R. Gwinn, Gristleizer  [documentation]

Original effects with schematics, layouts and instructions, freely contributed by members or found in publications. Cannot be used for commercial purposes without the consent of the owners of the copyright.
Post Reply
User avatar
reneshelle
Solder Soldier
Information
Posts: 184
Joined: 25 Aug 2009, 11:28
Location: Denmark
Has thanked: 35 times
Been thanked: 47 times

Post by reneshelle »

The Bias knob should for sure be linear.

The level and Depth should probably be linear as well and the Speed be log, but they seem fine to me the way I’ve written them.

The letters A and B must have confused me…
Top
User avatar
TheLoneRoger
Information
Posts: 3
Joined: 23 Feb 2019, 08:53

Post by TheLoneRoger »

R.G. wrote:There's a schemo and PCB layout at GEO.
Who/where/what is GEO?
I'm looking for the docs that came with the original Phonosonics PCB for this project having lost mine - not sure if this is the one, but I'd love to find out...
Top
User avatar
modman
a d m i n
Information
Posts: 4898
Joined: 19 Jun 2007, 16:57
Has thanked: 4411 times
Been thanked: 2139 times

Post by modman »

TheLoneRoger wrote:
R.G. wrote:There's a schemo and PCB layout at GEO.
Who/where/what is GEO?
I'm looking for the docs that came with the original Phonosonics PCB for this project having lost mine - not sure if this is the one, but I'd love to find out...
http://www.geofex.com/Article_Folders/gristlecheck.PDF
Please, support freestompboxes.org on Patreon for just 1 pcb per year! Or donate directly through PayPal
Top
User avatar
TheLoneRoger
Information
Posts: 3
Joined: 23 Feb 2019, 08:53

Post by TheLoneRoger »

mictester wrote: ↑15 Mar 2013, 06:18 The final mod I sometimes add is to give the first stage the option of a clipper circuit in the feedback path - the additional harmonics really make the VCF shine!
gristle-schem-modded.png
Many thanks for this. I had literally just finished re-building and boxing my original PE/Phonosonics Gristleizer, which I first built in the early '80's, when I came across this post!
I'll be implementing your mods - swapping the IC's etc. - but could you elaborate on the last part? How/where would I add this clipper circuit to the original PE layout?
TIA
Roger
Top
User avatar
mictester
Old Solderhand
Information
Posts: 2924
Joined: 11 Sep 2008, 20:29
my favorite amplifier: Mesa Boogie, Roost Sessionmaster, AC30
Completed builds: Hundreds! Mostly originals, a few clones and lots of modifications.
Location: Somewhat closer to Amsterdam than before!
Has thanked: 32 times
Been thanked: 845 times
Contact:
Contact mictester

Post by mictester »

The simple clipper I've used is to put a pair of back-to-back diodes in parallel with the 100k feedback resistor in the first (input buffer) op-amp stage. Later, I changed the 100k resistor for 56k in series with a 470k pot wired as a variable resistor, so you can vary the amount of fuzzy clipping.
"Why is it humming?" "Because it doesn't know the words!"
Top
User avatar
TheLoneRoger
Information
Posts: 3
Joined: 23 Feb 2019, 08:53

Post by TheLoneRoger »

Excellent, thanks - I'll be giving that a go for sure!
Top
Post Reply

Return to “DIY Projects”