[sdiy] Building the ASM-1 Noise Source

[mmanard at columbus.rr.com]

I'm using PCB Proto soldered. I did check for shorts and checked for bad solderjounts with a DMM. The IC's are not in sockets, just soldered in. There is also an issue when I put my finger anywhere near the 4.7uf cap and transistor it makes a godawful buzzing noise. I do have some longish (3 in or so) wires that i'll try and shorten and I'll plug it in away from other electronics to check it out.

- Michael nil-x
- Pressure : Penetration

----- Original Message -----
From: jays at aracnet.com
Date: Monday, December 20, 2004 6:01 pm
Subject: Re: [sdiy] Building the ASM-1 Noise Source

> Michael,
> 
> You never mentioned in you are using a PCB proto-board (solder) or 
> an 3M/El type proto-board (push in). The 3M/EL boards are 
> nortorious for bad connections and being flaky.
> 
> Go though and check your grounding. A lot of times excessive hum 
> is caused by grounds not hooked up or not hooked up correctly.
> 
> ICs sockets are another place that bad connections can happen.
> 
> Like Magnus said to. Keep wires short and away from things that 
> could act as 'noise sources' (other than the one you're working on).
> 
> Might get the ohm meter out and give a quick check to make sure 
> everything is connected up properly and you do not have any high 
> resistence connections.
> 
> Jay S.
> 
> 
> Magnus Danielson <cfmd at bredband.net> wrote :
> 
> > From: mmanard at columbus.rr.com
> > Subject: [sdiy] Building the ASM-1 Noise Source
> > Date: Mon, 20 Dec 2004 17:28:35 -0500
> > Message-ID: <3df67b3e01f7.3e01f73df67b at columbus.rr.com>
> > 
> > Michael,
> > 
> > > I breadboarded the ASM-1 Noise Source:
> > > http://home.swipnet.se/cfmd/synths/friends/stopp/asm1ns.pdf
> > 
> > http://rubidium.dyndns.org/~magnus/synths/friends/stopp/asm1ns.pdf
> > 
> > is the new URL for that. The SWIPNET site could disappear at any 
> moment they
> > feel like it. Everyone should redirect their links to the 
> Rubidium site.
> > 
> > > I built the White and pink noise portions so far.
> > > 
> > > It's the first time I've actually breadboarded a circuit 
> (as opposed to
> > using a premade PCB). The noise works (kinda) but there's 
> 60cycle hum that's
> > pretty loud. I'm running on a MOTM powersupply. I assume a 
> groundloop but
> > nothing I do changes it. Except one thing I notice is that if I 
> remove the
> > groundwire from the output jack the hum lessens about 50% but 
> still pretty
> > loud. Another thing of note I did was use fairite beads instead 
> of the 22R
> > resistors on the power input. When I use the 22R resistors it 
> doesn't make
> > noise but just makes an oscilalting squealing sound. I've tried 
> 2 transistors
> > so far.
> > > 
> > > Well, I'm a newb so hopefully I explained well enough my issue.
> > > Any thoughts?
> > 
> > You have a fair amount of gain in there. Any small pickup in the 
> early stage
> > will be fairly well amplified. Check what you can do to lower 
> it. It may be
> > conducted in, but it could very well be a magnetic or static 
> pickup. Avoid
> > big loops (for magnetic coupling) and avoid wires far away from 
> ground> wires.
> > Actually, a small metallic box could be the solution to the 
> static pickup,
> > but
> > only to a small degree the magnetic picup.
> > 
> > Cheers,
> > Magnus
> 
> 
>