Transformers buzz when the multiple flat stamped out plates that make up the core holding the wire windings start to come loose from one another. They are formed and then sandwiched together and sometimes metal straps, or only the windings hold them together, but usually a varnish of some type is added to keep them bound tightly together.
The A/C current running through it creates an oscillating magnetic field, and the plates want to move in response to the changing field, hence the buzz.
The only real solution is to replace the transformer. The problem will not 'hurt' anything, a lot of transformers get this problem, but are used for many years afterward. If your unit is still in warranty, you should be elegible for a free replacement. It IS a manufacturing defect.
If your unit is out of warranty, possible super cheap attempts at a solution are to squeeze the plates back together tightly somehow. (any ingeneous folks out there?) and re-varnish them.
Also, have you tried to retighten the bolts holding the offending transformer? ?? 05% chance that will quiet it down, worth a try.
Solid state amps usually have toroidal transformers. If they buzz, I would suspect RCA interconnects, dimmer switches, flourescent lights, and maybe (maybe) the turntable motor. Start by a process of elimination. If the amp by itself (nothing attached) still buzzes, then you may have an ac wiring noise problem or the R/C shunt at the input (if there is one) has a bad cap. Of course, it is possible that the xfmr coupling to the chassis is loose, but both?. BTW, what make amp is it, and what is attached to it and how??
Gs5556, your post motivated me to fix a buzz in my shop stereo. One of my (1980 vintage) PS Model 2 power amps running in mono had a loose transformer mounting screw and a bad electrolytic in the input shunt R/C. A new cap and some duct seal under the transformer got rid of the hum. Now if I could just get rid of the fizzy sound that the same amp has that sounds sort of like pink noise from an FM radio with the tuner being slightly twizzled. Noisy input section transistor maybe? Thanks for any suggestions.
Thank you all for the thoughtful and very informative answers. I am currious, and maybe I should be posting a new thread for the following: I recall having read some years ago about a tweak that a reviewer of "positive feedback" performed on his amp's toroidal transformers. He removed the top holding plates and the screws that hold them to the chassis and just let the tranformers stand in place without any fasteners. He reported that the music was sort of liberated and that detail and inner resolution etc, etc, increased dramatically. Of course he warned that the transformers were loose now and any attempt to move the amps should be done very carefully! or disaster could ensue.
How do you like that?
Gs5556, You guessed it right, my transformers are toroidal. Their maker is obscure and out of business now, so I did not mention the name. They are "Acoustic- Electronics" "photons" One currious modification, that I think was added later by their first owner, was that they have a second smaller toroidal transformer sitting on top of the main one. I think this gave additional power to the amps.
Tphalieros, the "loose transformer" tweak makes sense. The 60HZ vibration from the transformer was decoupled from the PC boards etc. in the amp and removed a colouration. A rubber mount system would probably have a similar but safer effect. You see this in some amps (YBA being one) or a separate box entirely for the power supply.
Go to psaudio.com as they have a section on transformer buz! very interesting article! Happy Listening!
Your amps were originally made by some nice guys in New Jersey. The originator was Roger Paul. He has a new company that makes a preamp that I think is called Hcat. He has a website that I can't remember. He probably could give you some advice. The Photon was a great amp.
The amps aren't plugged into the PS 300, are they?
I just demo'd a "home-made" power amp and could hear the transformer hum from across the room. What a p.o.s.
Then the mfg'r bashes my stereo as the problem for his poor workmanship. That won some points - NOT!
I am answering in sequencial order:
asdf...I will probably let the transformers loose with the first opportunity I get.
Jsawhitlock, Thank you for the PS audio info. I will check the connections as they suggest, with the first brake I get.
Chriskeating, Roger Paul serviced my amps about 2 years ago. He took out 70% of the circuits and installed a completely homemade H-cat system, housed in... plumber's pipes and held together with tape, but it works! the amps became a model of neutrality and transparency. I pray that nothing happens to them because Roger is in the computer business now and unlikely to have time to fix them. How did you know about the "Photons"? Also, Roger's patented preamp that featured the new technology was reviewed by Anna Log who gave it glowing remarks.
zaikesman, My amps are not plugged in to the PS 300. They draw about 350 watts each and the PS 300 would have fried long time ago.
Thanks to all of you.
T, I used to live in NJ and knew Roger and Arnie when they manufactured the amps and their subwoofers. They were the first to make cylindrical woofers and separate amps. The woofers were really something. They made me a set of transmission line speakers and also modified a Dynaco stereo 70 that made great music. Roger is a genius. I have not been in contact with them in 25 years. I remember hearing the Photons and at the tiome thought that they were a solid state amp I could actually live with. ahead of their time.
Great story Chris, I love it!, Now I've got to tell you more about that stuff. Back in 1990 I met 2 guys that I became friends with. They had Photon monoblocks but also stereo units. Roger Paul was selling his amps through Victor Goldstein who was importing then the "Jadis" line. Victor knew my friends and had them audition the Photons side by side with a Krell, the Photons won hands down and even though they cost $6000 for the monoblocks My 2 friends bought them. Later they also bought one of the stereo units. The interesting, and a little unsettling thing
was that Roger kept experimenting, and each of his amps had different wiring or power cords, even different make caps. He never provided schematics and no one could repair the amps except him.
One fine day, one of my friends called me and said that he saw an ad for Photon monoblocks selling for $1.500. I bought the units immediately, they were heavily modified by a Techie tweaker and had a plethora of expensive parts added to them, their interior looked like a plummer's nightmare! In addition, UPS damaged BOTH packages dropping each one down and managing to bent each unit's faceplate at the point where the handles emerge. I got $1,200 insurance compensation and Roger suggested that he would install his newly patented H-Cat circuit which was inspired by his work on goverment computers, for just about the amount I got from the insurance. At that time Roger had closed his company and changed his profession. He never advertised, believing that word of mouth from satisfied customers, would be enough to sell his amps, a mistake, which backfired and he had to go out of business and in to debt.
My 2 friends still own the Photons but have since moved to tubed amps. I have stuck with them since mine are one of a kind and no one, that I know, has this tech in his Photons.
The only problem is that should anything happened to them, unless Roger accepts to repair them, I am out of luck!
In case anybody cares, I fixed the fizzy noise in my PS Model 2 amp. It was one of the input section transistors. Now the DC offset is 0 only with the pot turned all the way to one extreme, which is a little weird. Oh well, it seems to sound OK now anyway, and the noise is gone.
You said monoblocks. Both buzzing? If so, I don't know what the odds of both amps having a xformer failure at the same time are but I'll bet it's real low.
I had the same problem with a big Krell and a trip to the factory and a huge sum of money replaced the xformer and the buzz was gone. I hope you are not plugging your amps into the P300. I use a P300 on my front-end also and I know that it's not large enough for any kind of high current loads.
If you are starving the amps for current, the xformers could be complaining. Do you have dedicated circuits? Maybe not necessary but always better. Also, It could be as simple as loose wiring connections at your circuit breaker. These connections should be tight. If extremely loose you may be able to actually feel heat build-up on the front of the breaker. These should be checked. If you aren't comfortable doing this yourself get and electrician. It's tough to listen to music if you are dead unless you listen exclusively to harp music. Check the wiring connections at the outlets too, to be sure they are sufficiently tight. Loose connections can create a high resistance creating heat gain and can limit current to your amps. Especially if they are big.