Error in Aleph 3 schematic ?

[JEKYLL]

In the Aleph 2, 4, 5, 30 and 60 schematics the negative feedback resistor value is 100k, but in the Aleph 3 schematic the value is 10k.
Is the Aleph 3 schematic ok?

[Bobken]

Hi ,

Yes it is correct as the lower feedback limb is also reduced by a similar factor of ten, down to 1k (as opposed to 10k.)
It is the ratio of these 2 resistors which sets the overall gain, and in one case it is 100k/10k, and in the other it is 10k/1k.

One clear advantage of using higher overall values of resistance here is that the series cap in the lower limb can be reduced. This allows the use of a better performing (sonically) film cap instead of the much larger cap necessary with lower value resistors, which otherwise needs to be an electrolytic.

Regards,

[JEKYLL]

Thank you very much for your answer.

[Bobken]

Pas un probleme.

Regards,