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
Bob Reynolds wrote: "It may be that the Peachtree product's filter doesn't attenuate enough for high sensitivity speakers."

By definition, ultrasonic noise in an amp does not create audible hiss - its beyond the range of hearing. At worse, if unfiltered, it is going to create an intermodulation problem in the audio band, but that only exists when music (an audible signal) is being played. In that case, you will not hear hiss, but rather some type of distortion in the music.


Not sure what's going on w your set up, but Peachtree works fine on high sensitive speakers w no noise. Something is wrong w/your unit if there's an audible hiss, even w your ear to the speaker. I have a pr of excellent Zu Omen @ 101dB and 0 noise is present w the 125 or the novaPre/220 for that matter, although the 220 is way over-kill.
Also not sure whom you spoke w/at Peachtree, but if someone told you that our class D amps inherently produce more noise than a standard A/B, they were simply wrong.
Please send your unit in and we'll get it tested.

Best wishes,
David Solomon
davids@peachtreeaudio.com
Peachtree Audio
I have a pair of Tekton Lores (98db) and a novaPre/220.
Overkill yes but sound great together. No problems whatsoever.
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I thought you were kidding too. The 1st paragraph I can follow easily enough, but in the 2nd when you say to unplug the speakers, it doesn’t make sense. If you unplug the speakers, how will you here the noise?

Also, when you talk about the measurements from Stereophile, it looks like they used the filter just to take the measurements. I could be mistaken, but if you don't need the filter for regular listening, it may be relevant to this discussion.