| Aleph 5 DC offset and bias adjustment - Click HERE for Original Thread |
| Bertie |
Sorry if this has been covered elsewhere but I did try and I couldn't find it.
I'm just finishing assembly of my Aleph 5 clone monoblocks and all appears to work fine on the bench.
Two questions, what level of DC offset is typical or acceptable on the output and ho can I adjust it if it's wrong?
Secondly I have read Nelson saying that Aleph 5's work better with higher bias curent. Assuming I have the thermal capacity in the sinks how can I adjust the bias up? |
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| Nelson Pass |
To answer the questions anyway,
about 50 mv is my standard for DC offset in Alephs. If
you need to trim it you can do so in a number of places,
but adjust the the Source resistance in the current source
which biases the differential input transistors is a good
place.
Yes, you can increase the bias easily enough using the
resistor which feeds the Base of the NPN transistor on the
positive current source. I forget the number, but its the one
which goes from the Base to a capacitor which is charged
by a resistor to the positive supply.
Simply removing this will up the bias without any other
alterations needed. |
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| Bertie |
Yes I did search,
and thanks very much to Nelson for the reply. |
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