Feeler: ez760 - Compressor/Limiter/Expander/Gate

[bigbeaty]

Guys.

I have built a few projects using Gustav's boards now, and with no problems at all regarding solder flowing onto these pads.

The pads on Gustav's boards are indeed white, which had me a bit confused at first, but I was quite happy to see solder flowing smoothly and efficiently once I got assembling. I now have a G-SSL running, which worked as expected on first power up, as well as two Bo D.I's, and I'm most of the way through a G9 as well, all without issue regarding the PCB's.

Have you tried soldering on these boards yet? I hope you'll find the pads to be quite sufficient, as I did.

I'm looking forward to having a go at this project sometime, once I get the cash together! Great work as always, Colin and Gustav.

 

[tommypiper]

Let the pics speak.

The EZ760 PCB compared to a "normal" PCB above it in the same photo.  Notice the white paint on the normal PCB looks like the white on the solder pads on the EZ760 PCB.  Notice the silver on the "normal" PCB looks like, well, silver.  Notice the unscraped pads on the EZ760 PCB... Are they the same color as the silver pad on the other PCB?  Gustav believes they are also silver.  :  He says repeatedly that my PCBs are correct and the silver is throwing me off. 

Notice how if you scrape away the white paint on the EZ760 pad, you see something that looks a lot more like a silver solder pad underneath.... how can that be? 

BTW, the solder iron was VERY HOT at the time.  It made no impact on the pad's color.  The white coating remained intact, unburnt, undissolved, unmoved.  I had to physically scrape it off to expose the silver pad underneath.

So, what's going on here?  Gustav insists that I don't know what a PCB board or a silver solder pad looks like.  Am I nuts?  Maybe I am.  It would not be the first time.    The scraped pad sure looks a lot like the silver pads on the "normal" PCB next to it in the pic.  The white coating on the pad which is not scraped off sure looks like the white paint on the "normal" PCB. 

Does anyone else's PCB look like my EZ760 PCB?

EDIT: Cropped photo

 

[tommypiper]

Guys.

The pads on Gustav's boards are indeed white, which had me a bit confused at first, but I was quite happy to see solder flowing smoothly and efficiently once I got assembling. I now have a G-SSL running, which worked as expected on first power up, as well as two Bo D.I's, and I'm most of the way through a G9 as well, all without issue regarding the PCB's.

Have you tried soldering on these boards yet? I hope you'll find the pads to be quite sufficient, as I did.

OK thanks.  I've built the GSSL too and worked with many PCBs. 

This is what I have been asking Gustav and others.  If this is normal, then I've never seen it before.  But he has been telling me that they are supposed to be actually silver, not white, and that I am not looking at it correctly.  I'm happy to be mistaken --  ;D -- I often am.  Please someone just tell me that they are supposed to be white and look like mine. 

I've already tried a hot iron on it.  I will try to solder and post a pic.

 

[tommypiper]

No, the pad will not solder. 

The hot solder appears to have burnt the white paint off the pad a bit, exposing the metal silver underneath.  You can see the green PCB board shows white scorching too.

A "conventional / normal" PCB board is on the left in the shots as comparison.  It clearly shows silver pads and white markings, for reference.

Does anyone else have PCBs that look like this?

 

[tommypiper]

Better camera:

Notice the paint scrapings that came off the pad. 

In some photos you can see a chip of white paint still on the rim of the quarter where it scraped off.

Notice the color of the exposed scraped pad is the same as the silver quarter.  This shows they are the same approximate color.

Notice the color of the white on the pads is uniform and perfect -- there is no hint of silver in them.  This is not oxidation or tarnish. 

These pads appear to be painted.  I suspect the gerber file with the markings got mixed up with the pads, and the pads got painted.

There is no way to solder onto these pads.  They have no exposed silver.  And the white paint is very impregnable.  It requires a lot of force to scrape it away.  It does not burn away.  It is paint.

Again.  Does anyone else have PCBs that look like this?

 

[bigbeaty]

Ah, hmmnn... wish I had the answer for you Tommy, but I'm afraid this is beyond my meagre knowledge... I thought that hot tin would flow 

However, I notice that your good comparison board is an EZ1073... These things rock!!

Good luck man, I hope someone else chimes in and helps you solve this mystery.

 

[Gustav]

Once again, I asked you if you were familiar with commercially manufactured boards, NOT to put you down, but because some people aren't, and I have no way of assessing your level of expertise from an anonymous e-mail. Some people are surprised the PCBs are drilled, some are surprised there is even plating, because they are only used to seeing exposed copper. Usually, it is best to get those trivialities out of the way before assuming there is a special problem from a report of white pads.

I suggested the silver plating might be throwing you off, because it has happened to others (Even Jakob was a little confused by the milky white color after we we switched to silver to make the boards rhos compliant, but I asked him to try to make a joint, and he has been soldering white pads happily ever since).

I did not draw any final conclusions, and I asked for pictures. I have also stressed that I am willing to investigate further, but I am 100% sure that it is not the color of your pads that is a problem, and I stand by my statement that the pictures look fine (even thought there might still be a problem, of course!). The plating is 100% lead free chemical silver, and the silver quality used is in fact higher than you would normally get from standard PCB manufacturers. The surface settles very quickly into the white color when it is exposed to air (oxidation), but it does not hinder soldering.

For comparison, I took a picture of the pad that you showed a burned picture of (yes, they do hold up to abuse quite well, and again - I do not see it as a problem that you report that you have to abuse the pad to burn it) - pre and post soldering. I also added a random resistor to the board.

The milky white silver pads hold solder perfectly - as per usual.

I think its safe to say that the problem does not lie in the color of your pads or a layer of paint, and I am 100% sure it is not the gerbers, so I can't agree the customer is always right if your conclusion stands. I seem to be unable to communicate with you in a way that doesn't make you think I am trying to insult your intelligence, "blame you" or belittle you, and even though it would benefit me greatly to know what the actual problem is, so I have a chance of avoiding an outlier like this in the future, I am a bit lost for ways to progress with this in a fruitful way.

I cannot simply replace your boards, because the silver plating would be the same, unless I make a special production run using lead free HAL (tin based, lead free). We also have not come to any conclusions about what the problem actually is that would make me certain you would be better off with new boards.

I am also still not sure how my e-mail response to you could make you fell like I am talking down to you.


"Hi xxxx.

Im a little confused by your questions, so try sending me a picture. Either (assumption, which is almost always a bad idea), you are not familiar with commercially manufactured PCBs, or there is something really wrong with your boards!?

The pads are silver plated, sometimes you will find other platings of tin/lead variations done by hot air leveling, but if this is what is confusing you, and you are used to exposed copper pads,  I can assure you, the plating will make you very happy when you start soldering them."


I have really not meant to be unfriendly or unsupportive. I will refund your payment as soon as the Paypal dispute you opened is brought to a level where I can reply to it and access my paypal account again. I can't seem to top it off with my CC with an open dispute, and the funds are not there to close it now, so i will have to wait for a direct transfer from my bank account to transfer your refund.

I apologize for the obvious inconvenience this has caused you.

Gustav

 

[gyraf]

I suggested the silver plating might be throwing you off, because it has happened to others (Even Jakob was a little confused by the milky white color after we we switched to silver to make the boards rohs compliant, but I asked him to try to make a joint, and he has been soldering white pads happily ever since).

I can confirm that: When we started RHOS-certifiable production (Gyraf Audio), we initially had massive problems getting the lead-free solder working right on standard PCB's. When Gustav presented this white chemical-silver surface for us, I found it really strange looking - but the soldering got an absolutely perfect flow. We have never wanted anything else since then.

If you continue having problems, check with a different type of solder - there MAY be freak-accident-incompatibilities out there (although I've never heard of any).

Only other explanation would be if the board by accident got silkscreened with board-marking paint - but this would show for an entire production panel, i.e. several pcb's - and it would not cover so perfect inside through-plating holes as your photos show.

Jakob E.

 

[Slenderchap]

We built 9 of these PCB's (with the milky white coating) and there were no problems caused by the milky white coating.... we used lead free solder.

Seems more likely that the problem lies with the solder, soldering iron or solering technique.

Colin
www.audiomaintenance.com

 

[Dr Gris]

The Ez760 is still on my radar cause I know the originals are freakin' cool machines.
I wish more builders would give some feedback.

As a newbie still only using solder with lead, could you care to explain if these boards are meant
to be used with only lead free solder?
Or it will work with both, but better with lead free solder?
Not that it matters, just curious and it will be good to know for a newb like me when
I have the time and money to buy the parts to build this mythical beast 

Best
Magnus

 

[tonycamp]

just checked out my 2 sets of pcb's, the pads are indeed very white. I've got quite a few projects under my belt by now, this is the first time i've seen pads that are white, does it mean it's a problem? i haven't a clue, guess i'll find out soon enough.

flux pen, try a different solder, and alcohol that pcb as clean as you can get it?
good luck with it Tommy

 

[tonycamp]

We built 9 of these PCB's (with the milky white coating) and there were no problems caused by the milky white coating.... we used lead free solder.

Seems more likely that the problem lies with the solder, soldering iron or solering technique.

Colin
www.audiomaintenance.com

Colin, could you make a recommendation on what solder you were using on those 9? also, what temp is your iron set to for best results on these pcbs? I've noticed that the most effective temp varies contingent on pcb construction, but sometimes i've lifted a few pads before realizing i needed to turn down my iron, be nice to avoid that on the 760 project. Generally, i like to be hot and quick.

thanx for any info
T

 

[0dbfs]

Hopefully someone can provide something definitive but I usually set my iron to "just-melt" the solder I am using then move the temp up/dn slightly depending on the size of the component/pad. ie; 1/8W resistors and similar size (legs) don't usually need adjustment but larger (like large PSU caps or higher W resistors) components need a slight adjustment.

All you really want to do is heat the two parts (pad and component leg) high enough to melt the solder and make/flow the joint for a minimal amount of time then release. Neither too hot nor too cold. I find it best to experiment and find the sweet spot so as not to burn things up with high heat nor linger too long and lift pads, etc...

Cheers,
jb

 

[tonycamp]

^ interesting, i could swear i read somewhere that Jeff Steiger runs his iron very hot, so he can get the area intended for solder hot very quickly and get out, that makes sense to me...the longer it takes to heat the area, the more the heat migrates down line into parts, at least this is true when i'm Tig/mig welding. I also dab a little on the tip of the soldering iron(not welding torch lol), seems to spread the heat quicker to the intended solder area.

T

 

[0dbfs]

Depends on the iron wattage. ie; higher wattage iron will drop less temp with more mass connected. lower wattage irons will drop more temp with higher mass connected so you need to set and use them accordingly.

Too hot and the solder has a harder time flowing (seems to "run-away" from the heat instead of flowing), makes a less robust electrical joint, and tends to lift pads.

Also, use a heat-sink for heat sensitive devices so that only the leads come up to temp. ie; re-soldering a wire to a center terminated mic diaphragm.

This has been my experience anyway.

Cheers,
jb

 

[tommypiper]

Thanks for everyone's replies.

Gustav, thanks for the kind words.  I think it would have been better if you didn't tie the issue to the customer's level of experience.  I have never seen these types of white pads, but neither have others.  Speaking about the PCB and giving helpful information would be more productive.  I did not say the customer is right if the facts are not on the customer's side -- which you are saying.  I'm saying the customer deserves respect and the issue deserves investigation / explanation.  Keeping the discussion on the topic of the PCBs and how to move forward would be helpful.

Your pics looks similar to mine, but also more silvery than my boards.  I will look into my boards further.  This is very curious.

Thanks for everyone's patience and helpful replies.

 

[tonycamp]

My solder pads are very white also, I just soldered one of them to see if it would take, yes it did. Yes i have a hakko 808 ;D

i'm using Mg chemicals 60/40 2.2% flux, 22 gauge, no clean solder leaded.

good luck
T

 

[Sammas]

I just finished two of Gustav's boards. I have found them to be about the easiest to solder of any boards I've touched!

 

[Gustav]

Hi Guys.

Currently building one of these, and I can't find an available replacement for the 2N3820.

Any tips?

So far, I have found the following replacements for the rest of the discontinued parts. Please note, I have yet to try these in action, so I cannot vouch for the list. Double check the data sheets if you try them...

BC182B - > BC546B
BC184C - > BC549C
BC184L - > BC547C
BC212B - > BC560B
BC212L - > BC557B

Gustav

 

[Dr Gris]

You can try: http://www.cricklewoodelectronics.com/Cricklewood/home.php

I also want to build a stereo version of the ez760 some day and not too long ago I checked with
Cricklewood and they seem to still have them(and other discontinued transistors).

You, like me, live outside of UK so ther webshop doesn't work(if I'm correct??) but you can email or phone them.
They do sell to outside of UK.

If it works out, maybe you could buy some extra of obsolete transistors needed for the ez760 and sell
with your boards. I know I would be interested when the time comes, AND IT WILL COME SOME DAY 

If I'm not mistaken BC550B can also be used insted of BC182B (something I've read somewhere and haven't studied data sheets)

Please keep us posted on your progress.

Best regards
Magnus