Garage1217 Project Solstice

Asr

Headphoneus Supremus
Pros: Features & versatility; price/value; overall very good sound
Cons: Lack of clarity; inability to drive high-impedance headphones as configured
published on October 29, 2015
Manufacturer's Response added on November 3, 2015 (see bottom of review)
updated on April 25, 2016
 
solstice_1.jpg
(click any photo in this review for a larger version)
 
Intro
 
Garage1217's Project Solstice was released earlier this year as an alternative to their other amps, and when I asked them for a loaner unit back in June (for a Head-Fi meet in Denver CO on 6/27 that I was then organizing), they were happy to oblige. Once again I have to thank Garage1217 for being so willing & generous in providing me with loaner amp units! (Not that I'm really doing anything out of the ordinary btw—just trying to provide honestly-written reviews here on Head-Fi, as I've always done.)
 
Disclaimer: the time duration for all listening for this review was just about 3 weeks, which isn't as long as what I'm typically used to (most of my past reviews have been of equipment that I owned and were done over months), so I wasn't able to get quite as familiar as I would've liked with the amp and the set of tubes that I received with it. My listening impressions should not be seen as finalized and are likely subject to change.
 
April 2016 update: Garage1217 offered me an opportunity at a “second pass” at the amp shortly after I published the first version of this review, which I finally took them up on in December 2015. This second review period lasted approximately 5 weeks, which allowed me to get more familiar with the amp and some of the tubes that I’d gotten the first time. Most of the updates can be read as a new section at the bottom of this review, although some other sections throughout the review have been updated as well.
 
solstice_2.jpgOperation, Functionality, & Handling
 
The Solstice was packed with most of the same features as Garage1217's other amps, with its selectable gain, output resistance, and input attenuation. Note however that the Solstice's output resistance settings aren't the same as on Garage1217's other amps and are fixed at 0.1, 31, and 68 Ohms instead. The lack of a 120 Ohm setting will likely translate to worse performance with some headphones that are designed to work optimally from an output impedance of 120 Ohms, like some of Beyerdynamic’s models. On the plus side, one of the features new to the Solstice, OHV (Optional Heater Voltage), allows either 7V or 12V heater output so that other types of tubes can be used as well. However, I didn't use this feature as I didn't have any appropriate tubes to use it with.
 
The only operational quirk I found with the Solstice was that I needed to remove the amp's top plate in order to access any of the jumpers. Since I found myself changing the gain and resistance jumpers often, I decided to just leave the top plate unscrewed so that I could access them quickly.
 
Amp & Tube Assessment + Headphone Compatibility
 
As it turned out, unfortunately the Solstice arrived with an attenuation module that provided only enough volume range for my sensitive low-impedance headphones. The Audio-Technica R70x (470 Ohms and 99 dB/mW), on the other hand, was unable to get acceptably loud enough out of the amp. Even maxing out the volume knob completely (on high gain, no less) still didn't deliver enough volume into the R70x for it to sound loud. So I would recommend that owners of high impedance and/or inefficient headphones should make sure to get a properly-configured attenuation module from Garage1217 for less attenuation, in order to better work with those kinds of headphones. (Btw, as a comparison note, neither the Ember v2 nor Polaris had any problem pushing the R70x to earsplitting volumes on high gain—only the Solstice exhibited this issue.)
 
The Solstice worked well with my other headphones though, but rather than go into headphone pairings next, I'll break down the tubes I used first. I used these tubes primarily with the Solstice, but since I had an Ember v2 at the same time as well, I tried them in that amp too, so my comments are inclusive of my experience with the tubes in both amps.
 
- GE Smoked Glass 6DJ8
 
I previously used this tube with the Project Ember which I wrote a review of last year, and my experience with it again was mostly positive. My comments from the Ember review still apply: I view this tube as a great all-rounder, and at its best primarily with music containing male vocals and instruments like bass or overdriven guitars (i.e., rock & metal). It wasn't really the most spatial-sounding tube, especially compared to the other tubes I had, as both of the two other tubes were quite a bit more spatial-sounding. Compared to them, the 6DJ8 felt like it had flatter imaging and less soundstage width, so it may not be the best choice for those looking for a large soundstage—or for those looking for refined treble, as its treble was just a bit messy compared to the other two tubes.
 
solstice_4.jpg- 6H6N/6N6P
 
Note: for details on the 6H6N/6N6P and 6GU7 (below), please contact Garage1217 for more info.
 
I liked this tube the most, not only because of its sound but also because it had the coolest-looking glow when I turned my lights off at night (shown in the nearby night-time photo). The reason I liked its sound the most was because it sounded the clearest & cleanest to my ears and had the most sense of "distinctness" to its sound that really helped to separate musical elements out from the mix better. Its soundstage was notably wide as well, but it was definitely wider than it was deep, which made it sound relatively up-close. This ended up being a very good tube overall as well, and I ended up preferring it for music like ambient electronica due to its clarity.
 
- RCA 6GU7
 
The 6GU7 filled in for the aforementioned soundstage weakness of the 6H6N, and provided greater soundstage depth with a better illusion of distance. It clearly sounded the most "3D" between the three tubes, as it effectively pushed everything "out" (or "away", to use a similar word) so nothing sounded too close-up. Not that it sounded all that expansive though, it was more that the 6GU7 simply projected the largest soundstage among the three tubes, without disorganizing the musical layers into a spatial mess either (as I’ve heard other tubes and tube amps before that have done exactly that). On the flip side, the main drawback to the 6GU7 was a lack of some mid-range body and it wasn't very physical-sounding, but that’s what tube-rolling is for, right?
 
solstice_5.jpgAnd those were just 3 tubes that I was able to try with the Solstice. More info on other tubes (and on the Solstice, along with Garage1217’s other amps) can be found in these forum threads:
- http://www.head-fi.org/t/702826/project-ember-tube-rolling
- http://www.head-fi.org/t/641936/project-sunrise-ps2-tube-rolling-thread-and-maybe-even-project-horizon-and-project-ember
- http://www.head-fi.org/t/753479/garage1217-project-solstice
 
As far as headphone pairings, the only thing I can say is that most pairings will ultimately be very subjective, and will be further complicated through tube-rolling, so ultimately, almost any headphone pairing with the Solstice with a given tube will be up to individual preference. And when Garage1217 themselves call the Solstice a "tube roller's dream," it's pretty clear that this amp is meant for experimenters looking for variability and isn’t necessarily for those pursuing something specific.
 
I can also definitively say without reservation that most of my headphones sounded very good out of the Solstice, most noticeably the Sennheiser HD600 and Beyerdynamic DT990 (600 Ohm), but the AKG K712 and Audio-Technica R70x weren’t bad either. The only caveats that I’d add for the K712 and R70x is that both headphones can sound significantly better out of other, more technically-appropriate amps—for example, the K712 sounded more musically-dynamic out of Garage1217’s Project Ember with a 12AX7-type tube, and the R70x sounded more authoritative in the bass & mid-range out of Schiit Audio’s Valhalla 2.
 
Project Ember v2 Comparison
 
Unfortunately for the Solstice it didn't really have a fair fight against the Ember v2, since my Solstice unit was under-equipped with the wrong input attenuation module for the R70x, and the Ember had a significant advantage with a 6SN7 tube as well (which was sadly unusable on the Solstice). So it almost goes without saying that the Ember crushed the Solstice, well at least as far the R70x was concerned. And because the Ember's higher power output lends it to driving planar magnetic and other similarly-demanding headphones, I'd be inclined to recommend the Ember over the Solstice for those types of headphones.
 
However, the R70x aside, I actually did find that the Ember generally sounded marginally better than the Solstice on the same tube. It tended to sound a bit more dynamic musically (as in, a greater difference between soft & loud parts), and it exuded more texture and presence in the mid-range & mid-bass. That said, the Solstice wasn't much lesser-sounding than the Ember, and the differences I observed were only slight, and not large enough that anyone should feel compelled to spend $100 more to get the Ember for any sonic reasons. I'd say the primary reason to get an Ember over the Solstice should mostly be for the additional power output to drive planar magnetic headphones, and/or other features like the pre-amp output. But if your intent is simply to drive a set of regular dynamic headphones, then the Solstice may very well be all you need. Plus, with its OHV feature it can use tubes that the Ember can't, including the 12SN7, 6BL7, and 6BX7!
 
April 2016 Update
 
After the initial version of this review (i.e., the “first pass”), I was able to give the amp a “second pass” audition for about 5 weeks from December 2015 through January 2016, with a greater variety of headphones that included the Sennheiser HD600, Beyerdynamic DT990 (600 Ohm), Massdrop/Fostex TH-X00, and AKG K712. My source component during the “first pass” had been the Schiit Modi 2 Uber, but during the “second pass” I had the Bifrost 4490 instead, which allowed me to get a better idea of what the Solstice could really do. I also owned the Schiit Valhalla 2 during this period, which served as a reference point and allowed me to identify the stronger aspects of the Solstice in comparison.
 
- 30K vs 100K attenuation modules
 
At my request, Garage1217 supplied both attenuation modules this time so that I could make sure that I used the right one for the Audio-Technica R70x. I was able to repeat my “unacceptably loud-enough volume” results with the 100K attenuation module, but not with the 30K module, which led me to conclude that I had the 100K module the first time around (I wasn’t sure which module I had the first time, as I didn’t bother to check). So I might suggest that owners of high-impedance inefficient headphones may want to get a 30K module for such headphones.
 
- 6SN7 & 12SN7
 
Garage1217 informed me that both of these tube types sound identical to each other, but that the 12SN7 tubes can often be found for cheaper. So I tested the supplied 12SN7, but only once to make sure that it worked and ended up doing more listening with the supplied 6SN7 since it was more convenient to just leave the amp on its DFLT setting (since using the 12SN7 would have required constant re-configuration to the OHV setting). The 6SN7 was a very good tube particularly with the K712, as it provided the most musical dynamic range (fully spanning the dynamic range from piano to forte), the most intimate soundstage, and the deepest bass tones. The added presence & realism really made quite an appreciable difference. This was a very good tube with the DT990 and HD600 as well, but the difference was less dramatic with those headphones.
 
- Additional headphone notes (HD600, DT990, TH-X00, & K712)
 
The Solstice capably drove all of these headphones, although I did find that it wasn’t quite as good as the Valhalla 2 with certain headphones (more on that below). In general, though, all of my headphones sounded good to great on the Solstice with either the right output impedance setting and/or tube. The HD600 and DT990 were the least picky with settings and tubes, although rolling tubes did provide certain benefits, like the supplied 12AU7 helping to take the edge off sibilance with the DT990. The 6SN7 provided the best results with the K712, although both 6DJ8 tubes that were supplied (GE Smoked Glass along with an Amperex Bugle Boy) also sounded very good. Both of these 6DJ8 tubes were better with the TH-X00 though, as they filled in its relatively recessed mid-range & mid-bass so that male vocals and bass-oriented instruments (like bass guitars) sounded more full-bodied and “meatier.”
 
Although I’d recommend the Ember more for K712 owners, the Solstice pairing was surprisingly good, especially with the 6SN7. The only aspects that were noticeably lacking with the K712 on the Solstice compared to the Ember were an extra degree of musical dynamics (for a wider range from pp to ff) and overall bass/mid-bass quantity (30 to 200 Hz).
 
- Schiit Valhalla 2 comparison
 
It should first be noted that the Valhalla 2 is an OTL amp, while the Solstice is a tube hybrid, which means that the Valhalla 2 is technically more ideal for high-impedance headphones and the Solstice is more ideal for low-impedance headphones. With that said, the results of my listening were fully in line with expectations—the high-impedance headphones (HD600, DT990, and R70x) indeed sounded better on the Valhalla 2 than the Solstice (with configured high output impedance on both amps), and the low-impedance headphones (K712, TH-X00, AD2000, MSR7, and MT220) conversely sounded better on the Solstice than the Valhalla 2 (with configured low output impedance on both amps). What does “better” mean? In the case of the high-impedance headphones, they simply sounded more full-bodied with more mid-range texture and palpability, and exuded “heftier” bass too. Overall they simply had more “presence” x-factor and sounded more physical, tactile, and powerful. Oddly enough, the high-impedance headphones also exhibited more clarity on the Valhalla 2, which was a bit unexpected.
 
In the case of the low-impedance headphones, all of them simply sounded cleaner on the Solstice with less overall haze and audible distortion, particularly in the bass region. However, rolling tubes on the Solstice sort of allowed it to mimic certain “OTL-like” sonic traits when used with either high- or low-impedance headphones, notably adding the ability to inflect a huskier, more textured mid-range & mid-bass through tubes like the 6SN7 and 6DJ8s. Or in other words, these tubes added “warmer”, deeper tones to male vocals and instruments like bass guitar and cello.
 
Although I felt that the high-impedance headphones clearly sounded better on the Valhalla 2, to the Solstice’s credit it really wasn’t that far behind, and the high-impedance headphones sounded nearly as good on it, for the most part lacking only some of the “presence” x-factor. So it was a small difference between the amps, but it was also very clear that the Valhalla 2 was distinctly superior, at least as far as the high-impedance headphones were concerned. But to reiterate, the Solstice was very close to the Valhalla 2 and was virtually right behind it when configured with the right settings and/or tube. I really only recommend the Valhalla 2 for those who want maximum performance out of a collection of only high-impedance headphones, because the Solstice was much more versatile and my high-impedance headphones still sounded nothing short of awesome on it. The Valhalla 2’s primary downfall was its incapability at driving my low-impedance headphones—none of them really sounded that great on it, even with the low-gain setting.
 
solstice_3.jpgClosing
 
Like my previous experience with Garage1217’s other amps, the Solstice wasn’t the most clear-sounding amp (even with the 6H6N it was still beaten by my solid-state Gilmore Lite in that aspect, and the Ember v2 provided marginally more textural detail regardless of tube), and I ultimately came away a bit underwhelmed too, in this case mostly because of its inability to drive my R70x with the supplied attenuation module. However, with that said, I have no qualms recommending it for Head-Fiers looking for a capable tube amp that can drive any set of regular dynamic headphones, and the variety of tubes it can use is really quite amazing. And when it's just $250 for a built version, I think the better question is: why not?
 
Equipment Setup
 
- Source components: NAD T533 (DVD player) and Windows 7 desktop & laptop PCs as transports to Schiit Modi 2 Uber and Bifrost 4490 (via coaxial & USB, respectively)
- Analog interconnects: Emotiva X-Series RCA
- Comparison headphone amplifiers: HeadAmp Gilmore Lite w/ DPS (as a point of contrast); Garage1217 Project Ember v2 and Project Polaris; Schiit Audio Valhalla 2
- Headphones: AKG K712; Audio-Technica ATH-AD2000, ATH-MSR7, and ATH-R70x; Beyerdynamic DT990 600 Ohm; Massdrop/Fostex TH-X00; Sennheiser HD600; Yamaha MT220
 
Evaluation Music CDs
 
Dave Brubeck - Time Out [50th Anniversary Legacy Edition]
In Flames - The Jester Race
Infected Mushroom - Vicious Delicious
Julia Fischer - Bach Concertos
Lucius - Wildewoman
Massive Attack - Blue Lines, Protection, Mezzanine
Medeski Martin & Wood - Uninvisible
Nickel Creek - A Dotted Line
Olafur Arnalds & Alice Sara Ott - The Chopin Project
Periphery - Juggernaut: Alpha
The Crystal Method - Tweekend
Trifonic - Emergence
Trivium - Shogun
 
Manufacturer's Response
 
Quoted below is Garage1217's response to my review, received via e-mail on November 3, 2015. Copied with permission.
 
- Solstice, while it will power the R70X very well at 1mW / 99dB sensitivity / 470ohm, is designed to much better power low impedance headphones. You would not want a different module over our stock with the majority of dynamic / planar headphones made in the 16-300R range. If I shipped the amplifier with a higher input level module, it would have given limited range on the volpot with the majority of headphones it would normally be paired with. However with your description, I am wondering which module it shipped with or if I made a mistake in your review unit (my own personal amp) and shipped it with a module I was testing with.  At 99dB / mW and if it had a 70-100K module installed (stock is a 30K) it would likely be as you stated. Solstice is easily able power the R70X to very LOUD levels.
 
Reference the power output:
http://www.garage1217.com/POWERSPECS/Solstice.jpg
 
- The output resistance settings are virtually the same as with our other headphone amplifiers that are more dedicated to lower impedance headphones like Starlight and Sunrise. We do not include a 120R output resistance setting on any of these designs as there would not be a lot of oomph up top but as you stated, a different module would help out here (if I shipped it with a high R module by mistake)... but I would not expect the most stellar results compared to our designs with high impedance headphones in mind (Horizon, Polaris, Ember). In short, Solstice will rock lower impedance headphones quite well!
 
Reference Sunrise Vs. Horizon to see difference in design goals. Both designed for two specific impedance ranges / reference their specific output power specs into different impedance ranges:
http://www.garage1217.com/POWERSPECS/SunriseIII.png
http://www.garage1217.com/POWERSPECS/HorizonIII.png
 
- Both Ember, Polaris (as well as horizon) are 48V designs, thus they have significantly more power into high impedance headphones Vs. Solstice, Sunrise and Starlight which are all 24V designs that have power focused into the common, lower impedance headphone range.
 
Reference Ember vs. Solstice (example solstice can produce around 100mW clean into 470ohm / Ember around 440mW (a little over 6dB louder / 200% technically).
http://www.garage1217.com/POWERSPECS/Ember.png
http://www.garage1217.com/POWERSPECS/Solstice.jpg
 
- One thing overlooked, Solstice is full auto bias which makes tube rolling incredibly easy. This is a feature not found in our other $250 and lower amplifiers. Voltage is manual of course because of the custom settings, but auto bias is a very nice thing which is why we stated (a tube rollers dream) as there is not a tube amplifier available that can utilize the qty of tubes we can in our designs. Most limit you to 1 range of tubes such as a 6dj8 / 6922 or very similar as bias is either not adjustable at all or is very limited.
 
- 6sn7's can in fact be easily used with Solstice. It takes a differently configured adapter that we have available. Bummed you did not get to listen to that pairing.

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