I agree with no romance! Unlike SS diodes a tube rectifier can only handle a limited amount of capacitance. What is your first capacitor after the GZ37?
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