Review: Headamp Gilmore Lite

[Zanth]

Life seems to throw some lovely punches now and again. For some, the punches hit harder than for others. No biggie, I try to roll with it when I get hit a few times below the belt. Like for example, most recently. My landlord who is Genghis Khan reincarnated; she has broken 12 laws, 4 by-laws and about half a million ethical principles. Yes I have the means to pursue legal recourse and moreover, I should stick it to her, but frankly I’m just too tired, stressed out about other more pressing matters and I just don’t want to waste my time preparing a case against her. So instead, my wife and I have decided to move – December 29th is the big day. Christmas won’t be relaxing, though it should have been. I have not had a vacation since my honeymoon in 2000. I worked a ton this past summer to bank lots of time off, I had slated about 6 weeks off, basically as soon as my classes finished this semester, which is next week, and I would have returned to work in January when classes started up again. So why not take the time now? For one, I don’t want to be home with Genghis living next door. For another, now that being home means packing the house…well I would rather work. My wife and mother-in-law have agreed to pack up the place as much as they can. I’ll take my vacation in the spring.

Besides the obvious breaking out of the tiny violin, playing my sad wallowing tune, what has this got to do with music? Music is my greatest stress reliever. I can be having the absolute worst day but if I can strap on some cans after my wife and son have gone to bed, turn out the lights, spin up a disc, and crank up the volume – well, my day doesn’t seem to be as bad as I had initially perceived it, or if it has been, the music makes me forget about it for an hour or so.

Recently I had the opportunity to listen to the new Gilmore Lite from Headamp. I have heard two other Gilmore amps: the first was a Gilmore V2 back summer 2003 and the second was a DIY V1 last Christmas at the Ottawa meet. I wrote about my impressions about the Gilmore V2 here. If interested, one can read about them, but a brief recap is that I liked it. I liked it a lot with Sennheisers, Etymotics, and Joe Grado phones. I was not so thrilled with John Grado phones, mainly because I felt the sound was too forward, lending to brightness in the highs. What magic that was created with the other phones was lost on me when using John Grados. This was a surprise for me because the Gilmore had been designed for Grados in particular. Kevin had used HP-1’s to voice the amp so it is not surprising that they sounded great with this amp when I tried the combo out, but when John started tweaking the drivers…and moving the sound more forward, well, this discreet amp was too much for them, at least my ears felt so. Certainly on paper this amp should have been perfect for the John Grados, especially given the high current output. But alas, it was not so for my tastes.

After spending a month with the new Gilmore Lite and taking another month to formulate my thoughts (or more truthfully, to find time to write up this review) I have some new thoughts on the relationship between Kevin and John, or at least the synergy of their respective components.


Design

When I first opened up the box from Headamp, the box was well packed with a plethora of popcorn packaging foam. Tucked neatly somewhere in the middle was a large bubble-wrap package, deep inside this wrap was the sexiest solid state amp I have set my eyes on. My top choice had previously been the Sugden Headmaster, but this new brushed aluminum beauty tops my charts. It was smaller than I had expected it to be. I mean, conceptionally I knew its footprint was about the size of a Redbook jewel case, but I guess I had not consciously thought about it. Given my experience with the other two Gilmore amps, both much larger, I was pleasantly surprised with this little guy.

Its size is comparable to the RA-1, which is perfect for those that need an amp that doesn’t take up precious real-estate. This amp fit perfectly on top of my RA-1 on my desk, and would have fit nicely between my phone and computers at my lab. Though I am often drawn to massive hulking amps, I can’t deny that those large units are cumbersome and hard to deal with given my limited space issues.

The enclosure is constructed from a single-piece of brushed aluminum with a flattering 1/4 inch thick front panel. The front plate sports high quality silk screening, an inset 1/4 jack, the ever popular blue power LED, and a classy custom made volume knob. This knob feels great in the hand and from memory, is far superior to the plastic knob that I used on the V2 in my previous review. The entire unit measures in at 5.5W x 4Dx 1.1H, and weighs about 1 pound - a very practical size. A size that perhaps gives the illusion that this amp is somehow less than its bigger brothers, it is not.

The Lite v.2 (since it is the second carnation of this design) houses the same discreet circuit designed by Kevin Gilmore as all of the other amps in the Headamp line. However, there have been some changes in the circuit since my experience with the Gilmore V2. There is a new board layout incorporating a ground plane which is said to reduce noise and increase stability as well as upgraded caps. The build quality is also dramatically improved and said to be the driving factor for any perceived sound I may have.

As for the circuit, I’ll quote from my previous review since it is the same:

:Borrowing from the Headwize.org page and from Headamp.com the design is an all discrete design in the signal path with opamps only in the power supply circuit. “Stage 1 is a dual is a dual FET fully-differential fully-balanced front-end. The idling current is 2mA total per dual FET (1mA per FET) and 4mA for the complete front-end stage which consists of both dual FETs. The dual FETs generate the bias which runs the second stage, and keeps it and the resulting output section in class A at all times. The FETs are ultra low noise dual units specifically designed for audio uses. The total voltage gain of the first stage is 50.

Stage 2 is the driver stage and is a standard class A voltage amp. The voltage gain is 0.5 and the idling current is 4.3 mA. The push-pull class A output stage is a series of paralleled emitter follower, current buffers. The voltage gain is 0.9 and the current gain is 75. The idling current is 15mA per transistor (or 60mA for the 8 transistors off the +16VDC rail and 60mA for the 8 transistors off the -16VDC rail).

And finally:


The servo circuit:

"most of the servo designs (Mark Levinson and Krell, for example) put the output of the DC servo back into the - leg of the amplifier.” Headamp does not agree with this approach because it “puts the noise and non-linearities of the opamp inside the audio loop.”
Instead the new “servo feeds back to the current sources for the dual FETs in stage 1. Like all servos, it is an integrator. Due to the large (relatively) integration capacitor and the 1 meg resistor, the frequency of this filter is 0.05 Hz. With even a decent opamp, the servo's noise is in the tens of microvolts, and does not affect the operation of the current sources significantly. The servo opamp in this amplifier measures the DC at the output, if any, integrates it and applies it to the midpoint of the two LEDs. The LEDs do have a slight change in voltage with respect to current, about 3 or 4%, and that is enough to make the servo work.”

What the Gilmore Lite does not have is an internal power supply. Instead it uses either a custom made power supply available in addition to the amp, or it comes stock with an Elpac Power supply whose input jack is nicely inset on the back of the amp adjacent to the power switch and rca jacks.



All in all the amp is very well constructed, neat and tidy inside, solid enough to withstand an accidental bump or drop, sexy enough to pass the WAF test and small enough to fit practically anywhere. However, given its Elpac Power supply, does it have the juice to drive my phones? Most importantly, does it sound good?

Sound

The phones I had on hand were the Grado HP-1’s, the Grado RS-1’s, the Grado SR60’s and the Etymotic 4P/S’. Since my main attraction to this amp was in its capability for driving Grados, I don’t feel I am short changing the readers of this review -- unless somehow this little amp didn’t have enough power to drive these phones and others.

I wanted to compare this amp directly with the RA-1, so I unhooked the RA-1 from the SS stage of my cd player and placed the Lite into the chain. I was eager to discover its ability to drive the HP-1’s and since I had had good success with the Gilmore V2, I figured this was a solid place to begin.

Immediately I recalled the characteristics of its bigger brother, the V2. The sound was fast, linear (I could not detect any glaring colouration) and palpable. The bass was solid, deep, controlled but quite visceral best of all there was ample separation between the notes. HP-1’s really excel at providing the listener with clean bass of which the listener can easily follow the various bass lines in a complex piece. This combo did not take away from this phenomenon but provided the drivers with what they needed to get the job done. Since the HP-1’s require the most current of any phone I have experience with, and since my head was bopping, my foot was tapping and I was not put off by any apparent faults, I can confidently write that this amp does indeed provide the current necessary to drive Grados. Moreover, many of the attributes of the larger offerings were present. To write they equalled or surpassed the V2 would require a direct comparison of which was impossible at this time. I am confident though, that the Lite would hold its own against the V2, never being embarrassed. Perhaps the Lite’s bass was not as palpable as the V2’s and certainly not as palpable as my Melos’, but then this is expecting a lot from an amp with an Elpac psu. Perhaps the upgraded psu improves the strength of the bass. Don’t get me wrong, the bass was there, very enjoyable but I am anal when it comes to the force of the notes and this amp does lack when compared to my Melos which has been tweaked to maximize this characteristic of the sound.

With a smile on my face, I reached for my RS-1’s. This would be the breaker for me. If the sound was the same as my experience with the V2, then frankly, I would end up passing on this unit if it was intended to be used with a John phone. To my surprise no such passing would be necessary! The Lite’s changes certainly affected the sound, where once the sound was too dry for my tastes (with the HP-1’s the sound is as flat as I could ever imagine reproduced sound sounding, at times perhaps a bit boring) the sound had a more body and warmth to it. Perhaps the upgraded caps are the culprit? Or perhaps it was a result of the servo circuit? Whatever the cause, I’m pleased with it. The RS-1’s stayed on my head for 5 discs straight, about 4.5 hours. Whereas with the previous V2, the RS-1’s couldn’t stay on my head for longer than RS-1’s without me ripping them off. The sound was extended, full, palpable and controlled. The Lite certainly did a better job at controlling the bass than the RA-1 does, separating the notes well just like with the HP-1’s. This enabled me to detect lower notes in the passages than I am normally able to with the RS-1’s when using the RA-1’s. The highs were very nice, sparkling but not overly so, with as much extension as I have heard while using the RS-1’s and plenty of control with sibilance. The mids…well the Grados excel so much in the mids that it takes a lot for an amp to screw them up. Certainly they sounded great and on par with the RA-1. In fact, if I had never owned an RA-1, I would choose the Lite over the RA-1. Since I do, and the prices are comparable, there is no point in my selling off the RA-1; also, it was a gift, so it stays. The RS-1’s are a very sensitive phone. I can often hear a hiss from an amp if it is not dead quiet. The RA-1, likely because of its battery power, has a black background, no detectable noise at all, the same could be said about the Gilmore Lite. I could hear no hiss even when cranking the volume to max without music playing. Very impressive.

The PRaT of Grados is perhaps its crowning achievement, and the Gilmore amps live up to their praise when they accommodate the Grados fine PRaT, my foot rarely stops tapping when listening to these combos.
The sound is not as liquid as with tube amps nor with the RA-1 (perhaps it is because of the discreet vs. opamp aspect?), but there was a nice coherency in the sound using the Grados. I have no complaints about the sound and I could live with this amp for a long period of time. Certainly it would work well with an HD DAP at work.

Now then, how about using it with the Ety’s? I had previously written that the V2 was the best amp I had ever heard driving the Ety’s. The Gilmore Lite equalled this experience and even surpassed it with its smoother sound and its upgrades leading to less shrill in the high end. This family of amp would still be king if it were not for my recent experience with Fix-up’s SuperMacro. In all fairness, the bassboost of the Macro was the added magic that really sealed it for me. If the Gilmore Lite incorporated a bassboost for use with the Ety’s, I’m sure it would jump back into the number one spot. That said, the bass is still fantastic and solid but a bit thin, which is more a handicap of the Ety’s vs. the Gilmore Lite.

Conclusion

The Gilmore Lite surpassed my expectations and sound wise, lays waste to its preceding design, at least for my tastes when using John Grados. I can now enjoy a fine amp with fine phones listening to fine music sipping a fine wine and sucking back a fine stogie. The build of the amp is top tier, the look is my favourite thus far out of solid state amps and its small form factor make it ideal for almost any system. Where it may lack is in the “oomph” department, likely caused by the Elpac psu. This may be corrected using the custom psu (an additional $175) or if not, then one could always go up the product line for one of the bigger amps. They too have incorporated better parts and the new servo circuit. Thus, I assume, their sound will be the same or better with the John Grados. Is this amp a winner? It sure is in my books. At $299 I can’t think of a better home amp for the money. If the additional psu is out of this world in combination, the certainly at just under $500 this is a combo to beat, certainly when listening with Grados. Does it surpass that magical synergy of the RA-1/RS-1 combo? No, but it sure beats it in the bass area, an area many don’t particularly appreciate with the RA-1/RS-1 combo. That said, going for this amp over the RA-1 would be a no-brainer for these folks.

Thank you to Headamp for the opportunity to have an extended listen to this fine amp. I hope to hear some of the other offerings, particularly the Reference.

Associated Equipement

Shanling CD T-100 with Bendix Redbank 6385’s
W Enterprises NW Music Timbre .5m IC’s
Grado RA-1
Grado HP-1’s, Grado RS-1’s, Grado SR-60’s
Etymotic 4P with S adaptor cable