[sdiy] PAiA 2720/R rebuild

[gm]

People (and I'm one of them) loved to diss PAiA for cheapness;  however, 
I've recently been working on an EML 200 synth --  compared to the 
circuitry in that, PAiA is the model of sophistication.
~G


On 10/26/2014 5:12 PM, Michael E Caloroso wrote:
> PAiA loved those sucky 748 opamps.  Ideal candidate for upgrades.  I
> did that with my 4700 modular that I built back in 1981.
>
> MC
>
> On 10/26/14, Dave Brown <davebr at earthlink.net> wrote:
>> 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-----
>> From: David G Dixon [mailto:dixon at mail.ubc.ca]
>> Sent: Sunday, October 26, 2014 3:59 PM
>> To: 'Dave Brown'; synth-diy at dropmix.xs4all.nl
>> Subject: RE: [sdiy] PAiA 2720/R rebuild
>>
>> 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-----
>>> From: synth-diy-bounces at dropmix.xs4all.nl
>>> [mailto:synth-diy-bounces at dropmix.xs4all.nl] On Behalf Of Dave Brown
>>> Sent: Sunday, October 26, 2014 2:00 PM
>>> To: synth-diy at dropmix.xs4all.nl
>>> Subject: [sdiy] PAiA 2720/R rebuild
>>>
>>> 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
>>>
>>> David J. Brown
>>> Email davebr at earthlink.net
>>> Website http://modularsynthesis.com
>>>
>>>
>>> _______________________________________________
>>> Synth-diy mailing list
>>> Synth-diy at dropmix.xs4all.nl
>>> http://dropmix.xs4all.nl/mailman/listinfo/synth-diy
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