Upgrade from Fubar III amp to HeadRoom MicroAmp

Well, so much for being happy with what I got...

I didn't take my own advice, and after a few weeks with my just Fubar III, I decided to splurge on getting the Micro Stack so I could 'spoil' my HD650s. I was originally going to start a thread describing the differences I found between the Micro Stack vs. the Fubar III, but after finding this, I don't see any reason to.

Aimlink's advice on my other thread was spot-on, so I kept with it and got HeadRoom's Micro Stack. At first the differences were not overtly pronounced to my ears. Actually, at very first, I thought they were *extremely* pronounced, but I realized that the crossfeed switch was on. *** Once I figured that out, I didn't think I was hearing a difference that warranted me spending twice the cost of my Fubar III/PSU. However, after ten days straight of just listening to the Micro Stack, as soon as I switched back to the Fubar, the Micro's improved sound quality became accessible to me. The improvement wasn't overwhelming, but it was definitely there. Like you've mentioned to me before and again here, I began to fully understand that the Fubar III/PSU is a great deal for the money.

The same day I gave the Fubar a second chance and was able to pick up on the Micro Stack's strengths, I then rolled the Fubar's op-amps, replacing the stock OPA2227 with the Burr Brown 2627. I had seriously underestimated the role of op-amps and the sound of the Fubar III improved far more than I thought it would. Still though, to my ears the Micro Stack was ahead of the Fubar.

Here's the interesting part; after playing around with all the units for the next few days, I felt the combination of the Fubar as the DAC (via its RCA outs) used with the HeadRoom Micro Amp, outperformed the Micro Amp + DAC. The strengths I originally heard over the Fubar from the Micro Stack - better defined bass, broader sound stage, faster response, were again magnified with the Fubar III (rolled op-amp & PSU). The difference was slight, but to my ears, that's what I was hearing. When I had originally tried the Fubar III (with the stock op-amp) as a DAC for the Micro Amp, the differences were surprisingly minimal compared to the the Micro Amp + DAC.

After hearing all the nut-huggery HeadRoom's crossfeed was getting, I've been pretty let down. In the very beginning, I thought it sounded great, but after my very first intensive listening session, the crossfeed's effect sounded really intrusive and artificial. The bass is ridiculously magnified, and the sound stage gets mashed into an echoey cardboard box.

So far, there's only been two situations I've felt the crossfeed was a 'plus', 1) rap/hip-hop. I feel the added bass lends itself quite well to rap's intended musicality along with the vocals blending in with the instrumentals. 2) old stereo mixes of early rock (i.e. Beatles). When the vocals are located entirely on one side, and instruments on the other, the crossfeed definitely does help. What actually helps much more though, is listening to the remasters of the mono mixes instead.

Actually, the incredibly altered sound created by the crossfeed shocked me because so many 'audiophiles' here love it. The effect is far from subtle and runs counter-intuitive against all these people claiming to be in search of, and preferring, more neutral, transparent sounds of expensive h-fi. Don't get me wrong, the crossfeed is a definite plus, but only with rap and recordings with poorly mixed stereo. I'm boggled that certain hi-fiers aren't distracted by its unsubtle impact.

All in all, I'm basically in agreement with most of what you said about the Micro Amp and your comparison of it with the Fubar III. I'd be curious what you think of the Fubar's sound after adding the 2627 op-amp, which I felt made just as much of an improvement, if not more of one, as the PSU did.

Tomorrow, I'll be calling up HeadRoom to return the Micro DAC. I'd rather save that money and get the Denon D2000's you had suggested earlier, perhaps with the "lite" Markl mods (hmmm, I smell a whole nother thread a brewin), than keep the Micro DAC. The only objective value I see for the Micro DAC is the extra inputs, but since I only used listen to my 'phones off the computer, that's not a major plus for me.

Questions: how do you feel the D2000 matches up with the Micro Stack/Fubar compared to the HD-650? As far as I can tell, except for the added bass, the 650s beat the D2000s in all other areas (detail, soundstage, etc). Are there certain genres or whatever that you prefer the D2000s to the HD650s or feel they are equal to? Also, how much of the difference does the Astrodyne Power Supply make with the Micro Amp? Are the differences noticeable, have you tried the Micro without it? Is it comparable to the Fubar III and its PSU? Basically, is it worth the $120? I ask cause I'm thinking about ordering it when I retrun the DAC...

I just realized that this is actually the 'sponsored forums' so I'll include a few more things for the guys at HeadRoom (or Firestone, etc):

- Good job having the switches up front. Inexplicably, the Fubar puts them in the back, jammed between wires. My guess is they liked the look of a streamlined faceplate, but the consumer just ends up eating a crapsandwhich of inconvenience... However, Headroom, there isn't any reason to make them so absurdly tiny. I have 20/20 vision and still have a hard time reading them, and the switches themselves could be made bigger and still have room on the faceplate. The Micro seems to relish in its 'micro' size, but I think some larger switches would actually accentuate that even more. Just food for thought.

- It's not a big issue because my HD-650s came with a great adapter, but why use a mini-stereo jack? Aren't most people who drop $333 on a dedicated headphone amp going to have the 1/4" jacks?

- Great job making them secure while stacking! Firestone should take note to not just make products the same size, but have some way to make them secure when stacked, no reason not to.

- Volume knob could be bigger. I agree with aimlink that the Fubar's volume knob is more ergonomical, and I think it just feels/looks better. The Micro's knob suffers from its 'EVERYTHING-MUST-BE-CRAZY-TINY' syndrome. Don't be afraid to make it shiny and large, us users know it won't bite us!

- 3 level gain switch. NICE! The two level gain switch with my Fubar III was sorta like mama and papa bear's porridge, either too hot or too cold. With a 'medium' setting, I feel I can get some porridge that's 'just right'. Should also be another plus once or if I get the D2000s.

- Why not allow the op-amps to be rolled? This smells like some plainly evil up-selling malarkey to me. Why should someone have to pay $260 more for the addition of the OPA627s found in the "Ultra" Micros? Because they are, as you say "rare & astronomically expensive." Really? I bought a pair AND an adapter for $51, and that was after a price mark-up from the seller! C'mon, that shtinkkayy! Headroom would probably gain a lot more buyers within the knowledgeable hands-on community, and still be able to sell the same amount of "ultra micros," if not more, for the other things they offer that the non-ultras don't. Actually, if they allowed for rolled op-amps, I undoubtedly would be keeping my DAC (and feel a whole lot happier about my amp), so there's one person they lost with that.

Well, my experience with the Fubar III vs. Micro was that the crossfeed made a much bigger impact on what I heard, rather than whichever amp I was using. This is just my opinion, and I'm not exaggerating it, if only because there is zero reason for me to do so.

Like you suggest, I do all my 'testing' using music I am extremely familiar with, mostly songs I am usually able to ABX without much trouble (320 CBR, lame 3.98 vs flac). It took some rather long, intensive listening sessions to clearly distinguish what I was hearing with the Fubar and the Micro. The most obvious, as you have already pointed out, was in the low-end, and the Micro's ability to extend on its definition. I also found a smidgen more clarity with the Micro across the board along with with it being a little faster. All in all, I was really shocked how close they sounded - the Fubar III/PSU is just a pinch over half the price of the Micro Amp + AC.

The crossfeed, on the other hand, was rather obvious for me to pick out, too much so for my taste. When looking at most of the comments on the crossfeed here at hi-fi, I understand how my view on it comes off as exaggerated, but it is just my own personal experience.

For me, personally, I have a hard time focusing on the details of the music that I enjoy engrossing myself within when the crossfeed is on. This is mostly because of the added bass when it is on. An example would be some Etta James songs I listened to, and her voice with the crossfeed can create a noticeable 'boom' that bottoms out my 650s. Vocals are more midrange-ish, so this was really distracting for me. Another example would be Kings of Leon's bass lines, which are already heavy, but dominate the recording when I used the crossfeed.

I think this just boils down to principles. The crossfeed's concept, which is by definition artificial, is just not for me, as I would generally side with 'purity' over most other things. There's no "right" way to enjoy listening to music, so this is really a matter of taste. I don't need things to be "pure" nor am I under the assumption that what I'm listen to is supremely neutral, I just happen to enjoy a more 'pure' sound than what the crossfeed offers. I can't comment on the exact level of purity found within my systems, just that the crossfeed is a step in the wrong direction for my subjective tastes.

I am still interested to hear whether or not you found the Astrodyne Power Supply to be a worthy addition to the Micro and if you would recommend it. I would also really like to hear how you felt the D2000 matching up with with the Micro. Your comments have been really helpful before, so I'm definitely interested in your ideas on the Astrodyne and D2000 along side the Micro.

I agree with you about the crossfeed. I rarely use it on mine, but when I need it I'm glad it's there.

As to the small design of the amp, have a look at the circuit board photos if they still have them up on the new site. It looks like it was all they could do to fit four switches, a volume pot (and knob!) and 1/8" adapter on the front. I'd think a 1/4" socket would either A) make the amp much bigger or B) cause many of the switches to be moved, and there certainly isn't any room on the back of the unit to move them to.

As to the small screen printing... well, the best thing to do is memorize what each switch does. Like, three from the left=gain and so on.

Yeah, I'm not trying to say that the crossfeed is junk or unlistenable, just I prefer it off most of the time. I fully understand how people enjoy its sound, which can be good and sometimes great, I just find its effect contrary to many audiophile's supposed preference of 'purity' . Basically, I get distracted by hearing an emphasis on things I know aren't there. This is only my very limited two cents, though, so take it for what it's worth

Despite all my documented grievances with it, believe it or not, the crossfeed was actually *the* deciding factor why I kept the Micro Amp. When I'm listening to hip-hop, I found it immensely enjoyable and I believe it takes this genre's musicality to a level that isn't normally accessible (through headphones) without it. I listen to about 20% hip-hop, and after hearing the crossfeed's definitively positive impact on it, I couldn't bear the thought of giving it up. Yeah, the Micro Amp sounded slightly better in general than the Fubar III, but without the crossfeed, I probably would have kept saving my money for something that offered a greater leap in sound quality.

Moogoob: Through necessity, I quickly memorized all the switches! I'm not really sure there's any other practical way to go about it. The Fubar III (and the PSU) place the controls, aside from the volume knob, on the back, which I think is a significantly worse location. This is especially true since these small switches are jammed between the input/ouputs and when stacked, whichever is on bottom is really hard to get to. Ergonomically, I think the Micro is a generally better designed unit, but that the Fubar III does looker 'cooler', for whatever that is worth.

Aimlink: If you still use the Fubar III, I think you might consider ordering the 2627 op-amp from Firestone Audio - Headphone Amplifier - USB DAC - Digital to Analog Converter With the adapter and shipping it comes to $61, and, in my opinion, is on par with the PSU's level of impact. It's really easy to put install, too. The sound-stage becomes much more 3D, the transitions are faster and more detailed, and scientifically speaking, it gives the sound more 'pa-zang'

the ultra micro is maybe a little bit smoother than the regular micro, although i still find my ultra micro stack a little too bright sounding with my HD650, but with my AHD5000 it just PERFECT!
I find the headroom sound very accurate and neutral,maybe just a hint of warmth...so they say. that's why it goes so well with the denons, its providing them all the dynamic and bass tightening that they need and the sound is the best I heard so far.

I am waiting for a earmax pro to use with my HD650,hope that it can smooth em' up.

I just love the crossfeed on my ultra micro stack (HD650s). I had a total bithead once though, where the crossfeed was less impressive, so maybe it is something that scales according to the model.
It does tend to squash the stage a little, but what you said about echoey cardboard box was ungenerous to say the least. I always think the soundstage on headphones appears too wide in comparison to depth anyhow, so losing some of that width in favour of (percieved) depth doesnt seem like too much of a bad thing to me.
It does seem to make headphone listening even more "intimate" than it already is, which could be perceived either way I guess

You know, I think the number of times we're fooled by our own heads with audio stuff is far more common than our heads let us believe.

I fully agree as well. When my Micro Stack from HeadRoom first arrived, I tested them back and fourth for about an hour and thought they offered only a minimal gain in resolution over the Fubar III/PSU. I gave my Fubar III a break, and for the next three weeks listened solely to the Micro Stack and became completely adjusted to its sound. It was only after I pulled the Fubar off the shelves again that the differences became less subtle. To me the Micro has better resolution and cleaner, speedier transitions - it just took an extended break from my Fubar III for it to come into focus.

Unfortunately, I was running short on time and only had a day to compare the Micro DAC to the Fubar III, matching both with the Micro Amp. I felt like the Burr Brown 2627 op-amp I had just rolled help give the Fubar III the edge and I sent the Micro DAC back. To this day I still wonder if I made the right choice - only having a day to decide was far from optimal. I also hope I won't be needing any other inputs aside from USB, because the Micro had both coaxial and optical, which the Fubar III lacks.

I am taking some artistic license describing the HeadRoom crossfeed, but I feel like them calling it "subtle" is just as far of a stretch (and solid marketing, too). Either that, or I just have amazing ears To me, the crossfeed is apples to oranges. Personally, I don't find headphone's inherent sound in need of constant fixing. It seems like for some the crossfeed creates a more 'speaker-like' sound, but that's not a no-questions-asked, leave-it-on-all-day-and-night plus in my book. Listening to music should only be about personal tastes, so whatever tickles your pickle or jams your clam is ultimately whatever's right.

For all my criticism on the crossfeed, at the end of the day, like moogoob said; when I need it, I'm glad it's there.