First time DIY synth builder and dreadbox Antiphon

From circuitbending to homebrew stompboxes & synths, keep the DIY spirit alive!

Moderators: lisa, luketeaford, Kent, Joe.

Post Reply
Demonument
Learning to Wiggle
Posts: 6
Joined: Wed May 27, 2020 11:21 am

First time DIY synth builder and dreadbox Antiphon

Post by Demonument » Sun Jun 14, 2020 3:14 am

I'm new to synth DIY and electronics work in general. I've recently been learning how to solder and now I have some modules to work on. The first modules I have are the dreadbox Antiphon and kasstronics 3340 vco and vcf. I believe that these are all probably not recommended for a beginner. The antiphon has a large number of components and the kassutronics boards are quite densely packed.

I've started out with the antiphon board as the initial part of the build involves soldering a large number of resistors and I thought that would be good practice. Initially I struggled as I was using a tip that wouldn't transfer heat, perhaps because it was too small (1mm) and actually I've found it much easier with a 2.5mm tip. I've also discovered how important it is to keep the tip free of dirt in order to efficiently transfer the heat.

I'm wondering what kind of problems am I likely to have as a beginner building this synth? I know that the slider potentiometers and trimmer pots can potentially be damaged by excessive heat and the guide states a max soldering temperature of 260c. At the moment I have an antex 25 watt iron which seems to be performing well but has no temperature control. Also I appreciate that the IC components are susceptible to both heat and electrostatic discharge. The antiphon kit is only supplied with sockets for one type of IC but I've bought additional sockets for the others to reduce the risk of cooking them and then need to desolder from the board. I'll also be careful to properly ground myself while handling these components.

I'm happy to spend time learning and debugging the board if I make mistakes but as this is quite new to me I'm wondering what kind of challenges I might face. Also how can I check my work as I go? So far I'm inspecting my solder joints carefully and repairing them if they don't look ideal. I'm also testing continuity between components. Is there anything else I should be looking for as I go?

User avatar
Pav
Wiggling with Experience
Posts: 306
Joined: Sat Mar 19, 2016 3:21 pm
Location: UK Hampshire

Re: First time DIY synth builder and dreadbox Antiphon

Post by Pav » Mon Jun 15, 2020 6:28 pm

With the antiphon, getting the correct orientation of sockets was my build mistake. Solder joints especially ones to the earth plane of the pcb are the main culprit of problems once built. Particularly a problem with this kit. Also because there are a lot of resistors, there's a danger of inserting a wrong value.

Search on antiphon and you will find a thread specific to issues others have had.

Don't worry too much about the overheating components with the iron, that just makes you more nervous and under heat.

You are wise to socket all ic s. Not doing so an be a false economy imho.

Welcome to the forum.
rgds Pav

Demonument
Learning to Wiggle
Posts: 6
Joined: Wed May 27, 2020 11:21 am

Re: First time DIY synth builder and dreadbox Antiphon

Post by Demonument » Wed Jun 17, 2020 4:05 pm

Thanks for the reply. I'm trying to get quicker with my soldering so hopefully the pots won't be a problem. Yes I found a couple of threads on here which might prove to be helpful. I'm hoping to finish the build over the weekend so it will be interesting to see to what degree it works.

Mayo
Learning to Wiggle
Posts: 3
Joined: Tue Jun 12, 2018 6:10 pm

Re: First time DIY synth builder and dreadbox Antiphon

Post by Mayo » Wed Jun 17, 2020 5:58 pm

Like Pav said some of the joints connected to the large ground plane were the biggest annoyance for me. I also had a potentiometer that was broken (only worked when pushed down on). I'm not sure I broke it or if it was already broken but might be worth testing them before you put them in!

Demonument
Learning to Wiggle
Posts: 6
Joined: Wed May 27, 2020 11:21 am

Re: First time DIY synth builder and dreadbox Antiphon

Post by Demonument » Fri Jun 19, 2020 2:38 pm

I've been soldering the IC sockets today and there are some pins that just don't seem to get hot enough to form a good joint. A couple of times I've ended up with the solder just stuck to the pin. Then I'll move onto another pin and it's fine. I wonder if that's related to the ground plane. Apparently circuit designers are supposed to add thermal breaks to prevent soldering issues. I have at least 4 or 5 joints that I'll need to repair now but I've no idea how as I can't get them hot enough.

Demonument
Learning to Wiggle
Posts: 6
Joined: Wed May 27, 2020 11:21 am

Re: First time DIY synth builder and dreadbox Antiphon

Post by Demonument » Thu Jun 25, 2020 3:20 pm

I've completed the build and tested it. It all seems to work. The only problem I've had is with the tempo resistors. Some of them won't fit over the ICs and some that will fit don't stay put on top. If tuning stability is a problem I might have to look at it again. I'm surprised they just sit on top because not much of the resistor is in contact with the chip anyway. Maybe that's all that is needed.

User avatar
Pav
Wiggling with Experience
Posts: 306
Joined: Sat Mar 19, 2016 3:21 pm
Location: UK Hampshire

Re: First time DIY synth builder and dreadbox Antiphon

Post by Pav » Fri Jun 26, 2020 4:56 pm

Well done for having a working build. A little thermal paste applied with a matchstick or similar to avoid messy application should solve the tempco issue.

I managed without by bending and putting the leads in pcb first, then retracting them to get the body of tempco just to cover the ic by a couple of mm , then press down firmly on tempco with finger whilst bending the leads to hold tight for solder. Solder one lead, then take any slack out of the second lead by pulling gently. At this point opportunity to make the tempco parallel to edge of ic, and solder second.

Easier to do than type this explanation. But may help a future build.
rgds Pav

User avatar
Pav
Wiggling with Experience
Posts: 306
Joined: Sat Mar 19, 2016 3:21 pm
Location: UK Hampshire

Re: First time DIY synth builder and dreadbox Antiphon

Post by Pav » Fri Jun 26, 2020 5:02 pm

Oh and it's more common in builds I have completed at least to have a single tempco aligned lengthwise so body sits centrally on top of ic.
rgds Pav

Demonument
Learning to Wiggle
Posts: 6
Joined: Wed May 27, 2020 11:21 am

Re: First time DIY synth builder and dreadbox Antiphon

Post by Demonument » Sat Jun 27, 2020 3:58 pm

Thanks for the tip. I really struggled soldering those resistors as I couldn't get my 1mm tip to heat the joint sufficiently so I ended up using the 2.3mm which was a very tight fit between the components. I may try desoldering them and replacing using your method if tuning is a massive problem. Yes I did consider some thermal paste, that will probably be enough on a couple of the tempcos that do fit.

How long does your unit's tuning take to stabalize once it's switched on? Mine drifts upwards after powering on and continues to do so for at least 40 minutes. If I turn it off even for just a few seconds then once it's powered on again the tuning will already have drifted flat. I'm wondering how stable I can expect it to be if I make some improvements.

User avatar
emmaker
Veteran Wiggler
Posts: 622
Joined: Sat Mar 10, 2012 5:07 pm
Location: PDX

Re: First time DIY synth builder and dreadbox Antiphon

Post by emmaker » Sat Jun 27, 2020 4:13 pm

Clean both sides of the board before you solder it. I use a cleaning powder like Ajax or Comet, water and a hard tooth brush or cotton ball. Wash all that off and wipe it down with isopropyl alcohol.

Demonument
Learning to Wiggle
Posts: 6
Joined: Wed May 27, 2020 11:21 am

Re: First time DIY synth builder and dreadbox Antiphon

Post by Demonument » Sat Jun 27, 2020 5:01 pm

Thanks. Cleaned the board with isopropyl alcohol beforehand. Didn't try any other cleaners though. Those resistors had a lot of residual glue on the leads and I cleaned that off as best as I could but it's possible they weren't as clean as they could be. I feel like the problem might be with the 1mm tip. Either the tip is no good or iron just can't deliver heat quickly enough to keep the tip hot when applied to a component. The 2.3mm one I have is fine but it's just too big for some jobs. I managed to use it for the temp co resistors but I was very close to other components and it would have been easy to accidentally melt something.

Post Reply

Return to “Music Tech DIY”