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Old 24th May 2021, 10:48 am   #1
nzoomed
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Join Date: Feb 2016
Location: Tauranga, New Zealand
Posts: 118
Default Advice on this linestage build

I've put this together from different sources.

I basically want a buffered line stage with minimal gain since most digital sources today are able to drive a power amp fine, but may still require a little gain for the phono, I will have an RIAA stage fed into this for the phono input, but may need some gain depending on how much gain I get from the 6922/E88CC that it uses.

I have built on the Baxandall design found here:
https://www.angelfire.com/electronic...mp-Tone-A.html
https://www.angelfire.com/electronic...e-fig-06-1.gif

It uses a 12AU7 as a cathode follower for the input, I've modified it by adding an EF86 in triode mode at the end, which should give a modest gain, but make up for the losses in the tone stack.
The EF86 configuration is essentially based on the Svetlana preamp schematic.

I have also added balance controls and a tone bypass. I'm not 100% sure how this will behave.
Im also interested if there is a way to add NFB to the EF86 to reduce gain and improve linearity like ive read a bit about, I might be able to incorporate a switch into this, or utilize the tone bypass switch to do this, as its possible the volume/gain may increase when bypassed?
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