TFM-45

John0551 · Post by **John0551** » Mon Apr 16, 2007 4:26 pm

My TFM-45 has a noisy transformer, . Loud 60 cylce hum from the amp itself, not through the speakers. As the caps charge up the noise dimishes quite a bit, but it is still there. Is this familiar to anyone, and does it mean I have a problem? The amp seems to work fine, but when I had Infinity Preludes connected to the amp, it killed the infinity sub amp in the right channel. Then while one sub was being repaired, I had the other sub hooked to the right channel, and it quit also. Now I am afraid to connect the amp to the new (replaced under warranty) subs.
Is this familiar to anyone?

F1nut · Post by **F1nut** » Mon Apr 16, 2007 10:02 pm

Time for a trip to the repair shop or to buy a new amp.

elgrau · Post by **elgrau** » Tue Apr 17, 2007 6:24 pm

uh, perhaps I'm not understanding what you are doing, but it would seem to me that the input to your sub should come from your preamp, not the high voltage/current output from your amp....

mikekohut · Post by **mikekohut** » Thu Apr 19, 2007 7:10 pm

What is a "60 cylce hum" and how do you label hum in such a way? And, might the hum and the fact that the right output blows speakers be a coinky dink?

John0551 · Post by **John0551** » Wed May 23, 2007 11:48 am

Since the noise is coming from the power transformer, and it is the plates in the transformer that are buzzing, I make the assumption that the humm is 60 cycle. If I lived in Europe, I would have assumed it to be 50 cycle. Anyway I have done some more research, and apparently when the transformer starts making this kind of noise, the only option is to replace it. So now I am looking for a replacement transformer for a
tfm-45. Any Ideas?

avguytx · Post by **avguytx** » Fri May 25, 2007 8:48 am

I would get in touch with one of the Carver techs like Rita at Sunfire or the other one that I just went blank on! Sheesh...one of those days.

It could be more involved than just a transformer and having someone look at it could save a second trip getting outputs replaced. Just my $.02.

Bill · Post by **Bill** » Fri May 25, 2007 8:53 am

The other one is Rolland. He should be able to give some ideas if you are against sending it in....

mikekohut · Post by **mikekohut** » Fri May 25, 2007 10:39 am

Does it sound like when you power up a model train set? This "cycle hum?"

avguytx · Post by **avguytx** » Fri May 25, 2007 11:01 am

My M-1.0t makes a slight buzzing sound after it's turned on but it's not very audible unless you're really close to it. It did this before and after it was sent to Rita for repair/upgrades. It doesn't bother me, though.

mikekohut · Post by **mikekohut** » Fri May 25, 2007 11:23 am

avguytx, I'm thinking every single carver amp I've ever owned powers up this way - just the transformer doing its thing. You're talking power up noise, yes? Nothing constant?

Bill · Post by **Bill** » Fri May 25, 2007 11:29 am

mikekohut wrote:avguytx, I'm thinking every single carver amp I've ever owned powers up this way - just the transformer doing its thing. You're talking power up noise, yes? Nothing constant?

One of my Cubes has a slight constant hum if you get up close to it, but it doesn't bother me and it works great, so I live with it. I figured this was normal anyway.

avguytx · Post by **avguytx** » Fri May 25, 2007 11:31 am

It's a tad louder when it's first powered up...maybe one second if that. But once powered, it still has a very slight noise. I just think it's common to power transformers working. It's most likely just resonating because of the contact to its mounting plane.

Now I just have to get the 2nd M-1.0t repaired that I have (the one Fedex lost and found) and find something to use it for! Seems like most in here aren't too keen on the bridging of amplifiers for full range applications. I can always use it for something else. Too bad my Polk SDA 1C's aren't bi-ampable!

Bill · Post by **Bill** » Fri May 25, 2007 11:33 am

avguytx wrote:It's a tad louder when it's first powered up...maybe one second if that. But once powered, it still has a very slight noise. I just think it's common to power transformers working. It's most likely just resonating because of the contact to its mounting plane.

That sounds about right, My M200t did that before it really crapped the bed.

John0551 · Post by **John0551** » Thu May 31, 2007 10:00 am

I have come to the same conclusions, re the noise. It is definately louder when powering up, but it is always there, although you only hear it between songs. The only other symptom I hear is the thump about 2 seconds after I shut it off, this noise coming from the speakers. Both my Phase Linear 400 amps make the same noise, seems to be a Bob Carver trademark.
I am looking for a replacement transformer, (or a dead TFM45) if anybody has one to sell.

Magnaryder · Post by **Magnaryder** » Thu May 31, 2007 6:04 pm

Both of my TFM-55s buzz when they're turned on. Sorta like this .....hit switch...little buzz(for maybe 1/2 second)while lights in room dim(no shit)...and click, we're ready for business. Takes all of 3/4 of a second total. They've aways been like that, but I've never heard a sound through the speakers(they're dead quiet), these sounds are from the amplifiers themselves. Maybe it's a trait of the Magnetic Field Power amplifiers?

CarverAudio.com

TFM-45

TFM-45

TFM-45 Transformer hum.