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georgehifi 18th April 2012 01:56 AM

Input Impedance of the Aleph 0s
Hopefully Nelson will see this and give the designers answer.
I have seen some hopfully correct circuits of the Aleph 0s on the web and it shows for the single ended input a 100k to ground and also a 10k to ground. Can the input be raised without any problems to say 50k? for passive preamp use?

Cheers George

Zen Mod 18th April 2012 03:29 AM


which exact version of pcb is in case ?

in most cases you can ditch R3 (4k75 .... not 10k as you wrote) out and then have R5 (100k) as dominant for input impedance of positive leg

check output offset then , just for fun

georgehifi 18th April 2012 03:51 AM

Sorry choky, I don't know version yet as I'm still negotiating the sale, so your saying that 100k is possible for input impedance for a single ended input?
I thouight that the circuit I saw somewhere on the net was a bit screwy, I didn't even save it, now I can't find it again to show you.

Cheers George

Zen Mod 18th April 2012 04:02 AM

1 Attachment(s)

georgehifi 18th April 2012 05:12 AM

Thanks Choky, that makes sense, remove R3 4.7k and the input becomes 95.25k and check dc offset at output.

Cheers George

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