[auvgeek]

Do you mean rotational or translational play? Mine has a couple mm of play in it translationally in every direction, but it doesn't affect the volume control at all.

 

[JoeDoe]

  Do you mean rotational or translational play? Mine has a couple mm of play in it translationally in every direction, but it doesn't affect the volume control at all.

It was rotational. I was able to find an appropriate allen wrench to tighten her up. I opened the amp up before I found the wrench to see if it was a potentiometer issue and noticed that ever so slightly. the truss rod is crooked. It translates into a section between 10-12 o'clock being slightly smoother than the rest of the turn. Nothing to be done about that. Oh well! 

 

[Joong]

I thought it was normal, considering the long shaft volume knob which might have some back lash due to the sleeve and the shaft being loosened at time of assembly.
Sorry Joe.

 

[olek]

That shaft is held with ball bearings at the side of volume knob, and the ball bearing is being tightly pressed into drilled out cavity by heads of 2 screws. Tolerances there are all very tight on my H10, and there is no play at all (feels rock solid), which is probably why it starts to bind so easily with the slightest misalignment (maybe I should try to introduce some slop there!). I would say that this design of volume shaft requires a bit more precision in assembly than manufacturing facility was able to provide.

 

[olek]

Originally Posted by BassDigger /img/forum/go_quote.gif
He said his 'bread and butter' work was changing capacitors in equipment that people had left 'always on'; particularly the Arcam range of CD players that had their DACs permanently connected, bypassing the on/off switch.
 
...
 
Regarding class A operation: it uses maximum power at zero output; the bigger the output signal, the less the power requirements and the cooler it will run, strangely enough.

 
Your technician was correct: capacitors (electrolytic) are rated for their expected (pessimistically, I guess) life time, and here is the fun part - normal capacitors are rated for 3-4k hours, there are some that are designed to last 7-10k hours (but are typically unfit for audio applications), but if you look at high audio grade capacitors (like Nichicon KZ series, or even FG), they are rated for only 1-2k hours. You can't have it all I guess.
 
I see that 'life time' as a fairly pessimistic outlook, and capacitors usually last much longer than that - with diminished capacity and other properties drifting from specs, yes. Still, electrolytic capacitor life time is limited, otherwise manufacturers would not spec that out. Oh, and I forgot to mention - in environment hotter than 85F, expected life time drops quite quickly. And those class A amplifiers tend to run quite hot (they pretty much consume same current/power during both idle and full load, it is only that during full load some of that energy is being dissipated outside of amplifier).
 
Of course, if you do not turn on your equipment at all, those same capacitors will dry out and go kaput on you as well. And if you turn it on and off constantly, you equipment will eventually die from inrush of current. Looking at it realistically - one thing is certain - and that is any equipment is going to fail at some point.

 
I typically keep equipment ON for initial burn in period, but after that turn it off when it is not going to be used for more than couple hours. Finding my way between Scylla and Charybdis, so to say.

 

[stuartmc]

  That shaft is held with ball bearings at the side of volume knob, and the ball bearing is being tightly pressed into drilled out cavity by heads of 2 screws. Tolerances there are all very tight on my H10, and there is no play at all (feels rock solid), which is probably why it starts to bind so easily with the slightest misalignment (maybe I should try to introduce some slop there!). I would say that this design of volume shaft requires a bit more precision in assembly than manufacturing facility was able to provide.

Actually, I think their quality control issue with the volume knob/potentiometer  assembly is probably within the acceptable range for most manufacturers.  There are quite a few H10's in the field and it seems that very few have this issue.  It's a very nice functional design.  The amp is VERY similar in design to the Violectric V200, but they shortened the signal path considerably by mounting the potentiometer at the back of the board.  This of course necessitated the long connecting shaft to the front mounted volume control. It costs more to do this and creates some potential mechanical problems that would have not otherwise existed.  I applaud Gustard's engineers for doing this.

 

[olek]

Oh, do not get me wrong, I like the fact that potentiometer is left at the back of the enclosure to keep signal paths short - and this likely attributes to the awesome sound H10 is producing. It is just that this design is finicky and requires more precision and effort to execute it right, and being one of the people affected by the issue skews my outlook on quality a bit

 
Overall I think we are in violent agreement, and I applaud Gustard's engineers for choosing this design. It is just their manufacturer needs to kick up QC on that particular subsystem a notch.

 

[stuartmc]

  Overall I think we are in violent agreement,

 
At least our agreement is merely violent and not appalling or heinous. LOL

 

[LancerFIN]

 
Anyone encountered problems with USB? I tried all of my USB cables and different USB ports. Nothing.

 

[Arnotts]

 
 
Anyone encountered problems with USB? I tried all of my USB cables and different USB ports. Nothing.

Did you install the XMOS drivers that came on the mini-cd? If you didn't get a mini-cd, download the drivers here: http://pan.baidu.com/s/1ntNXwN3
The download button is the one that says (1.2M) and is just above the thumbs up sign near the top right.

 

[LancerFIN]

Uh. Of course not. I wasn't going to use USB so I left it in the box and didn't remember it at all. Will try after I get home.

 

[Liu Junyuan]

Haha you noob.

 

[conquerator2]

99% of DACs require external [manufacturer's] drivers with Windows. The disc was included with your X12 

 

[LancerFIN]

  99% of DACs require external [manufacturer's] drivers with Windows. The disc was included with your X12 

 
If I said I am actually pretty competent with this stuff I probably wouldn't be very convincing.
 
But yeah. I started working on Monday after 3.5 months of being unemployed. Didn't sleep at all on Sunday - Monday night and after that less than 6 hours per night. Sleep deprivation is serious thing. Some problems trying to adjust after 3.5 months of not giving two ****s about time.

 

[Liu Junyuan]

Im glad you got it working and congratulations in finding employment!