Aleph P1.7 circuit question

[Peter Daniel]

I'm building Aleph P1.7. How important is the feedback resistor R48 (221K)? Can it be omitted? I understand that this resistor creates DC component at the input and that's why the coupling cap is required. Could this resistor be connected through the capacitor (I drew the example) and thus the input cap C9 could be eliminated?

 

[fmak]

I'm building Aleph P1.7. How important is the feedback resistor R48 (221K)? Can it be omitted? I understand that this resistor creates DC component at the input and that's why the coupling cap is required. Could this resistor be connected through the capacitor (I drew the example) and thus the input cap C9 could be eliminated?

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If this can be eliminated, great. The AlephP sounds different dependent on the quality of this, and the output caps. This is why I have never found the Aleph to be as great as it is made out to be by reviewers. The quality of the balance pots matters also. The factory units are not great.

 

[Peter Daniel]

The 2K pot and 2 100 ohm resistors can be replaced by one fixed value resistor. I know that the quality of capacitors have great influence on the sound of the preamp that's why I would like to use them only where really necessary.

 

[Peter Daniel]

Doesn't seem like a popular project this Aleph 1.7...

 

[jam]

Peter,

I think my choice would be a current sourced balanced Zen. I used to own a 1.7 and it was a very good unit but somehow I see more potential in the balanced Zen. With no input coupling capacitor and a different power supply.

Jam

 

[Peter Daniel]

I think Nelson Pass answered my question in the other thread (Zen Aleph-balanced). If I would like to AC couple the feedback resistor what considerations should I take in choosing the value of a cap?

 

[jam]

You probably want to use a capacitor large enough to cause a rolloff below 5Hz.

Jam