to 16/48 for these files? 

If it downsamples, would it be better for me to just re-encode and downsample the FLAC files to 16/48 (or 16/44.1) to save space on the iPhone's harddrive?

 

Another issue is that whenever I connect the HP-P1 to the PC to charge while connected to the 3GS, it shows up a "USB not recognized" on the PC every time. Also, once in a while (an odd bug?) when playing music like this while charging, it tends to "resync/reconnect" to the PC and shows the "USB not recognized" error message on PC again (although the audio keeps playing through the HP-P1), usually when I attempt to change tracks on the 3GS.

 

And uh... oh one final thing would be the minor half-second pauses/"lag skips" during playback (tested w/ both FLAC Player and regular iPhone/iTunes stock music app) when browsing things on the 3GS or using other apps. Is that normal, and if so is it due to the 3GS's onboard RAM/CPU/chipset clockspeed? Would upgrading to a 4S or iPhone 5 fix this issue? Thanks!

post #1177 of 1305

I'm pretty sure it's limited to 16/48 just like the clas and other i-compatible dacs. The only way to get 24-bit is through an ipad using the camera connection kit.

 

The hp-p1 doesn't work as an external soundcard via usb, so that's why you get those errors when you use a pc usb port. To avoid that I just use a usb charger on an outlet.
 

I use an iphone 4 (soon to be 5S) and I have the same issues with it pausing, etc. I don't know if other dacs do this or not, or if the lightning connector would fix it. It's such a brief disruption and so easy to correct (ie. just enjoy the music) that it doesn't bother me much. Good to know I'm not alone though. :)

post #1178 of 1305
Quote:
Originally Posted by silverharbinger View Post

I'm pretty sure it's limited to 16/48 just like the clas and other i-compatible dacs. The only way to get 24-bit is through an ipad using the camera connection kit.

 

The hp-p1 doesn't work as an external soundcard via usb, so that's why you get those errors when you use a pc usb port. To avoid that I just use a usb charger on an outlet.
 

I use an iphone 4 (soon to be 5S) and I have the same issues with it pausing, etc. I don't know if other dacs do this or not, or if the lightning connector would fix it. It's such a brief disruption and so easy to correct (ie. just enjoy the music) that it doesn't bother me much. Good to know I'm not alone though. :)


Wow, that was quick! :P

 

Hm, yeah, the prevailing response I've read from reading almost this entire thread and a bunch of other threads discussing outputting iDevices at 24/96 and etc is exactly that i.e. iPhone/iPad will "downsample" or output to 16/48 even if it's a 24/48 ALAC file. FLAC 24/96 and so on works through FLAC Player but is also "downsampled" to 16/48 even through a CLAS/HP-P1/etc due to some kind of iOS limitation or something along these lines. The only option for anything other than 16/48 resampled would be FLAC Player using an iPad through the Camera Connection Kit to an external desktop DAC; probably wouldn't work with the HP-P1/CLAS/etc.

 

I noticed prior to getting the HP-P1 that 24/96 files in FLAC Player worked fine through the onboard iPhone DAC headphone out and LOD, which is what made me suspect the "downsampling" to 16/48 in the first place. Apparently this happens even when output to the HP-P1 via the 3GS 30-pin -> USB DAC, so I don't know whether or not to re-encode my FLAC 24/96, 24/88.2, and 24/192 files to 16/44.1 or 16/48 since it would drastically save a ton of space on my limited 32gb 3GS that is almost full. I'm just worried that by re-encoding them to 16/48, it won't match the SQ of the hi-def 24-bit files that are "downsampled" to 16/48 on the iPhone.

 

Thanks for the tip about the mini-USB to PC charging/"USB not recognized" issue. I plugged it into one of my old Apple-supplied USB wallplugs and it seems to be working ok :)

 

And yeah, good to hear that I, too, am not alone in having those glitches/pauses/lag-skips while using the iPhone and listening to the HP-P1, especially during heavy/intensive browsing or app use. It is slightly irritating but not unbearable, although it would be cool to know if there's any way to help reduce or fix this issue (i.e. would sending it in to Fostex for the FW upgrade to 1.1.2 fix it, or does it still happen w/ the updated firmware?)

post #1179 of 1305

Happy to help. I love this little device, but it has it's drawbacks.

 

If you wanted to downsample your files that shouldn't be an issue as long as the software doing the conversion is decent and configured properly. I use two different programs for audio conversions and they both do a great job on everything I throw at them. I have never heard an audible difference between 16 and 24-bit audio file when everything else is equal and the bitrate isn't too low. I'm not saying that no one can hear a difference, but I also think a lot of the "difference" for most people is a placebo effect more than an audible reality.

 

As for your second question, I have the most current firmware for the hp-p1, so that's a negative.

post #1180 of 1305

Well, I did re-encode some of my 24/96, 24/88.2, and 24/192 files using Foobar2000 w/ SoX DSP (settings: 48000Hz re-sampled, Best quality, 95% passband, 50% phase response (linear) in SoX DSP; FLAC -8, no dithering, bit depth = 16-bit) to 16/48 and so far it doesn't sound really that great compared to the original 24-bit files. Although I don't know if it's placebo or if my settings are correct or not (should I apply dithering? should I re-sample to 24/48 instead of 16/48 to avoid having to choose dithering/etc?)

 

I wonder about the way the HP-P1 handles the "re-sampled" high-def 24/96, 24/88.2, 24/192 files in general and if this would be worth the extra space they take up on the iPhone (as compared to 16/48 or 24/48 files.)
 

post #1181 of 1305

Dithering just adds corrective noise and isn't likely to be necessary. I think the difference you're picking up on is placebo, but you should only downsample from your master audio file every time as you are probably re-encoding your copies. If you can adjust the phase response up try it that might help. I use dbpoweramp to convert files primarily, and it probably uses the same codec. I have never noticed a difference as long as I stopped thinking there would be one (expectation bias).My advice is just give it time and you'll probably stop noticing a difference.

post #1182 of 1305
Quote:
Originally Posted by silverharbinger View Post

Dithering just adds corrective noise and isn't likely to be necessary. I think the difference you're picking up on is placebo, but you should only downsample from your master audio file every time as you are probably re-encoding your copies. If you can adjust the phase response up try it that might help. I use dbpoweramp to convert files primarily, and it probably uses the same codec. I have never noticed a difference as long as I stopped thinking there would be one (expectation bias).My advice is just give it time and you'll probably stop noticing a difference.


I'm thinking maybe I'll just re-encode to 24/48 w/o having to worry about dithering to 16/48, but still am sorta conflicted as to whether or not the extra file size for the originals on the iPhone in FLAC Player are worth it or not.

 

It could be placebo/psychological, that's true. But yeah, either way I'm only re-encoding from (and keeping on the PC) the original hi-def 24-bit/96000Hz files for the sole purpose to upload to the iPhone to save space (to either 24/48 files or 16/48 dithered files...) I'm using SoX mostly due to these SRC comparison graphs http://src.infinitewave.ca/

 

edit: Apparently 99% passband is equivalent to SoX VHQ Linear in that chart... Would it still be better to let the iPhone -> HP-P1 downsample the original 24/96 -or-, to save space on the iPhone, re-encode the original 24/96 files on PC using SoX DSP Resampler (VHQ Linear 48000Hz settings, leaving it 24-bit)? Thanks again, :P


Edited by refault - 8/25/13 at 7:39am
post #1183 of 1305
Its been a good run but I finally sold my Fostex today.

I recently bought the Hifi-m8 and i am a one device at a time kinda person.

The Fostex hp_p1 is still a great piece of gear.
post #1184 of 1305
Quote:
Originally Posted by ExpatinJapan View Post

Its been a good run but I finally sold my Fostex today.

I recently bought the Hifi-m8 and i am a one device at a time kinda person.

The Fostex hp_p1 is still a great piece of gear.

 

Happy memories. I hope the HiFiM8 can the bar higher than the HP-P1. 

post #1185 of 1305

I posted this on the Hifi-M8 thread earlier today.

 

 

Hifi-M8 and Fostex hp_p1.

 

The difference is moar p`wer!

 

Hifi-M8 on 1ohm setting with low gain = Fostex hp_p1 high gain filter 2.

 

Hifi-M8 on 1ohm setting with low gain and treble +1 = Fostex hp_p1 high gain filter 1.

 

So are they comparable? well yes and now. Yes in that one can re-create the Fostex signature using the Hifi-M8 as above, but no when one starts to play with the ohm settings and add more gain.

 

Hifi-M8 = More clarity, options, balance and soundstage = Hifi-M8.


Edited by ExpatinJapan - 2/15/14 at 4:00pm
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