Purifi 1ET400A / Hypex NC500 Input Buffer

[Vavilen]

Hi Tom,
the problem is solved and I got sound from my speakers, thank you!

Two things I found for myself:

• maximum voltage in the speakers terminals without load is around 6V
• I got much less bass comparing to my old Denon PMA-1500

I have several versions of the reason why it could be:

• ow voltage and gain, because I use unbalanced connection shorting 1 and 3 pins to the ground - is it better to use unbalanced-to-balanced converter?
• I need to warm up the amp for some time (not sure if it's true - just following recommendations from audiophiles)
• I need to get used to the sound of the new amp - no EQ or any other bass busters

 

[tomchr]

So with the volume knob cranked to the max you're only getting 6 V output? Are you running in unity gain? The Purifi 1ET400A should be able to get up near 40 V RMS at the output.

There are a couple of reasons this could be:

• You're measuring at a frequency that's beyond the bandwidth of your voltmeter. Measure at 400 Hz as most DMMs can handle that.
• Your preamp has really, really low output. Have you measured it?

The reason you're experiencing less bass is most likely because the amp has better control of the speaker and also because it has lower distortion. I've always had that experience when switching to an amp with a high damping factor and low distortion.

If the performance of the amp depended significantly on temperature or aging I would be severely disappointed in the engineering at Purifi (and in my own engineering for that matter).

Tom