[sdiy] Hammond Aurora Keybeds

[Tom Wiltshire]

Didn't Hammond use palladium not gold? So it doesn't look like much (sort of dull silver colour), but actually, it's the same clean metal surface in was in 1940 when they put it together.

But yes, they still get crap on them, but generally cleaning with a a cotton bud and alcohol is enough. Certainly don't use anything abrasive - that'll scrape off the expensive palladium plating.

> On 16 May 2025, at 18:32, drheqx via Synth-diy <synth-diy at synth-diy.org> wrote:
> 
> The key wires are flat and bend quite a bit. Look like chrome  plated actually but the wire buss is not gold plated for sure. 
> 
> I have to give them a good cleaning first and then I'll look at them with a magnifier to see what's really going on. 
> 
> On Fri, May 16, 2025 at 8:42 AM Mike Bryant <mbryant at futurehorizons.com <mailto:mbryant at futurehorizons.com>> wrote:
> Are you sure they'll be oxidised ?  The ones I used back in 70s all had gold plated wires and busses so they couldn't oxidise.  MIght be a bit of crap on them but never anything worse.
> 
> From: Synth-diy <synth-diy-bounces at synth-diy.org <mailto:synth-diy-bounces at synth-diy.org>> on behalf of drheqx via Synth-diy <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>>
> Sent: 16 May 2025 13:07
> To: rburnett at richieburnett.co.uk <mailto:rburnett at richieburnett.co.uk> <rburnett at richieburnett.co.uk <mailto:rburnett at richieburnett.co.uk>>
> Cc: synth-diy mailing list <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>>
> Subject: Re: [sdiy] Hammond Aurora Keybeds
>  
> Yes sir, and they are. They're not the multi-bus wire type but they are direct metal strip on wire and they're going to be oxidized to a certain degree. 
> 
> On Fri, May 16, 2025 at 6:17 AM <rburnett at richieburnett.co.uk <mailto:rburnett at richieburnett.co.uk>> wrote:
> You can also do whatever flavour of switch de-bouncing that you want in
> software, if the key contacts are a bit old and scratchy!
> 
> -Richie,
> 
> 
> 
> On 2025-05-16 03:54, Ben Bradley via Synth-diy wrote:
> > "Each key closes a switch to a common bus."
> >
> > There's a couple things you need to make a "true analog" mono
> > keyboard. First is a constant current source to drive the resistor
> > divider, so that when more than one key is pressed the voltage remains
> > that of the lowest or highest key (unless you WANT a weird off-pitch
> > note effect when pressing more than one key). The other is  a separate
> > switch at every key that closes AFTER the key that gives the pitch
> > voltage as the key goes down, so that the proper voltage is sampled
> > and kept when the key is released. This is also the gate/trigger
> > output. Presuming there are several common busses, you need to bend
> > the contacts on each key to make sure these close in proper sequence.
> >
> > I don't see a problem of being off-pitch with a resistive divider, as
> > 1 percent resistors are cheap thesedays, whereas 1970s keyboards may
> > have used 5, 10 or even 20 percent tolerance resistors.
> >
> > But still, I'd as soon make a digital circuit to scan/read all the
> > separate inputs, one for each key, scan it into a buffer with a
> > microcontroller and do the highest/lowest/latest keydown logic in
> > software and the usual DAC for control voltage output.
> >
> > On Wed, 14 May 2025 at 22:54, drheqx via Synth-diy
> > <synth-diy at synth-diy.org <mailto:synth-diy at synth-diy.org>> wrote:
> >>
> >> Hi all,
> >>
> >> I have the keybeds and draw bars etc. from a Hammond Aurora organ.
> >>
> >> These are not matrix type keybeds. Each key closes a switch to a
> >> common bus.
> >>
> >> Is this a good time for me to consider doing a volt
> >> /octave keyboard controller?
> >>
> >> I definitely don't want to midify these. That would be a waste.   I
> >> was considering building a voice per key synth because i love these
> >> key beds and it would be so unique, but I'm short on time like so many
> >> of us.
> >>
> >> Anyone know of a good kit to make a 1v/ oct controller, maybe with
> >> some added features.
> >> ________________________________________________________
> >> This is the Synth-diy mailing list
> >> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> >> View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
> >> Check your settings at:
> >> https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
> >> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> > ________________________________________________________
> > This is the Synth-diy mailing list
> > Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> > View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
> > Check your settings at:
> > https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
> > Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>
> ________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org <mailto:Synth-diy at synth-diy.org>
> View archive at: https://synth-diy.org/pipermail/synth-diy/ <https://synth-diy.org/pipermail/synth-diy/>
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy <https://synth-diy.org/mailman/listinfo/synth-diy>
> Selling or trading? Use marketplace at synth-diy.org <mailto:marketplace at synth-diy.org>________________________________________________________
> This is the Synth-diy mailing list
> Submit email to: Synth-diy at synth-diy.org
> View archive at: https://synth-diy.org/pipermail/synth-diy/
> Check your settings at: https://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20250516/a9df8f0a/attachment.htm>