[sdiy] Vox Continental key noise

[Nathan Trites]

Thanks. That’s another thing I wondered about - to what extent do they
click/pop under normal conditions.

 I know it won’t be perfect but the noise is significantly louder than the
tones, sounds just this video but on every key https://youtu.be/NnwJZt3TifI

I’ll have time to dig in more tomorrow.

Nathan

On Saturday, May 1, 2021, Michael E Caloroso <mec.forumreader at gmail.com>
wrote:

> I don't think you can eliminate the noise.  Vox combo organs are cheap
> designs, the contact noise is DC transients when the contacts mate.
> In an isolated setting you may notice the contact noise, while in a
> band setting it will be masked out by all the other instruments.
>
> Don't expect these to be high fidelity.
>
> MC
>
> On 4/30/21, Nathan Trites <nathan at idmclassics.net> wrote:
> > Hi all,
> >
> > I've got a continental v301e here where I'm getting a nasty contact noise
> > on all keys, which varies in level (seemingly due to where the waveform
> > falls). It's definitely not just dirty bus bars & j wires, which have
> been
> > cleaned pretty aggressively. Most of the finger connections seem good,
> all
> > electrolytics replaced, and a few of the (film?) caps replaced for being
> > open.
> >
> > With all tone boards in, each bus has an offset of low double digit
> > millivolts. With a single tone board in it still occurs with an offset in
> > the single digit mV and it still happens. I've replaced coupling caps in
> a
> > few and they still have noise.  I can see the spikes on the scope even
> > without the preamp board installed. Would such a small offset cause
> popping
> > like that on the switches?
> >
> > The continental is a fair bit older than gear I'm used to working on so
> I'm
> > still getting my bearings on the construction and haven't checked this
> yet,
> > but I suspect the ground from the draw bars or going to the tone boards
> > needs to be looked at closer.  I do get some very low noise on the power
> > supply (even with nothing installed) again in the 10s of mV range p-p.
> >
> > Schematics can be found here:
> > http://www.theamericannight.com/voxproject/project.html
> >
> > Any guidance or advice would be appreciated! If anyone knows of a good
> > transistor organ repair forum or list that would be very helpful too.
> >
> > Thanks,
> >
> > Nathan
> >
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20210501/328c192e/attachment.htm>