Aesthetix Io strange behaviour

This morning, my Io won't play music. The only thing I hear is scratching/popping noise when I turn the volume controls. Same thing in both channels. Tried changing cables, etc, but no change. Anyone has an idea? The unit has played beautifully especially since I got a full tube replacement from Aesthetix some years ago. I've heard nothing to indicate a coming breakdown. The lights on the unit come on OK, and as far as I can see, the tubes light up normally too. Strange.
Best to call Glenn at Aesthetix. He will know.
(805) 529-9901
Thank you, I got no answer but left a message.
The problem is specific, perhaps the cure also?
I've changed power supply tubes and fuses - no help.
Obviously there is power out, since I hear these noises in the speakers when I turn the volume knobs, varying with their level. Only no music, the input does not get through. I tried just now once more with the aux input (to cd player), just to be sure it is not some analog player or riaa problem. But the result is the same.
(For the record, the Io has mainly been problem-free for me).
OK, cleared up. A local electronics repair shop was able to do it. They found "a defect regulator V1 in the power supply and changed the V1 tube". Reason for failure not known, may have been the fault of the tube. Whatever the case, music is back - great.
i think is good to send to local unless they replaced same parts,
My IO is still on repair almost a month now.
Csng1, I assume you mean, one should only use identical parts? Do you have your Io for repair at the factory, or locally?

For some reason, mine has failed once more, with exactly the same symptoms. After bringing it back from the repair shop, it worked OK for some days, then I turned it off for a day, and then, starting it, same thing as before. Sadness reigns. Strange how one can miss a piece of gear so much, I guess this says a lot about the Io. I can play a bit of digital, using the volume on the Squeezebox Touch through a Stello mk2 Dac connected directly to the amps - quite nice, but not the same. Not at all (sigh).

Obviously something is causing these failures that was not fixed, and I guess I have to try the repair shop once more. Jim White promised to get back to me on email, but that was some weeks ago - no further info.
(The digital comment may have been a bit unfair to the Stello DAC, which I bought recently. In my analog chain, the pickup alone costs quite a lot more than the DAC. However, even using the same source (digital), I prefer the DAC into the Io, rather than direct into the amps. Even if there is a bit of plus and minus on both sides, in that comparison. Direct is perhaps more precise and, well, direct. Through the Io it is a bit less immediate perhaps, a bit less precise. On the other hand the music is much more fleshed out, embodied, "humanized"; I don't quite know how to describe it, but it sure does create a more convincing illusion of live sound. Which is the goal of this hobby, for me. But as I said, the Stello is also fine).
I am no engineer, but I guess the possibilities are: 1 the new regulator was not quite the same, not correct, and broke down, 2 the tube went bad (seems unlikely), 3 something else / upstream. I wonder if this kind of failure should have made one of the fuses go, instead of components. My Io has four fuses, two inside the power supply box, 2 at the back of the box (none in the Io itself). After getting it back from repair, I changed the fuses to weaker amperage, thinking that it is better that a fuse blows. I tried changing the two at the back to 1 amp fuses, but the "B+" blew and I had to go back to 5 amp. The "Heater" fuse worked ok. I then changed the two internal fuses F1 and F2 to 1 amp (I had 5 amp in one channel - too much). It may be that this is still too much (could be 0.5A or 0.25A since we have 240 volts here in Norway). Both lights turn on, at the front, so I assume none of the fuses are gone. And it seems very unlikely that a fuse, by itself, is cause of the failure. I have also read (at this site) that Aesthetix later dropped the two internal fuses since they often blew and did not protect the components anyway.
Another remote possibility may be that the active shield power cable (Synergistic Research A/C Master Coupler X2) that I bought recently is not good for the Io, it gives some static effect, or whatever (even if it is plugged into the same course as the preamp). I know that the Io is very sensitive to the mains, and the problems have come after I changed from a Kimber power cable (standard type, no active shielding). Yet I have not seen users reporting problems with active shielding, so I consider this quite unlikely.
The mystery deepens. I brought it back to the repair shop some days ago, and got an email from the professional involved, today. He writes that they have the Io up and running once more, but he wants to keep it for further testing. He writes (my translation from Norwegian);
"I changed the fuses that had gone from 'fast' to 'slow' 0.5A. Did not find the BUSS [US] fuses that I thought I had, but found the documentation for those fuses and as far as I can see now it should be 'slow' 0.375A. For now, everything looks fine. Has been left on, for testing, yesterday and so far today. Want to test some more for checking power voltages esp around the regulator."
It could be as simple as two bad tubes in a row. Not so often, but it happens. Since this thread may be informative for other Io owners, I will keep you updated.
I got it back today, working fine. Morten said he could find no other fault, except for blown internal fuses. The were "fast", and he said, even if the amperage is larger, such fuses often blow before "slow" fuses. As far as can be seen, the new regulator and the EL34 tube work fine, and there is no problem with the Synergistic active shielding cable.
So, the mystery has been cleared up, it was one bad tube (only), the second time it was wrong fuses (my fault).
Let me add that Glenn, at Aesthetix, has been of help through email.
In conclusion, this thread should not be seen as negative for Io or Aesthetix, but a user discussion of problems that can occur in all tube preamps, and how to solve them in this specific case.
Hi O holter
Yes, Glenn said they repaired and are on burnt in mode, should be getting my IO next week.
Yes my dealer said must use the same part otherwise it will degrade the sound, is all about right measurement of resistant and so forth.
Yes, is so painful but i am still enjoying my Sony xa-9000es cd/sacd .

Call Glenn , you could replace bigger said a 5 amps or direct the internal fuse with hard wire solder. My Callisto sgn. Also have internal fuse but my 2011 io do not have internal fuse. Yes my Callisto fuse blown too,
But since replacement is fine.
I am following this up, and will inform later. I am considering a Io upgrade in a larger context, named "chasing out distortion from my system". Happily my Io is back on line.
Although the Io now works fine, I have decided to ship it to the factory for an upgrade. Having to do without it during the repairs, and using replacements, made me realise that an upgrade will most probably be well worth it in my system, even if it is costly.
Update: I am very happy with the Eclipse upgrade. Although it took a long time to burn in, it now sounds remarkably good. I have never heard a better preamp/phone stage. I had to get a new tube set from Aesthetix since the first one was noisy, but then it worked OK.

Only one complaint really. This is like having a big telescope in your living room - or something equally sensitive. Careful with footfalls! The upgraded Io is extremely sensitive especially to e g electrical conditions, even more than the mk2 version I had before. It clearly wants stability. It should perhaps come with a "do not disturb" sign. I keep it on all the time. I also would have liked even less background noise. Beyond these complaints, however, the Io E to my ears proves the thesis that the preamp is the heart of the system - it gives everything else in the chain a lift too.