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Paradise Phono Preregulator

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Hello,
if you want tomorrow I can make some tests on my boards.
In my opinion also the CMR coils after the transformer ring.
So I'd like to short their leads as first.
If you have any suggestion I'm here with my iron on the hands.
Ciao
Guglielmo

If the CMR-coils are humming, then get yourself a small can of clear urethane paint and immerse the coils for a few days (longer is better :)). After that take them out and hang them from one of the connection points so the can free themselves of excessive paint and dry.

Tomorrow I will add more comment on the transformers.
 
This is allmost unlikely.
In my experience the huge thickness of the actual boards
make a good resonance-body for the T-formers foolin' around.
But, anyways, if you get further enlightenment,
let us know.

Yes, that is certainly very true ... (the thick board actually helping with spreading the noise)

And now I come to think about that, you could add a (double) layer of dual sided sticky tape (the soft foamed type) between the board and the coil (also the transformers) this will (most probably) provide some dampening.
 
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After speaking with Peter, and after giving it some time, I have to conclude that people owning a 'Hummer' need to replace it/them with a new transformer. How did I get there;

1) You are not happy with the current one (so replace :))
2) The value of the transformer is 'kind-of' low, so, you should be able to replace it. So when not happy with these try some others :) [Sounds like 1)]
3) Technically, Block says there is nothing wrong but they did exchange, why? In my opinion something must be wrong. The report says that they are humming even when no power is taken from them (e.g. the secondary is disconnected). To produce noise, there must flow a current in the primary (e.g. there must be power to convert to 'hum'), this is only possible if there is DC on the net (I still advice; do try a DC blocker (it's easy)), or if the idle current of the transformer is high. There are two possible reasons for the high idle current (besides alien intervention (I just watched an old Star-Trek episode on Belgium television :))), bad design (you need a different brand of transformer) of a short in one of the windings (you need a new transformer).

There you have it, in my opinion, (if your transformer is humming), you need a new transformer (set of). My advice; try some other brand (Block failed! big time).
 
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Transformer noisy

hey guys,
because of your posts i fired up my preREG the first time today, to see how my transformers behave.
and YES
the are really noisy. mechanical noise (hum).
never heard hum as loud as this before at any transformer i had.

so as Frans suggests, best to get new one`s.
which transformers do you guys use without those block-humming-problems???

thank you very much.

ps.: peter i sent you a PM
 
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