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Ian Iveson Ian Iveson is offline
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Default Eico Tone Control Mod

Jon Yaeger wrote:

My latest project is to complete some modifications to an
Eico 2080
integrated amplifier, which uses 7591s in PP
configuration, and is similar
in many respects to the ST-70 circuit.

Among my goals we

1. To install a remote volume control, using the very
nice kit sold by
Mikkel Simonsen, formerly of R.A.T.

2. Remove the tone control circuitry;

3. Design a new faceplate for the reduced number of
controls.

In order to achieve goal #1, I used one of the tone
control tube positions
as a cathode follower, to drive the 50K motorized volume
control. Mikkel's
circuitry included a driver for a mute relay.

I am housing his circuit inside of a metal box installed
under the chassis,
to reduce interference as much as possible.

A schematic of one channel the proposed design is posted
on:

http://www.yaegeraudio.com/eico_mod.pdf

I welcome any comments / criticisms / suggestions on the
proposed design.

Thank you.


I would be interested to know how you make your decisions.
Such as:

Choice of valve, values of coupling caps, valve loading and
configuration.

That's everything, I suppose.

And why wouldn't you put Mikkel's remote in a Mac? Is this a
quality or a conservation issue? How is the remote powered,
BTW?

cheers, Ian