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Six-Way Review: Square Wave, GS-1, CanAmp, EC/SS, Gilmore Lite, Black Cube Linear

post #1 of 44
Thread Starter 
A Six-Way Solid-State Epic Throwdown!

This review originally began as a simple three-way between the HeadAmp Gilmore Lite, Eddie Current EC/SS, and Heed Audio CanAmp, when I owned them at the same time at the end of June '07. However, I recently realized that I also owned another similar amp at the time which I grew very familiar with, the HeadAmp GS-1, so I went back and re-edited to update the review with that amp included as well.

Now for those who haven't followed my crazed diatribes of the past year, I've always been a solid-state fanatic. Solid-state amps are just so convenient since you can just turn them on and go, and I've grown partial to the solid-state sound too. So all the writing below is by that of a true solid-state fanboy, a crazed lunatic hopelessly in love with the solid-state sound, continually seeking new and interesting takes to see where the next amp goes and what it does.

A big disclaimer that not all the amps reviewed below were necessarily owned at the same time: I did own the HeadAmp GS-1, Heed CanAmp, EC EC/SS, and HeadAmp Gilmore Lite at the same time at one point, but by the time I got the Lehmann BCL, the GS-1 and CanAmp had been sold. However, I had spent a lot of listening time with the GS-1 and CanAmp, and since the other components in my system hadn't changed, I feel I can fairly make a comparison between all the amps in this line-up.

To recap, these are the amps this review will cover:
- Lehmann Audio Black Cube Linear (partial discrete w/ OPA2134 op-amp), released 2004, $779
- HeadAmp GS-1 (discrete w/ JFET), released 2005, $849
- HeadAmp Gilmore Lite v2 w/ DPS (discrete w/ JFET), released 2005, $579
- Heed Audio CanAmp (NE5532 op-amp), released 2006, $450
- Eddie Current EC/SS (AD811 op-amp), released 2006, $429

Oh, and Merry Christmas 2007 Head-Fi, this is my present to you guys!

Equipment Used

Power cord:
- Signal Cable Silver Res Reference

Digital source:
- Arcam FMJ CD33 (CD player)

- Audioquest Python
- Signal Cable Silver Res Analog w/ Eichmann silver bullets
- PS Audio xStream Transcendent RCA

- AKG K701 (later re-cabled w/ SAA Equinox)
- Audio-Technica ATH-AD2000
- Grado SR325i
- Sennheiser HD650 (later re-cabled w/ SAA Equinox LE)

Evaluation CDs

Alison Krauss - Now That I've Found You, Lonely Runs Both Ways
Howard Shore - The Lord of the Rings: The Return of the King [OST]
Jewel - Spirit, 0304
Kevin Kern - Imagination's Light
Laika - Sounds of the Satellites, Good Looking Blues
Massive Attack - Blue Lines, Mezzanine
Neotropic - Mr. Brubaker's Strawberry Alarm Clock
Norah Jones - Not Too Late
Orbital - Middle of Nowhere
Peter Kater - Inner Works
Porcupine Tree - In Absentia
Portishead - Portishead
The Crystal Method - Vegas
Thievery Corporation - Richest Man in Babylon

Capsule Reviews

Lehmann Audio Black Cube Linear, $779 from Elusive Disc - Hardware, Accessories, SACDs, Vinyl LPs, DVD-As and MORE! Call us (800)-782-3472

Of the amps in this round-up, the Black Cube Linear has been around the longest, as it was released in 2004. Can it still hang with the competition that's been released after it?

Well, yes and no. On paper it looks like a nice enough amp. Compact form factor, IEC inlet, loop output, three-way gain (1, 3.2, 10), dual headphone jacks, partially discrete circuitry? (Caveat: output stage is driven by an OPA2134.) Those are all nice features, and they do make the amp look attractive from a features and usability point of view. Sonically it's very nice too. Immediately engaging with a slight mid-range warmth, the amp more than anything manages to catch your attention right away, on the opening notes of a track thanks to a sweltering fluidity and ease that swirls up and around and everywhere. Creamy you could say, though without the implication that "creamy" means overly warm, because it's not. The amp mostly exudes a relaxed, laid-back vibe that allows it to effortlessly track everything going on in a recording. It tracks dynamics easily too, as it contrasts well between soft and loud. Bass drives deep and nicely powerful on it (though not overly so - not as much as the Square Wave for example), and treble extends high enough for it to easily crank out squeaks and squawks and whatnot.

The main issue I found with the BCL was that it didn't stand out enough compared to the other amps I put it up against. It wasn't totally transparent, but neither was it that warm in the mid-range, more of an in-between characteristic. Not totally involving and direct, but not spatially wide/open & clean/transparent either (though it does have a fine open soundstage, just not as open as its nearest competitor the HeadAmp GS-1). Nothing really wrong with it, but not a true stand-out amp in any real way.

Available in silver or black.

Optimal headphone matching: AKG K701 (maybe - preferential), Audio-Technica ATH-AD2000, Sennheiser HD650

HeadAmp GS-1, $849 from HeadAmp - Audio Electronics

When it comes to achieving transparency on the input signal (the goal of wire w/ gain to minimize signal loss of any kind), HeadAmp's GS-1 is at the top of the heap, and then some. It's almost completely transparent on the input signal (estimating, about 96%-97%), and as long as you don't hear the GS-X, you might very well believe it is practically the last word in transparency. Built on a pair of modules utilizing the open-source discrete circuit known to DIY-ers as the Dynalo (designed by Dr. Kevin Gilmore), which currently operates with a JFET. New modules are in the works for an all-new custom circuit with a MOSFET output stage and hopefully we'll see them next year.

Of the amps in this round-up, the GS-1 is the most feature-loaded, as it gives you dual headphone jacks, two-way gain (3 and 8), dual inputs, loop output, and pre-amp output. The modules are also user-replaceable to allow for self-upgrading whenever HeadAmp's new modules are released. The amp also uses an IEC inlet which allows for use of aftermarket power cords. Finally, the amp can be installed with an optional DACT stepped attenuator upgrade.

The amp is built and finished in an attractive, clean brushed aluminum chassis and has sound to match those looks. A highly polished, Windex'd sound might offer the best description of what the GS-1 offers. There are amps that make you feel like you're listening to an amp. Not the GS-1. This amp instead makes you feel more like you're listening to your high-end source - unruffled, uncolored. Incredibly smooth and clean lines, with precision treble and deep clear bass. There's a very slight blanket-type warmth over the lower mid-range which does take away from its transparency but adds a very nice effect nonetheless. The amp also casts a thoroughly deep and wide soundstage that throws open a window onto a world of inky blackness, from which the music emerges and sinks back into with consistent purity.

Available in silver or black.

Optimal headphone matching: AKG K701, Sennheiser HD650 (caveat: both highly dependent on source)

HeadAmp Gilmore Lite v2 w/ DPS $579 ($379 w/o DPS) from HeadAmp - Audio Electronics

Technically, HeadAmp's Gilmore Lite is a stripped-down version of the GS-1. Of course it's minus several features, but that doesn't mean it has none - it has a couple. Besides its loop output, it can be ordered with either an Elpac wall-wart power adapter or HeadAmp's Dedicated Power Supply which is basically an AC power regulator & filter to provide clean power into the amp. In HeadAmp tradition, the amp can also be customized on order with alternate-color LEDs (blue is default but other colors are available on request) and even a different gain multiplier (default is 6).

In the Gilmore Lite, the Dynalo circuit is hardwired onto the main board. Sonically, the amp shares most of the transparency of the higher-end GS-1. There are a few minor colorations at a few points in its frequency response (added prominence to mid-bass, upper-mids, and upper-treble) but that doesn't detract from what's still a largely wire-with-gain sound. It too opens up more and more with increasingly higher-end sources. Agile & detailed, the Gilmore Lite is a sampler of the GS-1 and offers a similarly clean sound.

Available only in silver. A limited run of 15 units in black with matted-aluminum finishes were produced in December 2006 and are available only on the used market.

Optimal headphone matching: AKG K701, AKG K601, Audio-Technica ATH-AD2000, Grado SR225, Grado HF-1, Grado RS-1 w/ flat pads, Sennheiser HD650

This amp was reviewed by me on StereoMojo.com in March 2007.

Heed Audio CanAmp, $450 from blackbirdaudio.com (in USA)

Released in 2006, the CanAmp is a relative newcomer to the solid-state market. It has two notable oddities - its elongated rectangular shape may be unwieldy for most applications, and its AC power cord is hard-wired and ends in a two-prong AC plug (and may not be long enough for all applications either at just under 5').

The CanAmp is aptly named and delivers a lot of big sound from an unsuspecting box, or "can" as you might call it. Configured with a default gain of 11, the CanAmp is not ideal for efficient low-impedance headphones as it's very hard to get an ideal volume level with that gain multiplier. Much better paired with inefficient higher-impedance headphones like the AKG K701, AKG K501, AKG K340, or Sennheiser HD600.

With the appropriate headphone though, the CanAmp is capable of belching sound out with power and force, similar in line with the Singlepower Square Wave. Deeply powerful bass lines coupled with a warm, effusive mid-range makes it ideal for pairing with mid-range-lacking headphones. However, it lacks upper-treble sparkle and ultimately suffers from a weakness in attack that can make it sound slow or "podgy" on bass-heavy music. It doesn't recover fast enough to run through complex bass rhythms and can sound like it's being weighted down.

The CanAmp also conveniently includes loop output.

Available only in black.

Optimal headphone matching: AKG K701, AKG K501, AKG K340, Sennheiser HD600

Eddie Current EC/SS, $429 from Page 1

First released in 2006, but updated in 2007, the EC/SS is one of the few solid-state amps designed for the Grado RS-1. And with 3W @ 32 Ohms, the rest of the Grado line-up naturally can be expected to perform well with this amp too, along with various Audio-Technica headphones that also fall in at 32 Ohms, or close enough to it anyway.

For those who'd like to cure the bright treble inherent to most of the Grado headphones, the EC/SS is probably one of the best ways to go. With no treble sparkle of its own, the EC/SS fills the rest of the spectrum out with a warm, affecting, and broad mid-range sweep, along with a deep, taut bass. Not completely direct or laid-back, the EC/SS provides a well-oiled painting feel that allows the music to feel alive and colorful on Grado headphones. Highly musical with no glaring deficiencies apart from a few technical ones (one of which is excessive hiss & static at very loud volumes). It's too bad it runs only on an AC wall-wart adapter.

Optimal headphone matching: Audio-Technica ATH-A900 (theoretically based on previous ownership), Grado SR60, SR80, SR325i, and RS-1 w/ bowl pads

This amp was reviewed by me on StereoMojo.com in February 2008.

Subjective Stacked Performance Rankings

Soundstage Depth & Width (in descending order)
  1. HeadAmp GS-1
  2. HeadAmp Gilmore Lite
  3. Lehmann Black Cube Linear
  4. Heed Audio CanAmp
  5. Eddie Current EC/SS
- Range between first and last amp:

Depth - imagine an auditorium with three layers of curtains between you and the musicians. The GS-1 lifts all three.

Width - imagine an auditorium with a stage large enough to span a full-size symphony orchestra. The GS-1 spans the entire width of the stage.

Clarity Overall (in descending order)
  1. HeadAmp GS-1
  2. HeadAmp Gilmore Lite
  3. Lehmann Black Cube Linear
  4. Eddie Current EC/SS
  5. Heed Audio CanAmp
- Range between first and last amp: if the GS-1 is polished Windex'd, the CanAmp is like a thin film of grit on the window.

Perceptual Attack Rate (in descending order)
  1. HeadAmp Gilmore Lite
  2. HeadAmp GS-1
  3. Lehmann Black Cube Linear
  4. Eddie Current EC/SS
  5. Heed Audio CanAmp
- Range between first and last amp: Gilmore Lite accentuates attack a teeny bit. GS-1 is much more natural and life-like. CanAmp noticeably slow on fast leading edges. Separation between extremely fast notes is noticeably blurry.

Perceptual Decay Rate (in descending order)
  1. Eddie Current EC/SS
  2. Lehmann Black Cube Linear
  3. Heed Audio CanAmp
  4. HeadAmp GS-1
  5. HeadAmp Gilmore Lite
- Range between first and last amp: HeadAmp amps sound too fast on decay, particularly the Gilmore Lite. The amps above them sound realistic in this aspect. However, the EC/SS is a bit too lengthy and overdrawn.

Bass Depth & Force (in descending order)
  1. Heed Audio CanAmp
  2. Eddie Current EC/SS
  3. Lehmann Black Cube Linear
  4. HeadAmp Gilmore Lite
  5. HeadAmp GS-1
- Range between first and last amp: CanAmp found to unnaturally boost the original bass on a recording. EC/SS and BCL found to be much closer to actual realism. Gilmore Lite and GS-1 swing more in direction of control and reserve.

Treble Sparkle (in descending order)
  1. HeadAmp Gilmore Lite
  2. HeadAmp GS-1
  3. Lehmann Black Cube Linear
  4. Eddie Current EC/SS
  5. Heed Audio CanAmp
- Range between first and last amp: Gilmore Lite found to have unnatural upper-treble boost, GS-1 much more in line with actual realism. BCL very close to actual realism. All other amps found to dullen treble beyond realism.

Audible Noise Level (when disconnected from source) (in ascending order)
  1. HeadAmp GS-1
  2. HeadAmp Gilmore Lite
  3. Lehmann Black Cube Linear
  4. Heed Audio CanAmp
  5. Eddie Current EC/SS
- Range between first and last amp: absolute complete and total silence on GS-1 at all volume levels. Gilmore Lite exhibits 99.9% silence (very, very minor detraction). BCL found to have a very small amount of machine hum, nearly imperceptible. CanAmp found to have minor machine hum at max volume (most likely from the power transformer). EC/SS found to have high amount of hiss/static above 1 o'clock position.

Flat-Line Frequency Response Overall (in descending order)
  1. HeadAmp GS-1
  2. Lehmann Black Cube Linear
  3. HeadAmp Gilmore Lite
  4. Eddie Current EC/SS
  5. Heed Audio CanAmp
- Range between first and last amp: only the GS-1, BCL, and Gilmore Lite sound remotely close to flat. Merely minor deviations from each other. Latter 3 amps found relatively uneven throughout the spectrum.

Estimated Levels of Transparency

Assume input signal as 100%.

96-97% - HeadAmp GS-1
90-91% - HeadAmp Gilmore Lite
88-89% - Lehmann Black Cube Linear
--- (IMO, anything below this point is not transparent enough)
84-85% - Eddie Current EC/SS
78-79% - Heed Audio CanAmp

For reference, I rate the HeadAmp GS-X at 99-100% transparent.

Subjective Stacked Value Ranking
  1. HeadAmp GS-1 ($849) - for combination of features and sound
  2. Eddie Current EC/SS ($429) - for sound and headphone versatility
  3. HeadAmp Gilmore Lite ($579) - for features, sound, and headphone versatility
  4. Lehmann Black Cube Linear ($779) - for features and sound
  5. Heed Audio CanAmp ($450) - for features and sound
Subjective Headphone Synergies List

All headphones listed are models either currently or previously owned. Listings based on previous first-hand experience with the headphones. Theoretical guesses also included, marked as denoted.

This list is comprised of first-hand and educated recommendations. All headphones listed are either currently or previously owned, or were heard for a fair length of time in a quiet environment, except where noted otherwise.

Eddie Current EC/SS:
- Audio-Technica: ATH-A900, A700 and A500 as well?
- Grado: RS-1, RS-2 (unknown), SR325i, SR125 (unknown), SR80, SR60
- Sennheiser: HD650, HD600
- Sony: MDR-SA5000, MDR-CD3000, MDR-V6

Heed Audio CanAmp:
- AKG: K701, K501, K340, K271S, K240 (theoretically on higher-impedance vintage models)
- Beyerdynamic: DT880-250
- Sennheiser: HD600

HeadAmp Gilmore Lite:
- AKG: K701, K601, K401, K271S, K240S, K171S
- Audio-Technica: ATH-AD2000
- Beyerdynamic: DT770-80, DT250-80
- Grado: HF-1, SR225
- Sennheiser: HD650, HD600, HD595

HeadAmp GS-1:
- AKG: K701, K601, K401, K271S, K171S
- Audio-Technica: ATH-W5000 (especially w/ upcoming MOSFET modules), ATH-AD2000
- Grado: HF-1, SR225
- Sennheiser: HD650, HD600, HD595

Lehmann Black Cube Linear:
- AKG: K701, K601, K501, K401
- Beyerdynamic: DT880-250, DT770-80, DT250-80
- Sennheiser: HD650


Well there you have it, my collated opinions of six of the most venerable solid-state amps on the market today. Suffice it to say that I've had a lot of fun listening to solid-state amps and I hope to hear more in the future.

I honestly ended up liking all six amps for different reasons, so there's absolutely at least one reason to buy each one. The amp that you should go for depends entirely on your source, your headphones, and your sonic preferences. Each amp impressed me in its own way so I can't really blanket recommend any one of them for everyone.

My standard recommendation for anyone reading this is to audition if possible and then decide.

Post #5,000
post #2 of 44
Excellent review Asr!
I own Heed Canamp and yes, I believe the strong point that came from amp is the bass depth.

It would be great if you ever tried Graham Slee 'Green' solo and review it as well
post #3 of 44
Awesome reviews. I owned the Gilmore Lite & DPS; now i have a idea of what i had in relation to the other amps on the market. The gilmore lite convinced me to become a solid state fanatic.
post #4 of 44
Yes Sir! That review needed to happen. The Best and Most affordable Solid State. HEAD TO HEAD. Spot on ASR. YOU ROCK!!!
post #5 of 44

Great job putting this together.
post #6 of 44
If you can please include some DIY SS amps like CK2III, M^3 or PPAv2
post #7 of 44
Excellent review Asr!
post #8 of 44
Wow, another informative and fantastic review by Asr!

I've always been particularly interested in how the GLite w/ DPS stacked up against the GS-1, and how the ES/CC performed.
post #9 of 44
Excellent review, Asr! I'm glad someone else enjoys solid-state sound as much as I do. I believe that there is a huge range of sonic possibilities with solid-state designs.

It should be interesting to hear whatever Justin creates as a replacement for those Dynalo modules in the GS-1.

By the way, congrats on hitting 5,000 posts.
post #10 of 44
asr, thanks for your excellent review. I always appreciate the care you put into your efforts. It's also nice to read a comparison of good solid states home amps, as they seem to be neglected as of late around here.

I agree with you on nearly every point on the three amps I've heard, except the lack of treble sparkle on the EC/SS, though I heard the first version out, and only in a friend's home, so I certainly may not be the best judge.

Also, I have a Heed Canamp, though slightly tweaked with blackgates in the power supply. I use it, and love it with my K340s and like it also with K701s, but would eliminate recommendations for use with the Senn 600s and 650s, expecially the 650s. As you noted, it is not a fast amp, and it emphasizes and makes the already laid-back Senns seem dead-slow, and the bass overpowering and slow in the 650s. Not a great combo.
post #11 of 44
Well-written and meaty. Many thanks!

I agree with what you say about the Lehmann BCL. Surprisingly nothing special, but perfectly competent. Some folks may squawk about that, but you're right.
post #12 of 44
Great comparison!

I am glad to see such comparison in mid level desktop amps. It's surprising that one of the oldest design (GS-1 and G-Lite) still can hold it's top position even now. Makes me glad I went with GSX in my choice of SS balanced amp Not to mention, I am proud that Justin is local talent in Virgina
post #13 of 44
what version of the Gilmore lite is currently being sold on the headamp website?
is it better or worse than the version reviewed here?
post #14 of 44
Originally Posted by pearljam5000 View Post
what version of the Gilmore lite is currently being sold on the headamp website?
is it better or worse than the version reviewed here?
post #15 of 44
Thanks for the Christmas present!
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