Korg Poly800/EX800 Users

this kit is totally NOT for people who don't have experience with 
electronic kit building, or preferably electronic repair. i'm so glad that 
i own a solder-sucker!

and now for a critical review of what i've done so far...

i decided to destructively remove IC29 (on my board it was a CMOS 40H138, 
not a TTL 74138 as described in the docs) in order to minimize the risk of 
damaging the PCB.

my Hawk PCB is labeled rev 1.3, and some of the jumpers are a bit closer 
than i would have liked them, but i had no problem with the "small" solder 
pads. i was also surprised that i needed a jumper on the back.

the docs show the chip socket for the header-cable being different than 
the other chip sockets; all of my chip sockets look like the type used for 
the header, and some of them hit the jumpers and don't sit flush against 
the board, but they're close enough. some of the chips don't feel like 
they're seated 100%, so i'll probably hit them with some hot-glue before i 
call it finished.

i noticed that D2 is only used to keep a backwards battery from damaging 
anything, so i left that out along with the battery holder. i might wind 
up using the battery holder in something else.

C1 seems to be used to keep the power lines to the chips clean... but is 
it really effective when there's only one of them, and at the opposite end 
of the board from some of the chips it's protecting? i thought best 
practice was one cap per chip, located as close as practical to each 
chip...?

also the ribbon cables... i was expecting the red mark to be towards pin 
1; the larger cable had it on the other side, the smaller cable didn't 
have a red mark.

oh... when i got to soldering the two capacitors to the board i could only 
find one. i searched and dug through the kit to no avail. i ran to jaycar 
just before they closed for the day, got a pack of two, got back, put the 
second capacitor on the board, and as soon as i looked up i saw the 
missing cap, stuck to the tape on one of the IC tubes.

can i remove the battery from the EX800 main-board?

right now i've got it at the point where it powers up and says "FLASH". 
since my computers and my synths don't talk to each other, getting the OS 
loaded will be a non-trivial task for me. in the meantime i'll be looking 
at 1U rack enclosures. i'll hold off on the AtomaHawk until i have a 
better idea of the enclosure situation.

does anyone have any fresh leads for a 1U keypad?

all in all, it went smooth, and i probably spent 3-4 hours on the bench 
(not including my jaycar trip). one of the things that cost me time was 
not having a printout of the docs, so i had to keep getting up and looking 
at the computer, going back and forth.

i would highly suggest that anyone without the experience to do this 
either find a guitar/amp/electronics repair shop that will quote a price 
(or, if they insist on charging by the hour, at least get them to give you 
a maximum charge), or work out with someone on the list to do the mod. 
it's not for the inexperienced or the faint-hearted. another option for 
having it done ~might~ be an electronics shop at a local vo-tech or trade 
school... they might be able to assign it to a student as an extra-credit 
project, or hook you up with a student who is *capable* of doing it as a 
side project for a few bucks.

for those on the list who are comfortable with doing the kit, i'm curious 
how lucrative it might be to sell completed kits on evil-bay...?


-- 
         ...atom

  ________________________
  http://atom.smasher.org/
  762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
  -------------------------------------------------

 	"The basic difference between an ordinary man and a warrior is that a
 	 warrior takes everything as a challenge, while an ordinary man takes
 	 everything either as a blessing or a curse."
 		-- Don Juan (Carlos Castanada)

--- In korgpolyex@yahoogroups.com, Neil Wakeling <neil@...> wrote:
>
> So, what (freeware?) Sysex librarian or other method for transferring 
> the Flash etc do you guys recommend?
> 
>

There are a lot of freeware sysex dumpers, but one might as well stick 
with MIDI-OX for all the other useful features.

On Sun, 28 Dec 2008, Michael Hawkins wrote:

> I knew I couldn't escape the critical eye of atom!
==============

hehe.... no one can escape the critical eye of atom! it could be worse... 
you could be married to me >;)


> 1) I don't think the kit is quite as hard as atom is making it out to be 
> but, I am a littled biased. Yes, a professional desoldering station is 
> probably the most important tool that I would recommend to do the job.
===============

i used a cheap soldering iron (made for electronics, not stained-glass), 
and an old (halfway decent) solder-sucker that needs a new tip.


> 2) the supplied IC29 is a 40H138 or 74HC138. they are one and the same 
> just different part number from different manufacturers.
=================

the 74** is probably more resilient to static, and possibly more resilient 
to other forms of manhandling.


> 3) the jumper on the back will not be required on board rev 1.4
=================

cool.


> 4) if you don't pull the jumper wires taught so that they are flat then 
> yes, the IC sockets can sit up slightly. But if you solder one end of 
> each jumper and then feed the other end through the second hole and then 
> use a pair of long nose pliers to strain the jumper wire, you can end up 
> with a very flat jumper. Those sockets are high quality but they do 
> require a firm push to ensure that the chips are fully seated.
==================

the sockets i've got are made in a way that half of the bottom, along one 
side of pins, won't lay flat on the board if there's anything under them. 
being that they're only "bumped up" by the diameter of the jumpers, it's 
more of an ideological than practical concern.


> 8) now if you had done a proper inventory of your parts you would have 
> found the missing cap sooner. Perhaps I'll drop those two caps onto into 
> a little baggie just to keep them from getting lost.
============

bah!! that's almost like reading through the instructions before starting!

btw, i first assembled the board, then prepped the 800. then, after 
destructively removing the **138 from the 800 read about re-seating that 
and the EPROM for testing... i did look through (a small part of) my chip 
collection, but i didn't find a **138... oh-well... full steam ahead for 
the smasher! doh! the **138 is socketed in the hawk board!


> 9) I guess I figured anyone alive today that owns a Poly ought to know 
> how to get a syexe file into it. :-) But I didn't think that there would 
> be ppl out there that don't have a computer of any kind or brand to use 
> to do it.
===============

oh, i've got plenty of computers here... mine run freeBSD, and i've never 
even tried hooking up a midi converter. my wife runs ubuntu, our 3 year 
old just got an XO-1 (fedora based). i guess the usb-midi things are cheap 
enough now that i should experiment. my plan is to either a) load the 
sysex onto a floppy and use my MC-50mk2 to talk to the 800 or b) invite a 
geeky friend over with a laptop and a midi adapter. in all fairness, i was 
planning for this inconvenience, it's no surprise.


> 10) Eventually I will start selling fully modified Poly's on ebay. But 
> for now, I am still trying to finish the software. It's a long, lonely 
> road.
=============

i do hope that turns out to be profitable for you. the kit is just too 
amazing to rely on crusty and cynical DIYers (such as myself) as your 
market.


> Do let us know what you think of it all once you get past "FLASH" mode.
==============

man, after this review, you actually *want* another review from me, 
anytime soon ;)


-- 
         ...atom

  ________________________
  http://atom.smasher.org/
  762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
  -------------------------------------------------

 	"Now about Lankhmar. She's been invaded, her walls
 	 breached everywhere and desperate fighting is going
 	 on in the streets, by a fierce host which out-numbers
 	 Lankhmar's inhabitants by fifty to one -- and equipped
 	 with all modern weapons. Yet you can save the city."

 	"How?" demanded Fafhrd.

 	 Ningauble shrugged. "You're a hero. You should know."
 		-- Fritz Leiber, "The Swords of Lankhmar"

On Sun, 28 Dec 2008, Michael Hawkins wrote:

> 5) yes, the diodes and battery holder will be completely eliminated from 
> board rev 1.4
====================

have you thought about combining the two kits onto one board? or is the 
headache of doing the layout more trouble than it's worth? without the 
battery, it *almost* looks like both kits can be done on a single board 
the same size and shape as the HAWK-800 board.

oh, and what about the coin-cell battery on my 800 main board... is there 
any reason to keep that?


-- 
         ...atom

  ________________________
  http://atom.smasher.org/
  762A 3B98 A3C3 96C9 C6B7 582A B88D 52E4 D9F5 7808
  -------------------------------------------------

 	"Like many big companies, Microsoft wins by dominating
 	 distribution channels, not by having better products.
 	 Having a technical edge over competitors is not
 	 critical to their business."
 		-- Paul Graham

> I have to say that removing the IC29 is quite a step to
> take (What was it Atom said? Non-trivial? I agree). 
> You're kinda committed once you start this!  I think
> we'll need a T-shirt after all this - the "I
> removed IC29 and didn't fry my board" T-shirt.

I agree- it is a pretty scary thing to have to do, for relatively inexperienced modders like myself. Having said that, I'm personally more worried about installing the aTomahawk mod, which is why I've held off ordering it so far. I will though, because I'm looking forward to hearing what it can do!

a|x

Hi Neil,

Happy New Year and great to hear you've done the hard part of removing
the EPROM socket and IC29. Fun wasn't it?

Yes, if you are able to power up the Poly and get "11 P" then you are
looking good but it is certainly worth loading some patches and making
sure that all of the sound functions work before proceeding on any
further.

Check that detune and chorus works - tells you that "Latch A" is working.

Check that DCO mode single and double mode works and sounds play
correctly in either mode tells you that the TG and "Latch B" is OK.

Writing a patch from, say patch 11 to patch 88, and then checking that
the patch was in fact saved by switching to another patch and then
back to 88 should tell you that static memory (writing to it) is OK.

Sending some MIDI notes to and from the Poly will tell you that the
UART is OK.

Checking that all front panel buttons work, all rear switches work and
checking that all notes play tells you that the keyboard scanning
hardware is OK.

And that should be a good enough test.

Mike.



--- In korgpolyex@yahoogroups.com, Neil Wakeling <neil@...> wrote:
>
> Hi Mike
> 
> Happy New Year everybody from Scotland.
> 
> Congratulations on producing such a (so far anyway) detailed set of 
> instructions.
> 
> I have just got to the "test everything works" stage after prepping the 
> Poly800 main board - and it all seems to work!  Whether by skill on my 
> part, or by lucky chance?
> 
> Question: Does the mere fact that I can programme a sound and the 
> controls seem to work, indicate that it is OK, or should I reload all 
> memories and check all memory locations, sequencer, etc?
> 
>  I have to say that removing the IC29 is quite a step to take (What was 
> it Atom said? Non-trivial? I agree).  You're kinda committed once you 
> start this!  I think we'll need a T-shirt after all this - the "I 
> removed IC29 and didn't fry my board" T-shirt.  It would have been 
> easier if  my desolderer wasn't old and worn - and the nearest 
> electronics shop is about 150 miles away.  Its also shown up a serious 
> problem (don't worry - I don't blame you) - I can't focus quite so
close 
> to the board as I used to be able to!
> 
> I ended up doing the destructive removal, too.
> 
> I can't proceed to actually building the board and installing it 
> tonight, as we need the kitchen table back...
> 
> Best Wishes
> neil
> 
> 
> >
> > ============
> >
> > bah!! that's almost like reading through the instructions before
starting!
> >
> > btw, i first assembled the board, then prepped the 800. then, after
> > destructively removing the **138 from the 800 read about
re-seating that
> > and the EPROM for testing... i did look through (a small part of)
my chip
> > collection, but i didn't find a **138... oh-well... full steam
ahead for

> > the smasher! doh! the **138 is socketed in the hawk board!
> >
> >
>