No DC in input? Can input capacitor be removed?

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I have VAC CPA-1 Preamplifier and am using it in passive buffer mode. There is a capacitor per channel between volume (replaced by attenuator) and input to the grid of 12AX7.
Since the outputs of a tubed DAC and a tubed Phono have already passed serially 8 and 4 uf, respectively, I thought that DC was absent from the outputs and that input capacitor (1 uF) was redundant.
So I removed the capacitors and the output from attenuator was directly connected to 12Ax7. It sounds much better (or differently) after the removal but VERY LOUD TICK NOISE whenever the attenuator is stepped up or down and INCREASED HUM (sounds like AC hum). No hum or noise before the removal.
Is the capacitor still a necessity? Is it still DC that is causing problem? If attenuator is operated when preamp is muted, will there be no damage to preamp? Can the hum or noise be removed without replacing input capacitor?

I would appreciate your help.

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Topic - No DC in input? Can input capacitor be removed? - yhm23280 05:16:48 01/20/06 (5)

I do the same thing as you did, cut C1 and C2 - GrayW 05:17:20 01/21/06 (0)

Re: No DC in input? Can input capacitor be removed? - REL54 12:42:04 01/20/06 (0)

Depends upon one big thing - Russ57 07:00:39 01/20/06 (0)

Re: No DC in input? Can input capacitor be removed? - Chris O 06:39:33 01/20/06 (0)

A circuit digram would help.... - jub_jugs 06:10:16 01/20/06 (0)

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