They all vibrate to a certain degree. The crazy thing is the way manufacturers couple them to the chassis with bolts. 😳
Vibration noise from toroid transformer. Is it possible to get rid of it?
My homemade amplifier (D.Walton 300B
XLS MKIII schematic) is working normally with one exception. When I turn power
on the amplifier for the first 30-45 seconds appears vibration like silent but bored noise and this leads me
crazy. Others suggest not paying attention to this but I can't.
Maybe not quite well, I covered two main toroidal transformers under one cover and sealed it with epoxy.
My attempts to find the source of the noise were as follows:
I grounded inputs and verified voltages – everything – OK.
1. Then I removed all the tubes, turned power on – from the main transformers cover - dead silence - everything is OK. No load - no noise.
2. OK - I inserted GZ37 only, turned power on – after about 10 - 15 sec appeared growing vibrating noise from the main transformer, which after 30 seconds became poorly heard.
3. Then I disconnected one of toroidal transformers from the main. What was interesting I found high voltages in completely from the main disconnected second transformer, only not standard ones, but about 300 – 0 - 500 V. When connected again both transformrs, voltages also have become standart 450 - 0 – 450 V on both transformers.
Maybe this electromagnetic interaction between two closely fitting toroidal transformers under one cover is the cause of noise? But I can’t do anything because these transformers are already deadly buried in epoxy. Replacing them with new ones and making anew different layout would cost me over 400 € and almost all of the amplifier to be rebuilt. Is it possible to change something not so painfully? Maybe the vibrational noise reason is different?
Kindly Antanas
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- 7 posts total
- 7 posts total