[plakat]

I think it has more to do with 'reference implementation', i.e. going all out vs. keeping it sane
The A8 does many additional things, so the price difference does not come down to power, nevertheless it is easier to provide more output with a proper power supply (i.e. not bus-powered).
The Fostex website is currently unreachable, but as far as I remember the TH900 has a bit higher nominal SPL.
 
Edit: Yes, I think the fact that your music might not have compressed dynamics may well be the reason for  lower volume.

 

[mariowar]

I did not bring the price difference to the table.
 
For clarification purposes, the TH900s can even be powered straight from an Ipod Touch.
 
However, does it mean that they are properly powered to shine ?
 
Just my 2 cents.

 

[designbykai]

Even of they're the same impedence, th600 are 1 Tesla drivers while th900 are 1.5 tesla. So it makes sense that they might need more juice to make those drivers move. Rather than a simple matter of volume but to also fill out the sound more. Any ways still quite tempted to get this sexy little black box for my Th600 and new Sig Djs. Dang they're fun headphones very efficient and sound amazing even out of an e17

 

[plakat]

Even of they're the same impedence, th600 are 1 Tesla drivers while th900 are 1.5 tesla. So it makes sense that they might need more juice to make those drivers move.

 
Actually its the other way round: stronger magnetic field means less current is necessary for the same resulting force... If the only difference between two drivers is that one has a stronger magnet, thats the one thats more efficient.
 
I don't think the TH900 needs more power. It might resolve better and therefore scale better -- thats another thing apart from power needed to drive it.

 

[nicodunord]

Thanks for answering me about HP-A4 support for HD650
I finally bought an AMI Musik DS5.

 

[ahhui90]

i heard the opamps inside can be swapped. is it true?

 

[tuckers]

  I wanted to add a quick follow-up to my previous posts in this thread. Recently I acquired the rosewood LCD-2s. To my n00b ear, the pairing with the HP-A4 is impressive. The HP-A4 usually functions as my DAC with the RCA output to a WA6 with the Sophia Princess and 6GL7 upgrades. The HE-500s are brilliant in this setup.
 
However, the LCD-2s work better, I think, right out of the HP-A4’s native amplifier. There’s an increase in bass impact, clarity in the mids and highs, and overall punchiness. When I connect the LCD-2s to the WA6 with the Sophia Princess and 6GL7 upgrades, the sound is a bit out of focus, almost impressionistic.

 
I'm really glad to hear that Schopenhauer, as I have LCD-2s and not much other amplification to compare it too.  I thought it sounded pretty good, if a little bit thick and slow sounding in the bass when the volume cranks.  That may just be the characteristics of the LCD-2s that just tend to have a rich sound. The A4 definitely has a very smooth sound and with the LCD-2 richness it's quite intoxicating. The one thing I think could be improved on is macrodynamics or slam is not as good as I would expect with the LCD-2s.  But with bus-power, maybe that is asking too much.
 
I have been contemplating getting another HP-A4 for work, and then maybe getting the Alpha Dog headphones for a really sweet ride.  Any opinions on how the A4 works with the Alpha Dogs?

 

[tuckers]

Also, I got an iFi USB power supply to use with the HP-A4. Results are noticeable, but not dramatic.  Lower noise Floor, blacker background, even smoother sound, a bit more solid bass, and a bit more dynamics.  I was mainly hoping the power supply would improve macrodynamics and slam of the LCD-2s.
 
iFi Micro USB Power Supply

 

[Schopenhauer]

   
I'm really glad to hear that Schopenhauer, as I have LCD-2s and not much other amplification to compare it too.  I thought it sounded pretty good, if a little bit thick and slow sounding in the bass when the volume cranks.  That may just be the characteristics of the LCD-2s that just tend to have a rich sound. The A4 definitely has a very smooth sound and with the LCD-2 richness it's quite intoxicating. The one thing I think could be improved on is macrodynamics or slam is not as good as I would expect with the LCD-2s.  But with bus-power, maybe that is asking too much.
 
I have been contemplating getting another HP-A4 for work, and then maybe getting the Alpha Dog headphones for a really sweet ride.  Any opinions on how the A4 works with the Alpha Dogs?

Tucker: Quick follow up. I've since sold my HP-A4. My decision to sell was reached within days of acquiring ALO's PanAm. The pairing with the LCD-2 is divine. If you have the LCD-2s, I recommend the PanAm over the HP-A4 with urgency. 

 

[tuckers]

Too bad the Pan Am doesn't have an RCA output, as I use my HP-A4 more for my desktop speakers system than I do for headphones!

 

[Xpresser]

I almost jumped on this for my first DAC/AMP combo (for my upcoming PC build) but I don't want to have to worry about the HP-A4 not being able to to drive a high impedance headphone. What would be a great desktop DAC/AMP in the same price range, or lower, as the HP-A4 that can receive audio from a PC (USB?) but also be AC powered? I don't care if it's a all-in-one unit or two devices. I've just started my research and have these on my list to consider but mind you the list is beta/rough draft  
 
Schiit Modi/Asgard 2
Mayflower Objective2+ODAC
Maverick TubeMagic D1 Plus Edition
Fiio E9K/E17
 
 
To tell you the truth I haven't even checked to see if any of those choices above are AC powered as I didn't know I wanted that as an option until reading this thread. I love to research and research but to tell you the truth I'm burned out from picking my PC components and buying a new bike after 6 months of research. A huge point in the right direction would be great.
 
Is a DAC/AMP still the way to go for PC audio even over a high end sound card such as the Asus Xonar Essence STX or  Creative Labs Sound Blaster ZXR?
 
I would be gaming/music (streaming and lossless) on headphones 70%/speakers 30% of the time
 
Thank you so much

 

[plakat]

  I almost jumped on this for my first DAC/AMP combo (for my upcoming PC build) but I don't want to have to worry about the HP-A4 not being able to to drive a high impedance headphone.

 
I really don't think thats a problem... the A4 works fine with a lot of higher impedance headphones. I may be in trouble when confronted with some power sucking planar magnetic though, so if you're planning for some Audeze or similar that might not work out. So what cans are on your list?
 
In the same price region as the A4 things might get tight if you're looking for DAC+Amp... I think its a very good package overall, and at a very competitive price. Yes, the small Schiit stack might be an option if space, cabling and wall-power is of no concern.

 

[gjc10212]

Just purchased one of these, new from Sonicfiber £200 inc taxes & duties. Looking forward to its arrival!

 

[Otheronek]

I really don't think thats a problem... the A4 works fine with a lot of higher impedance headphones. I may be in trouble when confronted with some power sucking planar magnetic though, so if you're planning for some Audeze or similar that might not work out. So what cans are on your list?

In the same price region as the A4 things might get tight if you're looking for DAC+Amp... I think its a very good package overall, and at a very competitive price. Yes, the small Schiit stack might be an option if space, cabling and wall-power is of no concern.

I have yet to see or hear of anyone using high impedance cans with the hp-4. Can you point to a post or article citing this? I am eager to know..... Specifically high impedance Beyers... 250ohm versions.

Peace OOK

 

[plakat]

I have yet to see or hear of anyone using high impedance cans with the hp-4. Can you point to a post or article citing this? I am eager to know..... Specifically high impedance Beyers... 250ohm versions.

Peace OOK

 
Just tried both my T90 and my T70 on the A4 (both 250Ohm), on high gain it drives them to far higher levels than I'm willing to listen to. Volume setting at 12:00 (i.e. the marker sitting at the top, halfway through the range) is already much too loud. As I said: I don't see any problem using the A4 with higher impedance cans. It even drives the T1 with 600Ohm impedance to respectable levels, while a bit lower in volume than the 250Ohm headphones its still able to produce levels I'd never use for listening.