SEX 4 Noise Floor

[ScottAstroNut]

I have a question regarding the noise floor of the new SEX 4.

I have been running the SEX 3 as a headphone amp for quite a few years, and really love that amp. When listening to high impedance headphones, such as my 300 ohm Sennheiser HD 650's, the SEX 3 is dead quiet. However, when I switch to low impedance headphones, such as my 38 ohm Grado 325x's, I can easily hear noise even at lower volume settings. It's not such a problem when actually playing music, but it is something I become aware of in between tracks with the Grado cans.

Is the noise floor of the SEX 4 much lower than that of the SEX 3? Would it be worth upgrading to the SEX 4?

Thank you!

 

[Paul Birkeland]

Hello Scott,

For either amp, I would generally suggest wiring the output transformers for 4 ohm output if you want to use Grado headphones.

-PB

 

[ScottAstroNut]

Hi Paul,

Thanks for the quick reply and for the recommendation.

I'm pretty sure that my SEX 3 is currently configured for 8 ohms, as I have also been using 8 ohm speakers. I'll have to check. What effect would I see when using 8 ohm speakers with the SEX 3 configured for 4 ohms?

Thanks again!

 

[Paul Birkeland]

You'll deliver a little less power to the speakers, distortion will go down, and damping (bass control) will increase.

 

[ScottAstroNut]

All in all, it sounds like switching the SEX 3 to 4 ohms is a no-brainer.

Just out of curiosity, though, how does the noise floor of the SEX 4 compare to that of the SEX 3?

Thanks!