It may be buzzing due to load.
Disconnect the load, and check.
The thermal relay, if there is one inside, can also be a noise source.
Disconnect the load, and check.
The thermal relay, if there is one inside, can also be a noise source.
Thanks. I'm back on the road and will try these when I return, late next week. Wishing you all a great weekend, and thank you once again for all the help!
A couple of days ago I received a small carton with three small isolation medical transformers from Sedlbauer AG for my ever-going mains unit project. Just curious to know whether we selected the same brand?
Mine is a Noratel IMED150. A ready made certified medical device in casing so with switch, fuse etc. Left over from project.
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Thanks for sharing, mine is Ringkerntrafo Transformator 300VA 2x115V 2x115V 230V Sedlbauer RTO-825054
62 euro is not bad. An isolation transformer ia a very good upgrade for audio sources. IMO it is an obstacle but when I take it out of the chain the result is less good. Using it makes more of a difference than using mains filters. I use both.
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Absolutely, years ago I used one for all digital-related sources (including my separate DAC), another one for analog (preamp, tuner). Power amp went (and goes) directly to mains, through a parallel line filter.
Now I'm going to further separate DAC from devices operating only at digital level (yes I still happen to have a CD spinner 😀).
So, that's why three small trafos, way oversized for the VA declared requirements. Less load and hopefully less mutual interference.
And you can wire to have balanced mains feeding your unit.
Now I'm going to further separate DAC from devices operating only at digital level (yes I still happen to have a CD spinner 😀).
So, that's why three small trafos, way oversized for the VA declared requirements. Less load and hopefully less mutual interference.
And you can wire to have balanced mains feeding your unit.
Got hold of Imed 1000's for 100 a piece. With electronic soft start, test button etc. I also could have the 2000 but these hum extremely.
It seems you found a really good deal!
I installed two out of the three trafo I bought for my diy unit and so far I'm glad they're dead silent and the increased mains separation improved the pleasure of listening 😀
I installed two out of the three trafo I bought for my diy unit and so far I'm glad they're dead silent and the increased mains separation improved the pleasure of listening 😀
Will try the Imed1000 this weekend. It hums slightly mechanically (as usual with 1000 kVA...) but apart from that it is a ready built medical device so everything is well designed. These are custom built in a larger 19" casing for a certain brand medical gear. What surprised me is the very loud humming of the 2000 version. That one is absolutely unusable for audio when placed in the same room.
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Perhaps that's why I can't see the 2000 version on the web page:
Products ::: NORATEL - When PERFORMANCE matters
Products ::: NORATEL - When PERFORMANCE matters
Ops, forgive my dumbness... a question: is your output balanced [-115;+115] or [0;230]? Ever tried the second?