Well please do so and report back after a few weeks. Then open a thread and ask "Why?" 🙂
When the chip was still in vogue it was already known and to use the low type IC sockets with gold plated round contacts was a very good tip. Since I (hard headed like many here) tried it myself I learned that desoldering gives a very high chance that they will fail. Well I even did it twice (very short heating time with a Denon SC7000 ESD safe) thinking the first time was just bad luck and both times success. I did not open a thread but choose to inform instead.
When the chip was still in vogue it was already known and to use the low type IC sockets with gold plated round contacts was a very good tip. Since I (hard headed like many here) tried it myself I learned that desoldering gives a very high chance that they will fail. Well I even did it twice (very short heating time with a Denon SC7000 ESD safe) thinking the first time was just bad luck and both times success. I did not open a thread but choose to inform instead.
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Interesting. Did you unsolder pin by pin with a suction tool or did you use hot air?
I would think that if they survived the original soldering in a bath, both desoldering methods should result in comparatively little stress. Since the case is pretty huge, I don't think it could be heat getting to the chip, so either thermo-mechanical stress in the case is the issue or the thing is super ESD sensitive. Strange since BB were making industrial metrology ADCs and DACs in the same case that I hand soldered without issues.
Do PCM1704 have the same issue?
I would think that if they survived the original soldering in a bath, both desoldering methods should result in comparatively little stress. Since the case is pretty huge, I don't think it could be heat getting to the chip, so either thermo-mechanical stress in the case is the issue or the thing is super ESD sensitive. Strange since BB were making industrial metrology ADCs and DACs in the same case that I hand soldered without issues.
Do PCM1704 have the same issue?
You need to use a piece of metal on the not soldered side of the pin and heat the other side. Then you suck away the molten solder. This way you have a heatsink as a heat barrier. On DIP ICs thats the way to do. I desoldered my 2 PCM63s this way and they are working for 5 years now. I use rather solid copper pieces for this purpose and also some thermal paste to create a better heat transfer.
Which goes to show standard pro desoldering is not the way to desolder PCM63-K. In other words: one has to use quite cautious techniques to desolder them. Who can guarantee this when being offered desoldered ones?
BTW I only had this with the K version, no idea about the other versions. In that time I desoldered bipolar IC's like TDA1541A and PCM56 sometimes more than once without any issue, a habit I quickly abandoned after these experiences with PCM63.
BTW I only had this with the K version, no idea about the other versions. In that time I desoldered bipolar IC's like TDA1541A and PCM56 sometimes more than once without any issue, a habit I quickly abandoned after these experiences with PCM63.
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I can just maybe see how the PCM63 might be susceptible (odd case, large chip, laser trimmed resistors on chip), but the PCM1704 has a much more standard surface mount and should be designed to survive reflow. It is also a later design with hopefully better ESD protection.
Did you have this issue when using hot air for desoldering?
how about infrared desoldering? I have 24psc pcm63p-y desoldered this way. didn ttested them yet. hope they are ok
Same problem with infrared. If you dont cool them properly while desoldering its 50/50 if they survive a longer periode than some weeks...
It can be simplified by using only brand new ones and just discard old ones. Why would done taking the risk by using a high quality chip when it is know to die prematurely when desoldered? It is not so high quality anymore then. Maybe it is then time to use a modern state of the art DAC chip which can be found at suppliers.
Before we know it PCM63 will be the new TDA1541A 😀 Nostalgia always seem to win.
Before we know it PCM63 will be the new TDA1541A 😀 Nostalgia always seem to win.
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Well, PCM63 was never around in the same quantities as TDA1541A, and its K grade is potentially in a different league. It is very hard to come by a reliable source of new parts these days.
I think compared to newer parts, it may have lower noise than most, but it will be worse on distortion. Maybe that is a sound some folks like?
I think compared to newer parts, it may have lower noise than most, but it will be worse on distortion. Maybe that is a sound some folks like?
Indeed. The worst measuring stuff often is liked. Also stuff that is hard to find combined with nostalgia. I am not surprised anymore when I see a high quality high res streamer connected to a 30 year old jittery 16 bit DAC that “lifts the streamer to a higher level” 🙂
Anyway, using second hand ICs that have been desoldered gives the question how good the chips still are after desoldering. What is the use of IC's that have a question mark? They may give sound but how do they measure? It is a bit like buying second hand Michelin tires for a Porsche.
Anyway, using second hand ICs that have been desoldered gives the question how good the chips still are after desoldering. What is the use of IC's that have a question mark? They may give sound but how do they measure? It is a bit like buying second hand Michelin tires for a Porsche.
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But back to the PCM63. Desoldering is not a problem if you know how to do it. I used a routed adapter to cool the chips (also the TDA1541s, just to be on the safe side, but i know they always survived the desoldering process).
If someone needs the file, write a message, i had one milled from aluminium and one from copper, both were perfect for desoldering. used a lot of thermal paste and it always worked.
This way you can only heat up the solder and suck it away, the pins stay cooler and do not destroy the chip.
If someone needs the file, write a message, i had one milled from aluminium and one from copper, both were perfect for desoldering. used a lot of thermal paste and it always worked.
This way you can only heat up the solder and suck it away, the pins stay cooler and do not destroy the chip.
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Please let us also think that this is a thread by bigskyaudio who wants 2 new PCM63-K. We are, nice as it may be, threadjacking the positive way but still it is threadjacking.
Hi bigskyaudio,
Looks like this is the place to get them. Buy PCM63P-K BURR BROWN | AERI is a stocking distributor of electronic components
You need to register to get a price.
Kevin
Looks like this is the place to get them. Buy PCM63P-K BURR BROWN | AERI is a stocking distributor of electronic components
You need to register to get a price.
Kevin
I can confirm that desoldering pcm63p-k-y by infrared does not destroys it. tested 4 units units for 40hours each(2 weeks of moderate use as someone told here) others works , but also will got 40 hours non stop test.
i think 24x pcm63 dac is coming 🙂 directly i2s to dac, filtering options done on PC, total 48mA current should be quite fun to experiment with IV stage
i think 24x pcm63 dac is coming 🙂 directly i2s to dac, filtering options done on PC, total 48mA current should be quite fun to experiment with IV stage
