[wrhawk]

Well, after 25 hours of waiting, i've been granted the authority to post; let's get to it.

Let me outline my audio history such that you're all able to get a better idea of what my goals and ideals are:

I was raised in a musically-inclined family and consequently exposed to a good deal of live and recorded music. Everything from Bach's Goldberg Variations (Gould, '53 and '81), to visits to the Minnesota Orchestra Hall, to my dad's James Taylor albums, and even those days spent up north singing along to some classic Andrew Lloyd Webber with my cousins. I studied trombone, competed regionally and played with a local youth symphony. I've since taken up (a fine british columbian) acoustic guitar and have developed more diverse musical tastes. Some of my favorite contemporary groups include Sigur Ros, Radiohead, Stereophonics and Nine Inch Nails (to name a very few).

I worked in the home audio dept. of the local Circuit City for a year, and while there discovered my passion for audio equipment. Needless to say their selection offered little worth considering, i did pick up a modest consumer-electronics a/v rig. Here's the aural portion of it:

-Onkyo TXSR501 Receiver (they don't carry Denon, and HK just doesn't do it for me)
-Onkyo DVCP701 DVD Changer (had the DXC390 cd player, which i loved, but sacrificed it to accomodate a tv purchase)
-Polk RTi38 Bookshelfs (i've got a small room)
-Polk PSW404 Sub (the only piece i regret; i should've gotten a velodyne)
-Monster Interconnects all around (mid-level cables selected after a good deal of research; optical used for audio)

As far as portable audio is concerned, i'm fairly new. I purchased a pair of SR60s around three years ago and have loved them ever since. Having finally moved into a dorm, i now use them more than ever. I've got a set of Klipsch 2.1 computer speakers (which are supposed to be pretty decent), that i've found to be 'okay.' With the random noise levels here in my wing of the dorm, i've found myself increasingly annoyed with the fact that i've got to turn up my (normally quite modestly-amplified) cans. This being said, i've taken it upon myself to take my listening to the next level, as it were. Herein lies what i need my rig to accomplish:

-My computer must act as my primary source (currently most of my collection is 192kbps, but i'm perfectly willing and able to re-rip my favorites into lossless if it's required) *Note: I have a SB Audigy card in my tower
-The amp must be portable and of the highest quality that i can attain while observing the conditions of: a) being reasonably-priced and b) reducing the amount of long-term hassle on my part (see: battery-powered. well.)

I've done quite a bit of reading as of late, but not enough to complete my rig on my own. I've decided that, based on my conditions and the numerous rave (technological and emotional both) reviews, the Ety ER4Ss are my only choice for audiophile-quality sound from a portable source. *Note: I know there are plenty of reviews here that address amping Etys, but none match my specific conditions. So i ask that, unless i'm sorely mistaken in my observations, please refrain from linking me to an ER4P thread.

That having been said, let's talk about amps.

I use HeadRoom as my home base for non-a/v audio information (however it would appear that i've found a new mecca

), and consequently considered their amps first. That which meets my needs most specifically happened to be the Total BitHead - portable, reasonably-priced, long battery life, USB feed from my computer, and quality construction. Suffice it to say that this will be my amp in the event that no one responds to this thread. However, in my readings, i've come across several amps that, portable power aside, give HeadRoom's offerings a run for their money. Those that come to mind:

-HeadAmp's Gilmore line
-Other HeadRoom models (TAirHead, Little)
-DIY (Chu Moy, Dynahi, Mint)

What i'd like to know is, based on my provided information, which amp is going to best meet my needs without taking what little money i have away from me? I'm really just looking for a neutral, reliable amplifier that will compliment the ER4Ss without holding too much of their potential back. Any advice and/or guidance on this matter would be greatly appreciated. And, given the deadline for the Dynahi group buy, a bit of expediancy would also be appreciated

One final note: My brother just happens to be an Electrical Engineer and has offered to fab an amp for me, given i fund the project. He mainly does design work for a power supply company he works for, so micro soldering happens to be one of his more refined skills. If it's at all possible, i would embrace this alternative, especially considering the fact that HeadAmp posts their schematics and parts lists.

I've done a good deal of thinking on this issue, and really hope that the ridiculous amount of experience on this forum can help a future peer have a silly-assed grin on his face whenever he happens to fire up his cd player.

Thanks in advance for taking some time to hear me out,
Will

 

[episiarch]

I like JMT's portable PIMETA very much (www.jmtaudio.com). It's a 9V/8620-based amp. It sounds terrific with Etys and you can get it at a very good price. It does not have long battery life, but I think with a little drilling and wiring you could build yourself an external battery pack for it, or you could find a builder who will make you a similar PIMETA with a DC input jack.

I like the Headamp Gilmore Lite even more, but if you are trying to conserve cash then I would suggest a PIMETA as a starting point that drives Etys very well, with a Gilmore or other upgrade later when you're feeling more flush (or when you have time to build yourself a Dynahi).

Other amps I've owned, and my one-line review of each:
- MINT: don't like
- old-model (3xAAA) AirHead: don't like
(note, current-model AirHead/BitHead are a completely different design that I have not heard)
- SuperMini: like, but not in the same category as the PIMETA
- SuperDual: like quite a lot, but not quite as much as PIMETA

On your choice of ER-4S vs. 4S: I absolutely prefer the 4S sound and find it much more 'correct' than the ER-4P balance. Given what you've said about your listening preferences I think the 4S sound is the right one for you. But as of the last time I checked (maybe 2-3 months ago?) Etymotic still ships the ER-4S with its old-style rubbery cable, rather than with the lighter, more flexible braided cable of the ER-4P. That being the case, I would recommend the ER-4P plus the 4P->4S adaptor. I have Etys with both types of cords, and I find the stiffness of the old-style cord a pretty big annoyance.

 

[wrhawk]

Interesting. Did some reading over at jmt, looks pretty decent. My one concern, however, is using a pair of 4Ps as Ss via conversion. I know a bunch of people on the board currently do this, but i'm wondering if this isn't a terrible mistake. Many reviews i looked at claimed the microphonics of the stiffer S cables to be negligible when compared to the amazing sound that was being produced.

I'm wondering, if DIY amps are so successful, would i be a fool to opt for anything else, especially considering my brother's offer? It seems at this point that i may.

This input is helpful, but it raises a new set of questions:

[Edit] - quality question concerning the Ety Ss vs. Ps has been removed.

-How is the performance of the current (or recent) TAirHead or TBitHead amps? In all honesty i've never been able to find positive feedback for the TBH, i'm just assuming that when HeadRoom says that it's more neutral, that it's more neutral.

-DIY: Which design is the best for portable use, and are there any that cater to my <i>need</i> for use with my computer as source?

 

[sbulack]

I find the Headsave amp design to have a synergy with canalphones. For portable use, a Go-Vibe with stock OPA2227 amp is quite good. I prefer it for my canalphones over my PPA - better synergy. For home use, a new design Headsave Classic with AD8620/8610 opamps offers even better sound and synergy with canalphones, IMO. The design of these Headsave amps brings out the timbres and textures of the sound gorgeously, and gives the canalphones as much detail as they can present (with great clarity) without edginess or harshness in the highs.

 

[Spankypoo]

I'd also consider a Headsave Go-Vibe - it's a very good amp, inexpensive, and Norm can built it to suit your needs.

He can put in a DC jack, so you won't have to worry about batteries while in the dorm.

The 2227 opamp was mentioned - it does sound quite nice, and adds a bit of low-end bloat which can work with the Etys. I prefer the 823, tho, as it's just a bit cleaner and seems to work better with classical. (Also, battery drain is very very low, and it works down to low voltages.)

Good luck!

Oh, and the ER-4P with an S cable is probably your best bet - it's worth the flexibility.

 

[episiarch]

Quote:

Originally Posted by wrhawk My one concern, however, is using a pair of 4Ps as Ss via conversion. I know a bunch of people on the board currently do this, but i'm wondering if this isn't a terrible mistake.

I know of no reason it would be a mistake except that it costs more. Search around and you'll see plenty of testaments to the quality of the ER-4P + 4P->4S combination.

 

[wrhawk]

Wonderful. Many thanks for the responses.

Looks like my selections have been happily narrowed. As it stands it looks as though a pair of ER4Ps with a (thus far unspecified) P->S converter powered by a Headsave GoVibe with a to-be-determined op-amp.

And so it comes down to:
-Which P/S cable is going to give me the most value for both portable and home use?
-Which op-amp is going to best suit my tastes?

Available op-amps (as listed by Norm):

Quote:

OPA2227; Rich, smooth and clear sound with full bass. Well suited to most entry-level headphones. AD8620; Faster, more detailed and forward sound with very tight bass. A great match with Sennheiser HD series and Beyer headphones. AD8066; Similar to AD8620 with slightly less forward, more mellow sound. Dual OPA627/637; Very refined, natural and detailed sound, especially suited to the higher-end Grado, Audio Technica and Sony headphones. Due to it’s higher power demands, the OPA627/637 is not recommended for portable amps.

Spanky, you mentioned an 823 op-amp. The best i could come up with was this found on the HeadWize boards:

Quote:

I did later test this after that post in the thread cmoy referenced, and the AD823 is indeed noticeably weak when driving low-impedance headphones. With Grados (32 ohm) the combination isn't unacceptable, but it's a weak enough performance to prefer the OPA132/134 family in this case. With higher-impedance phones like Koss KSC-nnn's (60 ohm) there's still a small amount of weakness left. With high-impedance phones (most Senns, AKGs...) the 823 sounds better to me than 132/134s. Still, driving headphones directly from this chip is very edgy -- you're running it at its very limit. They can even get a little warm. (Not hot, just warm.) Adding buffers relieves the load on the AD823 and allows them to drive even very low impedance headphones. That's one reason I'm so exited about the Apheared 42 boards that are being built right now. It sounds like an ideal matchup, on paper.

[From the http://www.headwize.com/ubb/showpage...num=3&tid=2374 thread]

I know very little about these op-amps, but i do know that i want to have sufficient power to be able to use the amp for an extended duration, and thusly, i think the Dual OPA627/637s are out of the question. If those of you who have mentioned specific op-amps could elaborate on their qualities, it would be greatly appreciated. As it stands, Norm's description of the AD8620 sounds most appealing.

Once again, thanks in advance, and a most heartfelt thanks to those who have guided this thread already.


Will

 

[vranswer]

For me it's a slam dunk for the Xin SuperMacro (www.fixup.net). It's bass boost makes the Ety's so much fuller sounding, and the extreme portability is a terrific plus. I have ER4P and use the 'imped' switch on SM to convert the P->S. Dr. Xin is great to buy from too, and takes care of his customers.

 

[wrhawk]

Vr, i did some homework on the Xin SM and arrived at a few things. Initially, to purchase it with the 4 switches recommended for the Etys and other rational enhancements would put this amp way out of my price range. Additionally, the long preorder thread for the SM was a bit unsettling. I find myself siding with those who are weary of the prototypic-hype and instability (in some cases). Not to dissuade further amp suggestions, I truly appreciate your comment, but as it's simply too much money, i'd like for the thread to remain focused such that responses can be easily provided.

That being established, let's return to the question of the GoVibe and see if this is in fact the most viable solution.

The questions still stand:
-How should i solve the P/S problem? Should i be looking to achieve the fidelity of the 4Ss through a feature of the amp alone, or should i look elsewhere?
-Which op-amp is going to give the most neutral, complimenting sound in use with a pair of ER4Ps?
-And also, if the Total BitHead is out of the question (unless someone posts with some experience with the more recent models), what sort of mini cable should i be looking at to connect my sound card to the amp?

A few more specific questions:
Spanky, how does the 823 perform with other source material (ie rock, jazz etc)? And, since i own a pair of SR60s, will the output be too great to listen appropriately?
sbulack, does the low-end boost of the 2227 add simply a fuller, warmer tone to the Etys, much like a pair of colorful Grados would do to a straight source?

Progress so far is exceeding expectations; i hope now to hear even more helpful suggestions for catering to my intents and purposes.

Thanks,
Will

 

[episiarch]

A DIY amp would give you the opportunity to solve the P/S problem in creative ways. For example you could have two output jacks, one normal and one with the extra impedance to turn a 4P into a 4S.

(In case you haven't seen it yet, here is a link to the PIMETA DIY site.)

As for op-amps, my experience is rather narrow, but here it is: the PIMETA and SuperDual that I like use the 8620. I therefore recommend it. But I'm not in a position to comment on other choices.

The cable I use for non-portable applications is the Zu Pivot. It's not ultra-spendy, but it's not cheap. If on a budget, I would be happy with a Belkin Pure AV cable for about $15. I sometimes use one with my laptop, and it's just fine.

 

[Natsuiro]

I have a portable pimeta with AD8620 op amp and I quite like it with the er4s. But for home use I use my PPA with AD843kn, and I really like the sound of it since my PPA sounds quite neutral to me. But for some reason (I forgot), the AD843kn isn't recommended usually, because if you do it wrong, it can fry your headphones. But of course, I do like the dynahi much better than my PPA. I like all three of these amps because they sound quite neutral and transparent to me.

 

[wrhawk]

Natsuiro, how do you feel about your ER-4Ss? Personally, i feel a bit strange about getting the ER-4Ps and 'upconverting,' if you will. How do you listen to them, how significant of a concern are the microphonics and of all of your amps, a) which do you think is your personal favorite, b) how do the prices/quality compare between the three, and c) what sort of powering solutions do you use, or rather, what batteries do you use and how long do they last? Sigh, one more question (the last, i promise*): do you have the ability to plug your portable into the wall if you'd like?

Sorry for that barrage of questions, but i hope you can help me out.
Will



*not really, i'm sure i'll think of something

 

[Spankypoo]

Quote:

Originally Posted by wrhawk And so it comes down to: -Which P/S cable is going to give me the most value for both portable and home use?

You could probably find the Etymotic one for around $40 (I did) new. Norm would probably make you one for less than that. Is there a difference between the two? Probably not at all. But I'm fairly OCD and went for the Ety version.

Drop him an e-mail.

Quote:

Originally Posted by wrhawk Spanky, you mentioned an 823 op-amp. The best i could come up with was this found on the HeadWize boards:

In correspondence with Norm, he wrote: Quote:

The AD823AN is very battery friendly and has many of the sonic traits of the AD8620.

If you're planning on using it portably frequently, the 823 may be a better idea. The 8620 should sound a tad more refined, tho.

Quote:

Originally Posted by wrhawk Spanky, how does the 823 perform with other source material (ie rock, jazz etc)? And, since i own a pair of SR60s, will the output be too great to listen appropriately?

Tell him which 'phones you're planning on using, and he can set the gain appropriately.

The 823 performs very very well with jazz, and quite well with rock. The 227 has a slight 'groovalizing' effect on the output, but I tired of it after a while. (You may very well not.)

The opamps are socketed and easy to swap, and not very expensive.

Good luck! Ask as many questions as you want - you should be happy with what you get.

And don't expect the Etys to have the impact the Grados do - they're an entirely different approach.

Edit: Remember that any sonic difference in opamps will be less pronounced than differences introduced by headphones, e.g., Grados do much more for the low-end of a signal than any opamp will.

 

[Feanor]

Quote:

Originally Posted by wrhawk -My computer must act as my primary source (currently most of my collection is 192kbps, but i'm perfectly willing and able to re-rip my favorites into lossless if it's required) *Note: I have a SB Audigy card in my tower

Hello Will, I'd advise you to change that soundcard as well. I think it might make a bigger difference than the difference between a 100$ amp and a 200$ one. (EMU 0404 is about 80$ at a Guitar Center)

 

[Spankypoo]

Quote:

Originally Posted by Feanor Hello Will, I'd advise you to change that soundcard as well. I think it might make a bigger difference than the difference between a 100$ amp and a 200$ one. (EMU 0404 is about 80$ at a Guitar Center)

Quite right.