[AppleheadMay]

Decided!  

 
Will be mailing Justin tomorrow, for now, it's nusic listening time!

 

[justin w.]

i sent out 9 more GS-X mk2 today. thats almost all of them. there are still a few black ones w/ the Alpha pot left. 

 

[ogodei]

  i sent out 9 more GS-X mk2 today. thats almost all of them. there are still a few black ones w/ the Alpha pot left. 

 
Just got my shipping notice - thanks Justin & congrats on getting through the push !

 

[cooperpwc]

Black with DACT inbound.

 

[Sopp]

I don't know if this is common situation. A quite loud humming happens when the1964-V6 are plugged to GS-X immediately without turning the volume up at low gain. I also can hear a noticeable humming with Sennheiser HD540 gold at high gain. The problem is still there at mid gain but at least much better.

 

[Maxvla]

Is your GS-X pair stacked?

 

[Crashem]

I don't know if this is common situation. A quite loud humming happens when the1964-V6 are plugged to GS-X immediately without turning the volume up at low gain. I also can hear a noticeable humming with Sennheiser HD540 gold at high gain. The problem is still there at mid gain but at least much better.

 
This is not common.  As Maxvla said, is your GSX stacked.  If so, then don't do it.  Although I have run them stacked and didn't hear the hum.  Anything else near by that could be putting out a lot of RFI.  Try changing input cables too.  Or something could be wrong with your GSX.

 

[MacedonianHero]

   
This is not common.  As Maxvla said, is your GSX stacked.  If so, then don't do it.  Although I have run them stacked and didn't hear the hum.  Anything else near by that could be putting out a lot of RFI.  Try changing input cables too.  Or something could be wrong with your GSX.

 
Could also be USB noise bleed from a laptop/PC. I'd unplug the USB to a computer if you could.

 

[SilverEars]

   
Could also be USB noise bleed from a laptop/PC. I'd unplug the USB to a computer if you could.

This is not the same noise that you'd get from a laptop.  Hum is 60Hz AC wave.  It's related to the toroid giving off magnetic field.  Is the chassis fully metallic and grounded?  Somehow, the this hum is bleeding to the amp. An iem as sensitive as the V6 will pick it up easily.

 

[Sopp]

Is your GS-X pair stacked?

Yes, it is stacked. I am going to change the power cable and input cables tonight to see what causes the humming.

There is another amp, ECP Black Diamond, connects to the same DAC and is dead silent even with sensitive IEMs plugged. So I think the source should be fine and this problem is not resulted by the USB or the laptop.

 

[justin w.]

the problem is the stacking of the amp directly on top of the power supply. to get the advantage of the separate units, they should be placed side by side or on separate shelves
 
From the manual:
 

 Position the Power Supply and Amplifier boxes side by side or on different shelves of a rack with proper ventilation. Stacking the amplifier on top of the power supply is not recommended as it will increase the noise floor and block the power supply ventilation. Never stack the power supply on top of the amplifier as ventilation of the amplifier is even more important.

 

[cooperpwc]

I have decided to take this all to heart, especially since I will be using the GS-X mk2 in part with some very sensitive dynamic IEMs (FAD 1601SC, 1602SC; maybe the Flat-4 Kaede). I might be situating the power supply behind the amp on my desk and offset a bit for the power cord into the amp. That should work. 
 
(Well... maybe side by side.)

 

[Sopp]

  the problem is the stacking of the amp directly on top of the power supply. to get the advantage of the separate units, they should be placed side by side or on separate shelves
 

 
Thanks for the information. Problem solved. Put the power supply and amp about 8 inches away vertically, no more humming. Now I can use GS-X with 1964-V6 plugged to 4-pin balanced out.

 

[SilverEars]

   
Thanks Justin. Problem solved. Put the power supply and amp about 8 inches away vertically, no more humming. Now I can use GS-X with sensitive IEMs.

Sounds like you have away enough distance for the field from the PS to be much lower than the V6 can pick up.  Very insightful.  Anyway, glad you found a solution for the V6 which is quite sensitive.

 

[WiCKed666]

Today I received my GS-X. Thank You, Justin! Currently it's stacked but may be I will rearrange it. Made a few photos in it's current state. Sorry for blurry quality of the pics