Feeler: an "Eee-Zzz" christmas present...ez1073 and ez1073-500

[alex81]

Hello all,
i received 2 ez 1073 kits.
i started populating the 2 boards with all resistors, capacitors and transistors.
I stopped there, just before the voltage regulators step in ez1073 colourbook.
I had a lot of trouble trying to solder those components... THE SOLDER DOESN'T WANT TO STICK ON THE PADS, especially the small ones...
i don't know what to do, so many of my solder joints are bad looking... i'm 100% sure my builds are not going to work

I really don't understand.
I use Antex sw25 25watts solder iron with 0,55mm tip and good quality solder Sn62 Pb34 Ag2 with flux 0,8mm.
I tried with other type of solder, no change...
I did 2 Hairball Audio 1176 kits before and never had this kind of problem.
I thought it would be fun to build the ez1073 and it has become a nightmare.
The only solution i see is to order 2 new PCB with resistors (with uncut legs because some of them were really ttoo short), capacitors and transistors, buy a new soldering iron and try again.
I'm lost

Please help me guys
Regards

Alex

I had some problems with cold solder joints on the bigger capacitators and on the trimmers solder joints.
The solder joints for these parts on the PCB are quit small and Im not sure if its my solder point being to wide. Tried a smaller tip but didnt get much better.
Anybody else had the same problems? Or anybody have some helping ideas?

Hi Colin, love this project, but I also have some annoying problems with the pads. Solder simply refuses to stick to the small ones. Never experienced this before.  Higher tempereature doesnt help. Should I use different solder?

Cheers
Rune

Edit;
I discovered it´s all about technique, using a pointy tip, more heat, and sliding the tip forward while applying solder solved it

 

[sr1200]

Pads that are connected to larger ground planes are going to need a bit of heat to get the solder flowing over them.  I use a 40 watt iron set to about 2 o'clock on the temperature dial (4/6).  Some of the larger ground areas i may have had to bump up the heat a bit to get it flowing properly.  Also, a conical tip will work better (IMO) than a chisel tip.  Dont know what you're using.  But mine looks like a finely sharpened pencil.

 

[alex81]

The ground plane was definitely the problem. My soldering iron was not adapted (even though it worked with other kits such as 1176).
The tip was too small (0.5mm) and conical thus not heating the pads enough
I went to the electronic shop and the guy there told me to buy a larger tip (2,3mm) and chisel
I went back home, tried again I soldered all the components left without any problem !
Now i have to look for all the bad solder joints on resistors and capacitors and do them again.
I really hope it's going to work...
I also hope i have not damaged ant component

Pads that are connected to larger ground planes are going to need a bit of heat to get the solder flowing over them.  I use a 40 watt iron set to about 2 o'clock on the temperature dial (4/6).  Some of the larger ground areas i may have had to bump up the heat a bit to get it flowing properly.  Also, a conical tip will work better (IMO) than a chisel tip.  Dont know what you're using.  But mine looks like a finely sharpened pencil.

 

[mulletchuck]

I use a Hakko FX-888 with the smallest tip size.  I keep the temperature around 750F and I've never had any of the problems you've described.  Get a better soldering iron and stick with the small tip size.  No point using a sledge hammer when you need a jeweler's screwdriver...

 

[sr1200]

Gonna +1 Chuck on this.  larger and chisel tips are not really good to work with for this kind of stuff, especially if you have tiny pads like on the greyhills. 

 

[mulletchuck]

lol it's called the "like" button

 

[sr1200]

Its called IM NOT GIVIN' YOU A LIKE!! 

 

[alex81]

Actually, my tip is not that large.
I think chisel is not the right word in english.
The contact point with the board is actually about 1mm (see picture attached)
I finished soldering all the components without problems and repaired all bad solder joints from 1st attempt

 

[sr1200]

Yes, that's a chisel tip.  Conical looks like a sharpened pencil.

 

[alex81]

I just finished the 2 units !
I did the calibration and they both seem to work.
Mic inputs are ok, eq's ok, switchs ok
I didn't checked the line inputs, i'll do this tomorrow
I wait for the knobs from Cathedrale Pipes
Thanx Colin for the kits
I start a recording session next week so i'm gonna try them !

 

[exspence]

Hey,

Just powered up my ez1073 for the first time and... i'm getting some weird numbers.  J5 & J6 read .583 Volts.  J3 & J5 read 56.6 Volts. The LED isn't powering up, but it appears that the ac/dc conversion is ok. Any ideas on where I went wrong?

Spence

 

[mulletchuck]

The trim pot on the front panel turned all the way down = no output...    Why would you mess with what's included in the kit?  Colin knows his stuff, and chose accordingly...

 

[Aaronrash]

The trim pot on the front panel turned all the way down = no output...    Why would you mess with what's included in the kit?  Colin knows his stuff, and chose accordingly...

Hi Chuck,


Not questioning Collins work at all. I just want to be able to drive the pre without clipping my converters. Collin has stated earlier in the thread that it's a 9.5db trim and if you wanted to be able to use it as a complete attenuator a few resistor values would need to be changed.

 

[mulletchuck]

Just a guess, but R134, R135 and R149 are all that sit between the EQ output and the final amplifier stage, so i'd start looking there.  the schematic is near the end of the colorbook on colin's site for this build.

 

[Aaronrash]

Just a guess, but R134, R135 and R149 are all that sit between the EQ output and the final amplifier stage, so i'd start looking there.  the schematic is near the end of the colorbook on colin's site for this build.

I'm thinking the same thing. I think R134 and R135 are going to need to be changed but I just don't know what to. Hopefully somebody with further experience can chime in and comment further

Thanks!
Aaron

 

[guitar4444]

The 10k pot and R135 aren't in the original circuit. R134 is. I guess they are set up that way so the output and input impedance of the two stages stays reasonably constant. So you would need to change the pot and R135 to get the same effect but with more attenuation.
It sounds like it would be a bit pointless as you can either turn the gain down on the input or just put a fixed attenuator built into an xlr on the output, much easier and won't effect the circuit. Also that way you get to drive the output stage which will be part of the desired sound if that's what you are after, rather than just driving the input stage.

cheers  Greg

 

[Aaronrash]

The 10k pot and R135 aren't in the original circuit. R134 is. I guess they are set up that way so the output and input impedance of the two stages stays reasonably constant. So you would need to change the pot and R135 to get the same effect but with more attenuation.
It sounds like it would be a bit pointless as you can either turn the gain down on the input or just put a fixed attenuator built into an xlr on the output, much easier and won't effect the circuit. Also that way you get to drive the output stage which will be part of the desired sound if that's what you are after, rather than just driving the input stage.

cheers  Greg

Thanks Greg,

What type of xlr attenuator would you recommend? I'm just worried about impedance mismatching, and aversely affecting the output transformer (possibly feedback or some type of impedance loop) Forgive me, I'm pretty new to building gear.

Aaron

 

[guitar4444]

well I'm not an expert either, but I think if you build a 600 ohm attenuator you should be fine.
You can build it into an XLR to XLR adapter. It just consist of a few resistors.
Here's a calculator here
http://www.nu9n.com/tpad-calculator.html
and an idea on how to build
http://www.uneeda-audio.com/pads/

you could always wait for another expert to confirm. I would just go for smothing around 10 db then 20 db. I've never built one actually but was planning on it.

cheers  Greg

 

[sr1200]

The trim all the way down doesn't turn the volume "off" unless I built something wrong on both of mine.  It's there for when you need to either boost or cut a little bit between steps.  The center position is 0 meaning unattanuated, you can go up a little or down a little, but not off.

 

[Aaronrash]

The trim all the way down doesn't turn the volume "off" unless I built something wrong on both of mine.  It's there for when you need to either boost or cut a little bit between steps.  The center position is 0 meaning unattanuated, you can go up a little or down a little, but not off.

Yes, I'm wondering what resistor values would need to be changed to make it around 30db of attenuation instead of 10db. I have very sensitive converters