Another flaw of Slidex is that if someone sits on the console, puts a heavy tape box on top of them 
or otherwise bends the thin aluminum stalk of the fader knob, they don't work smoothly anymore. I 
assume ADM had a full-time guy fixing those things as they came in by the batch from broadcast and 
recording studio customers.

One the other hand, I have a batch of them that were used for 20 years in a TV station with some 
respect for its equipment, and all but one of them work well and were easy to clean and oil when I 
got them. I keep them as a curiosity, because they don't really have a modern application aside from 
restoring a vintage ADM console.

-- Tom Fine

----- Original Message ----- 
From: "Stephen Anderson" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Thursday, April 12, 2012 2:25 PM
Subject: Re: [ARSCLIST] The root of the slide-fader?

Having recently refurbished an early '70s ADM console (thanks, Tom!), I can state fairly firmly that 
the Slidex, which used a twisted piece of aluminum activated by the slider to turn a conventional 
Allen Bradley pot, was pretty crude, and very difficult to match mechanically, channel to channel.

Teac/Tascam in their Series 70 mixers used a string to turn a standard rotary pot, if memory serves, 
this was much better.


On Apr 12, 2012, at 11:08 AM, Tom Fine wrote:

> Art Davis worked for Cinema Engineering, which was marketing a form of this kind of attenuator in 
> 1953 and probably earlier.
> See:
> (I provided the scans, from old magazines)
> As we know, slide-faders became the preferred interface for analog mixing boards, eventually 
> replacing rotary faders in almost all applications (although small-format mixers sold by companies 
> like Behringer, Mackie, Alesis and others still use rotary faders). There have been many varients 
> on slide-faders over the years. In the 60's, Fairchild sold a fader that controlled the intensity 
> of a light source, which then interacted with a LDR to control gain, branded "Autoten." In the 
> 70's, Audio Designs & Manufacturing (ADM) patented a mechanical system that drove a pot that 
> controlled a VCA to control gain. The advantage of the ADM "Slidex" attenuator was that liquid 
> (perhaps coffee at a TV station, beer at a radio station or something more exotic at a recording 
> studio) could spill across the slider section of the console and not short out anything, within 
> reason.
> Here is the Slidex patent:
> -- Tom Fine

Stephen Anderson
631 E. Vista del Playa
Orange, CA 92865
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