A strange occurrence for my TSE 11, I just finished the build after approx 8 hours or so, the source plays inside the chassis as if it has a speaker, it happens every time it is turned on, it also plays normally through speakers w/o any noise whatsoever, it is affected by the volume controls, which are Goldpoint, if they are at 50% then I cannot hear the inside speaker. Has anyone experienced this?
Some parts can be microphonic. If the noise is annoying, you could try to track down which part it is,
and change it for one that is quiet. Examples are transistors and ceramic capacitors.
and change it for one that is quiet. Examples are transistors and ceramic capacitors.
I sent the OP an email explaining that this phenomenon is usually caused by the OPT, especially in an SE application. It said:
It is not uncommon for the output transformers to make sound. They have all the same components as a speaker, a coil of wire, some magnetism created by the DC current in the windings, and a metal housing that can vibrate in that magnetic field. Sometimes this effect can be reduced by tightening the bolts that hold the transformers together. Removing the bolts or taking a SE output transformer apart is not recommended as some do not use a spacer to establish the gap required for proper operation.
Often these vibrations are transferred to the chassis which acts as a "speaker cone" making them louder. Sometimes a rubber spacer or pad between the transformer and the chassis will reduce this effect.
It is not uncommon for the output transformers to make sound. They have all the same components as a speaker, a coil of wire, some magnetism created by the DC current in the windings, and a metal housing that can vibrate in that magnetic field. Sometimes this effect can be reduced by tightening the bolts that hold the transformers together. Removing the bolts or taking a SE output transformer apart is not recommended as some do not use a spacer to establish the gap required for proper operation.
Often these vibrations are transferred to the chassis which acts as a "speaker cone" making them louder. Sometimes a rubber spacer or pad between the transformer and the chassis will reduce this effect.
I once had a 5AR4 rectifier tube that made a rather loud and constant mechanical ringing sound when in use.
But never any transformers or other parts.
But never any transformers or other parts.
Tubes do occasionally ring at a nearly constant pitch, but some OPT's play music that's recognizable.
I have never heard a push pull OPT sing, but it is not uncommon with SE transformers. I have a pair of the large Edcors. One is quite loud from about 200 Hz to just over 1 KHz. The other is much quieter, but still makes some sound. Neither were mounted and laying them on their side with one end bell on the work bench makes them quieter.
I have never heard a push pull OPT sing, but it is not uncommon with SE transformers. I have a pair of the large Edcors. One is quite loud from about 200 Hz to just over 1 KHz. The other is much quieter, but still makes some sound. Neither were mounted and laying them on their side with one end bell on the work bench makes them quieter.
It is not ringing from tubes or components; it is music like an iPhone inside the cabinet. It is loud enough to hear from a few feet away; the volume adjusts with the v/c . The transformers are SE Hashimoto mounted on rubber mounts. They were also mounted on a different amp prior to this one, which did not have this issue. The difference may be that the other amp's chassis was SS, and this one is aluminum.
I think you should try to identify what it is where the sound emanates. Staring into the box probably won't give you a clue.
In the days we would put the end of the handle of a large screwdriver against our ear and then touch several points in the unit with the tip. You could easily find the loudest point/part.
BTW, works also for car engines 😎
Jan
In the days we would put the end of the handle of a large screwdriver against our ear and then touch several points in the unit with the tip. You could easily find the loudest point/part.
BTW, works also for car engines 😎
Jan
Are we not still in those days? I suppose mechanics stethoscopes are cheap and easy to find now. But the cheap pair I have is too tight, so I rarely use it.
The option I still exercise is a piece of vacuum hose with a nail shoved in the end and the open end in your ear. But then, working on cars now hardly ever means spare vacuum hoses laying around, unlike when I was a kid.
My money is on the OPTs, or in connection with the chassis, as Tubelab suggests. To carry the car analogy farther, I replaced the worn fluid-filled stock motor mounts in my 911 with more antiquated but more robust rubber mounts. And despite providing far more mechanical isolation than say, a solid aluminim mount, and despite the considerable rigidity of the of the chassis and carpet, etc in the cabin, more than a little noise and vibration makes its way to the driver. Moreover, transformers are not immune from mechanical changes. Not unlike bearings, plenty of PTs that long worked in silence come to complain at an older age.
Or it could be something different. You might also find the offending part by playing a loud sine wave and pressing hard on things with a chop stick until something makes a difference.
Paul
The days of backyard mechanics are over for me; I will use my stethoscope when I get a chance. However, I believe that George is correct, which begs the question, "Why does the chassis act like a speaker"? I added structural corner braces, so maybe I need to dampen it.