Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › X-cans problem/question
New Posts  All Forums:Forum Nav:

X-cans problem/question

post #1 of 21
Thread Starter 
I noticed when plugging in headphones (or unplugging them) to my X-cans V2 there is a sound like a spring vibrating in the left channel. Tapping the volume pot, the headphone cord, or the top of the unit produces the same effect. The top of the unit has to be tapped harder to have an effect. The volume of the vibration seems to based on how hard the unit is tapped and is not influenced by the position of the volume control. When the unit is not plugged in, there is no sound from tapping the unit. I noticed this behavior with both my Grados and Sennheisers. Have other people heard of anything like this or is something damaged?

I haven't noticed any problems during normal listening.
post #2 of 21
When I had the MG Head DT, I used to get the same sound when I'd flip the impedance switch with the headphones plugged in, or when I'd flick any of the metal parts (which I only tried after the switch sound was discovered). I believe it was tube-related microphonics. Maybe that's what you're hearing? I could be wrong, but that's what I guessed it was.
post #3 of 21
Strange... I've just been smashing my X-Cans around my room, jumping up and down on it and suchlike, and I just cannot get that noise to happen on mine
post #4 of 21
You mean through the headphones, right? Mine does the same thing - tap on pot or plug, and it make some weird sound in the right channel. In fact, sometimes all you have to do is touch the pot. As Jude said, appears to be tube microphonics. I have never noticed this noise while listening though.

After a few months, a slight crackle also developed when I turn up the volume, happens only occassionaly, and sounds completely different to the noise you describe.

*But I have a question to X Can folks about the noise floor of this thing. When I turn the volume up past half way, I can hear a touch of background noise, nothing major. However, I have noticed that after about a 1/3 of the way up, at about the 10 O'clock position, you start to loose some punch and tranparency while playing music. Still sounds good after that position, but is curious to me.

Alot of mass market receivers or mini - systems, for example, have their volume pot designed so you reach maximum output at about 1/3 of the way, or the 10 - O'Clock position. They are designed, I think, to trick the average person into thinking that the component is powerfull, at the expense of large gain increments, and to mask the high noise floor.
With most so-called high-end equipement, the noise floor is lower and the gain increments are very small - I can turn my power amp's input levels, or my preamps volume close to the max without hard clipping, and without a noticeable loss in tranparency well past the 12 O'Clock positions.

Not that I'm claiming that X-Can is junk, in fact it's my favorite headamp, it's just that the gain increments are a little too big, and the noise floor a little high, but not to the levels of mass-market junk IMO.

I would be curious to hear what other people thought about the Can's noise floor and pot.
post #5 of 21
I think its called being microphonic. The case picks up where you tap it


Quote:
Originally posted by Duncan
Strange... I've just been smashing my X-Cans around my room, jumping up and down on it and suchlike, and I just cannot get that noise to happen on mine



Good Grief Duncan what the HELL is your x-cans made out of??

Mine went pop after a 6 week light use


Enjoy......
post #6 of 21
Thread Starter 
I emailed AudioAdvisor about it and they seemed to think it was microphonics too.

The email also indicated that microphonics could be an indication the tube was going bad. I don't hear any distortion or unequal balance during listening so I am not too worried. For Jude and Ben, did your tubes die shortly after the microphonics developed? As of now, I don't want to deal with sending the unit to Audio Advisor to change the tubes when I could just wait till they die and upgrade them myself.


As for the noise floor and pot.... I've noticed that I usually don't have to turn the pot past 10-11 o'clock to be at a good listening level. However, when I plug my phones into the line out of the cd player I was using, they are usually a little above my normal listening level. When turning the pot past 12 o'clock with my Grados, I notice some background noise, but compared to the music at that level it's unnoticeable. For the crackling your hearing on the pot, it could be a sign that the pot is going. I had a volume control on my cambridge microworks that started doing that and soon at certain volumes I only got one channel sound. Fiddling with it fixes the problem, but it's slightly annoying. I don't use them enough to spend $13 bucks on a new one.

One last question, I plan on moving/flying back home in a few days and feel better packing the x-cans in my carry-on rather than a suitcase. Do you think this would cause problems at the x-ray machine? I mean, if I'm a person at the machine and see some wierd looking electrical components in a tube, I'd be a little suspicious.
post #7 of 21
Quote:
Originally posted by Jacobh
I emailed AudioAdvisor about it and they seemed to think it was microphonics too.

The email also indicated that microphonics could be an indication the tube was going bad. I don't hear any distortion or unequal balance during listening so I am not too worried. For Jude and Ben, did your tubes die shortly after the microphonics developed? As of now, I don't want to deal with sending the unit to Audio Advisor to change the tubes when I could just wait till they die and upgrade them myself.


Mine started doing this and then started to develop a fault, whether the two were related I have no idea

Mine also had a weird "blowout" (sounds mildly rude sorry) in both ears when ever I switched the x-psu on. Sounds like I had a real duff one It'll be interesting comparing the two experiences. (I managed to cut and copy the review of the unit when headwize WAS back up so I have a fair idea)
post #8 of 21
Yay hit 100 post mark (sorry for ot but what the heck
post #9 of 21
Since Jacob is talking about *my* X-CANv2 (I sold it to him ), I hope it really is microphonics, although as he and I have discussed privately, it never exhibited this behavior when I had it -- is this something that might have happened to the tubes in shipment? If so, I'd like to file a claim since it was insured. Or is this fairly normal, and if so, why wouldn't I have heard it (I was using HD600s)?

As the X-CANv2 was my first tube gear of any kind, I'm not too familiar with some of the behaviors being discussed. Can some of the tube people here talk a bit more about this phenomenon of "tube microphonics"?
post #10 of 21
Well, you dont have to be a genius to work out that the changing of vibrational energy into electrical energy is microphonic - (Thanks audioadvisor for that stroke of genius).

The question is WHAT component is the most microphonic, and can we reduce its susceptance? It might not be the valves, but this is where i'd start. - is there anything you can attach/put over the valve to dampen it, add weight to it or absorb the vibration? The heaters on the valves arent that pumped, so the temp they give off in the X-Can isnt huge. I'm sure you can get some valve covers somewhere???

Seeing as things don't get *that* hot, perhaps just the smallest amount of blue tac would dampen thing. Try putting a little bit at the base of the valve where its coolest. If it seems to hot, and that it mind start boling after a while (!) perhaps an alternative damper is called for
post #11 of 21
Jacobh:

I doubt that their scanners can penetrate the metal housing of
the X-cans (and we're not talking about tin foil here!)

So all they're gonna see is a black cylinder which could contain anything.;. well, I know how I would react. But since they scan anyway, I'd rather had it on me (carry-in) so I can explain everything than have them take apart my luggage.

When I flew back from Europe last Jan I had a thermo mug in
my suitcase. They scanned it before you even check in, so I had a good look at the screen. There was just a huge dark brown spot in shape of a mug, but you couldn't see anything behind or inside. I could have had anything in this mug, ranging from coke to c-4 and some elecronics....and a half litre mug is definitely enough to take down a plane.
But those morons they just didn't care - I don't think they even looked at the damn screen...


Bye

Redwoood
post #12 of 21
The airport will be the first people to agree with you Redwoood - that the system is FAR from perfect.

However, short of stopping every single little tiny black spot big enough to contain C-4 to take down a plane, 99.99999%(u get the idea) of the time with out a "result", would just be hell for travellers wouldn't it?

They need better systems, but i cant see what it could be. Maybe more and more staff and machinery to allow searching of every suspicious item. Its a mammoth job.

These systems are of course supposed to act more as a deterrant, than a perfect solution. I mean, if you DID have c-4 in that mug, would you take the risk through the systems you went through?? I know i wouldn't.

Now back to the X-Can...
post #13 of 21
Thread Starter 
I am assuming opening the unit to try to dampen the valve would void the warranty on the unit. While I couldn't find anything on their webpage, I would assume Audio Advisor would still have to honor the warranty even if I am not the original owner.

The only time I really hear the sound is when I plug in phones will they are on my ears or tap the pot or the cord at the plug. Can audio advisor tell if the unit has been opened or not? I definately feel comfortable opening it up an looking, but if it is something else I would have screwed myself.

The unit was packed very well so perhaps the tube came a little loose or something. While listening to music I hear no ill effects.
post #14 of 21
Seems though it could be a "Characteristic" of the X-Can, rather than a fault such as a loose tube. in my experience of the X-Can, the tubes are prettytight in their sockets anyways. - a loose one is unlikely.

This is one of those times you will have to jsut decide whther the hassle of contacting audioadvisor, sending it off etc etc is worth the potential gains on offer.

No ill effects during listening. Hmmm, sometimes little things can be annoying though. It's worth finding out how many other people have a similar prob with their X-Can and if many have it, then you can just put it down to the x-can design.

The decision, as they say, is yours.
post #15 of 21

Re: X-cans problem/question

Quote:
Originally posted by Jacobh
I noticed when plugging in headphones (or unplugging them) to my X-cans V2 there is a sound like a spring vibrating in the left channel. Tapping the volume pot, the headphone cord, or the top of the unit produces the same effect. The top of the unit has to be tapped harder to have an effect. The volume of the vibration seems to based on how hard the unit is tapped and is not influenced by the position of the volume control. When the unit is not plugged in, there is no sound from tapping the unit. I noticed this behavior with both my Grados and Sennheisers. Have other people heard of anything like this or is something damaged?

I haven't noticed any problems during normal listening.

Hi Jacob,

In the another thread headed "Smooth Cables", started by blr, I have commented that the X-components are quite microphonic, ...

Quote:

" Happy to help, Blr.

FWIW and simply FYI, I felt that I should mention that I have auditioned the various X-components from Musical Fidelity and I have consistently discovered that the they generally are quite "microphonic" even though they are quite solidly built gear. I have tried the X-Act, X-24kDac, X-Pre, X-Can, and X-10D and they all seemed to benefit from some additional isolation, from the hard surfaces they were resting on. Glass shelves certainly did them little favours and placing them directly on top of another component is also not recommended, IMO. "

So, Jacob, ... the X-Act and X24k Dac are relatively less prone to microphonics, whilst the X-Can and X-Pre are relatively more sensitive to resonance/vibrations and based on my own listening experiences, they do tend to exhibit more microphonics. Saying that, these units does response positively with some level of isolations, using say, vibrapods, sobothane and other similar resilient type feets.

Well, check out the "Smooth Cable" thread, and you will read about blr's experiments, in his attempt to isolate his X-Can, with the hope of taming some subjective HF peaks that are annoying him.

Finally, the vol switch in the X-Can is nothing great ... cheap stuff really, mass produced, cost efficient and it works ... but do realise that the X-Can is built to a limited budget, to a price point, and because it so happen to sound very good for the money, many of us tend to expect too much from that little marvel. I would not be surprised if a major portion of the budget has gone into the casing itself and inevitably, some "corners-cutting" cannot be avoided, but fortunately, the MF people still managed to squeeze out relatively good sonic performance and make it look funky as well as incorporating a tube output stage !!.

Well, that's my 2 cents worth.

Cheers,
New Posts  All Forums:Forum Nav:
  Return Home
  Back to Forum: Headphone Amps (full-size)
Head-Fi.org › Forums › Equipment Forums › Headphone Amps (full-size) › X-cans problem/question