Peachtree Audio Nova125 & sensitive speakers


I wanted to inform any potential buyers of the Peachtree Audio Nova125 (Class D, 2x125W) its inherent incompatibility with high sensitive speakers. I learned this the hard way.

I own a pair of the excellent Klipsch Reference RF7 Mk.ii floorstanding speakers. They are horn loaded and have a very high sensivity (101db); you could practically run them on a clock radio. They used to be powered by a top-of-the-line Rotel pre+power combination. I sold this combo and bought the Nova125 instead because I wanted something simpler and/or more pleasing to the eye.

To my horror I noticed the Klipsch speakers produced a very loud hiss when connected to the beautiful Nova125. I had never heard this before with the Rotel combination. The hissing was clearly noticeable from 8 meter away (30 feet)! When the amp was switched on and nothing was playing, my living room was actually immersed in this horrible noise. The hissing was present and unaltered even when no source was connected and the volume knob was turned down to zero.

I contacted my dealer, who offered a new Nova125 and power conditioners. The hiss remained exactly the same.

I thus contacted Peachtree Audio directly. They simply stated that Class D amplifier tend to have a higher noise floor than typical Class A/B amplifier and that high sensitive speakers should be avoided in combination with an amp like the Nova125.

I am currently selling the Klipsch speakers and will buy the PSB Imagine T2 speakers, which are rated at 90db sensivity. I hope the hiss will not be present with these speakers.

All in all not a very pleasant experience.

I hope this will be helpful to anyone considering Peachtree Audio products (or any other Class D amp).
f_r_e
Two comments.

I used to have a Bel Canto S300 amp and there was no hiss whatsoever, even with my ear to the tweeter. It was dead silent. I don't buy the explanation that class D has an inherently higher noise floor.

Second, is there a source connected and on (but not playing) when you hear the hiss? If so, the origin of the hiss could be the source and a gain mismatch between it and the amp.
Hi Mlsstl

The explanation came directly from Peachtree Audio HQ. I don't actually buy it either, but what can I say?

Like I said: hiss was unaltered, even with no source connected at all and/or the volume knob turned down to zero. It's just there...
@Stereo5: Actually, that crossed my mind also. Yet I quickly grew to love the form factor, ease of use and energy efficiency of the Peachtree Audio Nova 125, despite it being a 'noisy' amplifier. Switching my system on in the morning is literally one push on the remote away; no separate DAC, no extra remotes...

Anyway, I got really excited about the PSB Imagine T2 speakers now (hedonic adaptation anyone?). The Klipsch RF7 II speakers have always seemed a bit overkill in my home. I do hope they will be quiet with the Nova125... Fingers crossed.