[sdiy] MF4CN filter /YMF262/YAC512 chip uses

[Jim Thompson]

It's not removing them that's the problem (they're through hole 8 pin DIP, 
besides I use the Pace PRC2000 on page 5).
http://www.paceworldwide.com/documents/MBT-PRC.pdf

it's finding something creative/noisy to do with them.

Incidently if ANYBODY needs assistance with surface mounted parts, I would 
be MORE than happy to help. I have the tools and have been doing it reliably 
for a long time. Too long... before SDIY I got bored and cloned an Electro 
Harmonix Big Muff fuzz with SMT parts. 8-\
(I have boards if anyone is interested).
It's the least I can do for the plethora of SDIY circuits and knowledge I 
have gleaned from this very helpful list.

Thanks

Jim

>From: "anthony" <aankrom at bluemarble.net>
>To: <synth-diy at dropmix.xs4all.nl>
>Subject: Re: [sdiy] MF4CN filter /YMF262/YAC512 chip uses
>Date: Tue, 14 Nov 2006 15:47:13 -0500
>
>I have removed these very chips from an old Compaq motherboard. This is 
>what I do:
>
>1: Desolder the bulk of the solder with a desoldering iron from Radio 
>Shack. I haven't found an inexpensive built by any other manufacturer and 
>the RS unit's quality has been steadilly declining. That said, it is 
>imperative that you use a relatively new tip and that all openings are 
>relatively unobstructed (I find that these units give the best service when 
>rigorously mainainted - which usually involves removing the bulb and 
>jamming debris out the tip end with the tip removed and the iron hot). The 
>more solder you remove here the easier the next step is.
>
>2: Place a strip of Radio Shack desoldering braid over the leads. Touch 
>each pin through the braid, held with a tweezer, with a very hot iron - at 
>least 25, but better 30 maybe even 40 watts - a chisel tip is best. The 
>point is to get the joint hot very fast without overheating the bulk of the 
>chip. This may require several passes. Take your time and don't let the 
>body of the chip get too hot.
>
>2.5: Often these chips were glued in before soldering so it can help to 
>heat the back of the board under the chip to soften the glue.
>
>3: This is the tricky part. When it appears that you have soaked up all of 
>the visible solder with the braid, gently pry at the edge of the chip with 
>a flat screwdriver. Use a light pressure. If it doesn't pop up, don't force 
>it, but quickly touch the pins closest to the screwdriver with the very hot 
>iron. Sometimes the momentum when the first few pins come loose can cause a 
>sticky pin to break, but if you use gentle but firm pressure this should 
>not happen.
>
>I have successfully desoldered hundreds of chips using this technique and 
>have broken relatively few chips. Being in a hurry is the usual cause for 
>disaster. And I have indeed lost some very desirable chips in haste.
>
>If it seems like I've left anything out, let me know.
>
>
>enjoy,
>Anthony
>
>
>>The Yamaha chips are used by:
>>http://www.ucapps.de/mbhp_opl3.html
>>
>>If you have a good way to get them off the pcb I'd be interested to
>>hear it.  I have one lying around waiting for the Yamaha chips
>>to be pulled off...
>>
>>
>>>Does anybody have any suggestions whether these devices are usable for 
>>>SDIY.
>>>I am prepared to yank them from an old Aztech soundcard after surfin' up 
>>>their datasheets and was hoping to put them to use.
>>>
>>>http://cache.national.com/ds/MF/MF4.pdf
>>>http://www.labmaster.com/surplus/parts/html/ymf262/ymf262.pdf
>>>http://www.labmaster.com/surplus/parts/html/yac512/yac512.pdf
>>
>>
>
>

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