Looking for an amp like this.

[luisdent]

I have an apogee duet (firewire) that sounds excellent with my new pfe232 IEMs.  My ipod touch isn't "as" good, primarily, I believe, because of the impedance being lower.  This causes a slight treble boost around 10khz.  The duet also has slightly better overall detail/smoothness/tightness/etc.
 
I'm looking for an amp that will be for my ipod primarily.  The duet has a 32ohm headphone output, so I would assume I should look for something like that with at least the quality of the duet.
 
Size isn't critical, but it does have to be portable.  I carry a backpack, so larger portable to an extent is o.k.  Something like the Fiio E17 looks nice, but I don't need the DAC.
 
Does anyone that has heard the duet have any recommendations.  If it fit in a large pocket, awesome, if not, that's fine too.  Audio quality is paramount.  I want no noise added from the amp and a flat reference frequency response if possible.  Tone controls are nice, but if it is truly very flat would be unnecessary.  I never use EQ or processing on anything, so they aren't important to me really.  Bass boost if very high quality and with small increments might a nice addition, but again, not needed.
 
Please let me know.  My price range would be $100-200.  The closer to $100 the better, but I realize to some degree you get what you pay for.  And perhaps that won't even cut it, but just let me know your recommendations...

 

[tzjin]

It would be more accurate perhaps to say the added impedance dampens the treble, since most modern headphones are designed for low impedance sources such as your iPod. Typically the output impedance should be less than 1/8th that of the headphone (1/8th rule). High output impedance is not really an asset, as it does change the FR of low-impedance headphones, not always for the better.
 
Impedance adapters do exist; you can take a look at impedance adapters (ER4S-4P adapter, or find someone with the TF10 accessory). 
 
Unfortunately, I've never heard the Duet before. However, two top performing amps in the price range you listed are the C421 and UHA4. A bass-boost, the EQ on you iPod or a different set of IEM's might be what you want instead of high output impedance.

Hope this helps!

 

[luisdent]

I was discussing the same thing with ClieOS.  Perhaps you are correct in that the duet is "dampened", but it seems a little odd, because it sounds more natural on the duet.  Maybe there are other factors involved, but just as an example, and this is relatively speaking, listening to gypsy by fleetwood mac on the duet sounds "right".  The cymbals are bright, but they sound well mixed relative to the other instruments and don't really "stand out" in a bad way.  Now, I have heard this song on a lot of different speakers and headphones.  I know the drums are mixed pretty brightly, but on the ipod touch they almost smack you in the ears with brightness (again relative to the duet).
 
On the duet they sound like everything else I've heard before but just "better" in clarity and detail.  To me I would describe the ipod touch as unnaturally bright in the cymbals.
 
This is pretty consistent across everything I listen to.  Things sound brighter, but not always better.  On the duet things might not always sound as bright, but they sound just as "good" and never bad.  My goal is to imply get that from my ipod touch.
 
Maybe these are showing the mix the way it was actually recorded, but it just seems unlikely.  I wish I had someone here to hear what I'm hearing.  Keep in mind, these are still the best i've ever heard my ipod, but the duet is better.  I just assumed from some graphs and reviews I've seen that the drop in treble is due to the impedance of the duet being higher.  If that 'was' the case, i would prefer a 32ohm output for the pfe232.  ClieOS mentioned the adapters.  Would those retain the overall sound quality while acting essentially the same as the duet impedance wise?  Or do you think the duet might just be a much better amp, and that i'm better off getting a higher quality amp?  Also, the ety adapter is 75ohms.  If that dampened it further it might be too much dampening... In fact half way between would be perfect. lol  I have some electrical experience.  Perhaps I can find the correct resistor values and just solder then in series with an old adapter I have to give me, say, 16ohms more than the ipod?
 
I've read that the ipod dac/amp is at the point where you hit diminishing returns (navguy website)...

 

[tzjin]

ClieOS is extremely knowledgeable in the audiophile arena, so I'm glad he's been able to help you out like he helped me in the past.
 
 
Impedance adapters should have the same effect as high output impedance. It is possible that the iPod Touch has a spike in the treble region where cymbal crashes reside, and such an adapter would help with it. I actually do use the attenuator (same thing) from the TF10 set for certain headphones to both turn down the volume and to provide a shift towards the low end, so I can understand what you mean by more natural. The clarity and detail is probably due to the Apogee's DAC and Amp, and is not necessarily a product of it's impedance. However, the toning down of bright sounds may very well be. 

The attenuator I use can be found here. I believe it is something near 100 ohm impedance, which still should not be too large a difference from that of the Duet. If you want to make your own, just make sure that you're using resistors matched (rated) to the 0.1%. It's not a terribly difficult project and I'm sure you're more than capable 

I am also relatively certain that very few portable amps have an output impedance of over 10 ohms. The first version of the C421 was pretty high (almost 10 ohms), but was revised to be much close to zero. Most amp designers prefer a low output impedance to avoid affecting the FR in an unpredictable way, since output impedance would have varying effects on different headphones. 
 
 
At this point, you can either:

• Just try the impedance adapter directly out of the iPod Touch. You may not gain clarity and detail, but the treble will be toned down.
• Use a LOD to bypass the iPod amp and see if if using a portable amp solves your problem. You'll most likely gain better sound, but might not solve the brightness problem if it arises from the iPod's DAC.
• Use both a portable amp and an impedance adapter. 

 
 
As for diminishing returns, you did buy a $600 IEM so I'm guessing it's not a huge deal. If it is, just buy a Sansa Clip. 

 

[luisdent]

Quote:

ClieOS is extremely knowledgeable in the audiophile arena, so I'm glad he's been able to help you out like he helped me in the past.
 
 
Impedance adapters should have the same effect as high output impedance. It is possible that the iPod Touch has a spike in the treble region where cymbal crashes reside, and such an adapter would help with it. I actually do use the attenuator (same thing) from the TF10 set for certain headphones to both turn down the volume and to provide a shift towards the low end, so I can understand what you mean by more natural. The clarity and detail is probably due to the Apogee's DAC and Amp, and is not necessarily a product of it's impedance. However, the toning down of bright sounds may very well be. 

The attenuator I use can be found here. I believe it is something near 100 ohm impedance, which still should not be too large a difference from that of the Duet. If you want to make your own, just make sure that you're using resistors matched (rated) to the 0.1%. It's not a terribly difficult project and I'm sure you're more than capable 

I am also relatively certain that very few portable amps have an output impedance of over 10 ohms. The first version of the C421 was pretty high (almost 10 ohms), but was revised to be much close to zero. Most amp designers prefer a low output impedance to avoid affecting the FR in an unpredictable way, since output impedance would have varying effects on different headphones. 
 
 
At this point, you can either:

• Just try the impedance adapter directly out of the iPod Touch. You may not gain clarity and detail, but the treble will be toned down.
• Use a LOD to bypass the iPod amp and see if if using a portable amp solves your problem. You'll most likely gain better sound, but might not solve the brightness problem if it arises from the iPod's DAC.
• Use both a portable amp and an impedance adapter. 

 
 
As for diminishing returns, you did buy a $600 IEM so I'm guessing it's not a huge deal. If it is, just buy a Sansa Clip. 

I'm going to try some of those things.  I think the treble issue is in fact impedance, but i'm wondering if something like the fiio e17 might improve the overall ipod quality anyway?  I can't do the sansa clip, because I have too much music. Ha.  I can't even do the ipod touch barely at 64GB.  I'm switching back to an ipod classic soon 160gb.  And my music is 256aac, which is also not as good as i want it.  I can hear it more clearly with the pfe232 that it is 256aac.  I want 320aac with 160gb, then I can almost fit everything i listen to. haha

 

[ostewart]

Fiio E12,

 

[luisdent]

Quote:

Fiio E12,

Is that out yet? hmmmm.  price?

 

[tzjin]

Quote:

Is that out yet? hmmmm.  price?

 
E12 is not out yet. Fiio has stated that it will be under $199, but that's the only information on price right now.

 
256AAC is pretty much on par with other 320kbps mp3's, which is indistinguishable from FLAC for most. It's not likely that you will be able to hear a difference unless you have an extremely resolving setup and sensitive hearing. I personally would not bother.

 

[luisdent]

Well, this whole idea may be going down the drain anyway.  I'm having a horrible time with this headphone search.  I was listening to the pfe232 last night and I was in love.  Then today, switching genres and trying all sorts of songs I was completely disappointed about as many times as I was in awe.  It's like the treble on these is a double edge sword.  The iPod makes it twice as bad, but even on the duet it varies so much based on song.
 
Through research I believe the impedance difference of the devices is why the treble is more laid back on the duet.  However, ClieOS and a few others I've discussed it with seem to agree an amp may not fix that, as they strive to be lower output impedance not higher.  Plus, an amp that retains the duet quality would easily be over $100 and that puts me higher than I'd like to spend really.  I'm already above what I set out to spend, but I just cannot live with the flaws of all of these headphones.  It's either unlistenable sibilance, lack of all bass, lack of all treble.  I'm truly in shock that more balanced decent quality headphones aren't out there.  And if they are it's even more frustrating that it is so hard to know what they will sound like before you buy them.
 
Everything is online now, no stores let you try IEMs, at least in NH, let alone sell IEMs.  How many times do I want to buy and return a headphone?  I've already done so more than I really wanted to.  I'm going to write a review on the PFE232 so you'll know what I'm talking about, but basically the treble is unnaturally bright on a lot of songs.  Sometimes this makes cymbals sound far too in your face and almost sibilant in a way that I literally can't listen to the song.  Other times the treble opens up a song so well it shows more depth than I've ever heard.  And not just in a "ooh that's bright" way, but actual detail resolution.  But the point I'm at now is that I have probably found 50% of the music almost unlistenable and 50% very enjoyable.  That is not acceptable for me.  I realize no headphone is perfect, but even my ex85lp sounded "good" on everything I ever threw at it.  All I wanted in the first place was something flatter than the ex85lp.  Less bass and better treble extension.  Not even better treble really, just extension further up, say past 13k or so.
 
I'm not sure if I should just quit or start the whole process over with "over the ear" headphones.  Or keep trying IEMs in the 300-500 range.  But then that becomes a challenge, because a lot of places don't allow returns that sell those quality IEMs, and I have no way of trying them.  I can't afford to go through 5 pairs and lose 30% on each sale.  Ugh.  I have no idea where to go from here.

 

[tzjin]

I would consider selling the PFE232 and switching down to a slightly more bassy IEM such as the 3.ai or the GR07. Even if you lose a bit of money either on resale or return, those two would both leave several hundred dollars in your pocket. 
 
If you first ask the owners in their respective threads with a list of your preferred genres, you should be able to get a pretty good idea of what fits you.

 

[luisdent]

Quote:

I would consider selling the PFE232 and switching down to a slightly more bassy IEM such as the 3.ai or the GR07. Even if you lose a bit of money either on resale or return, those two would both leave several hundred dollars in your pocket. 

I had the same problem with the gr07.  I couldn't listen to the sibilance on most vocal songs.  Perhaps I'm more sensitive than others, but it never "burned in" or got better for me :-/.  Plus, I would really prefer to go more neutral.  I don't mind a little more bass, but the mids and treble I find really need to be close to flat.  The best I've ever heard so far in that regard would be the pfe112.  I actually would rate it higher than the 232, only because it didn't have any sibilance or other issues.  I just found it too bass light.  Not even by a lot, but enough that it mattered.
 
The site I bought the 232 on does allow an exchange for any reason if the price is at least the same.  That would give me a few options if I could really narrow it down I could try another set.  That would give me the shure 535, westone 4R or the UM3X or Westone 3 or Sennheiser IE80 if I didn't mind taking a small price hit on the last three for being lower than I paid originally.  So primarily the Shure 535 or Westone 4R if the same price.  Otherwise I pay 15% of the difference of price, which would probably end up being 15-45 dollars depending on the set.  But they might still end up costing less.  Anyhow, of those, the shure 535 seems amazingly well reviewed, but even most people that love them will say they lack the high details of other sets.  I wonder how they compare to something like the pfe232 in highs?  I know they aren't as "bright", but realism and details and "airy"ness...  The Westone 4R look very V shaped from the engoldenears.net graph.  This seems like the opposite of what i'm looking for, but I won't rule it out completely.  If it has no sibilance and still sounds very "realistic" and natural then it is a possibility.

 

[tzjin]

Sorry I'm not too familiar with those higher-end IEM's. I also seem to be pretty sibilance-deaf, so I've really enjoyed my GR07.

As a last ditch resort, why not try EQ? It's not ideal, but it's worth trying.

 

[luisdent]

Quote:

Sorry I'm not too familiar with those higher-end IEM's. I also seem to be pretty sibilance-deaf, so I've really enjoyed my GR07.

As a last ditch resort, why not try EQ? It's not ideal, but it's worth trying.

That's the irony, I found that eq doesn't help much, because I really think it has to do with reflections in the ear or something.  Jamming them in further isn't as comfortable but it helps a little, but also reduces the overall treble quality.  And with the treble quality reduced I can easily cut the bass of my ex85lp in half and get "almost" the exact same result as the pfe232.  The 232 has a little more detail and depth, but very very slight difference.  In fact, I'm surprised the signature is so close to the ex85.  That's probably why I liked it so much   An ex85lp with less bass and better treble.  That's the exact signature i was looking for when i started, but minus sibilance, which the 85 has zero of for me.  This is on the ipod mind you.  The duet sounds a little more noticeably better with the pfe because it tames the treble issue more.
 
My last possibilities are to exchange them for the shure535 or westone 4 or westone um3x.  Or potentially any lesser, but i'd have to pay a restocking fee if it isn't equivalent value, which is understandable.

 

[tzjin]

That is extremely unfortunate. One more idea came to mind over dinner. Have you tried using the foam tips? They tend to reduce treble presence and possibly sibilance. 

If that doesn't work, best of luck in your search. Perhaps the iPod classic will sound better. Sorry for not being able to be of more help.

 

[ostewart]

Get the SE535, it will sound excellent without harsh treble. I loved them