[sdiy] PAiA 2720/R rebuild

Tue Oct 28 01:18:33 CET 2014

Hi Dave,

My dad taught me to solder when I was about 6 or 7 years old in the late
60s' building Heathkits. I started my instruction by feeding the solder as
he held the soldering iron. Then, we spent twice as long making sure to
scrape all the rosin flux off the PCB.

David

>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl [mailto:synth-diy-
>> bounces at dropmix.xs4all.nl] On Behalf Of Dave Brown
>> Sent: Monday, October 27, 2014 3:09 PM
>> To: 'Tom Wiltshire'; 'John Speth'
>> Cc: synth-diy at dropmix.xs4all.nl
>> Subject: Re: [sdiy] PAiA 2720/R rebuild
>> 
>> I wasn't meaning to rag on the original kit builder.  We all have to
start
>> somewhere and I shudder to think what my first soldering jobs were like.
>> What I don't get though are people who don't mount components flush to
>> the PCB.  I still get DIY repairs where the parts are anywhere from 1/4
to
>> 1/2"
>> off the PCB.  I think the biggest issue for first time kit builders is
the wrong
>> soldering iron.  When I started many years ago I started with a gun,
albeit a
>> small gun.  Later I upgraded to a pencil type but even that wasn't very
>> good.  It had copper tips that just wore out so it was hard to heat a
pad.
>> Finally I found some gold plated tips that worked quite well and I used
that
>> iron for many years.
>> 
>> I didn't built too much PAiA stuff but I built a lot of Heathkit and
SWTPC
>> kits.  Most were pretty good but some of the Heathkit stuff was bare
>> copper PCBs and I remember leaving a lot of flux on those.  I imagine
they
>> look pretty bad now as the copper will have corroded fingerprints all
over
>> it.
>> When I make a DIY on a copper breadboard I always solder the complete
>> pad so there is no exposed copper.  Of course I would rather have a
plated
>> breadboard but sometimes I can't find those in the form factor I need.
>> 
>> Dave
>> 
>> -----Original Message-----
>> From: synth-diy-bounces at dropmix.xs4all.nl
>> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Tom Wiltshire
>> Sent: Monday, October 27, 2014 12:04 PM
>> To: John Speth
>> Cc: synth-diy at dropmix.xs4all.nl
>> Subject: Re: [sdiy] PAiA 2720/R rebuild
>> 
>> Absolutely agree. Looking at my old stomp boxes with the back off is like
a
>> soldering horror show, but you've gotta learn somehow, and getting stuck
>> in is one of the best ways.
>> great to
>> I doubt many PAIA synths ever looked so good. Nice work indeed.
>> 
>> Tom
>> 
>> On 27 Oct 2014, at 17:45, John Speth <jspeth at avnera.com> wrote:
>> 
>> > I too drooled over the affordable PAIA goods as a teenager.  My paper
>> > route was not enough to fund my desire.  But I'm sure you can forgive
>> > the poor build quality.  Whoever built it was learning what we've all
>> > developed passion for.  I still have some of my first-built stuff from
>> > 40 years ago (the ones that actually worked).  They're far from high
>> > build quality too. :)
>> >
>> > My hat's off to your for tackling that project!  Nice work.
>> >
>> > JJS
>> >
>> >> Yeah, poor soldering on DIY kit. I was restoring Formant once (well,
>> >> I
>> > still
>> >> am) and literally every solder joint on every board had to be sucked
>> >> and resoldered. All panel wiring removed and redone from scratch as
>> >> it was
>> > sooo
>> >> wrong it hurts.
>> >>
>> >> Anyway, great job on your PAiA! I can imagine how tough that was.
>> >> But I miss "before/after" photos, they make any restoration report
>> > great.
>> >>
>> >> Roman
>> >>
>> >> W dniu 2014-10-27 00:30, Dave Brown pisze:
>> >>> He didn't on this one.  I've never seen so much flux all over
>> > everything.
>> >>> Leads extended through quite far, were bent over, and about 3X too
>> >>> much solder was used.  I don't think it was acid core solder but it
>> >>> had about that much flux on it.  I ended up sucking every pad and
>> >>> resoldering and fixing the pads that had lifted.  I think the sheer
>> >>> weight of the solder on the underside was enough to lift the pads!
>> >>>
>> >>> Dave
>> >>>
>> >>> -----Original Message-----
>> >>> Wow!  Looks great!  That was on my Christmas wish list from the age
>> >>> of
>> >>> 12 (I turn 50 on Wednesday).  Santa never brought it.  I did try to
>> >>> build a Gnome with a friend in 1976, and failed utterly (he actually
>> >>> bought it, and was too impatient to use flux with the solder - every
>> >>> solder joint was stone cold).  I didn't attempt Synth DIY again
>> >>> until 2008.  Now, of course, I look at the PAiA stuff, and can't
>> >>> believe how cheap it looks and how simple it is.
>> >>>
>> >>>> -----Original Message-----
>> >>>> In case anyone is interested, I just was given a PAiA 2720/R synth
>> >>>> that I decided to restore.  A lot of the work was improving the
>> >>>> construction techniques of the original builder and dealing with
>> >>>> the general degradation of the electro-mechanical parts over time.
>> >>>> There is a list on the site but the biggest issue was rebuilding
>> >>>> the Pratt and Read keyboard which meant everything had to be
>> >>>> disassembled.  The wood cabinet needed some TLC but the only
>> >>>> improvements that I made were the increase in PS filter caps and
>> >>>> the replacement of just a handful of parts.  Most all the wiring
>> >>>> and soldering though had to be redone and it required a lot of
>> >>>> cleaning.  The keyboard S&H could benefit from a modern op-amp
>> but
>> >>>> I
>> decided to keep it original.
>> >>>>
>> >>>> Photos and information at
>> >>>> http://modularsynthesis.com/paia/2700/2700.htm
>> > _______________________________________________
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>> > Synth-diy at dropmix.xs4all.nl
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