Alpha Design Labs ready GT40α and Stratos digitizers


Tokyo’s Furutech puts out a more affordable line of products under the Alpha Design Labs (ADL) banner that made serious waves some years ago with its GT40 – a tidy unit that housed headphone amplifier, MM/MC phono stage and USB DAC under one roof, giving users a single-box solution for digitizing vinyl (or ANY analogue source). Inputs were a simple choice of either USB or phono.

The pricier Esprit took the GT40’s essentials to the next level by adding pre-amp circuitry, a second line-level input, coaxial and optical inputs and an optical output (for USB pass-through).

Both models were super-popular with the audiophile press and you could easily make a case for ADL being ahead of the vinyl resurgence curve on this one.

With comes product refresh time at Alpha Design Labs. Now featuring elevated USB decoding/encoding ceilings of up to 24bit/192kHz apiece, the GT40 has been switched up to the Google-confounding GT40α status, stepping into shoes vacated by the now discontinued Esprit. The GT40α will holds firm to its predecessor’s US$499 pricing. Down under it’s yours for AU$750.

The thousand dollar Esprit has been replaced by the all-new (and less expensive!) Stratos. Out goes the Wolfson DAC and in comes the ESS Sabre ES9018K2M for single- and double-rate DSD decoding as well as PCM up to 32bit/192kHz. DXD sample rates are absent.


“Indeed, the STRATOS is far more than a classic GT-40 with DSD capabilities—every square inch of the STRATOS has been reconsidered and rethought using the latest technology and the latest designs.”, promises the press release.

The ADC chip still comes from Cirrus Logic but this time it’s a CS5340 that replaces the Esprit’s CS5361.

ADL’s ongoing recommendation for use of 16 Ohm – 300 Ohm headphones suggests that little has changed on the headphone output front. The continued presence of a TI TPA6120A2 op-amp confirms this.

The Stratos’ specifications be all like:

  • USB Playback Resolution: 32bit/192kHz (Max.)
  • USB Recording Resolution: 24bit/192kHz (Max.)
  • Frequency response: 20Hz ~20KHz (+/-0.5dB)
  • SN ratio: >95dB (A WTD)
  • Analog Output Level: 5.0 Vrms
  • Line Input Level: 2 Vrms
  • S/PDIF Input: 24bit/192KHz (Max.)
  • MC/MM Input Level: MC: 0.4mV / MM : 4.0mV
  • MC/MM Input Capacitance: 100 PF
  • Line Input Impedance: MC :100 ohm / MM :47K ohm / Line : 47K ohm
  • Headphone Output Level: 1% THD 1kHz (Max.) 156mW(16 ohm),224mW(32 ohm), 241mW (56 ohm), 130mW (300 ohm), 76mW (600 ohm)
  • Power Supply AC Adaptor Rating: Erp step2 compliant, 2Wire AC Input Type, Class II, AC/DC Switching Adaptor output DC 15V / 0.8A / 12W
  • Dimensions: 150 (W) x 141 (D) x 57 (H) mm
  • Weight: 930g Approx

At US$719 the Stratos presents as a more wallet-friendly alternative to PS Audio’s more flexible NuWave Phono Converter. Note that the PS Audio can encode to DSD whilst the ADL cannot and the PS Audio offers variable gain and cartridge loading whilst the ADL’s is fixed.

Arriving in Australia this October the Stratos’ local pricing might raise some eyebrows: AU$1100. And despite being launched at the Munich High End Show in May, these new models have yet to be detailed on the ADL website. Moon Audio has the skinny instead. (Press shots were also thin on the ground at time of writing).

With such a varied feature set it’s worth reminding ourselves that both the Stratos and GT40α aren’t just for digitizing vinyl. You can just as easily deploy them as standalone DAC, phono stage, pre-amplifier and/or headphone amplifier.

Further information: Alpha Design Labs

EDIT October 2014. Shot a couple of snaps of the GT40α at September’s New York Audio Show ’14:

ADL_GT40alpha_2 ADL_GT40alpha_1

Written by John H. Darko

John lives in the NOW + HERE = NOWHERE. He derives an income from the ad revenues of DAR. John is also an occasional staff writer for Stereophile, 6moons and TONEAudio.

Twitter: DarkoAudio
Instagram: DarkoAudio
Facebook: DAR


Leave a Reply
  1. I concur with GAN SOLO”S sentiment. The ESS Sabre DAC’s screechy sonic character is best avoided. And projected Australian recommended pricing is certainly on the high side…………

    • “Screechy sonic character”, hey? How do you know it’s the chip that causes that and not something else within the DAC’s design? I haven’t noticed anything close to screechy with DACs made by, say, Resonessence Labs or Peachtree Audio or AURALiC or Mytek.

      • YMMV, as ever, Johno. Auditioned several Sabre implementations, and also read many similar reactions from experienced audiophools world-wide with reference gear allied to lengthy grounding in all-manner DAC playback, we all seem to arrive at similar subjective impressions. Mind you, in the main, we do not bother appraising rock, indy-rock, commercial pop or other lo-fi recordings, or anything else that is amplified, treated, doctored, over-saturated or compressed; that is, only reference acoustic recordings and masterings of known quality.

        Just about every DAC chip has a character, which is readily discernible. IMHO a key positive attribute for any DAC is sonic playback that does not dismember the music into splinters of etched, stark hype-fi detail, which might impress for all of two bars, then cause total aural revulsion. Music should remain organically wholesome!

          • Listened to most types of music, and played it, over the years. (Classically-trained BTW.) Still get pumped by punk rock/new wave 1977-83. Iconoclastic music and culture. That era’s recordings/fidelity leave a lot to be desired, though. Like some other faves: reggae/dub and African/world music. Even electronic, hiphop etc are generally lo-fi.

            Here’s the rub. There is little need to acquire SOTA audio playback equipment *if* one’s tastes are limited to “doctored” recordings. Pretty much any affordable, listenable gear will do, as long as it’s not dynamically-challenged.

            Often what I find amusing is industry critics/reviewers’ lists of so-called “reference recordings” (no offence intended). Most haven’t got a clue. Since source material is paramount, the only means to accurately assess the technical merits of audio gear is to ensure music used is of highest fidelity, bereft of any “doctoring”, and acoustic in nature. Let incendiary flaming commence!

          • No offence taken 35YA. 🙂 I’m not stoking that fire. Besides, one of DAR’s fundamental points of difference is a providing coverage of gear with more contemporary music tastes deployed. And if that means listeners like me (and DAR readers) don’t require SOTA equipment to make it sound bloody amazing then that’s a win for me and them. And more dollars down for listeners like you! 😉

            I’m turned on by gear that makes me wanna listen to more music. However, to offer preferences is not my only role as a reviewer. I see my primary job as a one of describing sound or – rather – sonic attributes of audio equipment. That’s why comparisons are so important. Preferences play second fiddle.

  2. Eh? I was just jesting. However, I’ve yet to hear a sub $1500 Sabre DAC that didn’t give me digititus-induced tetanus.

    So far, my conclusion is that you have to throw a funkton of money (more than I can afford) at a Sabre implementation in order for it to sound decent.

    Having said that, I’m not anti-Sabre specifically. Also not a fan of those Cirrus-Logic new-gen AKs, Would take the old Wolfson based 120 over the new one any day.

    • The new A&K 120 II does seem to be more lively up top than the old model. Mind you, there’s also a lot of delicacy in its treble delivery.

  3. you have touched on the digital capabilities of this unit but not much about the phono section nor how it measures up as a headphone amp. those are important details that i would love to hear about.

    if those two features are in the excellent category, it would make the gt40a a must have.

    • Hey Tommy – this is a ‘proof of life’ piece and not a review. Therefore the details presented are all I could extract from Furutech/ADL.

  4. Hi John,

    Your USD retail pricing on the Stratos and GT40α is incorrect. The correct USD prices are $825 (Stratos) & $549 (GT40α)

    If you need any clarification of specs or pricing for any of our products I am happy to help.

    Michael – Reference AV

      • It seems that the Stratos was 719, but has gone up to 825 if you look at ADL’s US website. I guess dealers who were early to list it haven’t gotten the memo that the price went up before it’s release.

      • Yes the prices I have stated are the correct USD retail prices. I am unsure where the $719 price came from as our cost price was the same as the Esprit model, hence why our retail for the Stratos is the same as Esprit.

        In regards to the GT-40a, that model has gone up in price from the factory over the older GT-40.