[nofacemonster]

I just got my Little Dot MK II and i am excited. It sounds awesome out of the box with stock tubes paired up with my FX Audio DAC-X6 (as a dac). But however there is a little problem remains.

I straight away put the high gain settings on it before starting up with HD6XX because it is 300 ohms. Even though it sounds all good, i can hear a low buzzing in the background as if i am running a low impedance sensitive headphones on a amplifier that is dedicated to drive high impedance can. I can hear this on the silence and when i put the volume pot all the way to top end. it disappeared.

According to the manual i put it back to default "LOW GAIN mode" which is all dip switches set to "ON" mode.

Miraculously the buzzing disappeared regardless of where the volume pot it. So i was just wondering what is the recommended settings on LD MK II for HD650. Is it low gain setting or high gain settings?

 

[ProtegeManiac]

You're supposed to use the lowest setting that can achieve the volume you want since that will always have the lowest noise levels.

Alteranately you can upgrade the tubes to ones that are less microphonic as well as having lower noise, like Mullards (especially NOS Mullards) without getting lower gain, then try high gain on those. If the noise is still there then back to low gain and just enjoy an even lower noise floor.

 

[nofacemonster]

You're supposed to use the lowest setting that can achieve the volume you want since that will always have the lowest noise levels.

Alteranately you can upgrade the tubes to ones that are less microphonic as well as having lower noise, like Mullards (especially NOS Mullards) without getting lower gain, then try high gain on those. If the noise is still there then back to low gain and just enjoy an even lower noise floor.

The manual which came with it is messy. I found another manual that looks legitimate when it comes to dip switch settings. i just attached it to my post so anyone who is in the same issue will find sanctuary here in this thread. How ever with the stock tubes i can only use the lowest gain mode with my HD6XX (300ohm). If i go high gain mode there will be lots of volume as well as the noise. The online manual i found makes a lot of sense because they recommend

Low gain settings for "High Impedance / High Sensitivity" headphones. I think i should use this in HD6XX regardless of the volume.

http://195.84.101.101/~goranl/projects/nad_stereo/little_dot/LittleDot_MKII_Guide.pdf

that's the link to manual.