Buzzing sound from Peachtree Nova 150 - anybody else had similar experience?


I bought Peachtree Nova 150 around 10 months ago. While I was very satisfied with the amp to begin with, I slowly started getting more bothered by the high frequency buzzing it makes when it is powered on. The sound comes from the device itself, not from the speakers, very high frequency, similar to the sound from old CRT screens. It is very noticeable when standing close to the device, but if it’s otherwise quiet I am also hearing it as long as I am in the same room. And though I probably will be able to ignore it while playing music, it does bother me as long as there’s a pause in the music or while watching movies. I don’t think I am being overly sensitive, I have other electric devices that make far more noise, like my projector or hard drive RAID, but it is just the high pitched whine from the Peachtree Nova that bothers me. With simple measuring software on my phone, the sound is measurable from about 1 meter from the device, and shows up as a sound with a peak of 8 kHz and a smaller peak at 16 kHz.

After I sent complaints to the dealer I bought it from, the the amp was sent back for repair. Twice. Both times it came back with absolutely no changes to this issue, as far as I can hear. The guy who did the repairs measured the sound after the last repair to be "significantly reduced". But I can’t hear any difference. He indicates that the current in my house can be the culprit, but I have also tried it in my office building, both in grounded and ungrounded outlets, without any changes to the buzzing. What I haven’t tried yet is any kind of expensive AC filter to deal with noise. Could I expect that such a filter (fx IsoTek Corvus) would make any difference here? I am hesitant to try it, since I wouldn’t expect that a relatively expensive amp (for me) would need such a thing just to function properly.

That the repair shop claims the sound is "reduced" indicates to me that some kind of buzzing from the device itself is to be expected, just that it should be at a significantly lower level than what I am experiencing. Is this on par with with what other owners of Peachtree Nova have experienced - could I expect it to be dead quiet?

It seems to be the same issue discussed in this thread.


oysteinvidnes
Two things 1. Contact Peachtree directly. They are very good with communication, repairs, etc even out of warranty

2. I had the same thing many years ago with a Sony TV. It took many weeks back and forth with Sony Japan. They fixed it by having the repair person put glue on some vibrating part on circuit board. I know this does not help...but probably similar electronic issue
Peachtree has always been very helpful in the past as aberyclark stated and fixed an issue with a Grand Pre I bought used. Having said that however, both Peachtree units I've owned have needed to be sent in for repair.

 As much as I want to like their products the reliablility issues they seem to suffer has pushed me to seek out other brands. 

Many times it is the transformer ,at the 50-60 hz region mechanicalhum 
the better transformers donot do this much since they are double potted in
Opoxy for vibration .Torroidal transformers. Are by far the worst offenders.
Piltron  , Triad  make very good models myself have paid extra to get  the Black 
double potted Piltron  transformer if this amplifier you are Very happy with .the 
transformer itself is under $100. Speak with peach tree. I doubt they  used a top 
transformer .personally  I see this happen all to often for an extra $30-40 dollars 
when being built would avoid a lot of this problem ,another issue is their grounding scheme .if all used 3 point star grounding this extra step would eliminate a lot of headaches. It is very frustrating I  went through 3 amps  one time 3 different brands  just to get a good one . Pass Labs never an issue, 
spread Spectrum ,Son of Ampzilla fantastic dead quiet , just an example of 2 of my current amps .
Update: The dealer agreed to have the Nova exchanged, and I had it exchanged for a Nova 300. But: The 300 has more or less the same issue. The buzz is a bit lower in volume, but somehow more aggressive, and enough to bother me. So either I am overly sensitive, or the Novas in general react negatively to the mains line in my area (and there wasn’t anything special up with my old Nova either, after all). I have ordered a PS Audio Dectet filter, and if that does not take care of the issue, I have the option of returning both the filter and the amp.
By any chance are the speaker-level outputs of the amp connected to a powered sub, or to a speaker that incorporates a powered woofer, or to anything else that is powered?  If so, given that the speaker-level outputs of the Nova 150 and 300 are described as being differential, and the negative output terminal as well as the positive output terminal therefore has a full amplitude signal on it (which might be grounded via some unknown impedance in a powered speaker or sub), that could conceivably be the root cause of the problem.

Regards,
-- Al
 
The sound is the same without anything connected (except the mains cable, of course), and whether or not the outlet is grounded.
I received a current filter that I had ordered, but using it makes no difference whatsoever. 

I am now in contact with Peachtree, and they are willing to replace the power supply in my Nova 300. I am glad they are taking this seriously, but at this point I am not confident that the issue will be resolved, since I already went through the very same process with one unit of the Nova 150. Maybe I’ll give it a shot, but I am guessing that the Novas in general just don’t play nice with the mains line in my area. Or I am being way more sensitive about this than any other Nova owners. But I really find the buzzing unbearable.

Here’s a recording of the sound (sound begins about six seconds in, turning on the unit first).


I don't know if this interests anyone at all anymore, but I thought I should just post a follow up to this story. I have been in contact with Peachtree about what to my ears is a buzzing sound from their amplifiers, and the conclusion basically is that I am overly sensitive. Their techs can not hear any sound at all from the amp on the recordings/videos that I have sent to nail the issue (like this one -- to my ears the sound comes on about 3 secs in). So basically I am hearing something that they are not able to hear. But to me, unfortunately, it is quite irritating, and not something I can accept. I am now just hoping that they will let me return the unit in exchange for a refund.




I just received my nova 300 from my brother in Detroit.  I’m experiencing the same problem with the buzzing.  Especially through my headphones.  I have the th900 mk2, all the colors. The utopia, and the LCD-4Z and I’m hearing the buzzing noise from all the headphones.  I purchased the b-stock on eBay. Assuming it was refurbished, a return.  Now that I currently reside in South Korea, I have no idea how I can contact Peachtree to try and resolve this issue.  Usually most headphone amps are dead silent, I’m hearing buzzing noises when the music is playing.  Especially when the high starts to go up, I’m hearing like distortion like noises, low continuous  zzzzz noises and buzzing.  It’s very annoying.  This is through usb-a and usb-b.  I’m listening it through tidal on my iMac, iPad, and my iPhone. I hear the buzz when even the music is paused!  Hear it when I play them.   I don’t know how Peachtree missed this issue.  The noise is very obvious.  My HEGEL H360 or my Allnic 5000XL tube amp have no issues.  They are all plugged into the same outlet.  I’ve tried plugging the nova300 separately.  Same problem, different location.  
OYSTEINVIDNES, it’s not you, it’s the amp. If anyone has a solution, please feel free to post a message! 
I sympathize, kevinjkim, but the issue in this thread is not the same as what you describe. I make it quite clear that I am talking about a buzzing sound from the actual device, not through the speakers or headphones. It was very irritating, to be sure, and enough for me to return the amp and not to buy another peachtree product again. But what you describe is worse than that.

I do hope that you can get it resolved - I got great contact with Christian Ballard at Peachtree, through the normal support form. For me it didn’t work out in the end, because they seem to look at a slight buzzing from the amp itself as normal. But what you descibe is an issue that they do not see as normal.

Anyways, the experience didn’t just scare me off Peachtree amps, I more or less gave up on brand new stuff for the time being, at least class D amps, and spent some of the money on a used Accuphase 406v instead. This 23 years old amp has nothing in common with the Peachtree nova, of course, it doesn’t even accomodate a DAC board, but sounds so extremely much better with my speakers that it’s hard to believe.
Kevinjkim, just a thought... I would try using a power conditioner. Depending on the region and country, the power can be “dirty”. I had an amp that hummed a few years back, uses a power conditioner and it resolved the issue. Many amps have a power conditioner built into the unit but maybe not Peachtree.  Btw, does the Peachtree support both 110/220 or are using a step down transformer? 
based on your description, it sounds like a cap is going in the switching power supply.

I'd contact them and arrange for repair.

Transformer buzzing is relatively low frequency. If it sounds almost like a whine, it's more likely to be an issue with the switching power supply. Get it fixed.