Kondo Overture PM2i - buzzing noise from transformer


Hi to all, 

could anybody please share their experience with Kondo amplifiers concerning noise from transformer.

I experience a little (but disturbing) buzzing sound coming directly from the left transformer of my Kondo Overture amplifier (no noise through the speakers, but directly from the transformer itself).

In a quiet room and when listening at very low volume, you can hear the buzzing noise at the seating position 2-3 meters away from the amp...

Thanks in advance for sharing any experience with Kondo amplifiers.

Best
Robert

128x128robchrou

I wish that I had a problem with my Kondo, because that would mean that I had a Kondo.

Maybe the can isn't tightly secured? Did you buy it from a dealer or used? If a dealer have him take a look ASAP

@rsf507 Thanks, please explain what is the "can" (I am not native english).

Thank you :)

I think he meant the bells (covers) of the transformer that is mechanically buzzing; try tightening the four bolts. Also make sure the transformer is tightly secured to the chassis. Typically, mechanical buzzing of transformers is due to DC on your AC line.

Thanks vinylvalet. Bolts are tight. Tried different AC lines - at home, at company, without HMS DC filter, with HMS DC filter. Buzzing all the time. Mavbe I am t sensible concerning side noises.. 

You need a better AC power conditioner. It's possible that it's the transformer, but I would put my money on DC on your AC power line. There are good DC blockers and not so good, best wishes.

Call Audio Note.

In my 1990 OnGaku, which I play a lot, last year slight hum started and I ended having to replace the transformer , I am glad I had a couple original.

You are lucky you can, and should, call Audio Note.

Thanks astolfor, I had an intensive and very helpful communication with Kondo Team in the meantime and we did several measurements with a certain app to measure noise in dB. Laying the iPhone on the buzzing transformer on my and their Overture made things clear. My Overture produced even 6.6 dB less noise (32,6 dB) than their 39.2 dB. So I guess my ears are just too sensitive.

Transformers should not be audibly buzzing. It is not normal. If that were true, all of your transformers would be buzzing.

Hi chayro, well Kondo sent me a photo with the iphone and "NIOSH SLM" app positioned on top of the transformer of their reference Overture amp showing 39.2 dB. I used the same app with same app settings and mine was even quieter at 32.6 dB. Now what does that mean..?

It means that Kondo is saying your buzzing is within their specifications.  If you bought it new, you should contact your dealer.  You should not have to put up with anything annoying in a product that is so expensive.  Very unfortunate.  

Yeah, you are right. I will try to trade in to the Overture to replace it with the Melius power amp. 

Overture audio has an excellent reputation. I have no doubt they will resolve your issues. Maybe they have another Kondo that doesn’t buzz. But I wouldn’t be shocked if you bring your amp into them and it doesn’t hum. Transformers can be sensitive to power lines, as you well know.  Let us know how it comes out. 

Well yeah, they were very helpful but in the end, their and also my conclusion was, that because the measured buzz/hum noise is within their specification and even lower than the buzz of their reference Overture in factory. The CEO himself took care of measuring and provided a photo of measured result. The buzz is supposed to be normal. For me the solution is to sell the amp or to but it in a sideboard with enough ventilation to reduce or eliminate buzz at listening position at very low volume. I must add, that my listening room is very quiet at 26 dB noise level. iPhone put directly on transformer resulted in 32,6 dB and at listening position there was measured only 1 dB higher noise level 🤷🏼‍♂️. 

Oh, I thought you bought the amp from Overture Audio.  My mistake.  Who did you buy it from?

So call your dealer. I cannot tell you how many times I see this. People have issues with equipment and they don’t contact the dealer.  Dealers make big margins on these items and part of that goes to customer service. I cannot believe that any dealer would not take very good care of a Kondo customer.