Been quiet lately... too much DIY ?

[Tim Ressel]

Report:
What I did on my Memorial Day vacation:

Hammered out a design for a (gulp) uP controlled ADSR generator. I know, its
easy to do with a 555. In fact, I have one. But I want linear ramps for some
reason, so I am wanging up a dual ADSR using an HC11. My ADSR question last week
came after I did the initial state diagram.

Sent off to Mr. Patchell for some MAT-04's. I want to see if I can replace the
CA3046 in my VCO design. I am doing thermostat heating, and I plan to use two of
the MAT-04 trannies for temp-sense and heating. Of course, then I discovered 2
MAT-04 samples as I was cleaning...

Studied the timber modulators in Barry Klein's book... Might just have to proto
a few of those...

Studied 3-D sound effects. Is anyone interested in a module or an expreimenter's
kit that will do some kind of true 3-D??

But mostly, I cleaned the Dungeon (basement) where my lab is. I'm not what you'd
call a tidy person. In fact, I'm a bit of a slob. But I've been pecking away at
it every day, and now I can actually what color the tables are!  This is good,
because I have these anti-static mats to put down.

oh, yeah: I got the pool clean, just in time for 100 degree California days!

That's all...

Tim Ressel--Compliance Engineer
Hewlett-Packard
Verifone Division
916-630-2541  
tim_r1 at verifone.com                     



-----Original Message-----
From: Harry Bissell [mailto:harrybissell at prodigy.net]
Sent: Monday, May 29, 2000 7:48 PM
To: synth-diy at node12b53.a2000.nl; efm at xavax.com
Subject: Been quiet lately... too much DIY ?


Class...
I expect a report from all US members tomorrow following the holiday
weekend.
World class members... no excuse! Unless you had a national holiday,
emergency,
etc. Then a note from your mother (or wife) will suffice. Your
assignments are still
due on time...

your Teacher !!!

I've been
1) Building my MiniModular (about half done... want to wash it tomorrow
in ozone-safe
<don't worry, still toxic to humans...>  defluxer before putting in the
pots and polystyrene
caps. Spent a hour painting in the lines in the tiny little pots. Used
fluorescent red and a
5-0 paintbrush (left over from negative retouch... eh oldtimers ???)

2) Resurrection of my stereo hex fuzz (from the early 80's). Storage has
not been too
unlind... the bypass relays no longer work (contact corrosion) and there
is a big difference in the gain of my G-Vox pickup (low) and my old 360
Systems pickup (high) so I can
only get slightly into the fuzzes "face" right now. But early
"crunchies" indicate I have been
missing this too long.  What a sweet sound. Double stop bends... no IM
distortion. With
the "slight crunch" it has real nice sustain without the typical harsh
distortion.

3) So I need a new Hex Fuzz module.  I'm planning a Voltage controlled
Fuzz unit, with
sustain, volume, and tone all voltage controlled. It will probably
include an envelope follower (with compression on/off) and VCF, and
final VCA, driven by a separate compressed (on/off) envelope follower.
The idea is that the final VCA can act as a noise gate without killing
sustain too much.

So far I've got a 3080 driving a current to voltage output stage
(inverting) with clipping.
Nice fuzz... not too noisy. The 3080 is the direct preamp for the hex
pickup, but I'm thinking of trying an NE553X  (2, 4???) as a low noise
preamp stage fronting the 3080
(to drive the envelope followers...)

The idea is for a (single... double???) rack unit, with knobs to set the
fuzz parameters.
And a preamp output to go to P/V conversion at a later date. I have a
nice circuit that I'm using to get the pitch output reliably.

The "stereo" function was originally every other string left/right. This
svcked! So I used
low 3 - high 3 so you can use two amps (like a bass amp and a guitar
amp)... IMHO
Stereo outputs are not worth the extra circuitry. What do you think ?

Anyone have any favorite fuzz box ideas ???  Anyone want to play ???

BTW this is a "Guitar Synthesizer" module without VCO's. So don't tell
me to go to
alt.guitar.effects... eh ???

H^)  harry