I have a book The Art of Circuitry written by American experts Paul Horowitz of Harvard University and Winfield Hill of Rowland Institute of Science, Cambridge, Massachusetts. , which I read back in 1989. there is just described the influence of the dielectric of the capacitors in the sampling circuits. It can be assumed that a similar effect will take place in amplifiers. But how strong it really was in the measurements shown by dadod. Moreover, for example, a Teflon dielectric also has disadvantages. Rather, it was just about Teflon, not polystyrene. https://www.elspecgroup.de/fileadmin/user_upload/Coaxial_Cables_1-3.pdf
Finally NAIM began to produce amplifiers with complementary pairs of transistors at the output. As always, a huge toroidal transformer, and polystyrene capacitors in critical places.
It's funny to look at a printed circuit board where different assembly technologies coexist, which confirms that they used only the best for sound. By the way, the model is successful according to the reviews, it sounds great.
https://www.stereonet.co.uk/images/articles/Images/2959/supernait_3_topless__large_full.jpg
First Listen Review of Naim Nait XS3 and Supernait 3 | StereoNET United Kingdom
It's funny to look at a printed circuit board where different assembly technologies coexist, which confirms that they used only the best for sound. By the way, the model is successful according to the reviews, it sounds great.
https://www.stereonet.co.uk/images/articles/Images/2959/supernait_3_topless__large_full.jpg
First Listen Review of Naim Nait XS3 and Supernait 3 | StereoNET United Kingdom
Wow! My experience is exactly opposite; it is difficult to keep the soldering iron tip in tight contact with the braid unless you are pressing down somewhat. This pressure seems to help dislodge the pads.
With the Hakko 808 no contact is needed with the pad itself, just the fillet needs to be contacted to start the melt process, plus I feel the rush of air through the cleared via helps cool it down, of course having the bulk of solder removed means very little retained mass to stay hot. The whole process takes under 3 seconds.
In terms of clearing the solder in the plated-through via, the Hakko 808 works much better for me than wick. Very often the part just falls out when I use the 808, no messing around to free the lead from residual solder in the via. I now only use wick for SMD pads, or terminal strips where the scrubbing of the wick helps dislodge oxide.
YMMV!
Howie
To solder and unsolder SMD parts I use hot ear solder gun similar to this one. Hot Air Gun 8858 SMD Rework Desoldering Station Hot Air Blower Welding Repair Tools|Heat Guns| - AliExpress
I never used it for THT parts, probably if to try to heat up side down PCB from back side, transistors could fell out by gravity?
I never used it for THT parts, probably if to try to heat up side down PCB from back side, transistors could fell out by gravity?
The Hakko FR-301 vacuum desoldering gun works well about 40% of the time, in my experience. "Techspray Prowick" brand desoldering braid for all the others. After Prowick, I'm often forced to use stainless steel desoldering needles to un-plug the hole and restore it to full open diameter. You heat the needle and poke it through the hole. Solder doesn't stick to stainless steel so when it cools down it's not mechanically joined.
I buy mine on eBay so cheaply they're almost disposable; here is a set on amazon
I buy mine on eBay so cheaply they're almost disposable; here is a set on amazon
I can recommend the Zephyrtronics ZT-2. I've used other hot-air stations (Hakko), and I like the slim pencil-like handle of the ZT-2. Like all of them you have to learn the balance between air temperature and air flow rate. Too cool and it takes forever to melt the solder. Too high air velocity and you blow the SMDs all over the PCB.
Speaking of desoldering stations, I used a Hakko combined station, but the pressure/vacuum drop over the hose gives that approach an inferior performance compared to the vacuum pump in the handle approach like the 808.
Just my 0.02 worth...if that...
Howie
The issues are interesting in teflon cable used in microwave applications, particularly in VNA's with .01 degree phase sensitivity. It doesn't mention the gore construction (teflon wrapped cable) which will be different with the entrained air.
However the changes documented would be really hard to identify in an analog amplifier application in a cap. The scale across temperature is like .1%. There are many other elements of an amp with bigger changes vs. temperature.
For through hole work I have a Metcal desolder pistol. It was an investment (fortunately I already have extra supplies) but it works really well. I had to change out 25 Jfets in an attenuator array and it would have been really risky any other way but between controlled heat and lots of thermal reserve it worked really well.
The hot air pen looks really interesting until you get to the price. . .
The hot air pen looks really interesting until you get to the price. . .
One trick I learned for using wick on a double-sided board was to start from the top side if space permits. For some reason I always got more complete removal that way, with a lot less screwing around (especially with ICs) and less chance of "trace trauma." Not sure why this works, but it does. Sometimes had to start by adding solder to the joint to create a fillet on the top side if there wasn't one already, to have something to work against.
Also, fortifying the braid with extra flux from a pen beforehand seems to help. More to clean up, but preferable to board repairs.
Oh, and also more heat instead of less. I always used an 800° F tip on through-hole stuff - you can get in & out quicker, before the traces get a chance to overheat.
Also, fortifying the braid with extra flux from a pen beforehand seems to help. More to clean up, but preferable to board repairs.
Oh, and also more heat instead of less. I always used an 800° F tip on through-hole stuff - you can get in & out quicker, before the traces get a chance to overheat.
Last edited:
Thats why large studios have 5 different kinds of large diaphram condenser mics. Heres a look at that world.
Microphones: Large Diaphragm Condenser Shootout at Vintage King - Warren Huart - Produce Like A Pro - YouTube
There are many tricks in removing components. Everyone has some. Some techniques work better than others, but if you manage to change the part and not do any damage it is the same end result.
I remember working at Motorola, the techs/EE's were not allowed to re-work orders on the production floor. Too many damages to customer orders. It was amazing what the Asian re-work girls could do with a de-solder bulb.
Lot of miles on my old soldapullt. I have never had enough de-soldering to do, to warrant getting a proper solder sucking machine. Been close but I do not do much service work anymore.
I rarely use solder wick but I do use it to clean up smt pads after removal of a device. It does a nice job.
Try to heat up all the leads at once, if possible, to remove both TH ad SM comps. Once leads are out of holes, much easier to remove solder from plated holes, if necessary.
Use two irons to remove smd passives and some sot/sod types.
The QFN/DFN package is a challenge to solder by hand. need a special footprint for that one. Removal can only be done with hot air or a hot plate.
The SparkFun hot air machine functions just as well as the Hakko one I used to use at a fraction of the cost. It uses the same nozzles as the Hakko.
You know your a pro, when you have re-placed a BGA.
Happy soldering
I remember working at Motorola, the techs/EE's were not allowed to re-work orders on the production floor. Too many damages to customer orders. It was amazing what the Asian re-work girls could do with a de-solder bulb.
Lot of miles on my old soldapullt. I have never had enough de-soldering to do, to warrant getting a proper solder sucking machine. Been close but I do not do much service work anymore.
I rarely use solder wick but I do use it to clean up smt pads after removal of a device. It does a nice job.
Try to heat up all the leads at once, if possible, to remove both TH ad SM comps. Once leads are out of holes, much easier to remove solder from plated holes, if necessary.
Use two irons to remove smd passives and some sot/sod types.
The QFN/DFN package is a challenge to solder by hand. need a special footprint for that one. Removal can only be done with hot air or a hot plate.
The SparkFun hot air machine functions just as well as the Hakko one I used to use at a fraction of the cost. It uses the same nozzles as the Hakko.
You know your a pro, when you have re-placed a BGA.
Happy soldering
>You know your a pro, when you have re-placed a BGA...
One of the last things I got to work on at Intel, they wanted to replace a CPU BGA in the field...by building heaters into an interstitial piece of FR4. The idea was to connect that to a control box appliance, heat it up, pop off the old CPU and solder a new one in place. ALL umpty thousand solder balls had to flow and make a good connection. I got to do the control system design, where I used the copper heater traces to measure the temperature during the off cycle of the PWM. I'm sure it's well beyond NDA stage with all the patents issued; apparently they didnt like the interleaved temperature measurement enough to pursue. I got to learn about solder temperature profiles, like what you see effected in a reflow oven. A longshot, I think they actually got it to work - after they closed the site.
I can see a couple of techs in a remote repair center "oookaay - now it says to take some solder wick and clean off / smooth out all bumps off all those pads - and be sure to not short any two together..."
One of the last things I got to work on at Intel, they wanted to replace a CPU BGA in the field...by building heaters into an interstitial piece of FR4. The idea was to connect that to a control box appliance, heat it up, pop off the old CPU and solder a new one in place. ALL umpty thousand solder balls had to flow and make a good connection. I got to do the control system design, where I used the copper heater traces to measure the temperature during the off cycle of the PWM. I'm sure it's well beyond NDA stage with all the patents issued; apparently they didnt like the interleaved temperature measurement enough to pursue. I got to learn about solder temperature profiles, like what you see effected in a reflow oven. A longshot, I think they actually got it to work - after they closed the site.
I can see a couple of techs in a remote repair center "oookaay - now it says to take some solder wick and clean off / smooth out all bumps off all those pads - and be sure to not short any two together..."
The article describes the properties of Teflon depending on its processing. Temperature bending and hysteresis in Teflon are also described. And despite the fact that polystyrene was obtained in the 19th century, polystyrene capacitors appeared only in the early 60s of the 20th century, i.e. after teflon and polyester capacitors. Not in the early 50s, as John wrote. https://www.diyaudio.com/forums/the-lounge/349926-black-hole-530.html#post6377920
Last edited: