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Still no hum/buzz this morning, so I think I can happily declare that the issue is resolved.
Obviously there is noise on the mains, and the common mode filter I added into the BB3 case did nothing, so I assume that the noise is on the earth line, and there is nothing I can do about that.
Have you considered using a mains noise filter? https://laplace.co.uk/wp-content/upl...ns-filters.pdf. By "noise" I assume you mean hiss having frequency components of around 1kHz or more.
Are there other items of equipment used in your house that might be causing the problem? Are you able to switch them all off, pull out the plugs to see if the problem disappears? Apologies if I have asked you this before.
PS This is worth reading: https://www.soundonsound.com/techniq...upply-problems
I have a common mode filter inside the BB3 case.
The noise is what I believe to be a third harmonic of mains noise (about 150Hz).
I have not heard it for 24 hours, so I am happy.
As for eliminating what is causing it,that will be complicated, as it may not be originating from my house.
Innthe previous troubleshooting I did turn off all unnecessary equipment.
I did leave on everything that I considered important.
I have been doing some further reading on the ground loop breaker. If Iincrease the capacitance slightly (100nF to 180nF) it is supposed to have a better effect on the third harmonic.
So I ordered some new Y2 capacitors today to implement the change.
I had also bought two 35A diode bridges, so I implemented the second in the transformer earth line. This seems to have a good effect on the occasional buzz, as I now struggle to hear it with the volume turned up, without the UPS feeding the clean power. My safety earth to the chassis has remained untouched.
Having the fan running all the time was slightly annoying, as it runs full speed. My UPS is supposed to vary the fan speed based on internal temperatures. I have a feeling that my workaround for the fan fault has stopped this from working properly, so I have a fan simulator onnthe way that will generate the square wave the UPS is expecting to see. Hopefully this will allow me to get the variable speed working.
The new, improved ground loop breakers are installed.
I have not heard a buzz yet, but I am sat patiently for the first one to arrive.
You know how it is? No buzzes for ages, and then three arrive at the same time....
Hopefully this will not be the case.
I was thinking that you might/will end up replacing the PSU, the bearing, the platter and the feet ;)Quote:
Originally Posted by Tim
The journey is fun though.
I think we all did that back in the day.Quote:
Originally Posted by mikeyb
Nah, I'm a bit odd there Mike - I'm not aiming for anything better than good enough and I suspect my good enough bar is a lot lower than most. I'm just looking to improve on what I have and then I'm stopping. It's an odd concept I know :)Quote:
Originally Posted by mikeyb
I totally get that, it's what I did AFTER I did all the upgrades in my 1210, I then tried an SP10 with panzer plinth and expensive arm, then sold the lot including, amp, phono stage and put the money into something else and lost very little in audio quality.Quote:
Originally Posted by Tim