Aesthetix Io Users Group

[Tirebiter]

Sudden power supply tube failures....

I have an older issue IO Signature with dual power supplies and a couple of weeks ago lost the right channel. I have an ancient Hickok that has come in handy for just such events and tracked the failure to the V1 Marconi & Osram KT66. Note, the failure of this tube was very sudden and without the Hickok would have been tough to track down because it was not a filament failure (was still glowing)...the tube simply went dead.

I should mention that these power tubes are suddenly hard to come by. I ordered a quad set of new issue EL34's but they are still a couple of weeks out because of the shortages. So I found a quad set of TAD KT66's on EBay that were available for delivery and they arrived on Friday. I installed the set and went to have a listen and found the left channel was out. Hmmm...a check revealed that the brand new TAD in the V1 position was similarly dead. Moved the V5 TAD to the V1 and put in a spare M&O KT66 only to find this morning when powering the system up that the TAD failed after about 5 hours of listening yesterday. Dead as a door nail.

So what gives? Simply bad tubes from TAD or is it something in the power supplies themselves that I should be concerned with? The failures have occurred in both the right and left boxes so I find it hard to believe that there are other problems but want to see if any of you have experienced similar issues.

Brock

 

[audioquest4life]

Sudden power supply tube failures....

I have an older issue IO Signature with dual power supplies and a couple of weeks ago lost the right channel. I have an ancient Hickok that has come in handy for just such events and tracked the failure to the V1 Marconi & Osram KT66. Note, the failure of this tube was very sudden and without the Hickok would have been tough to track down because it was not a filament failure (was still glowing)...the tube simply went dead.

I should mention that these power tubes are suddenly hard to come by. I ordered a quad set of new issue EL34's but they are still a couple of weeks out because of the shortages. So I found a quad set of TAD KT66's on EBay that were available for delivery and they arrived on Friday. I installed the set and went to have a listen and found the left channel was out. Hmmm...a check revealed that the brand new TAD in the V1 position was similarly dead. Moved the V5 TAD to the V1 and put in a spare M&O KT66 only to find this morning when powering the system up that the TAD failed after about 5 hours of listening yesterday. Dead as a door nail.

So what gives? Simply bad tubes from TAD or is it something in the power supplies themselves that I should be concerned with? The failures have occurred in both the right and left boxes so I find it hard to believe that there are other problems but want to see if any of you have experienced similar issues.

Brock

Man, that is awful. I have never experienced such issues on my 17 year old unit, which is updated to the most of the latest Eclipse options. But, I also never swapped that particular position of tube either. Only the power supply 12ax7 tubes and the preamp tubes.

At least it did not take out the Io entirely. How old is your unit? Has it ever been sent back to Aesthetix for a check up and/or power supply upgrades to the latest versions? It does seem odd that you experienced all of these symptoms around the same time with the TADS. Perhaps it is a bad batch if tubes and that would be the best outcome since the Io is still operational. These things are work horses. Do you have any original Aesthetix tubes to test out? My initial hypothesis from what you stated is that it is a bad batch of tubes. In another component, i was using RFts and the preamp would snap and pop sporadically. When I pulled them out and put in some PSvanes, all was good. The RFts went to the trash.

good luck

 

[Kcin]

Have you checked the fuses in the PS' ?- make sure the KT66s did not take them out.

If you have a tube tester then check the 12AX7s as well for fun.

Too coincidental for both boxes to fail - I am not sure ebay is the best place to buy tubes either YMMV. At this point I suspect the tubes.

Can you make one good channel for the PS with the original KT66s you have left. I would do that--- and then if you could and plug it in both sides of the phono stage .. you want to make sure nothing upstream is dragging the PS down.

Other than that substitution with known good EL34s / 12AX7s before off to a tech if required. Maybe just maybe caps or a bridge are failing and taking things out .. It would be a simple fix for a tech especially with a schematic... but its always a pain pulling things out and dragging them in for service. If its 10+ years old and never been serviced. The PS can benefit from that regardless.

If you're not comfortable with high voltage... take the precautions regarding power down time between tube rolling from Aesthetix


Good luck

 

[OGH]

If both power supplies have failed, I would suspect something else than tubes. Something in the Io itself, rather than the power supplies?
If it was me, I would double check, inserting 'stock' new production tubes into the units. But I get the impression, changing tubes does not help.

 

[Tirebiter]

Have you checked the fuses in the PS' ?- make sure the KT66s did not take them out.

If you have a tube tester then check the 12AX7s as well for fun.

Too coincidental for both boxes to fail - I am not sure ebay is the best place to buy tubes either YMMV. At this point I suspect the tubes.

Can you make one good channel for the PS with the original KT66s you have left. I would do that--- and then if you could and plug it in both sides of the phono stage .. you want to make sure nothing upstream is dragging the PS down.

Other than that substitution with known good EL34s / 12AX7s before off to a tech if required. Maybe just maybe caps or a bridge are failing and taking things out .. It would be a simple fix for a tech especially with a schematic... but its always a pain pulling things out and dragging them in for service. If its 10+ years old and never been serviced. The PS can benefit from that regardless.

If you're not comfortable with high voltage... take the precautions regarding power down time between tube rolling from Aesthetix


Good luck

Yes the tube tester confirmed it was dead while the others checked out as OK. I also checked all of my 12AX7's and did some pin and socket cleaning while I had everything pulled apart. Fuses were also good.

I agree on EBay being suspect but I reasoned that BC the site was associated with TAD that they should be brand new and in functioning, Plus I figured the German tubes might be a bit better than Chinese or Russian. FWIW, the TAD looks like an exact carbon copy of the M&O KT66.

Based on the responses here I am going to replace the last bad TAD with another used M&O and see what transpires....

Man, that is awful. I have never experienced such issues on my 17 year old unit, which is updated to the most of the latest Eclipse options. But, I also never swapped that particular position of tube either. Only the power supply 12ax7 tubes and the preamp tubes.

At least it did not take out the Io entirely. How old is your unit? Has it ever been sent back to Aesthetix for a check up and/or power supply upgrades to the latest versions? It does seem odd that you experienced all of these symptoms around the same time with the TADS. Perhaps it is a bad batch if tubes and that would be the best outcome since the Io is still operational. These things are work horses. Do you have any original Aesthetix tubes to test out? My initial hypothesis from what you stated is that it is a bad batch of tubes. In another component, i was using RFts and the preamp would snap and pop sporadically. When I pulled them out and put in some PSvanes, all was good. The RFts went to the trash.

good luck

The history is unknown to me but logic and reasoning tell me that it started out life as a single power supply unit, at least that is what serial numbers tell me. The Io would have been the 16th made assuming the first off the line was #1001 and one power supply matches that number...it may or may not have been a Signature Edition at that time but does have a sticker now and the guts confirm. The second PS is more on the order of #1278 so my assumption is that it went in for at least a PS upgrade at some point. Other than that, who knows...

As far as tubes go, all I have are the ones that came with my purchase with a few spares. The two PS contain RCA 7025's plus the M&O/TAD KT66's. The Io contains mostly Tele 12AX7's, a couple of RCA Red Base 5692's and a couple of Amperex 6922's...so not much for me to work with in that regard.

I am going to go with a spare M&O to replace the TAD and see what happens next....oh boy!

 

[audioquest4life]

Speaking tubes, I am testing out some Linlai E 6SN7 tubes in the Io. These replaced the NOS Russian tubes I had in that position.

So far, so good. I am liking what I am hearing and what I am not hearing, bland, rolled off or muffled sounding, etc.

I can’t say these are a night and day difference to the Russian 6SN7s that came from the factory, but the soundstage and imaging are great and frequency response seems to be even handed, nothing bloated or exaggerated. Bass still feels deep and taught and midrange vocal resonance sounds extremely realistic with nice and detailed upper frequencies which showcase cymbals very well. My impressions thus far are that they are a decent replacement. Perhaps I might experience more profound changes after some tube burn in. At the end of the day, if you are looking for a modern 6SN7 tube for your Io, this may be it. Now, that being stated, my system sounds superb as is with the tubes I am using and these tubes contribute to maintaining the same sound qualities I cherish. Can’t go wrong there.

 

[Tirebiter]

PS tube failure update.

After communicating with the TAD rep and knowing that Aesthetix does not recommend the KT66 as a power tube for the Io, I have decided to abandon the KT66 and return to the EL34 lineage. In short, I was told that the KT66 is not rated to handle 600V plate voltage whereas the EL34 is rated up to 800V. Because none of my tube failures have occurred while listening, I have concluded that they popped when initially powered up due to voltage surges. A set of TAD Red Base EL34 are in transit.

As a side note, the TAD rep asked to see a pic of a power supply and then questioned the need for 2 separate PS boxes when each already contains dual mono power supplies. I could not answer that question and thought I would ask here...what is the reasoning behind the quad power supplies? When modified for dual PS, is the power in the Io then split between sections of each phono amp? The TAD rep couldn't see the sense in the design....

 

[audioquest4life]

With two power supplies, it becomes true dual mono. With one PS, it is a split stereo power supply to the preamp unit. In other words, it is somewhat of a Y connection with one, and with two, each Channel is powered by the separate power supply, thus true dual mono.


One defining characteristic of the Jupiter Series is separate power supplies. Each main unit, or audio chassis, is dual mono in construction; there are completely separate left and right audio boards and each has its own power connector on the rear of the chassis. Each main unit requires at least one power supply, a single power supply cannot power both an Io and a Callisto.

There are two versions of power supply available: Stereo or Dual Mono. In the stereo configuration, a single power supply powers both audio channels and has two power connectors on the rear. In the Dual Mono configuration, two separate power supplies are used, each with a single power connector. In the Dual mono configuration, the unit becomes pure dual mono, all the way down to the ac wall connection!

The Jupiter Series Power Supply is the size of a power amplifier and weighs approximately 50 pounds. The Power Supply has two main sections, the heater supply and the high voltage plus and minus supplies. At the heart of the heater supply is its massive, low flux, 210 VA power transformer which has fourteen separate secondary windings that are individually regulated and supply both the Power Supply and main unit heaters. The high voltage supply is composed of a similar massive 170 VA transformer which feeds a common-mode choke input filtering network and then high current vacuum tube regulators (one EL34/6CA7, three 12AX7 tubes per regulator). Each regulator is capable of supplying 600 volts at 100mA. There are two such regulators in the Power Supply. Each separate amplification or buffer stage has its own power supply filtering network and regulated heater supply to isolate individual sections and prevent stage interaction.

 

[Kcin]

When did sense in design have any place in high end audio

Why would we be running a phono stage with 32 tubes otherwise?

 

[Tirebiter]

The TAD rep ultimately figured out the dual PS design concept and now understands. He was confused between the latest generation dual units, the older separate dual and the stereo iterations. He thought I was using two of the new generation dual PS. The Aesthetix website was a little murky on older model details.

The new EL34's should arrive on Monday. So far, no additional problems with the KT66's in current use...

 

[OGH]

Testing my Yes recordings from the original UK vinyl albums, in my cottage system. Recordings made with the Io. In DSD format some years ago. I am impressed. Comparing it to digital streaming from Qobuz. Including the Steve Wilson remasters. Yes these are maybe 'clearer' but my recordings preserve the original ambience and atmosphere very well. E g on Tales ... maybe their best album. Great tonality, timbre, depth. Thanks, Io...

 

[oldvinyl]

Please spin a few records for me. My power supplies have been sent in for the new transformers and to resolve a popping sound in one of them. My guess is that they will be there at least a couple weeks.

 

[audioquest4life]

Please spin a few records for me. My power supplies have been sent in for the new transformers and to resolve a popping sound in one of them. My guess is that they will be there at least a couple weeks.

Glad that Aesthetix is going to upgrade your power supplies. Hoping That your downtime will not be so long.

 

[OGH]

Please spin a few records for me. My power supplies have been sent in for the new transformers and to resolve a popping sound in one of them. My guess is that they will be there at least a couple weeks.

I will! I've found that recording from LPs through the Io is well worth it, including situations like yours, where the Io is in for repair (or your cartridge is broken...etc). I just found that even the single dsd speed recordings made on my Korg mr1, that I used some years ago, are quite good, in some ways better than typical streaming, although the double speed dsd made on the Tascam DA3000 is better.

 

[OGH]

Another recent experiment:

I took my new desktop speakers from my office to my main living / listening room system with the record player and the Io. These are Arche audio FR2 single driver speakers.

I was amazed by the sound these small speakers were able to project in this large room, driven by very good tube amps (MA1). They are limited, not much bass below 70 hz or so, and there are other problems also. Yet I am impressed by what they do right. Single driver = no crossover. More coherent timing and phase (hopefully). Whatever the reason, these small speakers were able to give a coherence and pitch/rhytm factor to the upper bass, and especially, midtone and treble, that in some ways rival my big floorstanders - or even go beyond them.

I already have transformer-less amps, so what about crossover-less speakers - it got me thinking, even though I know there are lots of problems making single drivers sound good, esp in a large room. And I like the wider and partly reverberant sound of my big speakers, even if pinpoint sound can be thrilling.

Anyway, the small FR2 speakers were very good, listening for the sound from my LPs through the Io, compared to the sound from digital streaming (Qobuz through Teac nt505). Although they mainly confirmed the results from my Dream Maker speakers, by highlighting the mid tone and treble especially, and getting it very time-coherent, they give me new insight as to why I prefer analog reproduction through the Io. (Even if the best of digital is now often quite good).

I could try to run the Teac to the Io aux input. But I doubt it would make a change. The aux input of the Io is good - in my experience. But the special magic is in the phono input - the first gain stages. And in the record - stylus - the analog tech itself.

 

[oldvinyl]

I will! I've found that recording from LPs through the Io is well worth it, including situations like yours, where the Io is in for repair (or your cartridge is broken...etc). I just found that even the single dsd speed recordings made on my Korg mr1, that I used some years ago, are quite good, in some ways better than typical streaming, although the double speed dsd made on the Tascam DA3000 is better.

I’ll have to “slum” it with my CD/SACD player and silver discs until the power supplies come back. Eager to hear what the new transformers can do.

 

[Lagonda]

Please spin a few records for me. My power supplies have been sent in for the new transformers and to resolve a popping sound in one of them. My guess is that they will be there at least a couple weeks.

HaHaHa a couple of weeks ? Anything Aesthetix does takes at least a couple of months ! 6 months if you live in Europe. My Io gave of a loud pop on warmup last week , and now only plays in one channel. I have used it sparsely since the last time it came back from repair, this time will be the fourth time it brakes down. I am so disgusted with it i haven't even opened it up yet, worst reliability of any equipment i have ever owned.

 

[audioquest4life]

. I have used it sparsely since the last time it came back from repair, this time will be the fourth time it brakes down. I am so disgusted with it i haven't even opened it up yet, worst reliability of any equipment i have ever owned.

That is an unfortunate experience you are having with the Io. You must have a built on a Monday or Friday model. Just like cars, those are the days apt to have some glitches. Your experience is definitely the exception and not the rule compared to the vast majority of Io owners who have owned these things for many years without major issues, myself included. I have owned my Io since 2005 and feel Blessed with the ruggedness of the Io as I have traveled across the Atlantic a few times with it and have not had any down time with it. Good luck working out the gremlins.

 

[Kcin]

HaHaHa a couple of weeks ? Anything Aesthetix does takes at least a couple of months ! 6 months if you live in Europe. My Io gave of a loud pop on warmup last week , and now only plays in one channel. I have used it sparsely since the last time it came back from repair, this time will be the fourth time it brakes down. I am so disgusted with it i haven't even opened it up yet, worst reliability of any equipment i have ever owned.

Sorry to hear of your problems.

I have had my Io , now Eclipse- for 15+ years. Only one self induced tube rolling problem- resolved 15 years ago. It has been remarkably reliable for me. I let mine run 24hrs over weekends and such when I do most of my listening.

I hope it is just a tube for you.

 

[OGH]

Re: Reliability.

I bought a Io mk 2 with volume and one power supply back in 2004, and then upgraded to Partial Eclipse ("partial" = keeping the old chassis) with a second supply in 2012. I had few problems, in this period. However I was a fool. Going for the extra inch of sonic performance, I let the Io run all the time - almost allways on. I came from a solid-state system and did not think much about it. Idiot me!

Soon after I got the three-box Eclipse version back from the factory, problems started to appear, At first small things that could be repaired locally here in Norway. Like a resistor or cap or something gone, that could be explained by a bad tube.

But soon things got worse. I heard sharp scratching noise turning one of the volume controls. Sounded like broken solder. Also, channel balance was off. And hum. Etc. I thought, why didn't Aesthetix catch these errors, when it was at the factory, for upgrade? I took the Io to a local "wizard", but after several months it was clear that he could not fix it, arguing that he did not get the schematics from Aesthetix.

At that point, I gave up, and shipped the whole three box stash back to Aesthetix. Very expensive over the Atlantic! Next, several months passed, and I had a bad case of the blues. Where is it? How long is it gonna take??

However, all this time I was in communication with Glenn (and sometimes Jim) at Aesthetix, who answered my mails and calmed me down. They were puzzled at the factory, they could not find the source of the errors. Finally it became clear that both volume controls had to be replaced with new ones. It seems that shorts, bad solder etc in these caused problems down the line. So, I said yes to their offer to replace the volume controls plus other affected electronics.

At this point, the company was very fair. Sort of, giving me a good deal, since I had to wait for so long, and had this long list of problems, despite the recent factory upgrade. So I got the new (costly) volume controls for ca cost price I believe. Very reasonable. And especially, they did not charge for all the hours they had used, locating the problems.

After this repair (2016-17) I have not had major problems. But then again, my old "regime" has been changed. No more "allways on"! Also, I have a fan behind the main Io unit, for some cooling. And more air around the supplies.

I have a personal impression, why my Io broke down. Note that this theory has not been confirmed by the factory (but they've not said no, either!). To my mind, the Io said farewell due to three factors.

The first is heat. The second is time. Heat over time = worse for components. Even if the Io and p-supplies were fairly well ventilated, they stood in a rack, and I noted a lot of heat especially after several hours on. The third factor is heavy use of the volume controls, since for many years, I used the Io as preamp, direct to the amp(s), often adjusting the volume. I am not sure, if this played a role, but with the heat, I think it increased the chance of solder cracks in the volume controls (resulting in scratch noise). And it seems that problems at that point led to other component failures.

All in all, this track record over 18 years is not bad, with many trouble-free years of use, especially if some problems were caused by the user (me), with my "always on" idea.

I have found the waiting times and shipping costs frustrating, yet the customer communication and quality of service at the factory has been very good!. I have wondered, should they have more testing of older Io's and power supplies, that are turned in for Eclipse upgrade. Maybe, that way, I would not have had to ship the thing twice to the factory. But then again, the scratching and other problems were not manifest until a year or two, after I got Io back from the upgrade. So I may have had - simply - bad luck.

So I am not trading in the Io for an "easier" phono stage in the near future. I value the good customer relationship over the years. I appreciate quality companies communicating with their customers, standing by, over time, looking for long-terms improvements rather than short term profits.