iFi products Discussion Thread iTUBE will be out soon!!
Dec 8, 2016 at 8:12 PM Post #333 of 355
  In the music direct catalog (vol 17), page 71, there is an iTube 2 ($349).
 
What? When? Pre-release slip up? Did I miss the release of the iTube2?
 
3 3D modes. 3 XBass modes. Possibly a headphone/speaker selector?
 
Cat's out of the bag now. Talk, and no one gets hurt.

 
I saw the same thing but wasn't able to take a pic at the time; you beat me to it anyway.
 
Looks like iFi added Xbass and a Tube+? setting like the Pro series (perhaps to bypass the internal tube?; swapping between full tube, hybrid, and solid state modes?). Appears they also removed the Digital Antidote switch which I've come to like on my original iTube.
 
Pg. 11 of the catalog has a bit more info but no mention of when it'll be available (its not on their website yet; also not sure how it'll work with car stereos).
 

 
Dec 9, 2016 at 10:10 AM Post #334 of 355
Tube+? Hmmm wonder how does this differ from the gain switch on the current version which makes the sound more tubey.
 
Dec 13, 2016 at 10:43 PM Post #335 of 355
Found some more info on the iTube2 here:
http://www.phileweb.com/news/audio/201612/01/18113.html
 
via Google translate:
"Digital Anridote Plue installed on the previous micro iTube has been changed to "Harmonic Control" switch written as "Tube +". It is said to be used to switch between "Sound of Modern Vacuum Tube Amp" and "Sound of Modern Vacuum Tube Push-Pull Amplifier", "Sound of Single-Ended Vacuum Tube Amp", and the vacuum tube mounted in Pro iCAN It seems to be different from mode switching."
 
"In addition, the gain switching dip switch prepared on the bottom has been changed from the conventional 0/6 dB switching to 0/9 dB in both preamplifier mode and buffer amplifier mode. It can be seen that improvements are made everywhere, such as the power supply part is strengthened from 9 VDC to 15 VDC."
 
original silver iTube and space gray iTube2:

 

 

 
Jan 14, 2017 at 11:51 AM Post #339 of 355
Today we have a story for you all. It's about 'em tubes. Yes, again. But please bare with us, this tale really is special. You'll see soon enough...
 
 
The (5670) electron valve. It matters. - Part 1/3
 
 
Every audio aficionado likes 'em Electron Valves and for a number of reasons. The two most obvious ones are their influence on the sound itself and highly appealing aesthetics. Some of you might dislike the look of glowing glass and since this matter is highly subjective one, we won't focus on it. The rest though, well, that's a completely different story.
 
Our latest headphone amplifier - the Pro iCan - is loaded with a pair of GE5670 JAN double triodes. OK, there's a ton of valves out there. Therefore this question is in order: why we use this one specific type from this specific manufacturer? Now that's a story to be told. Here we go then.
 

 
Behold the WE396A double triode by Western Electric. These small critters were introduced in 1946 and shortly replaced by their 6922 variants. The former is the pinnacle, almost unfindable these days. The scenario isn't that grimm when it comes to the latter type. But as it turned out, there is one sonically as good model and made to very strict specifications - the GE JAN 5670 NOS type. It was under the radar of the audiophiles' scope for many years.
 

 
GE stands for General Electric manufacturer, which is self-explanatory. Said company was responsible for Electron Valves production for decades and is well-known for the quality of its products.

Moving on, JAN is the service branch of the US Armed forces and said three letters stand for Joint Army & Navy. Electron Valves marked as JAN were made for the Army/Navy (the airforce had to have their own naturally) and had to pass the most rigorous testing procedures at that time.

The Russian parallel system was OTK, which means "Отдел технического контроля" or technical control department. Even the Russian system was very decent as one does not wish for Mach 3 Jet Fighters at 100 million ruble a pop to be falling out of the sky on account of poor Electron Valves. This translated into modern money would be ~350 Million USD - the same as the F-22 Raptor today! And yes, it used Electron Valves for a lot of critical electronics.
 
It packed a targeting Radar so powerful it was a crime to even turn it on except in combat or exercise. It would kill small mammals at several 100 feet (microwaved to death). 
 

 
Side Note: The Mig-25 Foxbat (a Mach 3+ jetfighter that scared the poop out the USAF at the time and inspired the Clint Eastwood film, ‘Firefox’ was no cheap junk (even if it was not as rad as the Firefox). 
 
Germany/Europe never had an equivalent system, they got either JAN electron valves with US equipment (including export versions) or German Postal electron valves (CCa, C3g, D3a etc.) made in...Germany.

The British Empire had (surprisingly) its own inter-service system for military electron valves, it came into force in 1941. The British generally used civilian electron valves (and later transistors) that were tested and certified for military use. British Military electron valves are identified by the letters CV (Common Valve) and a number.
 
Generally JAN/OTK marked electron valves are more rugged, have very tight technical parameters and much less variation, yet are at the same time compatible with civilian types. German/European Postal electron valves in general were dedicated designs with the singular exception of the Cca and equally ruggedised. British and Chinese used selected (or not) civilian electron valves for military applications.
 
Stay tuned, there's more...
 
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Jan 17, 2017 at 10:59 AM Post #341 of 355
The (5670) electron valve. It matters. - Part 2/3
 
In many ways the 5670 when introduced was a revolutionary electron valve. Ostensibly an RF device for VHF use, thanks to a usable frequency range to 800MHz it also offered good linearity, low harmonic distortion and low-noise in audio applications. Yet the 5670 electron valves never really went into audio gear much. Why?
First, being a relatively expensive electron valve to make made them less attractive for mass production.
 
Second, they saw wide military equipment use, including fire control computers and communication systems.
 

 
So before the late 80's the US Military & Nato stockpiled most of the production. Production of the 5670 ended in the 1980’s almost completely, so stockpiles were retained until the equipment they supported was removed from inventory in the latter part of the 90’s.
 
Third, and in addition, the 5670 uses a non-standard pinout. If one looks at 12AX7, 12AU7 or 6DJ8/6922, all of these have an identical or very similar pinout. The 5670 pinout is radically different. Electrically and in terms of internal design it is very similar to the 6DJ8/6922 which became very popular in American high end audio gear, but one can't plug it into a 6922 socket.
 

 
Well, physically it's doable, mechanically the 5670 will plug into a 6922 socket, yet the result may be deadly for the Preamplifier/Amplifier as heater and anode pins are mixed up, shorting out the high voltage power supply. Just don’t go there girlfriend.
 
Now let's add the price factor to the mix. Military parts always cost at least 10 more in comparison to identical civilian parts. Which for 5670 model meant that no-one designed audio gear with these electron valves during the golden age of Valve Audio.
 
After the military blew out these stocks from their warehouses when the cold war ended (those cavernous places like the one shown at the end in Indiana Jones "Raiders of the Lost Ark")...
 

 
...still very few people used them, as they couldn't be plugged into existing gear due to the non-standard pin-out. Long story short, NOS 6922 became very popular and their rare cousins worth 100's of Dollars while no-one wanted the 5670.
 
For the last 25 years plus dealers and audiophiles have been depleting very limited 6922 NOS stocks and that's why today it is next to impossible to find decent electron valves of this sort. And what about the unloved but excellent 5670? It sat nice and snug in warehouses like the proverbial Ark of the Covenant waiting for someone to discover it. That would be first of all Eric Barbour of Vacuum Tube Valley Magazine (but his article was also widely ignored) and then us.
 
 
Stay tuned, there's more...
 
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Jan 19, 2017 at 4:58 PM Post #342 of 355
The (5670) electron valve. It matters. - Part 3/3
 
With new old stock 6922 and equivalent disappearing and getting more and more expensive, what happened to the unloved but excellent 5670?
 
5670 valves became somewhat popular when Shanling made CD-players and electron valve amps years back which used the Chinese 6N3, a Chinese copy of the soviet 6N3P (often incorrectly written as 6H3PI) which was the Soviet version of the 5670. As few people knew about the possibility to swap the 5670 for a 6N3 the good stuff mostly remained in storage.

Needless to say, now the 5670 cat is out of the bag as a workable NOS 6922 substitute, AMR/iFi Audio have bunkered the content of one of these military warehouses for future use. With either the correct socket wiring (which our Pro iCAN sports) or an adapter (like used for our NOS 6922 replacement) they will be hunted to extinction within a few years by all the ‘electron valve hounds’ of audiophilia... Grab 'em while you can.
 

 
So there you have it, GE JAN 5670 NOS is a marvelous piece of glass built to last (100,000 hours’ of lifespan are easily possible if the electron valve is operated conservatively), with marvelous sound quality. The very best among what's currently available for the money. Yes, you can go even higher. But it's not only just an expensive journey to be had; the money is the smallest issue actually.

The main problem is in availability and origin of the various Western Electric & Bendix 6N3 equivalents. Yes, counterfeits are out there, you've been warned.
 
Glass going on record
_____________________________________________________________________________________________________
 
Makers of 5670/2C51/ECC40 on record:  (we are not going to do a sonic ranking between the valves in each category - waaay too subjective).
 
Best
·         WE USA (as 396A) (there are D and O getter versions) - probably the best of the lot but good luck in finding original 'good' ones from reputable sellers for £££
·         Bendix USA (as 6385) - very rare and hyper expensive
·         GE 5670 USA - as used in AMR CD 777 SE/DP-777SE & iFi Pro Series/Tube2/iTube 
 
Middle
·         Raytheon USA
·         Tung Sol USA
           Old Soviet 6N3P-EV OTK marked Stock

 
Worst
·         Soviet Russia 6N3P civilian type (marked in Cyrillic so looks like 6H3П)
          China (as 6N3)

 
The 5670/2C51 has similar data and application as the later European ECC88 and variants, so European valve makers concentrated on that type of valve.
 
Some valves marked "England" have been sighted, these appear mostly remarked Russian units.
 
Sylvania also made a 5670 which was also seen remarked as ‘Mullard’ but it isn't a true Mullard as they never made this version of valve, just a rebranding job.
 
To conclude, with the AMR CD/DP-777 SE or iFi iCAN Pro/iTube/iTube2/NOS 6922, we would not spend our hard earned cash on anything but the WE396A or Bendix USA.
_____________________________________________________________________________________________________

 
Note 1 - some background, the 5670/2C51 from a technological point of view, the "premium version" of the 6922electron valve. Better design, strong plates, lower microphonics etc etc...
So if you have the 6922, you can roll the valves in your non-iFi device and get better sonics but with the 5670/2C51 family using adapters, you are already running with the big guns.
 
Note 2 - the 5670 and 6922 have the same physical pins but are not directly interchangeable as they different fundamental designs.

The AMR CD/DP-777 SE use 6922 Pinout and adapters to convert the 5670 to 6922 pinout, so both 6922 and 5670 with adapter can be used. The iFi iCAN Pro/iTube/iTube2 have the sockets wired only for 5670, you cannot insert a 6922.
 

 
C:\Users\Violator\AppData\Local\Temp\msohtmlclip1\01\clip_image002.jpg
Moving on, one might think that if magnificent 5670electron valves as we use in our product are quite available, then something's off. But that's not the case. As we've said above, this electron valve has ‘flown’ under the radar for many years, 6922 and alike were much more popular. Yet popularity isn't an indication of what's good.

From a purely technical side, GE JAN 5670 NOS valves are the best ones we could find in large batches enough to be commercial.
 
  • Excellent consistency of electron valves between batches
  • Glass is thicker than usual,
  • Controlled warm-up
  • Tight specifications on grid current,
  • Low noise and microphonics and exceptional longevity
 
And since genuine military grade New Old Stock 5670electron valves are reasonably well available (unlike many desirable electron valves), it'd be a shame not to exploit their potential. Hence we exploit as much as we can, fully aware of what GE JAN 5670 NOS performs and sounds like.
 

 
At iFi Audio we always strive to find the best parts for tasks given. This is not lip service – we ruddy well mean it!
 
We experiment with lots of components from a number of manufacturers, measure, audition and once extensive research is gathered, we cherry-pick. If every component’s related decision would be as simple as it was with GE JAN 5670 NOS, our engineering lives would be much easier and we’d spend a lot more time in the pub!
 
C:\Users\Violator\AppData\Local\Temp\msohtmlclip1\01\clip_image004.jpg
In conclusion, this electron valve has an incredible price-to-performance ratio, it honestly doesn't get much better than this. We've been there, we've done that – we’ve got the t-shirt and the blinking key ring.
 
You're of course free to experiment with our Pro iCAN past warranty period. But it's highly unlikely that you'll find anything better for sane money. Please trust us on this one; our Skin, she does not joke around when it comes to sound quality.
 

 
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Jan 20, 2017 at 5:41 AM Post #343 of 355
Micro iTube2

Sprinkle the ‘magic of SET’ into any system


Reloaded, next generation

The original iTube became the ‘go to’ tube buffer for any and every home audio system. The iTube2 with trickle-down technology from the flagship ‘Pro’ series has been redesigned with new parts and new circuitry. Only the GE5670 tube remains. 


 
The iTube2 is a tubed output stage; tube preamp; tube buffer and an impedance-matching device. There is nothing like it. 

Put the iTube2 before a solid-state preamp with another iTube2 after it to create the effect of tubing the whole audio chain. 

Or simply use the iTube2 as a very high-quality preamp by itself.


 
The iTube2 sounds, by and far, like a tube amplifier ‘done right with the inimitable magic of tubes‘:
 
  • Tube+® circuit for SET/Push-Pull/Classic tube amplifier signature 
  • 3D Holographic+® for Loudspeakers matrix system
  • XBass+® for Loudspeakers matrix system
 

Features/Technologies
 
  1. High-end Direct Tube Buffer/High-End Direct Pre-amplifier 
  2. Selectable tube sound signature (SET / Push-Pull / Classic)
  3. All-new 3D Holographic+® for Loudspeakers matrix system
  4. All-new XBass+® for Loudspeakers matrix system 
  5. Pure analogue volume control
  6. Ultra-low Total Harmonic Distortion (THD): <0.009% (Tube+ off)
  7. 0dB or 9dB selectable gain
  8. Reference class parts quality from ELNA Silmic to C0G capacitors 
  9. iPower (15V) included, ‘quieter than battery’ power supply


Comment

iFi Audio’s Head of US Sales says, “If you are looking to put back the natural, full-bodied sound of tubes into your digital system, then the iTube2 is the right piece of kit for you.” 

The retail price of the micro iTube2 is US$375 (ex-tax) or Euro450/£375 (incl VAT).


Full product info: http://ifi-audio.com/portfolio-view/micro-itube2


About iFi

iFi Audio, part of AGL, is headquartered in Southport, UK. It owns the hifi brand Abbingdon Music Research (AMR). They respectively design and manufacture portable and desktop ‘ultra-fidelity’ audio products and high-end audio ‘home-based’ components. The combined in-house hardware and software development team enables iFi audio and AMR to bring to market advanced audio products.

 
  1. Facebook: www.facebook.com/ifiAudio
  2. Twitter: www.twitter.com/ifi_audio
  3. Instagram: www.instagram.com/ifiaudio
  4. Pinterest: www.pinterest.com/ifiaudio
 
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Sep 17, 2019 at 9:58 AM Post #344 of 355
Just a bit of update: I have had the original 1st gen. iTube in my PC system since 2013 when it first released and had been using it almost everyday for the last 6 years. About 2 weeks ago it began to develop a very noticeable unbalanced sound where the right channel was much dimmer than the left. I reckon the 5670 vacuum tube inside must have reached its time after 6 years of active duty. I went ahead and ordered a couple of NOS 5670, and they have just arrived - spent a few minutes to unplug the old tube out and swap in the new NOS tube - now everything goes back to normal and great sounding again.

DSC_0241-1.jpg

Old on the left and new on the right

DSC_0242.jpg

Joy!
 
Last edited:
Sep 18, 2019 at 11:05 AM Post #345 of 355
Just a bit of update: I have had the original 1st gen. iTube in my PC system since 2013 when it first released and had been using it almost everyday for the last 6 years. About 2 weeks ago it began to develop a very noticeable unbalanced sound where the right channel was much dimmer than the left. I reckon the 5670 vacuum tube inside must have reached its time after 6 years of active duty. I went ahead and ordered a couple of NOS 5670, and they have just arrived - spent a few minutes to unplug the old tube out and swap in the new NOS tube - now everything goes back to normal and great sounding again.


Old on the left and new on the right


Joy!

That glow is pure joy indeed! Thanks!
 
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