UNCONVENTIONAL DESIGN
I told Caleb at ALO that I respect how they designed the Studio Six to be an unconventional flagship tube amp. They could’ve used typical 300B/45/2A3 tubes to build their $5K amp. Instead, they went with a fairly uncommon 5AR4-OB2-6SN7-6V6 boxed in another unconventional layout that I thought looked pretty bad-ass. The four headphone outs is another feature that tells me that the ALO guys are headphone-meet-addicts. What would you use four headphone outs for if not for those small meets when friends come over to listen to your new headphone? It would’ve been great if they could give us four individual volume controls but I can’t think of a reasonable way to achieve high end sound with four individual volume controls (which is why you only see that feature on entry level headphone amps).
Of course the four headphone outs would just be an accessory if the amplifier doesn’t have a wide genre-bandwith sound to cover any CD your friends bring during the meets. It may not be a strong performer in sound stage or it may not give that super-mellow female vocals, but the musicality is very strong and it’s easy for me to get lost in the music regardless if it’s Diana Krall, Beethoven, or Muse I’m playing. It can pull some serious speed when asked for, but it’s not always strung on a high-RPM and though it doesn’t go overly mellow and swinging, it’s flexible enough for a slow paced Jazz. The vocal rendition is clear, clean, and full bodied, maintaining enough swing and warmth to reproduce a palpable, sultry vocals. I think the choice of going with the 6SN7s and 6V6s is what’s giving the Six (hey, that’s where the amplifier got its name from! SIX-SN7 and SIX-V-SIXs) the solid-state-like pace and agility, though not quite the grand (but slow!) sound of the 300B tube. Of course they could’ve achieved that speed easily with a solid state, but most solid states I know don’t have the coherence, grainless, and liquidity of a tube set up.
Though it’s obvious to my ears that ALO was tuning the Six to make the Audez’e phones sound really good (Six+LCD3 ooohhh), it does play well with other headphones I’ve tried. Notable ones being the Hifiman HE-500 and HE-6, the AKG K1000, the Sennheiser HD800 and Beyerdynamic T1 and T5P. The Fostex TH900 also sounded great out of the Six though not as good as with the Bakoon amp I reviewed a while back. I must say though, it’s the LCD-3 pairing that seals of the deal for me. And on this amp I really can totally justify why the LCD-3 sells for almost $1K above the LCD-2. The two are really night and day on the Six.
The lack of a balanced in/out may seem like a drawback to some, but personally I don’t really care as the Six clearly trounces the dynamics of previous balanced amps I’ve owned (Beta22 and RSA’s Dark Star). It also comes with no gain settings so IEM users better have a variable-output DAC in their arsenal (I have the Violectric V800, Ayon Skylla II, and Fostex HP-A8 on the store, all with variable output levels). It does drive all four heavyweight headphones simultaneously to great fidelity levels (I tried hooking up an LCD-2, LCD-3, HE-500, HE-6 simultaneously with good results). I do sense a slight drop in dynamics and openness when more than one headphone is connected (ALO claimed no drop in sonic quality, sorry have to disagree). The good thing is that the sound is still extremely good, the dynamics still awesome, etc even when more than one is plugged in, but to get the best out of the six, I do recommend only plugging in one headphone at a time. With IEMs and sensitive headphones I do hear a low volume hum on the output and so this is definitely not the amplifier you want to use with IEMs and sensitive headphones.
I’m going to repeat what I said earlier in this review: “I wish ALO was not a site sponsor”, because for sure the six is my hero amplifier now. Earth shaking dynamics is factor #1. 4 headphone outs is factor #2. The unconventional design wrapped in a solid aluminium cage looks bad-ass and is factor #3. Pity I don’t have a high end turntable set up cause I’m sure it would be another league up.
TUBE ROLLING
The awesome thing about tube rolling, and of course this doesn’t just apply to the Studio Six, but rather all tube based amps, is that with different tubes you get a different tweak of the sound. In some ways it’s like applying an EQ as you may add/subtract bass from the sound, push/pull the vocals front and back. Change enough tubes, however, and you’ll find out that tube rolling far exceeds the boundaries of EQ-ing. You can enlarge the soundstage, dynamics and pace, dynamic range, attack, swing, coherence, focus, and many many more.
The Studio Six uses six tubes in total, three in the power supply section and another three in the amplification section. Starting from the most right, the 5AR4 is a very popular power supply rectifier tube that’s often subsituted with GZ34 variants. The next two tubes are OB2 tubes that’s rather uncommon but can still be found in plenty quantities these days. The next two tubes are 6V6 driver tubes, moderately common. And finally the 6SN7 input tube is one of the most popular input tube in high end audio applications.
The stock tubes set up that I received from ALO is the base of my impression above. Fast dynamics, powerful forward and moderately bright.
The first place to start for me is the 5AR4 rectifier where you most probably can improve the soundstage performance without altering tonality too much. I tried a few 5AR4 and GZ34s and ended up with a GE GZ34 plastic base. It improved the soundstage without changing the character of the six too much (One rectifier, while it brought a warmer sound, mellowed down the dynamics quite a bit). Later on I found the distinctively weird looking Raytheon 5R4GWB that offered an even more spacious sound but with a tiny bit of mellow and grain injected into the sound.
ALO Audio sent me two sets of OB2 tubes, a Raytheon set and a Westinghouse set. The Raytheon is clean spacious and very dynamic. I, however love the Westinghouse that despite the smaller sound stage presentation, injected a beautifully solid body into both male and female vocals while improving focus on the focals significantly. This is THE OB2 tube to use for vocals. Prior to discovering the Raytheon 5R4GWB, I was hesitant to use the Westinghouse OB2 as it took so much from the sound stage, but with the wider sound stage of the 5R4GWB, I was back to the Westinghouse in no time. Dynamics slightly lowered though, in comparison to the Raytheon, and if you’re into fast paced Rock or Metal very much, would be better off with the Raytheon.
The two 6V6 tubes left mostly untouched as nobody I knew has stock of those tubes.
The 6SN7 tube, while friends donated a multitude of them, I didn’t really find one that I thought was special with the exception of the smoked-glass JAN CRC 6SN7-GT. It brought the tonality down to a darker and beefier one, a tonal change that definitely falls more in line with my liking.
The parameters you can change from tube rolling are endless and perhaps even more vast than a source change. There is never one set of the perfect tube set. Adding warmth would usually compromises attack and speed. Boosting vocal body usually compromises sound stage space. Things like that. And not only do different tubes come with different sound, but even the same tube type with different emission levels would yield different tonality (lower emission should yield a darker sound). All of these are a lot of fun, but the “downside” is that I would be changing tubes depending on my mood of the day. Well, at least I can change tubes and I don’t have to change amps.
Almost finished, last page next…
Mike
And here is a slightly different angle from veteran reviewer Nathan
http://ohm-image.net/opinion/audiophile/review-alo-audio-studio-six
Jook Yos
Thank for more information, and i like your new style in giddy writing way so much.
Mike
Glad you enjoyed the article. 🙂
ohm image
Thanks for the shout out, Mike.
Japanese Headfiers will be getting a go with the ALO Studio Six. I’m pretty stoked about it.
George Lai
Wow. I think they should rename it the Studio Sex.
L.
It does look so sexy doesn’t it.
L.
So bass is like this?
http://24.media.tumblr.com/e27982fddded73c579cc5948a03c0048/tumblr_mgzv6mg4hF1ryxmgwo2_500.gif
Just kidding, sounds like a very good amp!
Dave Ulrich
Whoa… rock n’ roll!
Mike
No that’s called an explosion, L. 😉
Gneiss
Although I do not think this is a well priced amp, best review I have read in months!
Dave Ulrich
Agree with you on both counts.
Mike
Thanks, Gneiss!
Rūdolfs Putniņš
Yep good tube amps sound dynamic and unlike the stereotypical “tube sound”. After I finish my current amp build and a PCM1794 DAC I might actually do a nice tube build. 300ies or something like that.
Michael Mercer
Try a vintage RCA 6SN7! That’s what I ended up with in my Studio Six!!
Mike
Thanks, Mike!
I will keep an eye for a vintage RCA 6SN7!
Michael Mercer
right on! and GREAT job as always Mike!!
Mike
Thank you, Mike!
I suppose you’re using the Six with the LCD3 as well?
Michael Mercer
I am indeed! As well as my Sennheiser HD800’s and Mr. Speakers Mad Dogs! Can’t WAIT to hear it w/ the upcoming Alpha Dogs!!
John123John
Dude…
Havent read the review yet but I am so excited too 😀
Mike
🙂
Fabio_Rocks
Alo audio makes wonderfully products, no doubt about it. Hope in the future they can sell them with better price, let’s say 10-20% less, It will be perfect!
Mike do you have tried this alo cable:
SXC 24-Custom IEM ? I just got the Westone Um3x, and you were right about their uninvolving sound. In my opinion that is because they have somewhat recessed highs. Do you think I will get a more present treble responce with this cable?
Is Alo-Audio so nice to send you this cable for a review?:)
Sorry for the question off-topic, I was thinking to post this question in the review about audio cable, but comments are closed there.
Cheers!
Mike
No problem, we have the SXC24 both for JH and for FitEar on the store. It widens the soundstage, push the midrange and low treble out and adds a nice bloom. Some people like it due to the the more forward midrange, some don’t due to the more forward midrange.
The UM3X IMO needs more treble, not necessarily more midrange. I’m not sure if it’ll work well with the SXC24. Maybe the Silver Dragon would be a better suggestion but assuming the Silver Dragon IEM cable has the same sound as the headphone cable (I’ve only listened to the SD for headphones).
The SXC24 however works wonderfully with the FitEar 334ToGo.
Fabio_Rocks
Thanks Mike!
rich
A visit to my millionaire friend in Japan and I tried the Six against the rest of the top amps. The sound is like “wow”. “Rob, steal or starve” to buy this expensive amp. It will become a legend in years to come. ALO don’t change their models frequently compared to other manufacturers . Also buy the ones with special adds on for US$200 extra.
The magic of tubes- warmth to the sound in spades. But this amp is neutral too. After spending almost the whole morning with this set, I am very impressed. But always remember, the audio play back is a chain. The weakest link will rear its ugly head. Make sure the sources are excellent too. Also the interconnects and power supplies are premium.
I come from an mainstream component system,i.e. real stereo speakers, preamp, power amp and cd/ sacd players etc. The use of the Six with the best headphones can approximate or out perform real component box speakers. View from a component audiophiles point of view, this amp is not super expensive. An SACD player alone from Esoteric can cost upwards of US$10K.
STARSTERN
rich ; are you talking out of experience ? alo-six and stax 009 would compete with esoteric k-o1 or MSB DAC IV
L.
I listened to the Six for a few hours last friday and I can mostly agree with what Mike wrote. The tubes in this Six were all NOS and weren’t the original tubes supplied by ALO.
I have to say this is the best amplifier I have listened to, everything was great on it. Sure it’s not the smoothest, warmest or most tube like sounding amp, but oh my does it sound wonderful. With the tubes the Six had, I can’t remember which one, the sound stage actually was very wide and that’s the part I might disagree on with Mike.
I gave Mike a rare and good ADZAM 6SN7 tube for the Six. I know he loved it but I’d love to know how it improved the soundstage.
conclusion: extremely good looking and sounding amplifier that does great with a whole lot of headphones. Did I mention I’m in love with the Alpha Dog now?
Mike
It’s a good amp that’s what matters. 🙂
STARSTERN
the alo six best amp for the lcd3 ;how about a dac ?
STARSTERN
Fostex HP-A8 is your best pick all rounder dac/amp but i guess its the dac part of it that shines ,is their any supplement amp’ suggestion’ just to fulfill where the amp on this lacks ?
STARSTERN
The Antelope Rubicon AD/DA Preamp, The Atomic Amplifier with a lcd-3 ? ha “?
meh
damn..
Blaine Vonhagen
leben
L.
Talk about constructive comments 😀
Ernie
What are those mystery phones in the picture second from the top?
Kantx
How does the ALO Studio Six compare with WA5 LE + Upgrade ?
Not the same price bracket tough.