TFM-35 Soft Popping Noise

Hi everyone. This is my first post to the Carver forum. I have not found anything on the internet that sounds like what my amps are doing. Maybe it's just not a big enough deal for anyone to report?

I have a TFM-35 and two TFM-35X amps, and all 3 produce a soft popping sound when the source signal first hits the input. It's in both channels, and it pops softly for about 5-6 seconds (1 pop every second or so) and then stabilizes and dies out. Every once in a while the signal will somehow excite this behavior again and it will stabilize after another 5-6 seconds. Each pop almost sounds like the sound of a stylus initially dropping onto a record, but occurs with all sources including CDs. It also shows up on the power meter needles, so I can see it at the same time that I hear it.

I've tried Carver, Yamaha, and Marantz preamps, and Mordaunt Short, B&W, and home made speakers (as well as subs) and it happens with every combination. All equipment is plugged into the same outlet, so I don't think that grounding is an issue. I've even tried the entire system in 3 other houses with the same results. It's definitely localized to the amps.

Anyone else see this issue anywhere? It's not loud or to the degree of being annoying, but has me curious as to what's going on. They all sound very good otherwise, but this has been happening for as long as I've owned them. Bought all of them used, by the way. Any input would be appreciated.

I don't know but I'm sure some more technical help will be on the way soon!!! B.T.W....WELCOME!!!

...the beginnings of "motorboating"....?

...the beginnings of "motorboating"....?

What is considered "motorboating"? Different people may use different words, but I'm not familiar with motorboating.

It doesn't seem to have got any worse over the years, and it actually disappears when the amp has warmed up for a while. Anyone else experience this with any Carver amps?

No one out there has ever heard of such a problem with Carver amps? No one has seen their power meter needles jumping for a few seconds when the amp first receives a signal, before finally settling down? Very strange.

Welcome to the forum.

Not sure if I can help but I will ask a few questions:

1. Are all 3 amps having the same issue?
2. Are you using the same source and preamp on all 3?
3. Have you tried different sources and a different preamp?
4. Are you using a power conditioner or are your amps plugged directly in the wall?
5. Are you using all 3 amps at the same time and are they on the same power circuit?

@thuffman03:

1) Yes, all 3 amps do this (two TFM-35X's and one older TFM-35).
2) Yes, I've tried the same source and preamp on all 3 amps and they all behave the same way. Also tried different preamps (Carver, Yamaha, NAD, and Marantz).
3) This happens with every source I've tried, about a dozen different ones. Even with an ipod plugged directly into the amp, eliminating all other simultaneous power connections.
4) No, I'm not using any power conditioners. All components plugged directly into the wall on the same circuit.
5) No, I'm using one amp at a time. The others are not connected.

My system is a simple 2-channel stereo. I normally have one amp, one preamp, a turntable, and a CD player connected. Most of the time the other 2 amps are in the closet as spares. Every once in a while I change amps but the problem remains.

It happens in my own setup, and I've tried each of the amps in other people's systems with the same result. It occurs with every source and every preamp (even sub outputs from a receiver), as well as every speaker pair I've tried (4, 6 & 8 ohm). Since this has happened in different houses as well, there is no doubt that it is the amps as they are the only remaining factor common to the issue. Wiring issues also would be more persistent (and more apt to produce humming). This popping is excited when a signal first hits the amp's inputs, and lasts for only a few seconds until some instability has decayed out. The power meters show that each pop is about 20-30 watts at about 0.1 second each.

While the amps are popping, the overall sound isn't affected. The pops are just summed with the sound coming through the speakers. In my experience, dying capacitors make a much more harsh, annoying pop. This is a fairly gentle, short lived popping sound. This popping sound is exactly the same in all 3 of my amps, and it is in both channels.

Well....All I can suggest is to send one to a repair site and let them poke around and see if they can find anything.

Sorry I could not be more of a help.