Hi,
First, I want to apologize for any redundancy, as this is my first post on this platform. I have not found much beyond 1 or 2 threads on this matter pertaining to this specific amplifier, none of which I saw on this site. I will describe my "issue" below. In reality, this is likely not even an issue, but instead just some over thinking that I, for some reason, love to put myself through... I'm sure other enthusiasts can relate.
So here it goes. I have a Musical Fidelity A3.2 Dual mono integrated amplifier, which I use to drive a pair of RTR G200's. It really is a brilliant combination, & at 26 years of age, I am very pleased with the setup I have acquired. But there's one catch... The other night, my apartment was quiet... dead quiet. I live in Chicago, IL, & at the time I discovered this "issue" it was about negative 2 degrees out, all of my heat radiators were steadily ON, therefore the steam heat radiator clicking on or emitting steam, creating a hissing sound was not something that was audible in my apartment, which is rare. My refrigerator was also not running, and basically for the first time ever, my apartment was simply dead quiet. Getting up to change the record on my system, I heard something. A slight buzzing / vibrating noise. I was already exceptionally close to my prized mufi A3.2, but I moved my head even closer, essentially touching my ear to the chassis, &, well... I located the issue. Naturally I got to reading everything I could about whether or not others have experienced such a phenomenon. I have not yet measured DC current in my lines, & I am unsure how to even conduct such a measurement, though I have all kinds of equipment to do such, as my father is an electrician... He's not an audio person though & he thinks it's a hobby for the insane, (he's not wrong).
What I did do so far is the following: listen to hear if the noise is louder on one side of the chassis than the other. The noise is congruent on both sides, so the chances of BOTH transformers beginning to make this noise at the same time is.... unlikely & I do recall this unit making noise upon startup since the day I bought it roughly 8 months ago, which I believe I ultimately chalked off as it being my first high performance / output amplifier that likely idles at a slightly audible level, as opposed to vintage pioneer silver faced amps I have run in the past.
I disconnected everything (including speakers) from the amp, and plugged it in with different power cords in different rooms of my apartment. It is mechanical, meaning it is coming from the AMP itself, not speakers...
The issue persists anywhere in my apartment, no matter if the amp is on with everything connected, or if it is on with nothing connected. Volume knob does NOT increase or decrease the vibration hum / buzz. I do not think this is a "ground loop" but I guess it could be...
Now here's where it gets tricky, & also leads me to believe that it is not even a problem worth ripping my hair out over. That part includes: I cannot even attempt to diagnose this problem unless my apartment is dead quiet. No ceiling fans on, I need to unplug my refrigerator, I need to turn off my heat radiators, close any windows, etc just to hear if the "problem" has remained or resolved itself. This is what leads me to the overall question,
which is...
At what point is toroid transformer vibration a problem? Certainly there has to be some audible vibration coming from 2 toroid trannies in the same chassis. Even one would make some degree of noise... right? & mind you, this "issue" is quickly eliminated when music is introduced into my system & is NEVER audible between tracks. Some people seem to notice this kind of thing way more than others and I do have extremely sensitive ears. Some people say that no amp should buzz ever, while others say that it is likely normal. Basically my concern, as a 26 year old who makes under 50k a year right now is that I don't want to fry my prized amplifier. If I cannot hear it while music is playing, and can ONLY hear it when I'm right next to the unit, most of the time having to put my head up to the unit, is this even an issue? I'm genuinely curious...
Another helpful bit of information is that I live in a very old, yet amazingly sound proof and elegant building built in 1919. 2 ceiling fans, a fridge, no dimmers, no fluorescent lighting (in my apartment itself). It is also worth noting that I used to run my RTR's with the treble select all the way up, resulting in an idle hiss from my tweeters when music was not playing. I have reduced treble to half since upgrading cartridges, so the idle hiss is no longer there, which is another contributing factor as to WHY I can now sometimes hear my transformers buzz. For me, I'm not expecting a dead quiet amplifier, in fact it doesn't take much to please me & I already have more than I could ever want in life. What I do want is to able to keep all the beautiful things I own & if I'm slowly destroying my beautiful amplifier, I'd like to know, but only if there's factual evidence backing that up. If worse comes to worse, I can bring it to the dealer, which I'm fortunate to have nearby. Frankly, I do not want to though. So my question remains, how common is this "issue" and at what threshold does one consider it to be a "problem" worth pursuing? Thank you in advance for any and all responses.
First, I want to apologize for any redundancy, as this is my first post on this platform. I have not found much beyond 1 or 2 threads on this matter pertaining to this specific amplifier, none of which I saw on this site. I will describe my "issue" below. In reality, this is likely not even an issue, but instead just some over thinking that I, for some reason, love to put myself through... I'm sure other enthusiasts can relate.
So here it goes. I have a Musical Fidelity A3.2 Dual mono integrated amplifier, which I use to drive a pair of RTR G200's. It really is a brilliant combination, & at 26 years of age, I am very pleased with the setup I have acquired. But there's one catch... The other night, my apartment was quiet... dead quiet. I live in Chicago, IL, & at the time I discovered this "issue" it was about negative 2 degrees out, all of my heat radiators were steadily ON, therefore the steam heat radiator clicking on or emitting steam, creating a hissing sound was not something that was audible in my apartment, which is rare. My refrigerator was also not running, and basically for the first time ever, my apartment was simply dead quiet. Getting up to change the record on my system, I heard something. A slight buzzing / vibrating noise. I was already exceptionally close to my prized mufi A3.2, but I moved my head even closer, essentially touching my ear to the chassis, &, well... I located the issue. Naturally I got to reading everything I could about whether or not others have experienced such a phenomenon. I have not yet measured DC current in my lines, & I am unsure how to even conduct such a measurement, though I have all kinds of equipment to do such, as my father is an electrician... He's not an audio person though & he thinks it's a hobby for the insane, (he's not wrong).
What I did do so far is the following: listen to hear if the noise is louder on one side of the chassis than the other. The noise is congruent on both sides, so the chances of BOTH transformers beginning to make this noise at the same time is.... unlikely & I do recall this unit making noise upon startup since the day I bought it roughly 8 months ago, which I believe I ultimately chalked off as it being my first high performance / output amplifier that likely idles at a slightly audible level, as opposed to vintage pioneer silver faced amps I have run in the past.
I disconnected everything (including speakers) from the amp, and plugged it in with different power cords in different rooms of my apartment. It is mechanical, meaning it is coming from the AMP itself, not speakers...
The issue persists anywhere in my apartment, no matter if the amp is on with everything connected, or if it is on with nothing connected. Volume knob does NOT increase or decrease the vibration hum / buzz. I do not think this is a "ground loop" but I guess it could be...
Now here's where it gets tricky, & also leads me to believe that it is not even a problem worth ripping my hair out over. That part includes: I cannot even attempt to diagnose this problem unless my apartment is dead quiet. No ceiling fans on, I need to unplug my refrigerator, I need to turn off my heat radiators, close any windows, etc just to hear if the "problem" has remained or resolved itself. This is what leads me to the overall question,
which is...
At what point is toroid transformer vibration a problem? Certainly there has to be some audible vibration coming from 2 toroid trannies in the same chassis. Even one would make some degree of noise... right? & mind you, this "issue" is quickly eliminated when music is introduced into my system & is NEVER audible between tracks. Some people seem to notice this kind of thing way more than others and I do have extremely sensitive ears. Some people say that no amp should buzz ever, while others say that it is likely normal. Basically my concern, as a 26 year old who makes under 50k a year right now is that I don't want to fry my prized amplifier. If I cannot hear it while music is playing, and can ONLY hear it when I'm right next to the unit, most of the time having to put my head up to the unit, is this even an issue? I'm genuinely curious...
Another helpful bit of information is that I live in a very old, yet amazingly sound proof and elegant building built in 1919. 2 ceiling fans, a fridge, no dimmers, no fluorescent lighting (in my apartment itself). It is also worth noting that I used to run my RTR's with the treble select all the way up, resulting in an idle hiss from my tweeters when music was not playing. I have reduced treble to half since upgrading cartridges, so the idle hiss is no longer there, which is another contributing factor as to WHY I can now sometimes hear my transformers buzz. For me, I'm not expecting a dead quiet amplifier, in fact it doesn't take much to please me & I already have more than I could ever want in life. What I do want is to able to keep all the beautiful things I own & if I'm slowly destroying my beautiful amplifier, I'd like to know, but only if there's factual evidence backing that up. If worse comes to worse, I can bring it to the dealer, which I'm fortunate to have nearby. Frankly, I do not want to though. So my question remains, how common is this "issue" and at what threshold does one consider it to be a "problem" worth pursuing? Thank you in advance for any and all responses.