[herbie]

Hi. For some time I had been happy with my x-cans. Then it begun…

I changed interconnects -> more details, more precision
Replaced stock tubes by Sovtek’s 6922 -> more details, less distortions, less ambience, less “air”
Got a trafo replacement, 60VA -> some more details, less weak bass

All these steps introduced changes and more or less improved sound. But the main problems remain:

1)Higher frequencies tend to be bad. I find myself prefering music with low use of that “upper sounds”. It’s that annoying - the otherwise great sound being destroyed that way. Often higher voices are noisy, too. Can’t be on all that recordings. (Think the right characterization here are grain, hiss and sibilance.)

2)Second problem: Sound is distorted, maybe in the upper mids. There is often that strange reproduction, absolutely week (“cranked”?), randomly wrong. You never know when or where reproduction will be solid or total crap. I find myself hoping all the time that music played will sound pleasant.

Is my amp really that bad? Or do I have to blame my average source, cheap interconnects and cd collection…
I am barely willing to spend another 100 EURos on some other tubes, just to notice that sound has improved but is still crappy.

Will be a long way to satisfying sound...

Herbie

 

[noiseunit]

its probably not much help, but ive had a crappy source combined with stock interconnects give me almost the exact same sonic issues (vocal distortion at moderate volume, sibilance, etc.) with various low-end solid state amps. changing sources helped a _lot_.

other than that, cant help much...never heard the xcans, or any tube amp for that matter

good luck

 

[daycart1]

You shouldn't be getting outright distortion with properly functioning x-cans. It must be the source or a second set of bad tubes. (or bad cd-r?)

 

[Hirsch]

It would depend on your source. The X-Can should not be distorting at all. If it is, the first place to look is the tubes. The JJ/Tesla 6922 is one of the best of the new tubes to try in the X-Can. The Sovtek is a major step down, and will tend to make the amp sound more analytical and less warm.

Make sure that your power supply replacement is putting out the correct voltage. A problem there could damage the amp.

Grain, hiss and sibilance are not characteristic of the X-Can.

 

[elrod-tom]

It really does sound like the tubes are the issue, at least that would be my first guess. It's possible that there is something going on with the source, but it seems like your problems started at about the same time as you changed the tubes.

I've had the X-Cans V2 for awhile, and I used it as my main amp for some time. I like it a lot, as witnessed by the fact that I should sell it but can't bring myself to do so. I found that the high end could be a bit on the bright side with the wrong headphones, but other than that I was quite pleased.

What cans are you using?

 

[Sledge]

I have to agree with the others. Something must be wrong (either power quality, music quality, or something inside the X-CANS). I have never heard any distortion at all on my X-CANS.

 

[dudeupsh]

See if you can get pink floyd to make you a crossfeed circuit.
It really smoothes the sound out and gives a more focussed
sound.Especially in the bass.

Duane Upshaw

 

[PinkFloyd]

You certainly shouldn't be experiencing any type of "distortion" from your X-Can. Was this distortion evident before you replaced the valves or has it only come about after introducing them into the circuit?

Also, be absolutely positive that your 60VA transformer is giving out 12V AC. Make sure that you remembered to attach the earth wire from the PCB back onto the case when you reassemble the X-Can after replacing the valve...... failure to attach this securely can result in a "grainy" sound.

It could also be your source that's the problem, have you tried it with another amp? The sovteks are a nice sounding valve but it could be that you've got a dodgy pair, try replacing them with the original philips valves and see what happens.

If nothing cures the problems and you are "certain" it is the amp that's at fault then it would be a good idea to refit the philips valves and send it back to Musical Fidelity for inspection.

All the best.

Mike.

 

[herbie]

Hi,

thanks for all your replies. This one is a bit delayed.. BTW, I am using a HD600.

I went back to stock tubes. Seems like quite some of my complaints were based on the Sovtek's characteristics. They are more detailed, but also brighter and not good in the upper end. At least not with my x-can v2.
I am not sure wether it's the tubes fault or if they just make the source's or amp's weaknesses more obvious.

For now, I feel comfortable with the somewhat damped stock tubes sound. That might be because I did not hear them for some time, and especially not with the new power supply. Weaknesses will probably turn out again after some time.

Regarding the power supply: I measured 11-12 V when connected to the amp. The ground(?) is connected to the casing. I am a bit concerned about the heat the amp produces.
Sound improvement seemed to be small at first, but turns out to be very good. There is more detail, and less "bloff-ier"[weak] bass.

Still don't know about the quality of my source. Will try to figure that out.

Herbie

 

[Nick Dangerous]

I'd try the JJ's. They tamed the screechy brightness of the original Philips valves without sacrificing quality when I did this.

 

[dudeupsh]

Bad news guys.After just reporting that I had a channel imbalance
that appeared to have corrected itself,I,ve discovered a burning
smell coming from my x cans v2.Upon opening the unit I discovered what appears to be two smoked resistors or something.I have a friend who is also using the Ault P.S. and had
a premature tube failure.Now I have a failure as well.In a previous
thread their had been discussion about the article in Stereophile
and their recommendation to avoid this unit.The guy who posted
the thread claims to have verified the approval of this unit with
Anthony Michaelson of Musical Fidelity,and Stereophile.Because of
this information I began re-using my Ault P.S.Now I have a failure
and am not sure if it is because of this power supply.Has anyone
else out there had any problems with this unit.My unit is still
under warranty and has been sent in for repair.But I am unable to
determine whether this was just a defect or whether it is from the
Ault power supply.My amp was still working but probably not
correctly.Any thoughts would be appreciated.


Duane Upshaw