Posted by PakProtector [ 205.188.116.67 ] on December 01, 2005 at 15:57:39:

In Reply to: Re: Need favorite 12B4 for Guinevere line stage recommendations? posted by Norris Wilson on November 30, 2005 at 22:06:46:

Hey-Hey!!!,
The active load does isolate the amplifier stge from the PS. Some have suggested a minimum reactance( both C and L ). Like a few uF of capacitance, and that's all...I have personally liked the result of a good L-C stage. 20 Hy and 100 uF of motor run style Oilers.

WHen used as a mu follower, the PS is again included in the PS, but still to a large degree isolated...so a High performance PS is still a good idea, and contributes in a positive way to the sound.

On the detail construction of the CCS, there is some benefit to building with a few batteries and the R-C filter on the gate. ONe needs to protect the +/- 20 volt gate-source voltage maximum with a cathode-cathode Zener clamp. The batteries will prefer a low leakage version BZX79C18 would be my preference, though BZX55C18 is not far behind...:)
cheers,
Douglas

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