Discussion about the Korg PolySix synthesizer

I'm not sure about the boards you guys got - but in MINE (there don't seem to be revision numbers) C22 isn't even in the circuit. In the original, C22 hits the same ground trace on the same side as the leg of C23. It seems to be exactly the same kind of error that the other two resistors has - as mentioned in Jed's bugs/errors page.

now - i'm kind of wondering if this has something to do with the 'instability' noticed by some using 22pf cap??

I can't believe nobody's spotted this.... or maybe I just never got the memo?

I just checked my board. The gnd end of C22 does not connect to gnd.
Good job finding that! But my P6 works OK as is. Do I dare fix it...

Bob

--------------------------------------------

On Sun, 2/7/16, jw_dewdney@yahoo.com [PolySix] <PolySix@yahoogroups.com> wrote:

Subject: [PolySix] Jorgensen KLM367 Bug Alert - C22
To: PolySix@yahoogroups.com
Date: Sunday, February 7, 2016, 5:41 PM


 









I'm not sure about the boards you guys got -
but in MINE (there don't seem to be revision numbers)
C22 isn't even in the circuit. In the original, C22 hits
the same ground trace on the same side as the leg of C23. It
seems to be exactly the same kind of error that the other
two resistors has - as mentioned in Jed's bugs/errors
page.

now - i'm kind of
wondering if this has something to do with the
'instability' noticed by some using 22pf cap??

I can't believe
nobody's spotted this.... or maybe I just never got the
memo?











#yiv1243419895 #yiv1243419895 --
#yiv1243419895ygrp-mkp {
border:1px solid #d8d8d8;font-family:Arial;margin:10px
0;padding:0 10px;}

#yiv1243419895 #yiv1243419895ygrp-mkp hr {
border:1px solid #d8d8d8;}

#yiv1243419895 #yiv1243419895ygrp-mkp #yiv1243419895hd {
color:#628c2a;font-size:85%;font-weight:700;line-height:122%;margin:10px
0;}

#yiv1243419895 #yiv1243419895ygrp-mkp #yiv1243419895ads {
margin-bottom:10px;}

#yiv1243419895 #yiv1243419895ygrp-mkp .yiv1243419895ad {
padding:0 0;}

#yiv1243419895 #yiv1243419895ygrp-mkp .yiv1243419895ad p {
margin:0;}

#yiv1243419895 #yiv1243419895ygrp-mkp .yiv1243419895ad a {
color:#0000ff;text-decoration:none;}
#yiv1243419895 #yiv1243419895ygrp-sponsor
#yiv1243419895ygrp-lc {
font-family:Arial;}

#yiv1243419895 #yiv1243419895ygrp-sponsor
#yiv1243419895ygrp-lc #yiv1243419895hd {
margin:10px
0px;font-weight:700;font-size:78%;line-height:122%;}

#yiv1243419895 #yiv1243419895ygrp-sponsor
#yiv1243419895ygrp-lc .yiv1243419895ad {
margin-bottom:10px;padding:0 0;}

#yiv1243419895 #yiv1243419895actions {
font-family:Verdana;font-size:11px;padding:10px 0;}

#yiv1243419895 #yiv1243419895activity {
background-color:#e0ecee;float:left;font-family:Verdana;font-size:10px;padding:10px;}

#yiv1243419895 #yiv1243419895activity span {
font-weight:700;}

#yiv1243419895 #yiv1243419895activity span:first-child {
text-transform:uppercase;}

#yiv1243419895 #yiv1243419895activity span a {
color:#5085b6;text-decoration:none;}

#yiv1243419895 #yiv1243419895activity span span {
color:#ff7900;}

#yiv1243419895 #yiv1243419895activity span
.yiv1243419895underline {
text-decoration:underline;}

#yiv1243419895 .yiv1243419895attach {
clear:both;display:table;font-family:Arial;font-size:12px;padding:10px
0;width:400px;}

#yiv1243419895 .yiv1243419895attach div a {
text-decoration:none;}

#yiv1243419895 .yiv1243419895attach img {
border:none;padding-right:5px;}

#yiv1243419895 .yiv1243419895attach label {
display:block;margin-bottom:5px;}

#yiv1243419895 .yiv1243419895attach label a {
text-decoration:none;}

#yiv1243419895 blockquote {
margin:0 0 0 4px;}

#yiv1243419895 .yiv1243419895bold {
font-family:Arial;font-size:13px;font-weight:700;}

#yiv1243419895 .yiv1243419895bold a {
text-decoration:none;}

#yiv1243419895 dd.yiv1243419895last p a {
font-family:Verdana;font-weight:700;}

#yiv1243419895 dd.yiv1243419895last p span {
margin-right:10px;font-family:Verdana;font-weight:700;}

#yiv1243419895 dd.yiv1243419895last p
span.yiv1243419895yshortcuts {
margin-right:0;}

#yiv1243419895 div.yiv1243419895attach-table div div a {
text-decoration:none;}

#yiv1243419895 div.yiv1243419895attach-table {
width:400px;}

#yiv1243419895 div.yiv1243419895file-title a, #yiv1243419895
div.yiv1243419895file-title a:active, #yiv1243419895
div.yiv1243419895file-title a:hover, #yiv1243419895
div.yiv1243419895file-title a:visited {
text-decoration:none;}

#yiv1243419895 div.yiv1243419895photo-title a,
#yiv1243419895 div.yiv1243419895photo-title a:active,
#yiv1243419895 div.yiv1243419895photo-title a:hover,
#yiv1243419895 div.yiv1243419895photo-title a:visited {
text-decoration:none;}

#yiv1243419895 div#yiv1243419895ygrp-mlmsg
#yiv1243419895ygrp-msg p a span.yiv1243419895yshortcuts {
font-family:Verdana;font-size:10px;font-weight:normal;}

#yiv1243419895 .yiv1243419895green {
color:#628c2a;}

#yiv1243419895 .yiv1243419895MsoNormal {
margin:0 0 0 0;}

#yiv1243419895 o {
font-size:0;}

#yiv1243419895 #yiv1243419895photos div {
float:left;width:72px;}

#yiv1243419895 #yiv1243419895photos div div {
border:1px solid
#666666;height:62px;overflow:hidden;width:62px;}

#yiv1243419895 #yiv1243419895photos div label {
color:#666666;font-size:10px;overflow:hidden;text-align:center;white-space:nowrap;width:64px;}

#yiv1243419895 #yiv1243419895reco-category {
font-size:77%;}

#yiv1243419895 #yiv1243419895reco-desc {
font-size:77%;}

#yiv1243419895 .yiv1243419895replbq {
margin:4px;}

#yiv1243419895 #yiv1243419895ygrp-actbar div a:first-child {
margin-right:2px;padding-right:5px;}

#yiv1243419895 #yiv1243419895ygrp-mlmsg {
font-size:13px;font-family:Arial, helvetica, clean,
sans-serif;}

#yiv1243419895 #yiv1243419895ygrp-mlmsg table {
font-size:inherit;font:100%;}

#yiv1243419895 #yiv1243419895ygrp-mlmsg select,
#yiv1243419895 input, #yiv1243419895 textarea {
font:99% Arial, Helvetica, clean, sans-serif;}

#yiv1243419895 #yiv1243419895ygrp-mlmsg pre, #yiv1243419895
code {
font:115% monospace;}

#yiv1243419895 #yiv1243419895ygrp-mlmsg * {
line-height:1.22em;}

#yiv1243419895 #yiv1243419895ygrp-mlmsg #yiv1243419895logo {
padding-bottom:10px;}


#yiv1243419895 #yiv1243419895ygrp-msg p a {
font-family:Verdana;}

#yiv1243419895 #yiv1243419895ygrp-msg
p#yiv1243419895attach-count span {
color:#1E66AE;font-weight:700;}

#yiv1243419895 #yiv1243419895ygrp-reco
#yiv1243419895reco-head {
color:#ff7900;font-weight:700;}

#yiv1243419895 #yiv1243419895ygrp-reco {
margin-bottom:20px;padding:0px;}

#yiv1243419895 #yiv1243419895ygrp-sponsor #yiv1243419895ov
li a {
font-size:130%;text-decoration:none;}

#yiv1243419895 #yiv1243419895ygrp-sponsor #yiv1243419895ov
li {
font-size:77%;list-style-type:square;padding:6px 0;}

#yiv1243419895 #yiv1243419895ygrp-sponsor #yiv1243419895ov
ul {
margin:0;padding:0 0 0 8px;}

#yiv1243419895 #yiv1243419895ygrp-text {
font-family:Georgia;}

#yiv1243419895 #yiv1243419895ygrp-text p {
margin:0 0 1em 0;}

#yiv1243419895 #yiv1243419895ygrp-text tt {
font-size:120%;}

#yiv1243419895 #yiv1243419895ygrp-vital ul li:last-child {
border-right:none !important;
}
#yiv1243419895

thanks - well it happened when i was scavenging a 10pf cap from C22 in one of my old boards to transplant into C23 on the new one (per recommendation) - but now I'm wondering if the 'stability problem' doesn't in fact come from the missing leg to ground on C22... since they BOTH feed to the resonator.

Both C22 and C23 are connected to the resonator via ground. As for what that means for the resonator and circuit stability are a bit beyond my understanding however....

Wow, hard to believe a new bug was found so many years in. Nice work!

I'm on vacation but I'll get that posted on the website soon.

Thanks all,

Jed

On Feb 7, 2016 4:47 PM, "jw_dewdney@yahoo.com [PolySix]" <PolySix@yahoogroups.com> wrote:

 

thanks - well it happened when i was scavenging a 10pf cap from C22 in one of my old boards to transplant into C23 on the new one (per recommendation) - but now I'm wondering if the 'stability problem' doesn't in fact come from the missing leg to ground on C22... since they BOTH feed to the resonator.

Both C22 and C23 are connected to the resonator via ground. As for what that means for the resonator and circuit stability are a bit beyond my understanding however....